[Federal Register Volume 70, Number 217 (Thursday, November 10, 2005)]
[Proposed Rules]
[Pages 68350-68368]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-22432]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 70, No. 217 / Thursday, November 10, 2005 /
Proposed Rules
[[Page 68350]]
NUCLEAR REGULATORY COMMISSION
10 CFR Part 20
[RIN 3150-AE90]
Disposal of Radioactive Material by Release Into Sanitary Sewer
Systems; Withdrawal of Advance Notice of Proposed Rulemaking
AGENCY: Nuclear Regulatory Commission.
ACTION: Advance notice of proposed rulemaking: Withdrawal.
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SUMMARY: The Nuclear Regulatory Commission (NRC) is withdrawing an
advance notice of proposed rulemaking (ANPR) that presented possible
changes to the regulations governing the release of radionuclides from
licensed nuclear facilities into sanitary sewer systems. Changes were
proposed to account for the potential for radionuclide concentration
during some types of wastewater treatment processes. NRC is withdrawing
this advance notice of proposed rulemaking because it has determined
that there are no widespread public health and safety concerns due to
potential radiation exposures associated with the handling, beneficial
use, and disposal of sewage sludge containing radioactive materials.
This notice of withdrawal acknowledges public comments sent in response
to the ANPR.
FOR FURTHER INFORMATION CONTACT: A. Christianne Ridge, Office of
Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, telephone (301) 415-5673, e-mail
[email protected].
SUPPLEMENTARY INFORMATION: On February 25, 1994 (59 FR 9146), NRC
published an ANPR to seek information to determine whether an amendment
to its regulations governing the release of radionuclides from licensed
nuclear facilities into sanitary sewer systems was needed. NRC was
considering revising the approach to limiting these releases because of
the potential effects of newly-developed sewage treatment technologies
on radionuclide reconcentration during wastewater treatment. The
Commission requested advice and recommendations on several proposals
and asked related questions regarding whether and in what way the
regulations governing the release of radionuclides from licensed
nuclear facilities into sanitary sewer systems should be changed. NRC
received seventy-four comment letters in response to the ANPR. The
comment period expired on May 26, 1994.
Because there were concerns raised on the broader issue of long-
term effects of releases of radioactive materials into sanitary sewer
systems, action on the ANPR was deferred until studies were conducted
regarding potential radioactive contamination in sewage sludge. Since
that time, NRC participated in the Interagency Steering Committee of
Radiation Standards (ISCORS) and co-chaired, with the Environmental
Protection Agency (EPA), the Sewage Sludge Subcommittee to facilitate a
systematic and thorough study of the potential concerns related to
radionuclides in sewage sludge and to obtain data to support a
technical basis for a regulatory decision.
Regulatory Framework Relevant to the Release of Radioactive Material
Into Sanitary Sewers
NRC regulations governing the release of licensed material into
sanitary sewer systems can be found in 10 CFR 20.2003. This regulation
was published in the Federal Register (56 FR 23360; May 21, 1991) as
part of an overall revision of NRC standards for protection against
radiation. Licensees were required to implement this regulation by
January 1, 1993. As part of the 1991 revision of 10 CFR Part 20
regulations, NRC removed the broad provision that allowed the release
of non-biological insoluble materials into sanitary sewers because of
the potential for this material to reconcentrate in sewers, publicly
owned treatment works (POTWs), and sewage sludge. The current NRC
regulations require that any licensed material discharged into a
sanitary sewer system must be readily soluble in water or be readily
dispersible biological material. In addition, the concentration limits
for radionuclides released into a sanitary sewer system, listed in
Table 3 of the Appendix B to Part 20, were reduced by a factor of 10 as
part of an overall reduction in effluent release limits. In addition to
the limits in 10 CFR 20.2003, NRC recommends that licensees should
maintain doses as low as is reasonably achievable (ALARA) by setting
goals for effluent concentrations and quantities to be only a modest
fraction (10 to 20 percent) of their allowable limits, as described in
NRC Regulatory Guide 8.37, ``ALARA Levels for Effluents from Materials
Facilities,'' dated July 1993. NRC also conducts periodic inspections
to ensure that licensees are in compliance with NRC regulations.
Surveys, Studies, and Reports Relevant to the Release of Radioactive
Material Into Sanitary Sewers
In May 1992, NRC issued the results of a scoping study in NUREG/CR-
5814, ``Evaluation of Exposure Pathways to Man from Disposal of
Radioactive Materials into Sanitary Sewer Systems,'' which evaluated
the potential radiological doses to POTW workers and members of the
public from exposure to radionuclides in sewage sludge. The first part
of the analysis estimated the potential doses to workers for five cases
in which radioactive materials were detected at POTWs (Tonawanda, NY;
Grand Island, NY; Royersford, PA; Oak Ridge, TN; and Washington, DC).
Doses from the case studies were estimated to range from less than 10
microsieverts per year ([mu]Sv/yr) (1 millirem per year (mrem/yr)) to
930 [mu]Sv/yr (93 mrem/yr) for members of the public, using a
deterministic scenario analysis and the reported radionuclide
concentrations and/or discharges. The second part of the study
estimated the maximum radiation exposures to POTW workers and others
who could be affected by low levels of man-made radioactivity in
wastewater. The quantities of radionuclides released into the sewer
systems were assumed to be the maximum allowed under NRC regulations at
the time. Estimates of the hypothetical, maximum exposures to workers
ranged from zero to a dose roughly equal to the dose individuals
receive from natural background radiation.
In May 1994, the U.S. General Accounting Office (GAO, now U.S.
Government Accountability Office) issued a report, GAO/RCED-94-133,
[[Page 68351]]
``Nuclear Regulation: Action Needed to Control Radioactive
Contamination at Sewage Treatment Plants'', that described nine cases
where contamination was found in sewage sludge or ash or in wastewater
collection systems. GAO concluded that the full extent of contamination
nationwide was unknown. GAO also concluded that the ``problem of
radioactive contamination of sludge and ash in the reported cases was
the result, in large part, of NRC's regulation, which was incorrectly
based on the assumption that radioactive materials would flow through
treatment systems and not concentrate.'' In June 1994, a joint U.S.
House of Representatives and Senate hearing (June 21, 1994; S. Hrg.
103-1034) was held to officially release and address questions raised
in the GAO report. At the hearing, NRC and EPA agreed to cooperate to
develop guidance for POTWs and to collect more data on the
concentration of radioactive materials in samples of sewage sludge and
ash from POTWs nationwide.
Between 1994 and 1997, Federal, State, and industry studies were
conducted to assess reconcentration of radioactive materials that are
released into sanitary sewer systems. In December 1994, NRC published
NUREG/CR-6289, ``Reconcentration of Radioactive Material Released into
Sanitary Sewers in Accordance with 10 CFR Part 20.'' A review of the
literature demonstrated that some radioactive materials discharged into
sanitary sewer systems reconcentrate in sewage sludge. However, the
report concluded that the available data were not sufficient to assess
the adequacy of the requirements in 10 CFR 20.2003 in preventing
occurrences of radionuclide reconcentration in sewage sludge at levels
which present significant risk to the public; nor is the available data
sufficient to suggest strategies for changing the requirements.
In 1996, the Association of Metropolitan Sewerage Agencies (AMSA)
conducted a limited survey of reconcentration of radioactivity in
sewage sludge and ash samples from some of its member POTWs. Samples
were obtained from 55 wastewater treatment plants in 17 States. The
most significant sources of radioactivity were potassium and radium
isotopes, which are Naturally Occurring Radioactive Materials (NORM).
In December 1997, the Washington State Department of Health issued a
report WDOH/320-013, ``The Presence of Radionuclides in Sewage Sludge
and Their Effect on Human Health,'' that was based on sludge samples
taken at six POTWs in the State. The report concluded that that there
was no indication that radioactive material in sewage sludge in the
State of Washington poses a health risk.
The Interagency Steering Committee on Radiation Standards (ISCORS)
was formed in 1995, to address inconsistencies, gaps, and overlaps in
current radiation protection standards. In 1996, the Sewage Sludge
Subcommittee of ISCORS was formed to coordinate efforts to address the
recommendations in the 1994 GAO Report. Between 1998 and 2000, the EPA
and NRC (through the ISCORS) jointly conducted a voluntary survey of
POTW sewage sludge and ash to help assess the potential need for NRC
and/or EPA regulatory decisions. Sludge and ash samples were analyzed
from 313 POTWs, some of which had greater potential to receive releases
of radionuclides from NRC and Agreement State licensees, and some of
which were located in areas of the country with higher concentrations
of NORM. In November 2003, the results of the survey were published in
a final report, NUREG-1775, ``ISCORS Assessment of Radioactivity in
Sewage Sludge: Radiological Survey Results and Analysis.'' No
widespread or nationwide public health concern was identified by the
survey and no excessive concentrations of radioactivity were observed
in sludge or ash. The results indicated that the majority of samples
with elevated radioactivity had elevated concentrations of NORM, such
as radium, and did not have elevated concentrations of radionuclides
from manmade sources.
In February, 2005, the Sewage Sludge Subcommittee published a
report, NUREG-1783, ``ISCORS Assessment of Radioactivity in Sewage
Sludge: Modeling to Assess Radiation Doses.'' This report contains dose
modeling results for seven different sewage sludge management scenarios
for POTW workers and members of the public. Results of the dose models
and survey results indicated that there is no widespread concern to
public health and safety from potential radiation exposures associated
with the handling, beneficial use, and disposal of sewage sludge
containing radioactive materials, including NORM.
In February, 2005, the Sewage Sludge Subcommittee also published a
report, ``ISCORS Assessment of Radioactivity in Sewage Sludge:
Recommendations on Management of Radioactive Materials in Sewage Sludge
and Ash at Publicly Owned Treatment Works;'' (EPA 832-R-03-002B; ISCORS
Technical Report 2004-04). This report provides guidance to: (1) Alert
POTW operators, as well as State and Federal regulators, to the
possibility that radioactive materials may concentrate in sewage sludge
and incinerator ash; (2) inform POTW operators how to determine whether
there are elevated levels of radioactive materials in the POTW's sludge
or ash; and (3) assist POTW operators in identifying actions for
reducing potential radiation exposure from sewage and ash.
Reasons for Withdrawing the ANPR
The results of the survey and dose modeling work conducted by the
ISCORS Sewage Sludge Subcommittee regarding radioactive materials in
sewage sludge and ash provide a technical basis for withdrawing the
ANPR. The survey demonstrated that the most significant levels of
radioactive materials in POTWs are attributable to NORM. The dose
modeling work indicated that, in general, the doses from licensed
materials in sewage sludge present a sufficiently low health and safety
risk to POTW workers and to the public under the current regulatory
structure. Therefore, it is not necessary to modify the current
restrictions regarding the release of radioactive materials into
sanitary sewers (10 CFR 20.2003) as discussed in the ANPR. In addition,
public comments indicated that several of the options discussed in the
ANPR would be costly to implement and may not be consistent with
efforts to maintain doses ALARA. For these reasons, NRC is withdrawing
the ANPR.
Public Comments on the Potential Changes to 10 CFR Part 20
In the ANPR, NRC invited comment on the following aspects of the
regulation of release of radionuclides into sanitary sewers: The form
of materials suitable for disposal, the limits on the total
radioactivity of materials that can be released by a licensee into
sanitary sewers in a year, also called the ``total quantity limit,''
the types of limits applied, and the exemption for medical patient
excreta. The following is a summary of those comments and NRC
responses.
(1) Form of Material for Disposal
The May 21, 1991, final rule (10 CFR 20.2003) allows soluble and
readily dispersible biological material to be released but prohibits
the release of any non-biological insoluble material. Because NRC
recognized that new technologies for wastewater treatment, such as ion-
exchange and some types of biological treatment, can reconcentrate
radionuclides, NRC invited comments regarding whether and how
regulations should account for the effects of different wastewater
treatment
[[Page 68352]]
technologies on radionuclide reconcentration. NRC also invited comments
regarding the potential impacts that additional restrictions on the
form of materials allowable for release into sanitary sewers would have
on licensee operations. Public comments regarding the adequacy of the
current restrictions also were received.
Comment: Nine commenters, including representatives of the New York
State Energy Office, New York State Department of Environmental
Conservation, AMSA, and the Department of Energy (DOE), expressed the
view that the regulations should be reevaluated because of new sewage
treatment technologies or should account for the effects of new
technologies used to treat sewage or sewage sludge. One commenter
suggested that NRC limits should account for a variety of POTW-specific
factors, including sludge handling processes, and sludge disposal
methods, and restrictions on the POTW's treated water discharge.
Another commenter suggested NRC should take new sewage treatment
technologies into account only if the results of NUREG/CR-6289, which
was incomplete at the time the comment was made, indicated that new
sewage treatment technologies had the potential to cause significant
reconcentration of radionuclides in sewage sludge. Two commenters
recommended NRC develop technology-specific reconcentration factors to
help POTW operators to design appropriate pretreatment plans. A
representative of DOE suggested NRC should expect that advances in the
sewage treatment process would result in increasing concentration of
radionuclides in sewage sludge. Two commenters recommended NRC
regulations account for synergistic health effects of radiation and
pollutants in wastewater, and one suggested NRC evaluate the
synergistic effects of radiation and the chlorine and fluoride used in
drinking water treatment.
Response: NRC acknowledges the commenters' support for regulations
that would account for the reconcentration of radionuclides by
wastewater treatment processes. However, the regulations will not be
changed because the ANPR is being withdrawn for the reasons previously
explained.
