[Federal Register Volume 65, Number 8 (Wednesday, January 12, 2000)]
[Proposed Rules]
[Pages 1829-1830]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-725]
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NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[Docket No. PRM-50-68]
Bob Christie; Receipt of Petition for Rulemaking
AGENCY: Nuclear Regulatory Commission.
ACTION: Petition for rulemaking; notice of receipt.
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SUMMARY: The Nuclear Regulatory Commission has received and requests
public comment on a petition for rulemaking filed by Mr. Bob Christie,
Performance Technology, Knoxville, Tennessee. The petition was docketed
on November 15, 1999, and has been assigned Docket No. PRM-50-68. The
petitioner requests that the NRC amend its regulations concerning
hydrogen control systems at nuclear power plants. The petitioner
believes that the current regulations on hydrogen control systems at
some nuclear power plants are detrimental and present a health risk to
the public. The petitioner believes that similar detrimental situations
may apply to other systems as well (such as the requirement for a 10-
second diesel start time). The petitioner believes the proposed
amendments would eliminate those situations that present adverse
conditions at nuclear power plants.
DATES: Submit comments by March 27, 2000. Comments received after this
date will be considered if it is practical to do so, but the Commission
is able to assure consideration only for comments received on or before
this date.
ADDRESSES: Mail comments to: Secretary, U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, Attention: Rulemakings and
Adjudications Staff.
Deliver comments to: 11555 Rockville Pike, Rockville, Maryland,
between 7:30 a.m. and 4:15 p.m. on Federal workdays.
For a copy of the petition, write to David L. Meyer, Chief, Rules
and Directives Branch, Division of Administrative Services, Office of
Administration, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001.
You may also provide comments via the NRC's interactive rulemaking
website at http://ruleforum.llnl.gov. This site provides the capability
to upload comments as files (any format), if your web browser supports
that function. For information about the interactive rulemaking
website, contact Ms. Carol Gallagher, (301) 415-5905 (e-
mail:[email protected]).
The petition and copies of comments are also available
electronically at the NRC's Public Electronic Reading Room on the
Internet at http://www.nrc.gov/NRC/ADAMS/index.html. From this site,
the public can gain entry into the NRC's Agencywide Document Access and
Management System (ADAMS), which provides text and image files of NRC's
public documents.
The petition and copies of comments received may be inspected and
copied for a fee at the NRC Public Document Room, 2120 L Street, NW.
(Lower Level), Washington, DC.
FOR FURTHER INFORMATION CONTACT: David L. Meyer, Chief, Rules and
Directives Branch, Division of Administrative Services, Office of
Administration, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, Telephone: 301-415-7162 or Toll Free: 1-800-368-5642 or
email: DLM[email protected].
SUPPLEMENTARY INFORMATION:
Grounds for Petition
The petitioner performed a detailed review of the San Onofre Task
Zero Safety Evaluation Report (Pilot Program for Risk-Informed
Performance-Based Regulation) conducted by the NRC staff and dated
September 3, 1998, concerning that plant's hydrogen control system. The
petitioner is convinced that action by the Commission is necessary to
remedy possible adverse conditions at nuclear power plants.
Background
The petitioner includes three topics of discussion in support of
the proposed amendments:
A. Public Health Risk From Nuclear Electric Power Units
The petitioner states that since the publication of the Reactor
Safety Study (WASH-1400) in 1975, there has been a growing agreement
between the practitioners of probabilistic risk assessment and
licensing personnel (both at the NRC and within the industry) that
there is a greater risk to public health from the release of fission
products from the reactor core during a severe accident at a nuclear
power plant, than from a design-basis accident. The petitioner asserts
that the NRC staff has formally recognized this position. The
petitioner sets out the following excerpts from the San Onofre Task
Zero Safety Evaluation Report in support of his assertion.
1. ``Subsequent risk studies have shown that the majority of risk
to the public is from accident sequences that lead to containment
failure or bypass, and that the contribution to risk from accident
sequences involving hydrogen combustion is quite small.''
2. ``As mentioned in the previous section, the risk associated with
hydrogen combustion is not from design-basis accidents but from severe
accidents.''
3. ``The overall public risk and radiological consequences from
reactor accidents is dominated by the more severe core damage accidents
that involved containment failure or bypass.''
[[Page 1830]]
B. Consideration of Design-Basis Accidents
The petitioner also states that since the publication of the
Reactor Safety Study (WASH-1400) in 1975, there has been growing
agreement between practitioners of probabilistic risk assessment and
licensing personnel that compliance with some design-basis accident
requirements can be detrimental to public health. The petitioner
asserts that the NRC staff has formally recognized this position. The
petitioner sets out the following excerpts from the San Onofre Task
Zero Safety Evaluation Report in support of his assertion.
1. ``Although the recombiners are effective in maintaining the
Regulatory Guide 1.7 hydrogen concentration below the lower
flammability limit of 4 volume percent, they are overwhelmed by the
larger quantities of hydrogen associated with severe accidents which
are typically released over a much shorter time period (e.g., 2
hours).''
