[Federal Register Volume 60, Number 196 (Wednesday, October 11, 1995)]
[Notices]
[Pages 52943-52944]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25148]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-251]
Florida Power and Light Company (Turkey Point Unit 4); Exemption
I
Florida Power and Light Company (the licensee) is the holder of
Facility Operating License No. DPR-41, which authorizes operation of
Turkey Point Unit 4 (the facility), at a steady-state
[[Page 52944]]
reactor power level not in excess of 2200 megawatts thermal. The
facility is a pressurized water reactor located at the licensee's site
in Dade County, Florida. The license provides among other things, that
it is subject to all rules, regulations, and Orders of the U.S. Nuclear
Regulatory Commission (the Commission or NRC) now or hereafter in
effect.
II
Section III.D.1.(a) of Appendix J to 10 CFR Part 50 requires the
performance of three Type A containment integrated leakage rate tests
(ILRTs) of the primary containment, at approximately equal intervals
during each 10-year service period.
III
By letter dated August 8, 1995, and revised by letter dated
September 6, 1995, the licensee requested an exemption from the
requirements pertaining to the Type A testing interval required by 10
CFR 50 Appendix J. This section requires the performance of three Type
A tests of the primary containment at approximately equal intervals
during each 10-year service period. The requested exemption would
permit a one-time interval extension of the Type A test by one
refueling outage (from the March 1996 refueling outage, to the October
1997 refueling outage).
The licensee's request cites the special circumstances of 10 CFR
50.12, paragraph (a)(2)(ii) as the basis for the exemption. The
licensee points out that the existing Type B and C testing programs are
not being modified by this request and allowing a one-time scheduler
exemption will not reduce the current level of safety since the Type A
test frequency does not alter the containment leak rates.
IV
In the licensee's August 8, 1995, as revised by letter dated
September 6, 1995, exemption request, the licensee stated that special
circumstance 50.12(a)(2)(ii) is applicable to this situation, i.e.,
that application of the regulation is not necessary to achieve the
underlying purpose of the rule.
Appendix J states that the leakage test requirements provide for
periodic verification by tests of the leak tight integrity of the
primary reactor containment. Appendix J further states that the purpose
of the tests ``is to assure that leakage through the primary reactor
containment shall not exceed the allowable leakage rate values as
specified in the Technical Specifications or associated bases.'' Thus,
the underlying purpose of the requirement to perform Type A containment
leak rate tests at intervals during the 10-year service period is to
ensure that any potential leakage pathways through the containment
boundary are identified within a time span that prevents significant
degradation from continuing or becoming unknown.
The NRC staff has reviewed the basis and supporting information
provided by the licensee in the exemption request. It has been the
experience at Turkey Point Unit 4 during the Type A tests conducted
from 1982 to date, that the Type A tests have demonstrated that the
reactor containment buildings have acceptable leak rates that are far
below the leak rates assumed in the site's offsite dose calculation and
the ILRT acceptance criteria. The licensee has reported that the test
results are approximately one-third to one-fourth of the leakage
assumed in offsite dose rate calculations (0.25%) and approximately
one-half to one-third of the acceptance criteria for the ILRT
(0.1875%). The leak rate data from these tests do not show an
increasing trend, indicating that the containment liner and isolation
system are stable and supporting the conclusion that a one-time
scheduler exemption will not reduce the current level of safety.
The licensee will perform the general containment inspection
although it is only required by Appendix J (Section V.A.) to be
performed in conjunction with Type A tests. The NRC staff considers
that these inspections, though limited in scope, provide an important
added level of confidence in the continued integrity of the containment
boundary.
The NRC staff has also made use of a draft staff report, NUREG-
1493, which provides the technical justification for the present
Appendix J rulemaking effort which also includes a 10-year test
interval for Type A tests. The integrated leakage rate test, or Type A
test, measures overall containment leakage. However, operating
experience with all types of containments used in this country
demonstrates that essentially all containment leakage can be detected
by local leakage rate tests (Type B and C). According to results given
in NUREG-1493, out of 180 ILRT reports covering 110 individual reactors
and approximately 770 years of operating history, only 5 ILRT failures
were found which local leakage rate testing could not detect. This is
3% of all failures. This study agrees well with previous NRC staff
studies which show that Type B and C testing can detect a very large
percentage of containment leaks.
The Nuclear Management and Resources Council (NUMARC), now the
Nuclear Energy Institute (NEI), collected and provided the NRC staff
with summaries of data to assist in the Appendix J rulemaking effort.
NUMARC collected results of 144 ILRTs from 33 units; 23 ILRTs exceeded
1.0La. Of these, only nine were not due to Type B or C leakage
penalties. The NEI data also added another perspective. The NEI data
show that in about one-third of the cases exceeding allowable leakage,
the as-found leakage was less than 2La; in one case the leakage
was found to be approximately 2La; in one case the as-found
leakage was less than 3La; one case approached 10La; and in
one case the leakage was found to be approximately 21La. For about
half of the failed ILRTs the as-found leakage was not quantified. These
data show that, for those ILRTs for which the leakage was quantified,
the leakage values are small in comparison to the leakage value at
which the risk to the public starts to increase over the value of risk
corresponding to La (approximately 200La, as discussed in
NUREG-1493). Therefore, based on those considerations, it is unlikely
that an extension of one cycle for the performance of the Appendix J,
Type A test at Turkey Point Unit 4 would result in significant
degradation of the overall containment integrity. As a result, the
application of the regulation in these particular circumstances is not
needed to achieve the underlying purpose of the rule.
Based on generic and plant-specific data, the NRC staff finds the
basis for the licensee's proposed exemption to allow a one-time
exemption to permit a schedular extension of one cycle for the
performance of the Appendix J Type A test, provided that the general
containment inspection is performed, to be acceptable.
Pursuant to 10 CFR 51.32, the Commission has determined that
granting this Exemption will not have a significant impact on the
environment (60 FR 49926).
This Exemption is effective upon issuance and shall expire at the
completion of the 1997 refueling outage.
Dated at Rockville, Maryland, this 27th day of September 1995.
For the Nuclear Regulatory Commission.
Steven A. Varga,
Director, Division of Reactor Projects--I/II, Office of Nuclear Reactor
Regulation.
[FR Doc. 95-25148 Filed 10-10-95; 8:45 am]
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