Comment: Four commenters expressed the view that NRC regulations
should not take sewage treatment technologies into account. Reasons
included uncertainty that new technologies will be implemented and a
lack of information about the effects of the new technologies on
radionuclide reconcentration. A representative of the State of Illinois
Department of Nuclear Safety suggested NRC should keep informed of
technological developments, but should not implement additional
restrictions without significant evidence that the current restrictions
are not adequate. Two commenters suggested that, rather than revising
Sec. 20.2003 to account for new treatment technologies, NRC should
consider placing additional restrictions on individual licensees to
provide the necessary protection to the receiving POTWs in unusual
cases where the number of licensees, size of the sewage treatment plant
or nature of the technology used at the treatment plant may cause doses
above 100 mrem/yr. One commenter stated that it is unnecessary for NRC
regulations to account for sewage sludge treatment technologies because
local POTWs have the authority and mandate to account for these
technologies by developing industrial water discharge permits pursuant
to 40 CFR 403.5(c)(1).
Response: NRC acknowledges the commenters' opposition to the
proposed rule change, which supports NRC's decision to withdraw the
ANPR. With respect to the comment that POTWs have the authority and
mandate to impose limits on radioactive materials released into
sanitary sewers, NRC notes that, as described in Section 4.7 of the
ISCORS recommendations on management of radioactive materials in sewage
sludge and ash (EPA 832-R-03-002B), POTWs may not have the same
authority to regulate radioactive material as they do to regulate other
materials released into sanitary sewers.
Comment: Eight commenters expressed the view that NRC regulations
should account for the fact that several licensees may discharge to the
same POTW, and, of those, five expressed the view that the regulations
should also take the capacity of the POTW into account. Five commenters
stated that restrictions on the release of nonradioactive pollutants
established under EPA's National Pollutant Discharge Elimination System
(NPDES) account for the capacity of the receiving POTW, the wastewater
treatment systems used, and the number of industrial users discharging
to a POTW, and suggested any new regulations governing the release of
radioactive materials into sanitary sewers should take these factors
into account. A representative of DOE expressed the view that changes
to the regulations to account for multiple dischargers should be
considered but may not be necessary because sanitary systems serving
multiple licensees would probably be large systems in which the
licensees' effluent would be diluted by many other inputs to the sewer
system. One commenter suggested that, if limits on the total amount of
radioactivity individual POTWs could receive were developed, any cases
in which the limits are being exceeded by licensees that were already
discharging sewage into the sewer system before the limits were
developed should be handled on a case-by-case basis.
Response: NRC acknowledges the commenters' support for regulations
that would account for the capacity of individual POTWs and the number
of licensees discharging to a single POTW. However, the proposed change
will not be implemented for the reasons previously explained.
Comment: Twenty-seven commenters were opposed to additional
restrictions on the forms of material suitable for release into
sanitary sewers. Twenty-one stated that the potential for significant
reconcentration of radionuclides during wastewater treatment probably
had been addressed by the May 21, 1991 changes to Part 20 (56 FR 23360)
that restricted the forms of materials that could be released into
sanitary sewers and lowered concentration limits. Another commenter
expressed the view that it was unclear whether contamination described
in the case studies discussed in the ANPR occurred because of
violations of the existing regulations, and also that it would be
inappropriate for NRC to respond to individual violations of regulatory
requirements by making changes to the regulations for all licensees.
Representatives of six licensees indicated that additional restrictions
on the forms of material appropriate for disposal would impose a
significant burden on their operations. Commenters listed the costs of
building new storage facilities, analyzing samples of waste to
determine whether insoluble radionuclides were present, and
establishing new collection, handling, and disposal procedures as well
as retraining of personnel as expenses that would be incurred if
additional restrictions were imposed. In addition, three commenters
expressed the concern that further restricting the forms of material
appropriate for disposal in a sanitary sewer would not be consistent
with NRC's policy that doses should be maintained ALARA because the
additional waste handling that would be required would cause doses to
workers that would not be justified based on the minimal dose to
members of the public or POTW workers that might be avoided.
Response: NRC acknowledges the commenters' remarks, which support
[[Page 68353]]
the withdrawal of the ANPR. However, the NRC staff notes the need to
analyze samples of waste to determine if the waste contains insoluble
radionuclides should not impose an additional burden because the
restriction on releasing insoluble, non-biological wastes was already
in place when the comment was made.
Comment: Twenty-three commenters encouraged NRC to continue to
allow release of readily soluble wastes that met the quantity and
concentration release criteria in 10 CFR Part 20. Twenty-one of those
commenters indicated that they were unaware of any significant problems
caused by the disposal of soluble radioactive material in sewer
systems. Three commenters stated that they were not aware of any
mechanisms that would reconcentrate the wastes typical of biomedical
research in sewage sludge, and two of these stated that the activity
levels were sufficiently low that reconcentration, even if it did
occur, would not cause a significant dose.
Response: NRC acknowledges the commenters' support for the
continuation of the current regulations which allow certain
concentration and quantities of readily soluble radioactive material
into sanitary sewers.
Comment: Two commenters suggested that NRC should change the
regulation to re-establish disposal of dispersible non-biological
materials. One commenter suggested disposal of non-biological
dispersible materials should be allowed for materials that have half-
lives of less than 100 days or are below the concentrations listed in
10 CFR Part 20 Appendix C.
Response: NRC acknowledges the commenters' suggestion that release
of non-biological dispersible material into sanitary sewers be allowed.
NRC understands that reconcentration of a radionuclide in sewage sludge
can be limited by its half life. However, NRC has chosen not to change
the regulation governing the release of radioactive material into
sanitary sewers for the reasons previously explained.
Comment: Six commenters, including a representative of DOE, noted
that the chemical form of materials released into the sewer can change,
and that materials that are soluble when released may precipitate or
sorb to solid particles in the sewer or treatment plant. A
representative of the New York State Department of Environmental
Conservation suggested NRC study not only the effect of new
technologies on radionuclide solubilities, but also how the solubility
of radioactive materials change in sanitary sewers. A representative of
DOE noted that precipitation and sorption could cause risks to
individuals who work in POTWs, work in close contact with sewers, or
who incinerate or use wastewater treatment sludge. In addition, the
commenter remarked that, while it appeared to be reasonable to limit
sewer releases to soluble and dispersible biological materials, NRC
should realize that licensees could release insoluble or nondispersible
materials to sewer systems inadvertently. One commenter expressed the
view that NRC regulations should account not only for the form of
material when released, but the form it was likely to take after being
discharged.
Three commenters expressed the view that, because the form of a
material discharged is likely to change when it reaches the sewer or
POTW, the modification to 10 CFR 20 that eliminated disposal for non-
biological ``readily-dispersible'' materials may not have removed the
chance that radionuclides could reconcentrate in wastewater treatment
sludge. Two commenters remarked that reconcentration of radionuclides
probably would continue, in part because POTWs are designed to remove
dissolved contaminants from wastewater. However, both commenters
expressed the opinion that reconcentration is not necessarily a problem
if the dose any individual is expected to receive from exposure to
sewers, sewage, or sludge is low.
Response: NRC understands that materials that are released into the
sewer in a soluble form can precipitate or sorb to solid materials in
sewers or POTWs, as discussed in NUREG/CR-6289. Most of the commenters'
concerns about the potential risk to POTW workers are addressed in the
ISCORS dose modeling report (NUREG-1783), as previously explained.
Although the ISCORS dose analysis (NUREG-1783) does not include an
analysis of doses to workers that come into contact with sewers, those
doses are expected to be limited because of the limited amount of time
a worker would spend in close contact with a sewer and because of the
relatively low doses predicted for most scenarios that involve contact
with sewage sludge.
NRC acknowledges the concern that licensees may inadvertently
dispose of insoluble non-biological material. NRC also acknowledges the
suggestion that the regulations should account for changes in the form
of materials that are likely to occur in sewers and POTWs and the
concern about the efficacy of the 1991 revisions. For the reasons
previously explained, NRC has decided not to change the regulations
governing the release of radioactive material into sanitary sewers.
However, NRC staff notes that, in addition to restrictions on form, NRC
also has imposed annual limits in 10 CFR 20.2003(a)(4) on the total
amount of radioactivity that can be released into sanitary sewers to
limit the potential for reconcentration of radioactive material in
sanitary sewers, sewage sludge, and sludge ash.
Comment: Five commenters supported additional restrictions on the
form of materials that can be released into sanitary sewers. One
commenter expressed the view that the practice, used by some medical
research laboratories, of releasing pureed tissue samples to the
sanitary sewer was distasteful. Another commenter expressed the opinion
that NRC should impose any requirement that would minimize the amount
of radioactivity in the environment.
Response: NRC acknowledges the commenters' support for additional
restrictions on the forms of material suitable for release into
sanitary sewers but is not changing the regulations because it believes
the current approach is sufficiently protective, as previously
explained.
Comment: Three commenters requested clarification regarding the
distinction between soluble and readily dispersible materials. One
requested that an information notice be produced to address materials
used in the biotech industry. Another commenter expressed the concern
that it would be difficult to demonstrate compliance with the
restriction that only soluble and readily-dispersible biological
materials be released into sanitary sewers if colloids that flow
through filters and resins are classified as non-biological dispersible
material. The commenter proposed an operational procedure to
distinguish between soluble and readily dispersible materials. A
representative of the New York State Department of Environmental
Conservation noted that traces of insoluble radioactive material could
be released into sewers with soluble materials, and requested that NRC
establish a lower limit of detection for insoluble material.
Response: NRC acknowledges the commenters' request for additional
guidance on how licensees should demonstrate the solubility of
radioactive material released to sanitary sewers. Although NRC does not
have plans to provide additional guidance on this issue, the staff
notes that, as discussed in NRC Information Notice 94-007, licensees
are free to develop alternative methods of demonstrating the solubility
of materials they wish to release into sanitary sewers and to submit
these
[[Page 68354]]
procedures to NRC for evaluation on a case-by-case basis.
(2) Total Quantity of Material
In the May 21, 1991 final rule, NRC did not change the total
quantity limits, which allow a licensee to release 185 gigabecquerel
(GBq) (5 curies (Ci)) of H-3, 37 GBq (1 Ci) of C-14, and 37 GBq (1Ci)
of all other radioactive materials combined into sanitary sewers each
year. The use of total quantity limits has been a long-standing
requirement and was originally included in the rule (10 CFR
20.2003(a)(4)) to address concerns regarding the possibility for
reconcentration of radionuclides. In the ANPR, NRC invited comments
about the alternative approach of limiting the annual release of each
radionuclide individually. NRC also invited comments about the current
total quantity limits and the potential impacts that additional
restrictions on the annual releases into sanitary sewers would have on
licensees.
Prior to publishing the ANPR, NRC received a petition for
rulemaking to amend 10 CFR 20.303 (superseded by Sec. 20.2003) and
Sec. 20.305 (superseded by Sec. 20.2004) from the Northeast Ohio
Regional Sewer District (PRM-20-22). A notice of receipt of the
petition was published in the Federal Register (58 FR 54071; October
20, 1993). The petitioner requested that NRC amend its regulations to
require that all licensees provide at least 24 hours advance notice to
the appropriate POTW before releasing radioactive material to the
sanitary sewer system. The petitioner also requested that NRC exempt
materials that enter the sanitary waste stream from the requirements
regarding Commission approval for incineration under NRC's current
regulations. NRC solicited comments on the petition in the ANPR. The
denial of the petition was noticed in the Federal Register on January
27, 2005 (70 FR 3898).
Comment: Six comments received in response to the ANPR supported
annual total quantity limits. Two commenters, including a
representative of DOE, suggested total quantity limits should be
retained because they help prevent reconcentration of radionuclides in
sewage sludge and two supported the total quantity limits because they
are easy for licensees and regulators to understand and implement. Two
commenters, including the representative of DOE, suggested it may be
worthwhile for NRC to evaluate whether the regulation could be
optimized by changing the annual release limits for some radionuclides.
A representative of the Illinois Department of Nuclear Safety expressed
the opinion that the relatively low doses calculated for the case
studies described in the ANPR and predicted for other scenarios in
NUREG/CR-5814 indicated that reconcentration of radionuclides in sewage
sludge could be addressed on a case-by-case basis rather than by
changing the total quantity limits in Sec. 20.2003.
Response: NRC acknowledges support for the current approach of
using annual limits on the total quantity of radioactive material that
can be released into sanitary sewers by a licensee. In accord with the
commenters' suggestion, NRC performed a study to evaluate the
reconcentration of various radiounuclides in POTWs, the results of
which are discussed in NUREG/CR-6289.
Comment: A representative of the City of Oak Ridge made positive
and negative statements about NRC annual total quantity limits. The
commenter stated that both concentration and total quantity limits were
necessary to ensure protection of workers and to ensure that
traditional methods of sludge disposal remain acceptable. However, the
commenter also expressed the view that the current values of the total
quantity limits are too high and stated that disposal of 37 GBq (1 Ci)
of Co-60 annually to the Oak Ridge POTW would result in unacceptably
high concentrations of Co-60 in the POTW's sludge, especially if the
material was released during a relatively short time period. The
commenter also expressed the opinion that the total quantity limits are
inappropriate for low specific activity radionuclides because of the
large mass of the radionuclide that could be discharged. As an example,
the commenter stated that release of 37 GBq (1 Ci) of U-238 to the
city's POTW in a year would result in a mass concentration of uranium
of more than 0.05 percent in the POTW's sludge, making the sludge
licensable source material. In addition to these comments, the
commenter suggested that, because the mean retention time of sludge at
a POTW typically is one month or less, a monthly discharge limit would
be more appropriate than an annual limit.