2. ``From this information, the NRC staff concludes that the
quantity of hydrogen, prescribed by 10 CFR 50.44(d) and Regulatory
Guide 1.7, which necessitates the need for hydrogen recombiners and its
backup, the hydrogen purge system is bounded by the hydrogen generated
during a severe accident. The NRC staff finds that the relative
importance of hydrogen combustion for large, dry containments with
respect to containment failure to be quite low. This finding supports
the argument that the hydrogen recombiners are insignificant from a
containment integrity perspective.''
3. ``In a postulated Loss of Coolant Accident, the San Onofre
Nuclear Generating Station Units 2 and 3 Emergency Operating
Instructions direct the control room operators to monitor and control
the hydrogen concentration inside the containment after they have
carried out the steps to maintain and control the higher priority
critical safety functions. The key operator actions in controlling the
hydrogen concentration are to place the hydrogen recombiners or
hydrogen purge system in operation which involves many procedural
steps. These hydrogen control activities could distract operators from
more important tasks in the early phases of accident mitigation and
could have a negative impact on the higher priority critical operator
actions.''
C. Recommended Policy Statement on ``Design-Basis Accident Requirements
Versus Severe Accident Information''
The petitioner states that according to the San Onofre Safety
Evaluation Report, the NRC granted an exemption to San Onofre from the
design-basis accident requirements from the hydrogen control system on
the basis of information obtained in the analysis of severe accidents.
According to the petitioner, NRC staff's evaluation also indicated that
adherence to the requirements of design-basis accidents could have a
detrimental effect on public health. The petitioner asserts that it is
likely that similar situations exist with respect to the hydrogen
control systems at other nuclear units, and also for other systems at
San Onofre and other nuclear units. The petitioner believes that the
Commission should issue an interim policy statement concerning
requirements for design-basis accidents. The petitioner believes that
the interim policy statement would clarify the role of the NRC staff to
ensure that matters that present a risk to public health are given
appropriate high-level attention. The petitioner recommends the
following ``strawman'' statement.
All situations where there is an indication that adherence to
design basis requirements would be detrimental to public health must
be brought to the immediate attention of the Executive Director for
Operations of the Nuclear Regulatory Commission. The Executive
Director for Operations will make a decision on whether an exemption
to the design basis requirements should be granted on an expedited
basis.
The petitioner believes that the NRC would want all individuals who
may be aware of a situation where adherence to design-basis
requirements could be adverse to public health, to bring the situation
to the attention of the NRC staff without fear of recrimination and
regardless of the present licensing basis for each nuclear unit. The
petitioner states that, in the present culture of licensing at nuclear
electric power units, there are few individuals (at the NRC or within
the industry) who would suggest that adherence to design-basis accident
requirements can be detrimental to safety. The petitioner believes that
this culture must change and ``change with NRC blessings.''
The petitioner states that he recommends an interim policy
statement because the NRC, nuclear industry, and the public are in the
process of changing the NRC regulations to eliminate situations where
adherence to the regulations could present a risk to public health.
The petitioner believes that the current regulations concerning
combustible gas control systems have serious flaws and proposes that 10
CFR 50.44 be revised to read as follows:
Section 50.44 Standards for Combustible Gas Control System in Light-
Water Cooled Power Reactors
(a) An inerted reactor containment atmosphere shall be provided
for each boiling light-water nuclear power reactor with a Mark I or
Mark II type containment.
(b) Each licensee with a boiling light-water nuclear power
reactor with a Mark III type of containment and each licensee with
an ice condenser type of containment shall provide its nuclear power
reactor containment with a hydrogen control system. The hydrogen
control system must be capable of handling (based on realistic
calculations) the hydrogen equivalent to that generated from a
metal-water reaction involving 75 percent of the fuel cladding
surrounding the active fuel region (excluding the cladding
surrounding the plenum volume).
(c) All light-water reactors with other types of containment
than those in paragraphs (a) or (b) of this section, must
demonstrate that the reactor containment (based on realistic
calculations) can withstand, without any hydrogen control system, a
hydrogen burn for accidents with a high probability of causing
severe reactor core damage. If such an evaluation of reactor
containment capability can not be demonstrated, then the licensee
shall provide a hydrogen control system per the backfit process.
This hydrogen control system must be capable of handling (based on
realistic calculations) the hydrogen equivalent to that generated
from a metal-water reaction involving 75 percent of the fuel
cladding surrounding the active fuel region (excluding the cladding
surrounding the plenum volume).
(d) Each light-water nuclear power reactor shall be provided
with high point vents for the reactor coolant system, for the
reactor vessel head, and for other systems required to maintain
adequate reactor core cooling if the generation of noncondensible
gases in these systems would realistically lead to severe reactor
core damage during an accident. High point vents are not required,
however, for the tubes in U-tube steam generators.
The petitioner proposes that 10 CFR Part 50, Appendix A--General
Design Criteria 41 be revised to read as follows:
Appendix A--General Design Criteria 41--Containment Atmosphere Cleanup
As necessary, systems to control fission products, hydrogen,
oxygen, and other substances which may be released into the reactor
containment shall be provided, consistent with the functioning of
other associated systems, to assure that reactor containment
integrity is maintained for accidents where there is a high
probability that fission products may be present in the reactor
containment.
Dated at Rockville, Maryland, this 6th date of January, 2000.
For the Nuclear Regulatory Commission.
Annette L. Vietti-Cook,
Secretary of the Commission.
[FR Doc. 00-725 Filed 1-11-00; 8:45 am]
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