Response: NRC acknowledges the commenter's concern about the
release of Co-60 to a POTW and the suggestion that quantity limits
should be implemented on a monthly, rather than an annual, basis. The
staff notes that the 1991 revision to 10 CFR Part 20 that eliminated
the discharge of insoluble non-dispersible radioactive material into
sanitary sewers was implemented to reduce the possibility of
significant contamination of sewage sludge with insoluble
radionuclides, such as Co-60. NRC has decided not to change the
regulations governing sewer release of radioactive material for the
reasons previously explained. NRC acknowledges the commenter's concern
about the applicability of the total quantity limit to low specific
activity radionuclides. However, NRC does not agree that the
accumulation of large masses of low-specific activity radionuclides in
POTWs is likely to be problematic. In addition POTWs have some
authority to impose limits on the release of material into sanitary
sewers when the purpose of the limits is not radiation protection, as
discussed in Section 4.7 of the ISCORS recommendations on management of
radioactive materials in sewage sludge and ash (EPA 832-R-03-002B).
Comment: Twenty-three commenters described concerns about the
current approach of limiting the total amount of radioactivity a
licensee may release into a sanitary sewer system. Nineteen commenters
expressed the opinion that it is not appropriate to apply the same
total quantity limit to large and small facilities that discharge
different amounts of sewage and therefore dilute radioactive materials
to different extents. Another commenter stated that NRC should not
attempt to impose total quantity limits on large facilities. Seventeen
commenters expressed the view that NRC should consider relaxing the
total quantity limits because of the new restriction on the form of
material and lower release concentration limits implemented in the 1991
revision to 10 CFR Part 20. The commenters expressed the opinion that
adherence to the new form and concentration limits may eliminate the
need for total quantity limits. Three commenters suggested that,
instead of limiting the total quantity of radioactivity a licensee
could dispose of into a sewer, NRC should focus on the radionuclides
and chemical forms of radionuclides that reconcentrate in POTWs to a
significant extent. One commenter expressed the concern that a person
could dispose of 37 GBq (1 Ci) of Cs-137 within a month while remaining
in compliance with the current concentration and total quantity limits.
Another commenter suggested concentration limits are sufficient and are
superior to total quantity limits because concentration limits account
for the total volume of water a licensee releases to the sanitary sewer
system. The commenter noted that, although the nominal purpose of the
total quantity limits is to eliminate reconcentration, the total
quantity limits do not appear to prevent reconcentration, as evidenced
by the case studies described in the
[[Page 68355]]
ANPR. The commenter suggested reconcentration could be avoided by
reducing the allowable concentrations of those radionuclides that have
shown a tendency to reconcentrate in sewage sludge.
Response: NRC acknowledges the comment about the application of the
same total quantity limit to large and small facilities, but believes
that the system is appropriate. Because the total quantity limit is
designed to reduce the potential for reconcentration of radionuclides
at POTWs, an appropriate total quantity limit is more dependent on the
volume of sewage received by a POTW than it is on the volume of a
licensee's effluent.
NRC acknowledges the comment that total quantity limits should be
relaxed or eliminated, but does not agree that the limits on form and
concentration eliminate the need for annual quantity limits. As
discussed in NUREG/CR-6289, the form of radionuclides can change upon
entering a sewer or POTW because of sorption and precipitation. NRC
also acknowledges the concern that total quantity limits did not
prevent the cases of contamination discussed in the ANPR. NRC believes
that limiting both the form and total quantity of material released
into sanitary sewers is the best way to limit the potential for
significant reconcentration of radionuclides released by licensees into
sanitary sewers.
NRC acknowledges the commenters' suggestion that, instead of
imposing total quantity limits, it should focus on those radionuclides
that have been shown to reconcentrate in sewers or sewage sludge. NRC
also acknowledges the commenter's concern about the discharge of Cs-137
but believes the current approach to be sufficiently protective for the
reasons previously explained.
Comment: One commenter expressed the view that additional
limitations on the release of H-3 and C-14 into sanitary sewers would
not produce any public health benefit because any dose an individual
received from sewer-disposed H-3 and C-14 would be negligible in
comparison to the dose the individual would receive from naturally-
produced H-3 and C-14.
Response: NRC acknowledges the commenter's view that additional
restrictions on the quantities of H-3 and C-14 are unnecessary. The
comment supports the withdrawal of the ANPR and the current total
quantity limits which allow the annual release of 185 GBq (5 Ci) of H-3
and 37 GBq (1 Ci) of C-14 in addition to the release of 37 GBq (1 Ci)
of all other radionuclides combined.
Comment: Eight licensees expressed the view that additional
restrictions on the total quantity of radioactive material that could
be released into sanitary sewers annually would have a severe negative
impact on their facilities' operations. Representatives of a biomedical
company, a university, and the National Institutes of Health (NIH)
noted that a reduction in the total quantity limits would impose a
significant financial burden on organizations involved in biotechnical
research, development, or medical practice, especially if the limits
were reduced to a point that liquid wastes would need to be solidified
and disposed of as low level waste (LLW). The representative of NIH
estimated that solidification and disposal of liquid wastes as LLW
would cost NIH 2.8 million dollars annually, as of 1994. Two commenters
remarked that companies would bear the additional expense of acquiring
or building storage facilities or acquiring treatment technologies to
remove radioactivity from liquid waste streams. One commenter noted
that LLW disposal of many of the materials currently released into
sanitary sewer systems would be a particularly unnecessary expense and
inefficient use of LLW landfill space because, in many cases, the
material would decay to negligible quantities before it reached the LLW
landfill.
Five commenters associated with medical research facilities or
companies that produce radiopharmaceuticals suggested additional
restrictions on the total quantity of radioactive material that could
be released into sanitary sewers annually could harm public health and
safety by causing companies to limit biomedical research and
development efforts. One of these commenters stated that the amount of
radioactivity released into sanitary sewers in association with medical
research was insignificant as compared to the amount of radioactivity
released to sewers in patient excreta and concluded that release of
radioactive materials associated with biomedical research should be
allowed as long as the exemption for patient excreta is continued. Two
commenters expressed the opinion that additional restrictions on the
total quantity of radioactivity a licensee could release into sanitary
sewers annually would not be consistent with efforts to maintain doses
ALARA because workers would be exposed to radioactive material while
processing liquid waste to make it suitable for LLW disposal.
A representative of a company that offers health physics services
stated that, for most of its clients who want to release radioactive
material into sanitary sewers, the most limiting factor is the annual
total quantity limits. A representative of the University of California
expressed concern that the numerical limits in 10 CFR 20.2003 would be
lowered, although the university typically releases only 11.1 Gbq (0.2
Ci) of radioactivity into sanitary sewers each year.
Response: NRC acknowledges the commenter's concerns about the
potential impacts of additional restrictions on the total quantity of
radioactive material that a licensee can release to sewers annually. As
previously explained, the additional restrictions discussed in the ANPR
will not be implemented.
Comment: A representative of AMSA stated that, although the
organization understands that lowering total quantity limits could
impose financial burdens on licensees, additional restrictions are
appropriate if they are needed to prevent contamination of sewage
sludge.
Response: NRC acknowledges the commenter's statement, but has
decided not to change the total quantity limits because it believes the
current approach is sufficiently protective for the reasons previously
explained.
Comment: Twenty-one letters received in response to the ANPR
included comments on the Northeast Ohio Regional Sewer District's
request for NRC to amend its regulations to require that all licensees
provide at least 24 hours advance notice to the appropriate POTW before
releasing radioactive material into a sanitary sewer system. Six of the
twenty-one commenters supported a requirement for licensees to provide
the sewage treatment plant with some type of reporting on the
radioactive materials released into the sanitary sewer system. These
commenters supported a wide range of reporting requirements, including
the petitioner's request for a 24-hour advance notification before
licensees release radioactive material, monthly or annual discharge
reports, reports of releases that could be a threat to the POTW workers
or the environment, or notification of large accidental releases. One
commenter suggested licensees should analyze effluent samples and
include the results in discharge reports. A representative of AMSA
stated that advance notice of releases is necessary so that POTW
operators can ensure worker health and safety and make appropriate
decisions about sludge disposal and reuse.
Fifteen of the twenty-one commenters did not support such a
requirement for licensees to provide at least 24-hour
[[Page 68356]]
advance notice to the appropriate sewage treatment plant before
releasing radioactive material into a sanitary sewer system. Several
commenters said that a 24-hour advance notification would result in an
unnecessary regulatory burden without providing additional protection
against radiation or dose reduction. These commenters expressed the
view that the existing regulations for discharges of licensed material
maintain doses at or below the existing dose limits for members of the
public and if licensees meet the ALARA goals, the 24-hour advance
notification would be unnecessary. Several commenters noted that such
notification would be impractical because most releases are continuous
and involve very small quantities of radioactive material. For example,
discharges from hospitals and medical facilities would change daily
depending on the number of patients treated and types of treatment
used.
Several commenters also noted that there could be large cost
implications and regulatory burdens associated with such notification.
In addition, commenters were concerned that data about releases of
radioactive material could be misinterpreted if release reports were
received and interpreted by sewage treatment plant personnel rather
than radiation safety specialists. Several commenters stated that such
an NRC requirement for licensees to provide a 24-hour advance
notification was unnecessary because local municipalities have
authority over their local sewer district, already have requirements to
follow the Clean Water Act, and may establish a pretreatment program
for wastewater acceptance. One commenter noted that the usefulness of a
24-hour advance notification should be assessed after the new limits
for sewer discharges are in place.
Response: NRC has determined that a requirement for advance
notification of each release of radioactive material to a sanitary
sewer would impose an unnecessary regulatory burden on licensees
without a commensurate health and safety benefit. Additional reasons
for the denial of the petition are discussed in the Federal Register
notice published on January 27, 2005 (70 FR 3898).
Comment: Six comment letters received in response to the ANPR
included comments on the Northeast Ohio Regional Sewer District's
request that NRC exempt materials that enter the sanitary waste stream
from the requirement for NRC approval prior to treatment or disposal of
licensed material by incineration. Four commenters supported such an
amendment because, given the radioisotopes and activities involved, the
pathways for human exposure from radioactive wastes seem no more or
less significant if the wastes are dispersed into water or air. These
commenters suggested that, if release into a sanitary sewer system is
to be considered disposal, the limits should be set so that no further
regulation of the radioactive material is needed after release. One
commenter did not support such an amendment and expressed the view that
it would only serve to provide an open-ended system for radioactive
material to pass into the environment and to the public without
limitation or characterization.
Response: NRC approval to incinerating waste is required to ensure
that NRC may evaluate the potential impact to the public health and
safety and the environment on a case-by-case and site-specific basis.
Hazards associated with incineration of sewage sludge will depend on
the specific characteristic of the sludge and the radionuclides that
may be present. Additional reasons for the denial of the petition are
discussed in the Federal Register notice published on January 27, 2005
(70 FR 3898).
(3) Type of Limits
The present approach to limiting releases of radioactive material
into sanitary sewers is to specify limits on both the monthly average
concentration of each radionuclide in a licensee's sewage and the total
quantity of radioactive matter that a licensee can release annually.
Table 3, Appendix B, of 10 CFR Part 20 lists the allowable monthly
average concentration of each radionuclide in a licensee's release to
sewers. Allowable concentrations are based upon a calculated dose of 5
mSv/yr (500 mrem/yr) due to ingestion of 2 liters per day of a
licensee's effluent into the sanitary sewer.
In the ANPR, NRC invited comments on this regulatory approach.
Specifically, NRC invited comment as to whether it should continue to
base concentration limits on the assumption that an individual would
drink 2 liters of the effluent from a licensee's facility each day, and
whether exposure at other locations, such as at a POTW, should be
considered in developing release limits. In addition, NRC invited
comments about how other exposure scenarios, such as exposure to
radionuclides in contaminated sludge, should be accounted for. NRC also
invited comments as to whether it should establish limits in terms of
dose instead of limits on the quantity and concentrations of
radioactive material discharged. Included with the responses to these
inquiries were several comments about monitoring, enforcement actions,
and regulatory authority to set limits on releases of radioactive
material into sanitary sewers that have been addressed with the General
Comments.
Comment: Twenty-three commenters supported the current modeling
approach of assuming that an individual ingests 2 liters of water taken
from the licensee's outfall to the sewer system each day. Nineteen of
these commenters, representing hospitals, biomedical laboratories, and
universities, noted that this assumption is conservative and easy for
licensees to understand. A representative of DOE noted that the
approach appears to be bounding, and has been ``largely successful as a
regulatory measure''. The commenter also expressed the view that,
because this type of consumption is not expected to be chronic, it is
appropriate to base concentration limits on a calculated annual dose of
500 mrem instead of 100 mrem. One commenter did not specifically
address the assumption that an individual would drink 2 liters of a
licensee's discharge each day, but did support the use of a licensee's
sewer outfall as an appropriate exposure location. Two commenters
expressed the view that the modeling assumption was appropriate because
individuals, including children, could drink or otherwise be exposed to
water directly downstream of a sewer outfall. Another commenter that
supported the current assumption expressed the view that modeling
exposure at a licensee's outfall to a sewer system is consistent with
modeling exposure at a licensee's fence line, as is done in other NRC
assessments, and that considering a downstream location would be
inconsistent with modeling exposure to the maximally exposed
individual.
Response: NRC acknowledges support for the current modeling
assumption. The staff notes that several commenters appeared to believe
that the concentration limits were based on the assumption that an
individual would consume 2 liters of sewage from a POTW outfall, rather
than 2 liters of a licensee's effluent into the sewer system, each day.
Staff notes that the assumption that an individual would consume a
licensee's effluent is more conservative than the assumption that an
individual would consume POTW effluent because the concentration of
radionuclides in POTW effluent will have been diluted with effluent
from all of the other residential and industrial dischargers to the
POTW.
[[Page 68357]]
Comment: Three commenters expressed concern that the concentration
limits are based on an annual dose of 5 mSv (500 mrem) and stated that
the concentration limits should be based on an annual dose of no more
than 1 mSv (100 mrem), in accord with the 10 CFR 20.1301 limit on doses
to members of the general public from licensed activities. One
commenter expressed the view that the 1 mSv (100 mrem) annual public
dose limit should be lowered. Two commenters expressed the view that
the dose from ingesting a licensee's effluent should be included in the
1 mSv (100 mrem) TEDE annual public dose limit rather than being
calculated separately and excluded from the 10 CFR 20.1301 limit.
Another expressed the view that, if any activity were to be permitted
to be discharged into sanitary sewers, the limiting dose for exposure
to sewage sludge should be no greater than the dose limit for low level
radioactive waste.
Response: NRC acknowledges the commenters' concern about the
hypothetical dose used as the basis for the concentration limits. As
discussed in the ANPR, the NRC staff believes the concentration limits
based on an annual dose of 5 mSv (500 mrem) are reasonable because it
is unlikely that an individual would have access to and would consume
water at the point at which a licensee discharges water into the
sanitary sewer and because dilution from additional discharges into the
sewer is likely to reduce the expected dose to well below the 1 mSv
(100 mrem) annual dose limit.
NRC also acknowledges the commenters' suggestion that the dose from
consuming effluent released into the sanitary sewer be included in the
TEDE from other licensee operations. However, in the case of sewer
discharge, the point of exposure is expected to be remote from the
licensee's facility. Because individuals that could be exposed to a
facility's effluent are different individuals than those that live
closest to the facility, it would be unrealistic to include the dose
from exposure to a licensed facility's effluent in the total dose from
all of the facility's activities. The staff notes that comments
regarding the appropriate value of the annual dose limit for members of
the public from licensed activities specified in 10 CFR 20.1301 are
beyond the scope of this rulemaking.
Comment: Ten commenters did not support the use of the current
modeling approach of assuming that an individual ingests 2 liters of
water taken from a licensee's sewer outfall each day. Almost all of
these commenters expressed the view that the assumption is unrealistic.
One commenter expressed the view that, while the assumption that an
individual ingests 2 liters of water taken from a licensee's sewer
outfall each day is a reasonably conservative basis for concentration
limits, the assumption may not be a basis for total quantity limits
because it would over-emphasize the potential impact of short-lived
radionuclides.
Response: NRC acknowledges the commenters' opposition to the
current modeling approach. However, it will be retained because the
ANPR is being withdrawn for the reasons previously explained. With
respect to the comment about the basis for total quantity limits, the
staff notes that the assumption that an individual would consume a
licensee's effluent is used as the basis of the concentration limits
but is not used as the basis of the total quantity limits.
Comment: Ten commenters suggested alternate locations that NRC
should consider when developing restrictions on the release radioactive
materials into sanitary sewer systems. Of these, five suggested NRC
consider the dose to a person ingesting water once it has reached or is
leaving a POTW rather than at the licensee's sewer outfall. Three
commenters suggested NRC consider locations downstream of a POTW that
would be likely to be locations from which a municipality would extract
drinking water, while one suggested doses in the nearest residential
area should be considered. Another commenter suggested realistic models
would incorporate a factor of at least one million between the point of
discharge and a receptor locations, and suggested that, if NRC used a
more realistic dose model, it would become clear that additional
release restrictions are unnecessary. One commenter suggested that, in
considering potential doses to members of the public, NRC should
consider that sludge could be sent to a landfill, applied to
agricultural land, or made into compost for sale to the public.
Five commenters, including representatives of POTWs and DOE,
recommended NRC consider doses to sanitation workers and two commenters
suggested NRC consider doses to workers that come into contact with
sewage collection systems as well as POTW workers. One commenter noted
the importance of matching exposure locations to appropriate pathways
and suggested external radiation by gamma emitters may be an important
pathway for POTW workers, whereas ingestion of beta emitters would be
expected to be more important at a downstream drinking water source.
Five commenters suggested NRC consider that the careful treatment given
to sewage and sludge because of the other hazards it presents should
limit doses to sanitary system workers. One commenter added that NRC
regulations also should prevent contamination of sewers, POTWs,
receiving waters, and sludge and ash disposal sites. Another commenter
suggested NRC consider potential exposures to all POTW residuals,
including sludge, screenings, grit, and ash. The commenter also pointed
out that sewer pipes may leak and suggested NRC consider the potential
for groundwater contamination.
Response: The alternate locations that the commenters suggested
should be considered in dose models will not be used as a basis for a
revision to the regulations because the ANPR is being withdrawn for the
reasons previously explained. However, the NRC staff notes that several
of the modeling scenarios suggested by the commenters, including sludge
handling by POTW workers, sludge incineration, and exposure to land-
applied sewage sludge, were considered in the ISCORS dose modeling
project (NUREG-1783).
Comment: Six commenters, including representatives of POTWs and the
New York State Department of Environmental Conservation, suggested
that, in addition to protecting the general public and sanitation
workers, NRC regulations should ensure that POTWs can continue to use
traditional forms of use or disposal of biosolids (sewage sludge). One
commenter noted that events that have not resulted in significant
worker exposure have prevented POTWs from using or disposing of sewage
sludge.
Response: Additional restrictions on the release of radioactive
material into sanitary sewers will not be implemented for the reasons
previously discussed. Section 7.2 of the ISCORS recommendations on
management of radioactive materials in sewage sludge and ash (EPA 832-
R-03-002B) provides guidance to assist POTW operators in reducing
sources of radiation entering their treatment facilities.
Comment: Four commenters made suggestions about ways to account for
complex exposure scenarios, such as exposure to contaminated sewage
sludge. One commenter suggested that a variety of scenarios should be
evaluated and that the scenario resulting in the highest dose should be
used to establish limits on releases of radionuclides to sewers.
Another commenter expressed the opinion that dose models should reflect
limitations on access that are imposed to protect individuals from
other health risks associated with sewage and sewage sludge. One
[[Page 68358]]
commenter suggested no model could adequately represent complex
exposure scenarios because dose modeling was not sufficiently well
developed.
Response: The approaches the commenters suggested will not be used
as a basis for new restrictions on the release of radioactive material
into sanitary sewers because the ANPR is being withdrawn for the
reasons previously explained. NRC staff acknowledge the commenter's
statement about the capabilities of dose modeling.
Comment: Of the fourteen commenters that addressed dose limits,
seven supported implementation of dose limits. One commenter expressed
the view that dose limits are preferable to limits on concentration and
quantity alone because dose limits are easier to relate to risk. The
commenter suggested the assumptions used to evaluate compliance with
dose limits should be realistic. The commenter also suggested the use
of a tiered approach, in which simple bounding assumptions are first
used to evaluate compliance, and more complex models and more site-
specific data are used only if the simple bounding model does not
demonstrate compliance. Another commenter suggested that, if the
appropriate models were developed, releases into sanitary sewers should
be controlled under the requirements of 10 CFR 20.1302 and ALARA
guidelines just as other facility effluents are. The commenter also
noted that the potential doses calculated in NUREG/CR-5814 indicate
that the current regulations governing the release of radionuclides
into sanitary sewers are more restrictive than other NRC dose limits on
facility effluents. Two commenters expressed the view that dose limits
should be adopted only if the current limits were found not to be
protective of the public or POTW workers. Four commenters agreed with
the proposal in the ANPR that, if dose limits were adopted, NRC should
publish a regulatory guide that included concentration and total
quantity guidelines to facilitate compliance. One commenter asked if
licensees would have a choice of complying with the dose limit or with
the concentration and quantity guidelines published in a Regulatory
Guide. Two commenters advocated dose limits, but expressed the view
that the dose limits should be based on measured radionuclide
concentrations from samples taken from sewer outfalls and intakes or on
readings from dosimeters placed at POTWs rather than on concentrations
calculated based on assumptions about releases to and dilution in
sanitary sewers.
Response: NRC acknowledges the commenters' support for sewer
release restrictions to be expressed as limits on dose rather than
activity. NRC also acknowledges the commenters' suggestion that
compliance with dose limits be made based on sample measurements.
However, these options will not be implemented because the ANPR is
being withdrawn for the reasons previously explained. No response is
required to the commenter's question about compliance with dose limits
because the ANPR is being withdrawn.
Comment: Of the fourteen commenters that addressed dose limits, six
commenters opposed dose limits, and a representative of the New York
State Department of Environmental Conservation noted potential problems
with implementing dose limits but suggested NRC study the option.
Almost all of the commenters that opposed dose limits commented on the
uncertainty of assumptions about exposure pathways and the relative
complexity of implementing dose limits as compared to concentration and
quantity limits. Three commenters predicted dose limits would require
more regulatory oversight because NRC would need to review each
licensee's dose model. One commenter expressed the concern that dose
limits could make it necessary for licensees to require prior approval
for releases of radioactive material into sanitary sewers. One
commenter supported the current limits but suggested that, if dose
limits were adopted, the dose limit should be 500 mrem/yr, realistic
modeling assumptions should be made, and the modeling assumptions to be
used in compliance calculations should be clearly defined. Another
commenter advocated the use of limits expressed in ``verifiable units
of measure'' rather than limits expressed as dose and expressed doubts
about the capabilities of computer models used to calculate dose.
Another commenter stated NRC should not limit the dose a patient could
receive from a prescribed medical procedure.
Response: NRC acknowledges the commenters' opposition to dose
limits, which will not be implemented because the ANPR is being
withdrawn.
With respect to the commenter's concern that NRC should not limit
the dose a patient could receive due to a medical procedure prescribed
by his physician, the NRC staff notes the scope of the ANPR was limited
to potential doses due to exposure to radioactive material in sewage or
sludge. In general, NRC regulates the uses of radionuclides in medicine
as necessary to provide for the radiation safety of workers and the
general public and does not intrude into medical judgments affecting
patients. Additional detail on this topic can be found in NRC's Final
Policy Statement on the Medical Use of Byproduct Material, which was
published in the Federal Register on August 3, 2000 (70 FR 3898).
Comment: Two commenters expressed concern that NRC would consider
setting any non-zero dose limit for POTW workers. Both commenters
expressed the view that any dose received by a POTW worker because of
exposure to radionuclides released into sanitary sewers by licensees
would not be ALARA if the only reason such releases were allowed was to
provide an inexpensive method of waste disposal to NRC licensees.
Response: NRC acknowledges the commenters' concern about sanitary
system worker doses but disagrees with the view that only a dose of
zero could be ALARA. The staff notes that the ISCORS dose modeling
report (NUREG-1783) concludes that POTW worker doses typically are very
low and are dominated by exposure to NORM. Additional restrictions on
the release of radioactive material into sanitary sewers will not be
implemented for the reasons previously discussed.
Comment: Three commenters expressed views on the appropriate time
period over which releases should be averaged. A representative of a
municipality suggested monthly averages should not be used because the
practice encourages the use of dilution as a means of meeting the
regulations. A representative of AMSA suggested daily averages should
be used because POTW workers could be exposed to sewage and sludge on a
daily basis. In contrast, a representative of a public utility district
supported the use of weekly or monthly averages.
Response: NRC acknowledges the commenters' suggestions about
appropriate time periods over which releases should be averaged. NRC
believes monthly averages are appropriate because the effects of small
quantities of radioactivity released during a month are not expected to
depend on the time period over which the radioactive material is
discharged. Monthly limits will be retained because the ANPR is being
withdrawn for the reasons previously explained.
Comment: Ten commenters supported the development of annual release
limits for individual radionuclides or groups of radionuclides. Eight
commenters suggested limits for individual radionuclides should be
based on the results of dose models. Specific factors that commenters
[[Page 68359]]
suggested should be included in a dose model included a radionuclide's
specific activity, half-life, and solubility, and factors affecting the
radionuclide's fate and transport in sewers, wastewater treatment
process, and the environment. Two commenters recommended NRC consider
imposing different discharge limits for those radionuclides and
chemical forms that reconcentrate in POTWs to a significant extent and
those that do not. Another commenter suggested NRC set limits for
individual radionuclides based on whether they pose a risk primarily
due to internal or external exposure and specifically suggested pathway
modeling should include exposure to radionuclides that volatilize from
sewage at a POTW, exposure to raw river water, and ingestion of treated
river water. Another commenter suggested NRC consider the fate of
radionuclides in engineered wetlands that are used by some POTWs as a
final treatment step. One commenter predicted annual release limits for
individual radionuclides would provide more flexibility to licensees
and eliminate the need for special licensing exceptions to the current
total quantity limits. A representative of DOE predicted that only a
very few radionuclides would require reduced quantity limits even if
the limits were conservative to bound variations in sewage plant
designs and operating characteristics and to account for potential
improvements in waste water treatment technology.
Four commenters suggested that annual release limits should be
based on radionuclide half-life. A representative of the Texas
Department of Health predicted it may be difficult for licensees to
keep track of the quantity of each radionuclide released and suggested
NRC impose one quantity limit for short-lived radionuclides that would
be unlikely to reconcentrate in sewage sludge and a lower limit for
long-lived radionuclides that have a greater potential to reconcentrate
in sewage sludge.
A representative of the New York State Department of Environmental
Conservation noted that it may not be appropriate to use Annual Limit
of Intake (ALI) values as a basis for annual release limits for
individual radionuclides, as suggested in the ANPR, because the
ingestion pathway may not be the most significant exposure pathway and
because the chemical form of a radionuclide may be significantly
different when it is released from a POTW than it was when it was
originally discharged to the sewer. One commenter suggested both the
total quantity of all radionuclides as well as quantities of individual
radionuclides released should be limited, and that quantity limits for
individual radionuclides should be based on fractions, rather than
multiples, of ALI values. The commenter also suggested annual limits
should assure the lowest possible rather than the lowest ``reasonably
achievable'' exposure of members of the public to radionuclides.
Response: NRC acknowledges the commenters' support for the
development of annual release limits for individual radionuclides or
groups of radiounuclides. However, the proposed change will not be made
because the ANPR is being withdrawn for the reasons previously
explained.
Comment: Five commenters opposed the development of annual release
limits for individual radionuclides. Two commenters suggested the low
calculated doses received in the case studies discussed in the ANPR
indicate the current regulations are adequate. Two commenters suggested
that, if NRC were to change the annual quantity limits, it should focus
on Co-60, Sr-90, Cs-137, Ir-192, and Am-241, because these
radionuclides were identified in NUREG/CR-5814 as having the potential
to result in a significant dose, based on the pre-1991 release limits.
A representative of the State of Illinois Department of Nuclear Safety
recommended NRC change the total quantity limits only if the releases
of Co-60, Sr-90, Cs-137, Ir-192, and Am-241 that were determined to be
potentially problematic in NUREG/CR-5814 would still be permitted,
given the restrictions on form and lower concentration limits
introduced in the 1991 revision to 10 CFR part 20.
Another commenter noted that, although limiting the quantities of
radionuclides released would not necessarily be difficult, the need to
analyze batches of wastewater to determine the quantities of individual
radionuclides being released would be a significant burden as compared
to the current method the company uses, which is to base releases on
DOT shipping papers that identify the most limiting radionuclide in a
batch. However, the commenter also noted that using limits based on
multiples of ALI would be ``on the right track'' and would be similar
to methods used in Europe.
One commenter expressed the view that the biokinetics of individual
radionuclides could not be modeled well enough to provide a basis for
limits on the quantity, concentration, or form in which a radionuclide
could be discharged, especially because the models would not include
the synergistic effects of radiation and other pollutants. The
commenter also expressed the view that the exempt quantities published
in 10 CFR Part 30 represented quantities ``below regulatory concern''
(BRC) and suggested it would be inappropriate to use multiples of the
exempt quantity values as annual quantity limits.
Response: NRC acknowledges the commenters' opposition to annual
release limits for individual radionuclides, which supports withdrawal
of the ANPR.
(4) Exemption of Patient Excreta
The fourth topic on which NRC invited comment was the exemption of
patient excreta from the regulations governing releases of radioactive
material into sanitary sewers. NRC received fifty-two letters that
addressed the exemption for patient excreta.
Comment: Forty-four commenters, including a representative of AMSA,
recommended the exemption for patient excreta be continued and
suggested it required no additional evaluation. Thirty-three of the
commenters stated the exemption is necessary to maintain doses ALARA.
Several commenters predicted that the radiological risks to health care
workers, in the case of hospitalized patients, or family members, in
the case of patients released from the hospital, associated with
managing excreta would be far greater than any risk that the excreta
would pose to POTW workers or members of the general public once
released to the sewer system. Several commenters noted the possibility
that excreta could be spilled or inadequately shielded, especially in
the case of patients that had been released from the hospital. One
commenter expressed concern about radioactive materials volatilizing
from containers of urine. Another commenter noted that children or
pregnant women could be subject to increased risk from excreta stored
in the home if the exemption were withdrawn. Seven commenters noted
that, in addition to the radiological risks, collection and storage of
patient excreta also could pose biological hazards.
Twenty-seven of the commenters that supported the exemption noted
the short half life of most radiopharmaceuticals, and most of these
commenters hypothesized that the risk that radiopharmaceuticals could
pose to sanitary system workers or members of the general public would
be limited by their short half lives. Representatives of two hospitals
indicated that approximately 90 percent of the radioactivity used at
their hospitals was
[[Page 68360]]
in the form of Tc-99m, which has a half life of 6 hours, and that most
of the remaining radionuclides used have a half-life on the order of a
few days. Twenty commenters noted the soluble or dispersible nature of
patient excreta and five commenters suggested the dilution of patient
excreta that occurs in the sewer system affords ample protection to the
public and to the environment.
Four commenters remarked that, if NRC believes the regulation is
adequate, as stated in the ANPR, there should not be a need to modify
the exemption for patient excreta. Two commenters predicted
restrictions on the release of patient excreta into sanitary sewers
would not provide a significant benefit to public health and eleven
commenters suggested the current exemption creates no environmental or
public health hazard. One commenter remarked that none of the six case
studies presented in the ANPR indicated that patient excreta released
into sanitary sewers had caused a significant dose to any individual. A
representative of a large health care organization noted that no
complaints had been made about the sewage from any of the
organization's hospitals, although the hospitals' effluents were tested
by sanitary system staff routinely. Another hospital representative
expressed the opinion that hospitals should not be required to monitor
patient excreta because the practice causes undue anxiety in the
patients, creates additional burdens for nursing staff, and is
unnecessary because survey readings generally are low.
Response: NRC acknowledges the commenters' support for the
exemption for patient excreta, which supports the withdrawal of the
ANPR.
Comment: Fourteen commenters stated that elimination of the
exemption would impose significant burdens on their facilities'
operations. Commenters expressed concern about the costs of building
holding tanks for excreta, building separate plumbing systems,
retraining workers, and employing additional workers to manage patient
excreta. One commenter remarked that facilities would also incur the
cost of hiring professionals to assess their current waste management
practices and to recommend changes that would be needed to comply with
new regulations. Three commenters remarked that medical facilities may
also incur the costs of increased NRC licensing fees and inspections.
Several commenters suggested any net health benefits associated with
eliminating the exemption could not justify the costs of controlling
the excreta, particularly for patients being treated on an out-patient
basis.
Seven commenters predicted the costs of compliance with
restrictions on release of patient excreta into sanitary sewers would
cause a significant increase in health care costs for patients. Three
commenters predicted that health care costs would increase both because
of the increased infrastructure and labor required to manage patient
excreta and because patients' hospital stays would be extended so that
their excreta could be managed by hospital staff. A physician and
member of the NRC's Advisory Committee on the Medical Uses of Isotopes
(ACMUI) estimated that the national increase in health care costs would
be approximately 4.5 billion dollars for patients undergoing
therapeutic procedures and 62 billion dollars for patients undergoing
diagnostic procedures, as of 1994. The American College of Nuclear
Physicians and the Society of Nuclear Medicine jointly estimated that
elimination of the exemption would cause an increase in health care
costs of 5.9 billion dollars annually.
One commenter expressed the concern that medical facilities may
stop offering nuclear medicine services to avoid the legal consequences
that could result if patients did not comply with restrictions on the
release of excreta to sewer systems. Five commenters predicted that it
would be difficult to compel patients being treated on an out-patient
basis to store their excreta for decay or return it to a licensed
facility. One commenter expressed the concern that strict controls over
patients could infringe upon a patient's constitutional rights.
Several commenters expressed the concern that elimination of the
exemption would impact patient care. Four commenters expressed the
opinion that, if the exemption were eliminated, the costs or logistical
difficulties associated with managing patient excreta would cause many
facilities to discontinue offering nuclear medicine services and could
cause the end of nuclear medicine in the United States. Three
commenters expressed the concern that elimination of the exemption for
patient excreta would limit patient access to diagnostic and
therapeutic nuclear medicine services and five commenters expressed the
view that inaccessibility of nuclear medicine services would be far
more detrimental to public health than any adverse health effects that
could be averted by eliminating the exemption for patient excreta. One
commenter noted that many facilities already have eliminated some
clinical procedures because of the lack of access to low level
radioactive waste disposal facilities. Two commenters expressed the
concern that eliminating the exemption for patient excreta would
diminish the quality of care that patients received if facilities
limited patient doses to comply with restrictions on the radioactivity
of patient excreta released into sanitary sewers. One commenter
expressed the concern that patients may decline beneficial medical
procedures because of an objection to collecting or having someone else
collect their excreta. One commenter noted that patient well-being
would be compromised if patients needed to remain in the hospital so
that their excreta could be managed because it would prolong the time
away from their families and jobs. Another commenter suggested the
current exemption for patient excreta should be maintained until the
impact on health care could be assessed.
Response: NRC acknowledges the commenters' concerns about the
potential costs, legal implications, and impacts on patient care that
may be caused by removing the exemption for patient excreta. The
exemption will be maintained because the ANPR is being withdrawn for
the reasons previously explained.
Comment: Three commenters suggested the effects of the exemption
should be studied to determine if the exemption should be eliminated or
modified. A representative of DOE recommended NRC maintain the
exemption for the excreta of patients undergoing diagnostic procedures,
but consider placing restrictions on the excreta of patients undergoing
therapeutic procedures because they typically receive higher doses of
radiopharmaceuticals. Another commenter remarked that it would be
inconsistent of NRC to impose strict restrictions on the release of
excreta by hospitalized patients if the excreta of patients being
treated on an out-patient basis contributed more radioactivity to
sanitary sewer systems. A representative of an association of POTWs in
Minnesota stated that the organization is prepared to rely on NRC
judgement about the appropriateness of the exemption once NRC has
evaluated the amounts and types of radioactive materials released into
sanitary sewers through patient excreta, but expressed concern that the
ANPR indicated that the effects of the exemption had not been studied
and would not be included in planned modeling efforts. The commenter
also expressed the opinion that the safety of the exemption should be
evaluated irrespective of the origin of the waste in medical uses. A
[[Page 68361]]
representative of the New York State Department of Environmental
Conservation suggested that a range of possibilities, including
retaining the exemption, eliminating the exemption, and modifying the
exemption, should be evaluated in an Environmental Impact Statement
(EIS). The commenter stated an EIS would provide a ``long-needed''
record of the rationale for the decision to exempt patient excreta from
the sewer release restrictions and the expected impacts of the
exemption on the environment and public health.
Response: NRC acknowledges the suggested modifications to the
exemption of patient excreta and the suggestion that an EIS should be
performed. However, those suggestions will not be implemented because
the ANPR is being withdrawn for the reasons previously explained.
Comment: Two commenters suggested releases of radioactive materials
into sanitary sewers should be regulated uniformly, irrespective of the
origin of the wastes. One of the commenters questioned why the ANPR
specifically stated that doses from patient excreta were expected to be
``far below the NRC's dose limit'' when this description was equally
appropriate for the discharges from other licensees. Another commenter
remarked that, although it may be difficult for medical institutions to
meet restrictions on the release of patient excreta, the releases
should be regulated because they have been shown to contaminate sewage
sludge. Another commenter provided measurements of I-131 in sewage and
sludge in one municipality's POTW and expressed the concern that I-131
could be a source of radiation exposure to sanitary system workers. The
commenter also expressed the concern that, although it has a short half
life, Tc-99m could cause significant radiation doses to workers exposed
to sewage collection systems directly downstream of hospitals. In
addition, the commenter expressed the concern that, because I-131 is
very soluble, most of the I-131 that entered a POTW would be discharged
in the treated effluent and that the POTW's effluent may, therefore,
exceed NRC limits on the allowable releases of radioactivity to
unrestricted areas. The commenter also expressed concern that many
municipalities are not aware that releases of patient excreta are
exempt from NRC restrictions and can be a significant source of
radioactivity in wastewater.
Response: NRC acknowledges the commenters' suggestion that the
release of radioactive material should be regulated uniformly
irrespective of its origin. However, NRC believes the exemption for
patient excreta is appropriate because of the potential biological and
radiological hazards associated with alternate methods of managing
patient excreta. Additional limitations on the release of patient
excreta into sanitary sewers are not being imposed for the reasons
previously discussed. NRC appreciates the commenter's concern that
municipalities may be unaware of the potential for patient excreta to
contribute to the radioactivity of wastewater and sewage sludge.
Section 3.2 of the ISCORS recommendations on managing radioactive
material in sewage sludge and ash (EPA 832-R-03-002B) alerts POTW
operators that a significant amount of the radioactivity discharged to
POTWs that serve medical facilities can be discharged in the form of
patient excreta.
Comment: Two commenters suggested the exemption for patient excreta
should be eliminated to minimize the release of man-made radioactivity
to the environment. One commenter expressed concern about NRC's policy
on allowing patients who had received nuclear medicine treatments to
leave the hospital (described in NRC Information Notice 94-009). The
commenter also expressed concern about specific incidents in which, the
commenter believed, patients had not been warned that high residual
radioactivity would result from the medical procedures they had
undergone or had been told that releasing excreta to a septic system
would not cause adverse health effects. The commenter remarked that,
although the radionuclides used in nuclear medicine procedures may be
short-lived, each contribution of radioactivity to wastewater increased
the potential dose to a member of the public. Another commenter noted
that the contribution of radiopharmaceuticals to the radioactivity of
wastewater increases as the number of procedures performed increases.
The commenter also remarked that, if the half-lives of radioisotopes
used in medical procedures typically are short, as NRC stated in the
ANPR, the burden of storing the excreta until the radioactivity decays
to background levels should not be large.
Response: NRC acknowledges the commenters' concerns about the
potential effects of the release of patient excreta into sanitary
sewers. However, NRC believes the current regulations are protective
and has decided to retain the exemption and withdraw the ANPR for the
reasons previously explained. The staff notes that comments about the
regulations governing the release of nuclear medicine patients from the
hospital are beyond the scope of this rulemaking.
Comment: One commenter suggested patient ``vomitus'' should be
included in the exemption for the release of patient excreta into
sanitary sewers explicitly. Two additional commenters mentioned sweat,
saliva, blood, tears, and nasal fluids, but did not make any specific
suggestions about how those fluids should be addressed in NRC
regulations.
Response: The suggested change to the wording of the exemption will
not be made because the ANPR is being withdrawn. However, NRC staff
note that, in practice, the term ``patient excreta'' typically is
understood to include situations when patients vomit.
Comment: A representative of a company that manufactures equipment
that removes radionuclides from hospital waste noted German law
requires that radioactive materials be removed from hospital effluent
before it is released into sanitary sewers.
Response: NRC appreciates the information provided by the
commenter. However, the exemption for patient excreta will be retained
because the ANPR is being withdrawn for the reasons previously
explained.
Comment: Three commenters asked questions about the regulatory
implications of potential modifications to the exemption of patient
excreta from sewer release restrictions. Two commenters asked whether
patients would be required to store their excreta at home until it
decayed to background levels of radioactivity or if they would be
required to return it to the medical facility at which they were
treated. Two commenters asked whether the homes of nuclear medicine
patients would need to be monitored to ensure that proper waste
disposal procedures had been followed. One commenter asked if the
elimination of the exemption would result in changes to 10 CFR 35.75.
The commenter also asked whether restrictions would apply to all
patients treated with radiopharmaceuticals, irrespective of the dose
they had received. The commenter also asked how a licensee would
calculate the radioactivity released by each patient and whether
records of the releases would need to be maintained by the licensee.
Response: NRC acknowledges the many questions on this issue, but is
not responding to them because the ANPR is being withdrawn.
Comment: One commenter suggested NRC should exempt the excreta of
animals used in biomedical research from the restrictions governing the
[[Page 68362]]
release of radioactive material into sanitary sewers.
Response: NRC notes that this comment is beyond the scope of this
rulemaking.
(5) General Comments
In addition to comments on the topics discussed in the ANPR, NRC
received a number of comments on other aspects of the release of
radioactive material into sanitary sewers. These comments are addressed
in this section.
Comment: Sixteen commenters expressed the opinion that the current
regulations governing the release of radioactive materials into
sanitary sewers are adequate and should not be changed. To support this
view, commenters remarked that the number of incidents of contamination
is small compared to the number of POTWs receiving radioactive
materials and that the doses received in those instances are believed
to be low. Commenters also suggested the regulations should not be
changed in response to a small number of cases of contamination,
especially if some of those cases involved violations of the applicable
regulations. One commenter noted that modeling results described in
NUREG/CR-5814 indicate that releases of radionuclides used in
biomedical research are expected to result in doses below the ALARA
guidelines in NRC Regulatory Guide 8.37. A representative of the Texas
Department of Health suggested the regulations should not be changed
unless modeling results demonstrated that exposures other than
ingestion could cause an annual dose greater than 5 mSv (500 mrem). Two
commenters suggested the risk of adverse health effects associated with
exposure to radioactive material released into sanitary sewers should
be evaluated in comparison to the health risks associated with exposure
to hazardous chemical and biological materials in sewage and sludge.
One commenter suggested the current limits are appropriate because the
quantities and concentrations of radionuclides at affected POTWs appear
to be within 10 CFR part 30 limits for general licensees.
Response: NRC acknowledges the commenters' support for the current
regulations, which supports withdrawal of the ANPR.
Comment: Nine commenters, including a representative of DOE,
suggested the changes made to 10 CFR part 20 in 1991 may have
significantly reduced the potential for reconcentration of
radionuclides in POTWs, and that resources should not be expended to
address a problem that may have already been solved. Of these, five
commenters noted that the ANPR did not include any information about
contamination problems that had occurred since the modification of 10
CFR part 20 and two commenters noted that most of the contaminants in
the case studies presented in the ANPR were insoluble non-biological
materials and would not meet current release criteria. Several
commenters recommended NRC evaluate the effects of the lower discharge
concentration limits and prohibition against discharging insoluble,
non-biological materials into sanitary sewers before making additional
changes to 10 CFR part 20. One commenter expressed the opposite view
and stated that the NRC should not assume that the changes made to 10
CFR part 20 in 1991 would eliminate contamination of POTWs with
licensed radioactive materials.
Response: NRC acknowledges the commenters' recommendation that it
study the effect of the changes made to 10 CFR part 20 in 1991 on the
amount of radioactive material at POTWs. The NRC staff notes that the
ISCORS sewage sludge survey and dose modeling work were performed
several years after the January 1, 1993, deadline for licensees to meet
the revised requirements and should reflect the effects of the 1991
revision of the regulation.
Comment: Five commenters expressed the view that additional
restrictions on the release of radioactive materials into sanitary
sewers would not be consistent with efforts to keep doses ALARA.
Several of the commenters predicted that doses to workers that were
required to collect or prepare waste for disposal would be far greater
than the collective dose that could be averted by more restrictive
sewer release limits.
Response: NRC acknowledges the commenters' opposition to additional
restrictions on the release of radioactive materials into sanitary
sewers, which supports the withdrawal of the ANPR.
Comment: Four commenters stated that any additional restrictions on
the release of radioactive material into sanitary sewers would have a
significant negative impact on the facilities they represented. One
commenter expressed the view that banning the release of radioactive
material into sewers would impose a large financial burden on all
biological research facilities and estimated that, as of 1994,
alternative disposal methods would cost his company $150,000 to
$300,000 annually. A representative of a nuclear laundry stated that
additional restrictions on the release of radioactive material into
sanitary sewers could have a serious detrimental effect on his company
and its customers in nuclear laundries could no longer operate. Another
commenter suggested new restrictions should be implemented gradually by
adding new restrictions during license renewals.
One commenter expressed concern that additional restrictions on the
release of radioactive material to sewers would encumber facilities
that perform medical research, and requested that educational and
medical research institutions be exempted from the regulations because
the long-lived radionuclides that had been detected in the cases
described in the ANPR typically are not used by medical research
facilities. The commenter also requested that, if medical research
facilities were not exempted, more explicit guidance about the
implications of the regulations on specific practices used in medical
research facilities be provided by NRC. Another commenter proposed that
the regulation should explicitly permit disposal of medical diagnostic
products in aqueous mixtures that contain less than 370 kBq (10
microcuries) of radioactivity and which are composed of isotopes with
half-lives less than 61 days.
Response: NRC acknowledges the commenters' information about the
burdens that could be caused by additional restrictions on the release
of patient excreta into sanitary sewers, which supports the withdrawal
of the ANPR. The staff notes that requests for exemptions of certain
classes of facilities or types of waste are beyond the scope of this
rulemaking. NRC acknowledges that guidance written specifically for
medical research facilities would be helpful to some licensees, but
does not have plans or resources to develop such guidance.
Comment: A representative of DOE expressed the view that the
current rules are protective of public heath and safety and the
environment, and noted that, if the provision for release of
radioactive materials into sanitary sewers was not available, risks to
the public would result from other waste management options. As an
example, the commenter predicted elimination of the release of
radioactive material into sewers would cause an increase in traffic
accidents because of the need to transport more waste to LLW disposal
facilities. However, the commenter also recommended NRC increase
inspections of licensees' releases into sanitary sewers and perform
additional analyses of potential doses to members of the public and
sanitary system workers to ensure that adequate safety provisions are
in place to preclude accidental discharge of large quantities of
[[Page 68363]]
radioactive material. The commenter also recommended NRC contact AMSA
and industry trade groups to obtain additional information about
variations and trends in wastewater treatment technologies, practices,
and regulations.
Response: NRC acknowledges the commenter's remarks regarding the
risks that could result from additional restrictions on the release of
radioactive material into sanitary sewers, which support the withdrawal
of the ANPR. In accord with the commenter's suggestions, NRC
participated in the ISCORS sewage sludge survey (NUREG-1775) and dose
modeling report (NUREG-1783), the results of which provide a technical
basis for withdrawing the ANPR. The staff acknowledges the suggestion
regarding NRC inspection activities but notes the topic is beyond the
scope of this rulemaking.
Comment: A representative of NIH stated that, although NIH is a
large facility conducting both biomedical research and medical
diagnosis and treatment, and its usage of some isotopes fluctuates
considerably, NIH has been able to manage its radioactive liquid wastes
in compliance with NRC regulations. The commenter also stated that NIH
uses large, centrally-located tanks to hold short-lived radionuclides
for decay, and that NIH has been granted an exception to the total
quantity limits that allows it to discharge a total of 296 GBq (8 Ci)
annually.
Response: NRC acknowledges the commenter's information regarding
the adequacy of the current regulations governing the release of
radioactive material into sanitary sewers.
Comment: A commenter who was a member of ACMUI as well as a
physician and professor of Radiological Sciences at the University of
California, Los Angeles, expressed several concerns regarding the
possible changes described in the ANPR. The commenter expressed the
opinion that NRC resources would be better spent changing other parts
of 10 CFR part 20 than by making the changes proposed in the ANPR. The
commenter also stated that Agreement States had been reluctant to adopt
the changes made to 10 CFR part 20 in 1991 because of unspecified
problems with the revised rule. The commenter expressed concern that
user fees were used to support a National Council on Radiation
Protection study of the number of various types of nuclear medicine
procedures performed annually as of 1989. The commenter also expressed
concern that any change in NRC regulations governing the release of
radioactive materials into sewers would later be changed by an EPA
rule, and that NRC licensees would, in effect, pay for a rule twice by
paying both NRC user fees and paying taxes to support EPA.
The commenter asked why the NRC had published the ANPR and
expressed concern that NRC wasted licensees' time by asking for data
regarding various nuclear medicine procedures. The commenter stated
that the data had been given to NRC in 1990 and asked why NRC did not
use these data to derive concentrations of various radionuclides in
sanitary sewage. The commenter also suggested NRC could request data
regarding concentrations of radioactive materials in wastewater and
sewage sludge from POTWs in Agreement States. In addition, the
commenter suggested NRC review any proposed changes related to medical
uses of isotopes with the ACMUI and expressed an unfavorable opinion
about NRC's program to regulate medical uses of radionuclides.
Response: NRC acknowledges the commenter's statements about the
1991 revision to 10 CFR part 20 but notes that other parts of the
regulation are beyond the scope of this rulemaking. A response to the
commenter's displeasure at paying licensing fees to support this
rulemaking is not needed because the ANPR is being withdrawn. The same
applies to the commenter's concern that EPA would impact a change in
NRC's regulations. Because the ANPR is being withdrawn, that concern is
no longer applicable to this issue.
NRC published the ANPR to invite comments and recommendations from
interested parties on potential changes in the regulations governing
the release of radioactive materials into sanitary sewers. In response
to the commenter's concern about the time licensees may have spent
responding to the ANPR, NRC notes that the ANPR invited comment but did
not require a response. In addition, NRC notes that the ANPR invited
comment on a variety of issues and was not limited to a request for
information to support the derivation of concentrations of
radionuclides in sewage.
NRC acknowledges the commenter's suggestion that potential changes
to the rule be discussed with the ACMUI, and the commenter's statements
about NRC's program to regulate medical uses of radionuclides.
Comment: Three commenters expressed the view that cases of
contamination at POTWs demonstrate that the current regulations
governing the release of radioactive material into sanitary sewers is
inadequate. All three commenters expressed the concern that the
regulations did not adequately protect the health and safety of POTW
workers. In addition, a representative of AMSA expressed the concern
that the current regulations could jeopardize the ability of POTWs to
fulfill their environmental objectives. The commenter also expressed
concern about NRC's involvement with existing cases of contamination
and urged NRC to take a more active role in protecting POTWs from
contamination with radionuclides.
Each of the three commenters expressed the opinion that the current
regulations also fail to protect POTWs from the legal and financial
consequences of contamination of POTWs and POTW biosolids with
radionuclides. Two commenters noted that the public ultimately bears
the costs associated with contamination of POTWs and one estimated that
billions of dollars of public funds could be required to dispose of
contaminated sludge and decontaminate POTWs. A representative of the
City of Oak Ridge outlined the history of contamination of the Oak
Ridge POTW with Co-60, Cs-137, uranium isotopes, and I-131 from 1984 to
1994. The commenter noted that, as of 1994, disposal of wastewater
treatment sludge cost the City of Oak Ridge approximately $100,000 per
year, primarily because of radioactive contamination. The commenter
stated that, because of this expense, the city is in the process of
implementing its own limits to control releases of radioactive
materials into the sanitary sewers and provided a reference that
describes the approach that has been taken to control radioactive
materials through the municipality's industrial pretreatment program.
A representative of the Northeast Ohio Regional Sewer District
noted that, although no significant health or safety problems had been
found to result from the contamination at the district's Southerly
Facility, the district has had to manage difficult regulatory issues
and concerns from the public and from workers that had cost the
district, as of 1994, $1.5 million to resolve. The commenter remarked
that the sanitary district had over one hundred thousand cubic meters
(4 million cubic feet) of Co-60 contaminated ash at its Southerly
Facility and had recently discovered contamination at another one of
its POTWs. The commenter expressed the view that the District's
problems were attributable to inadequate regulations or ineffective
enforcement by NRC and suggested that major revisions to both 10 CFR
part 20 and to NRC's enforcement program were overdue.
[[Page 68364]]
Response: NRC acknowledges the commenters' concerns about cases of
contamination and protection of POTW workers. However, NRC believes
that the restrictions on the forms of material suitable for release and
lower concentration limits established in the 1991 revision to 10 CFR
part 20 have reduced the potential for significant contamination of
POTWs or sewage sludge with radionuclides. Although additional
restrictions on the release of radioactive material into sanitary
sewers will not be implemented, Section 7.2 of the ISCORS
recommendations on management of radioactive materials in sewage sludge
and ash (EPA 832-R-03-002B) provides guidance to assist POTW operators
in reducing sources of radiation entering their treatment facilities.
Comments about NRC's enforcement program are beyond the scope of this
rulemaking.
NRC acknowledges the information provided by the City of Oak Ridge
regarding the POTW's industrial pretreatment program. Information about
the program is summarized in Appendix F of the ISCORS recommendations
on management of radioactive materials in sewage sludge and ash (EPA
832-R-03-002B).
Comment: A representative of a sanitary district stated that,
contrary to the position taken by NRC in the ANPR, many cases of
contamination of POTWs are the result of relatively basic wastewater
treatment technologies. In addition, the commenter expressed the view
that NRC's emphasis on the concept of ``reconcentration'' as the cause
of contamination problems is misleading and noted that, at one POTW in
the district, it appeared that particles of Co-60 were removed from the
sewage through settling, as other solids are removed, rather than
through reconcentration of dissolved cobalt or agglomeration of fine
particles. The commenter expressed the view that the new restrictions
on the forms of materials suitable for release into sanitary sewers may
prevent many problems with insoluble materials such as Co-60 if the
regulations are properly enforced.
Response: NRC acknowledges the commenter's concern that the term
``reconcentration'' was used in the ANPR to describe all processes by
which the concentration of radionuclides in sewage sludge or ash could
be increased on volumetric basis. NRC understands that radioactive
materials may be concentrated by common wastewater treatment processes,
as discussed in NUREG/CR-6289.
Comment: Seven commenters expressed the view that discharges of
radioactive materials into sanitary sewers should be regulated locally.
Two commenters suggested that, because relatively few cases of
contamination had been observed, it appeared that the cases could be
resolved without NRC involvement. One commenter expressed the view that
local control would be easiest to implement if the problematic
discharges involved other hazardous, nonradioactive materials.
Five commenters, including a representative of AMSA, expressed the
opinion that POTWs should have the legal authority to establish local
limits for the release of radioactive material into sanitary sewers.
Three of the commenters expressed the concern that, although
municipalities are held responsible for the disposal or beneficial use
of POTW sludge, the municipalities have no control over the
radioactivity of materials discharged to the sewer system that affect
sludge quality. One commenter expressed the concern that the existing
regulatory framework is inadequate because NRC maintains that the party
in possession of the radioactive material is responsible for
remediation, offers no assistance to POTWs that have been contaminated
by a licensee's effluent, and states that the AEA indicates that its
regulations preempt more restrictive local regulations. The commenter
expressed concern that NRC has indicated that this position would not
change even if NRC had proof that material was illegally discharged by
a licensee and that a POTW's only recourse to recover remediation costs
is to take legal action against the discharger. One of the commenters
suggested NRC should either assume responsibility for disposing of
radioactive sludge generated in POTWs as a result of ``errant
discharge'' from NRC licensees or allow POTWs to regulate the discharge
of radioactive materials into sewer systems. The other commenter
suggested that, in cases in which the reuse or disposal of sludge is
restricted because of its radiological contamination, NRC should
cooperate with EPA to help affected POTWs establish local discharge
limits to protect the traditional method of disposal or reuse of the
biosolids.
Another commenter stated that it was not necessary, feasible, or
appropriate for NRC to develop new regulations that would limit the
disposal of radioactive material into sanitary sewers because POTWs
already had the legal authority and mandate to establish and enforce
appropriate pretreatment standards that would prevent contamination of
POTWs or sewage sludge, pursuant to the Clean Water Act (33 U.S.C.
1317(b) and (d) and 1319) and EPA Clean Water Act Standards (40 CFR
Part 403).
Response: NRC acknowledges the commenters' concern about the power
that local authorities have to regulate the release of radioactive
material to their POTWs. The U.S. Supreme Court has held that, for
certain activities covered by the AEA, Federal authority preempts other
regulatory authorities whose purpose is radiation protection. It is
difficult to predict whether unusual cost to the POTW caused by
radioactive effluent discharges would be a sufficient reason to impose
more restrictive discharge limits than those permitted under Federal
law because there are no Federal cases in which the specific facts
corresponded to the scenarios faced by local POTW authorities. More
information on this issue is presented in Chapter 4 and Section 7.2 of
the ISCORS recommendations on management of radioactive materials in
sewage sludge and ash (EPA 832-R-03-002B).
Comments regarding NRC's responsibility for the disposal of
contaminated sludge are beyond the scope of this rulemaking. As
discussed in Chapter 7 of the ISCORS recommendations (EPA 832-R-03-
002B), in individual cases of contamination, legal counsel should be
consulted to determine if dischargers may be liable for portions of
remediation costs.
Comment: One commenter recommended NRC exempt POTWs from any
regulations that would apply to material released into their systems
because the potential benefits of regulating POTWs would not justify
the costs.
Response: This suggestion is beyond the scope of this rulemaking.
Comment: Five commenters, including a representative of AMSA,
expressed the view that POTWs should be able to apply the same type of
pretreatment standards to radionuclides in licensees' effluent that are
applied to toxic materials discharged into sewer systems by industrial
dischargers as part of EPA's NPDES program. Commenters noted that local
limits can account for the number of licensees discharging to a single
POTW, the total flow into a POTW, and the effects of various treatment
process on radionuclide reconcentration. Three commenters noted that,
in general, local restrictions on discharges of pollutants to POTWs are
established by determining an allowable load of a pollutant to a POTW
that will not create a violation of the POTW's effluent limit and not
interfere with disposal or reuse of the POTW's
[[Page 68365]]
biosolids, and then allocating that limit among industrial facilities
that discharge effluent to the POTW. Two commenters expressed the view
that the same process should be used to develop individual limits for
each radionuclide, taking into account each radionuclide's specific
activity, half-life, and solubility. One commenter noted that this
procedure cannot be followed with radioactive materials because no
``acceptable'' levels of radionuclides in sludge have been established.
Another commenter recommended NRC coordinate any future regulations
affecting sanitary sewer discharges with EPA requirements for Clean
Water Act discharges, including Categorical Standards, NPDES permits,
and regulations pertaining to sewage sludges.
Two commenters suggested that, because setting limits for
radioactive materials will be new to many POTWs, NRC should provide
guidance on establishing local limits on the release of radioactive
materials into sanitary sewers. A representative of AMSA suggested a
number of topics that the recommended guidance should address and
recommended NRC consider two EPA resources used to develop limits on
industrial discharges to POTWs.
Response: This comment includes detailed recommendations about the
creation of a program in which the release of radionuclides into
sanitary sewers would be regulated by local, rather than Federal,
authorities, and is beyond the scope of this rulemaking. Although
guidelines for the development of local limits under such a program
have not been developed, many of the topics the commenters requested be
included in such guidance are included in the ISCORS recommendations on
management of radioactive materials in sewage sludge and ash (EPA 832-
R-03-002B), as is information about local pretreatment programs
established in Albuquerque, NM, St. Louis, MO, and Oak Ridge, TN.
Comment: One commenter was concerned that system-specific discharge
limits could be difficult to implement if, as is done in the NPDES
process, discharge limits are based on the ``waste assimilative
capacity'' of the receiving waterway, which, the commenter stated,
could be difficult to determine. The commenter also expressed concern
that licensees would need to obtain prior approval for sewer
discharges, and that regulatory agencies would need to keep track of
separate discharge allotments for each licensee and any changes to each
POTW's treatment processes. The commenter noted that an alternative to
establishing system-specific discharge limits would be to set activity
limits so low that regulatory limits or ALARA goals for public doses
would be met, irrespective of the wastewater treatment process used,
the capacity of the receiving POTW, or the number of dischargers
discharging to the POTW. The commenter noted that this approach would
not require as much regulatory oversight and suggested these approaches
should be evaluated in an EIS.
Response: NRC acknowledges the commenter's concerns about the
difficulties involved with implementing system-specific discharge
limits. An EIS that evaluates the alternatives will not be developed
because the ANPR is being withdrawn for the reasons previously
discussed.
Comment: One commenter asked for clarification as to how the
revised rule would relate to NRC decommissioning standards and various
EPA rules and suggested NRC hold public hearings on the issue.
Response: NRC is not responding to the request for clarification on
the relationship between the proposed rule and EPA or NRC standards
because the ANPR is being withdrawn.
Comment: Ten commenters expressed the view that any change to the
regulations governing the release of radioactive materials into
sanitary sewers should have a solid technical basis. Three commenters
recommended NRC delay decisions about the need for modifications to the
regulation until NUREG/CR-6289, which was incomplete at the time, was
made available to licensees. Two commenters expressed concern that the
ANPR was offered without a significant risk assessment. Six commenters
recommended that any proposed change in the regulation should be based
on a realistic assessment of either the collective dose or the risks to
members of the public and POTW workers that the new regulations would
avert. Two commenters expressed the concern that changes to the
regulations would be made for reasons other than technical reasons,
including regulatory convenience, a perception of public opinion, or
political pressure.
A representative of the New York State Department of Labor remarked
that some of the regulatory changes proposed in the ANPR would be
complex for both licensees and regulatory agencies to implement and,
therefore, should not be undertaken without a without a firm technical
basis. The commenter expressed the view that, except for the exemption
of patient excreta, all of the options discussed in the ANPR required
more analysis before NRC would have sufficient information on which to
base a decision. The commenter expressed the opinion that frequent
changes in the same regulation are especially burdensome for licensees
and urged NRC to perform the necessary analyses before changing the
rule again. Representatives of the New York State Energy Office and New
York State Department of Environmental Conservation encouraged NRC to
develop an EIS to evaluate the options discussed in the ANPR. The
representative of the New York State Department of Environmental
Conservation remarked that the current regulations, including the
revisions made in 1991, had never undergone a full environmental
review.
Two commenters expressed the concern that the current limits on the
discharge of radioactive material to sewers do not reflect the hazards
radioactive materials could pose in a POTW or after release to the
environment. The commenters recommended NRC initiate a study that would
include a POTW hazard identification and assessment, exposure and
toxicity assessments, and a risk characterization. The two commenters
also recommended NRC study the fate and transport of radionuclides in
sewers, POTWs, and the environment. A representative of the City of Oak
Ridge provided a reference that discussed the fate and transport of
radionuclides in the municipality's POTW. A representative of AMSA
recommended NRC cooperate with EPA, POTWs, and affected industries to
assess the exposure and contamination pathways of radionuclides, and
the impact of radioactive materials on wastewater treatment processes.
Response: NRC acknowledges the commenters' view that the 1991
revision to the regulations governing the release of radioactive
materials into sanitary sewers should have been based upon detailed
risk analyses. As discussed previously, NRC cooperated with
representatives of EPA and POTWs in developing the ISCORS survey and
dose modeling project to assess the radioactive contamination in POTWs
and pathways for exposure of POTW workers and members of the general
public to radionuclides released into sanitary sewers. The results of
these analyses served as the technical basis for the withdrawal of the
ANPR. An EIS for the rulemaking will not be performed because the ANPR
is being withdrawn for the reasons previously discussed.
Comment: Three commenters, including a representative of AMSA,
[[Page 68366]]
recommended NRC study the extent of the use of sewer discharges and
contamination of POTWs around the country. The representative of AMSA
suggested that, because NRC had acknowledged that it did not know how
many POTWs in the country were contaminated with radionuclides and
because it would be inappropriate to develop national standards based
on contamination in a few isolated cases, NRC should establish a task
force composed of NRC and EPA staff as well as representatives of POTWs
and licensees to study the nature and extent of radioactive
contamination of POTWs nationally. Three commenters recommended NRC
determine which licensees release radioactive material into sanitary
sewers and two of these commenters recommended NRC make the information
available in a national database. Of these commenters, one suggested
the database should be similar to the EPA's Toxic Release Inventory and
the other suggested the database should include information about the
mass of each radionuclide discharged per year by each licensee, the
volume of the licensee's discharge, and the licensee's POTW service
area. A representative of one utility district expressed concern that,
as of 1994, the NRC had not been able to provide a list of the
licensees discharging into the district's sewer system and that the
district had, therefore, been unable to initiate an appropriate
monitoring program.
Response: NRC acknowledges the commenters' request for a national
database, but notes that a database that contains information about
releases of radioactive material into sanitary sewers by licensees is
not being developed. As discussed in Section 5.1 of the ISCORS
recommendations on management of radioactive materials in sewage sludge
and ash (EPA 832-R-03-002B), POTW operators are encouraged to contact
the applicable NRC Regional Office, appropriate State Radiation Safety
Office, and any nearby DOE facilities if they have questions about the
sewer releases of facilities in the POTW's service area that use
radioactive materials.
Comment: One commenter requested that, because NRC had just begun
to study the fate of radionuclides in POTWs and because NRC did not
know which of its licensees discharged materials into sanitary sewers,
a moratorium be imposed on the disposal of radioactive material into
sanitary sewers until NRC had the information necessary to help POTWs
develop protective limits.
Response: NRC notes that this comment is beyond the scope of this
rulemaking.
Comment: One commenter expressed concern that the assumptions used
in 10 CFR part 20 ignored exposures to children, fetuses, elderly,
people with existing body burdens of radioactive material, and
individuals in other sensitive groups. The commenter expressed concern
that the risk of birth defects from ionizing radiation had been limited
to only two generations in NRC analyses and stated that the greatest
number of birth defects will be seen in generations beyond the next
two. The commenter also expressed the view that NRC should consider
non-cancer and nonfatal cancer health effects in risk calculations and
expressed concern that these effects were not considered in the
promulgation of 10 CFR part 20.
Response: The commenter's remarks about NRC's development of
standards for the protection against radiation are beyond the scope of
this rulemaking.
Comment: Three commenters recommended NRC perform a cost/benefit
analysis of alternatives to the release of radioactive materials into
sanitary sewers before proceeding with a rulemaking and two of those
commenters expressed the view that the proposed changes could not be
justified by either a risk analysis or cost/benefit analysis. One
commenter urged NRC to apply the backfit provisions that apply to power
reactors to a broader scope of rulemaking decisions, and expressed the
view that the alternatives suggested in the ANPR could not be justified
in a backfit analysis.
Response: NRC is not performing a cost/benefit analysis or risk
analysis because the ANPR is being withdrawn for the reasons previously
discussed. The staff note that the commenter's opinions about NRC's
backfit provisions are beyond the scope of this rulemaking.
Comment: One commenter expressed the concern that limits based on
overly-simplified dose models could be overly-restrictive and could
cause unintended harm to the public by limiting beneficial uses of
radioactive materials. The commenter suggested NRC consider the ``total
societal impact'' of its release limits, and expressed the view that
NRC and other regulatory agencies typically perform inadequate
assessments of the financial impacts of their rules. The commenter
added that NRC should not avoid this responsibility by claiming that
the AEA does not give it the responsibility to evaluate the total
societal impact of its rules, because evaluation of cost, benefit, and
total societal impact is inherently included in the concept of
maintaining doses ALARA.
Response: NRC acknowledges the commenter's concern about the
adequacy of financial impact analyses performed by NRC and other
regulatory agencies. NRC staff agree that, as defined in 10 CFR
20.1003, the term ``ALARA'' indicates consideration of societal and
socioeconomic impacts.
Comment: Five commenters expressed the opinion that, in general,
any changes to the regulations should allow less radioactive material
to be released into sanitary sewers. Reasons for this position included
new information about the adverse effects of chronic exposure to low
levels of ionizing radiation, information about the synergistic effects
of radiation and chemical pollutants, and concern about the cumulative
effects of multiple sources of radiation on public health and the
environment. Two commenters suggested that all radioactive waste should
be isolated in secure storage or disposal facilities. Another commenter
stated that NRC should not allow environmental build-up of multiple
sources of radiation even if each, individually, could be dismissed as
being minimal. One commenter stated that his organization had commented
on the revision of 10 CFR part 20 repeatedly and that it remains
concerned that the allowable concentrations of many radionuclides in
air and water increase.
Response: The ANPR is being withdrawn for the reasons previously
explained. Comments about the basis for NRC's standards for the
protection against radiation are beyond the scope of this rulemaking.
Comment: Four commenters expressed the opinion that the potential
burden that additional restrictions on the release of radioactive
material into sanitary sewers would impose on licensees is secondary to
the primary goal of protecting public health and safety and should be
given little weight in the evaluation of whether additional
restrictions should be established. Two commenters expressed concern
that, in the ANPR, NRC made several inquiries about the impacts of new
restrictions on licensees without expressing a similar interest in the
potential impacts of the release of radioactive material into sanitary
sewers on other parties. One of the commenters expressed the view that
the concern for licensees may be misplaced because it is
municipalities, and not licensees, that ultimately bear the costs of
disposal of contaminated sludge and POTW decontamination. The commenter
also remarked that it appeared to be more appropriate for
[[Page 68367]]
licensees, rather than the public, to bear the expense of the disposal
of radioactive materials used by licensees. The other commenter
suggested NRC should have solicited comments regarding the potential
impact of the regulations on public health, healthcare costs,
contamination of agricultural land, restriction of land uses, and
environmental degradation. Two commenters stated that it would be
inappropriate for NRC to allow any risk to members of the public to
lessen economic or regulatory burden on licensees. Another commenter
noted that, in cases in which contamination of a POTW has been
discovered, licensees must recognize that safety of the community is
more important than the desire for a licensee to use its current
disposal options.
Response: NRC acknowledges the commenters' concerns regarding the
specific requests for comment in the ANPR. With regard to the
consideration given to the potential effects of changes in the
regulation on public health and the environment as compared to
potential burdens on licensees, the NRC staff notes that a significant
effort was made to study the potential effects of the release of
radioactive material into sanitary sewers on the public and POTW
workers in conjunction with the ISCORS reports that were described
previously. Comments about the basis for NRC's standards for the
protection against radiation are beyond the scope of this rulemaking.
Comment: Six commenters suggested that detection of radionuclides
at a few POTWs is an insufficient reason to impose additional
restrictions on the release of radioactive material to sanitary sewers.
These commenters stated that radioactivity can be measured at very low
levels that are not expected to cause a significant adverse health
effect for any individual. One commenter stated that lowering release
limits to values that are significantly lower than limits needed to
protect the public makes it more difficult for licensees to assure
compliance of medical research and clinical staff with radiation safety
procedures and undermines the public's confidence in realistic exposure
or activity standards. Another commenter recommended NRC acknowledge
that the risks caused by radioactivity in sewage sludge are small
compared to the risks associated with the extra handling and
transportation of waste that would occur if releases of radioactive
material to sanitary sewers were eliminated.
One commenter also suggested that, because radioactivity can exist
in sewer systems and POTWs without causing a significant dose to any
individual, and because there are beneficial uses of radioactive
materials, that it might be better to attempt to build public
acceptance of the current practices than it would be to lower release
limits or eliminate sewer discharge. Another commenter suggested
incidents of contamination should be handled in a consistent, routine
way without undue alarm. A representative of DOE predicted that any
discovery of radioactive contamination of sewage pipes or sewage
treatment plants is likely to result in regulatory concern, even if the
possible doses are tiny, because it may take time to determine whether
the contamination poses a threat to public health and safety.
Response: NRC acknowledges the commenters' opinions, which support
the withdrawal of the ANPR. The staff acknowledges the commenters'
recommendations about proper treatment of cases of contamination, but
notes they are beyond the scope of this rulemaking.
Comment: Three commenters addressed the potential for accidental
releases of radioactive material into sanitary sewers. One commenter
hypothesized that the case studies presented in the ANPR may have been
the result of abnormal events and expressed the opinion that no amount
of regulation, planning or notification can prevent inadvertent
releases that result from system failures or other errors. Another
commenter suggested NRC should realize that, irrespective of its
regulations, an individual is likely to find a way to defeat
``reasonable safeguards.'' Another commenter expressed concern that the
modeling results described in the ANPR did not account for the
potential for accidental releases in excess of the 10 CFR part 20
limits and suggested the reported calculated doses may be
underestimates.
Response: NRC acknowledges the commenters' statements about the
possibility of accidental releases. NRC staff note that its inspections
are designed to ensure licensees' operations are conducted safely and
in accordance with good practices and license conditions. With respect
to the commenter's concern that the dose modeling results discussed in
the ANPR do not include the effects of accidental releases, NRC staff
note that the doses estimated in NUREG/CR-1548 did not include the
potential effects of accidental releases; however, the doses reported
in the ISCORS dose modeling report (NUREG-1783) were based on observed
levels of radioactivity measured in conjunction with the ISCORS sewage
sludge survey (NUREG-1775) and, therefore, reflect any accidental
releases that may have been made to the 313 POTWs surveyed.
Comment: Seven commenters addressed LLW disposal. Four commenters
noted that additional restrictions on the release of radioactive
materials to sewers would increase the amount of low level radioactive
waste that would need to be disposed of in some other way. Two
commenters recommended NRC evaluate the options proposed in the ANPR in
the context of the risks associated with the disposal of low level
nuclear waste and the limited capacity of LLW disposal facilities. Two
commenters noted that many licensees had, as of 1994, very limited or
no access to LLW disposal facilities and one of the commenters noted
that licensees without access to a LLW disposal facility would need to
store waste on site indefinitely. Three commenters noted that
additional restrictions on the release of radioactive materials into
sanitary sewers would be especially burdensome because the facilities
they represented lacked access to LLW disposal sites. One commenter
stated that sewer disposal is the primary way that many medical
research and biotechnology laboratories minimize generation of LLW.
One commenter expressed the concern that the use of sanitary sewer
disposal of radioactive material would increase because of the high
cost and limited availability of LLW disposal. The commenter noted that
the release of radioactive material into sanitary sewers itself can
lead to the creation of large volumes of LLW by contaminating sludge.
Another commenter opposed the implication that sanitary sewer disposals
would be used as a means of relief from the relative inaccessibility of
LLW disposal and noted that most types of LLW do not meet the
requirements for release into sanitary sewers.
Response: NRC acknowledges the commenters' concerns regarding the
impact that the proposed changes would have because of some licensees'
lack of access to LLW disposal facilities. These comments support the
withdrawal of the ANPR.
NRC also acknowledges the commenter's concern that limitations on
LLW disposal could lead to an increase in the release of radioactive
material to sanitary sewers. The NRC staff notes that the results of
the ISCORS sewage sludge survey (NUREG/CR-1775) do not indicate that
the frequency of POTW contamination incidents has increased since the
commenters' remarks were made in 1994.
Comment: Five commenters expressed the opinion that licensees
[[Page 68368]]
should bear all costs associated with waste disposal. One commenter
suggested NRC's descriptions of case studies should include a
description of the financial costs associated with the contamination
and should indicate the party paying the remediation costs. Two
commenters stated that NRC licensees should bear the costs of data
collection, data reporting, and worker training needed to implement any
new NRC studies or regulations needed to protect POTWs from
contamination. Two commenters expressed the view that licensees should
pay to have monitoring equipment installed at POTWs.
Response: NRC acknowledges the commenter's suggestion that NRC's
descriptions of case studies should include information about the
economic aspects of the contamination and notes that some information
about remediation costs is provided in Section 1.2 of the ISCORS
recommendations on management of radioactive materials in sewage sludge
and ash (EPA 832-R-03-002B). Comments regarding the costs associated
with implementation of new sewer release restrictions are moot because
the ANPR is being withdrawn.
Comment: Six commenters expressed opinions about NRC enforcement
actions. A representative of DOE stated that it was unclear whether one
or more of the incidents described in the ANPR involved violations of
the regulations, and suggested enhanced inspections, and not additional
rulemaking, would be the most appropriate way to eliminate
contamination of POTWs. Three commenters suggested NRC or POTWs should
verify licensee's reported discharges into sanitary sewers and one
commenter suggested compliance with NRC regulations should be
demonstrated at the licensee's outfall into the sanitary sewer system
so that POTWs would not be impacted and would not need to implement
special controls. Two representatives of POTWs noted that POTWs
routinely sample the effluent of major industrial users as part of
their industrial pretreatment programs. Another commenter suggested NRC
should assist POTWs with monitoring of licensee's effluents and
enforcement of the discharge limits.
Response: NRC notes that suggestions about inspection and
enforcement activities are beyond the scope of this rulemaking.
Comment: Six commenters made specific suggestions about monitoring.
Two commenters suggested licensees' outfalls and potable water intakes
should be monitored, and three commenters suggested monitoring also
should occur at POTWs. One of the commenters that advocated monitoring
at POTWs expressed the view that monitoring would limit uncertainty in
model results and would facilitate the study of the effects of influent
radionuclide form and quantity on POTW worker doses. The commenter also
suggested licensees should be encouraged to provide dosimetry and
elementary radiation safety training to POTW workers. One commenter
expressed the opinion that radionuclides in licensees' effluents should
be monitored to record the highest concentrations discharged and
facilitate a regulator's ability to link discharges with their sources.
Three commenters suggested the radioactivity of sewage sludge should be
monitored. One commenter expressed concern about the radioactivity of
an engineered wetland used to treat wastewater in his town.
Response: Recommendations regarding locations for monitoring a
licensee's effluent are beyond the scope of the proposed rulemaking.
Comment: A representative of the New York State Department of
Environmental Conservation recommended that the Notice of Proposed
Rulemaking for any change to the regulation governing the release of
radioactive material into sanitary sewers notice, for public comment,
the compatibility category NRC intends to apply to each provision so
that Agreement States and other interested parties can participate in
decisions about compatibility requirements. The commenter stated that,
as of 1994, Agreement States were required to develop regulations that
were compatible with the revised 10 CFR part 20 without NRC having
determined compatibility requirements and stated that this type of
situation must not recur.
Response: NRC acknowledges the commenter's recommendation that
intended compatibility categories be included in Notices of Proposed
Rulemaking. Compatibility categories for the options discussed in the
ANPR are moot because the ANPR is being withdrawn.
Comment: One commenter expressed a number of concerns about the
case studies described in the ANPR. Concerns raised by the commenter
included specific exposure pathways that may not have been included in
the dose analyses, the appropriateness of NRC's comparison of doses
with background radiation, and the concern that calculated doses to
individuals could have been higher if the sludge to which they were
exposed included radiation from multiple sources. The commenter
expressed the view that radioactivity in the environment may increase
because of human activity, and that it would be inappropriate to
consider manmade contributions of radioactivity to the environment in
the calculation of ``background'' radiation, or to allow releases
because they would be minimal in comparison to background radiation.
The commenter also remarked that the cases of contamination that had
occurred in Washington, DC, and Cleveland, OH, indicated the potential
for contamination to be significant to large populations. In addition,
the commenter asked specific questions about the assumptions used to
calculate the doses resulting from the case studies discussed in the
ANPR and what sources of radiation NRC included in its calculation of
``background radiation.''
Response: The commenter's concerns about the doses calculated in
the case studies are no longer applicable because more recent studies
served as the technical basis for the withdrawal of the ANPR. NRC
acknowledges the commenter's concern regarding contamination at POTWs.
The commenter's specific questions about the modeling assumptions used
to calculate doses for the case studies discussed in the ANPR are
addressed in NUREG/CR-1548. NRC notes that its definition of
``background radiation,'' provided in 10 CFR 20.1003, excludes
contributions of radioactivity from source, byproduct, or special
nuclear materials regulated by NRC.
For the reasons cited in this document, NRC withdraws this ANPR.
Dated at Rockville, Maryland, this 11th day of October, 2005.
For the Nuclear Regulatory Commission.
Luis A. Reyes,
Executive Director for Operations.
[FR Doc. 05-22432 Filed 11-9-05; 8:45 am]
BILLING CODE 7590-01-P