[Federal Register Volume 60, Number 51 (Thursday, March 16, 1995)]
[Notices]
[Pages 14308-14309]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-6483]
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NUCLEAR REGULATORY COMMISSION
[Docket No. 50-247]
Consolidated Edison Company of New York (Indian Point Nuclear
Generating Unit No. 2); Exemption
I
Consolidated Edison Company of New York, Inc. (Con Edison or the
licensee) is the holder of Facility Operating License No. DPR-26, which
authorizes operation of Indian Point Nuclear Generating Unit No. 2 (the
facility or IP2), at a steady-state reactor power level not in excess
of 3071.4 megawatts thermal. The facility is a pressurized water
reactor located at the licensee's site in Westchester County, New York.
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), at approximately equal intervals during each 10-year service
period of the primary containment. The third test of each set shall be
conducted when the plant is shutdown for the 10-year inservice
inspection of the primary containment.
III
By letters dated September 19, 1994, January 13, 1995, and February
3, 1995, Con Edison requested temporary relief from the requirement to
perform a set of three Type A tests at approximately equal intervals
during each 10-year service period of the primary containment. The
requested exemption would permit a one-time interval extension of the
third Type A test by approximately 24 months (from the 1995 refueling
outage, currently scheduled to begin in February 1995, to the 1997
refueling outage) and would permit the third Type A test of the second
10-year inservice inspection period to not correspond with the end of
the current American Society of Mechanical Engineers Boiler and
Pressure Vessel Code (ASME Code) inservice inspection interval.
The licensee's request cites the special circumstances of 10 CFR
50.12, paragraph (a)(2)(ii), as the basis for the exemption. They point
out that the existing Type B and C testing programs are not being
modified by this request and will continue to effectively detect
containment leakage caused by the degradation of active containment
isolation components as well as containment penetrations. It has been
the consistent and uniform experience at IP2 during the five Type A
tests conducted from 1976 to date, that any significant containment
leakage paths are detected by the Type B and C testing. The Type A test
results have only been confirmatory of the results of the Type B and C
test results. Additionally, the Indian Point 2 Containment Penetration
and Weld Channel Pressurization System provides a means for
continuously pressurizing the positive pressure zones incorporated into
the containment penetrations, the channels over the welds in the steel
inner liner and certain containment isolation valves. This system
provides continuous monitoring of these potential containment leakage
paths, thus providing further assistance during power operation that a
leak path does not exist and further obviates the need
[[Page 14309]] for Type A testing at this time. Therefore, application
of the regulation in this particular circumstance would not serve, nor
is it necessary to achieve, the underlying purpose of the rule.
IV
Section III.D.1.(a) of Appendix J to 10 CFR Part 50 states that a
set of three Type A leakage rate tests shall be performed at
approximately equal intervals during each 10-year service period.
The licensee proposes an exemption to this section which would
provide a one-time interval extension for the Type A test by
approximately 24 months. The Commission has determined, for the reasons
discussed below, that pursuant to 10 CFR 50.12(a)(1) this exemption is
authorized by law, will not present an undue risk to the public health
and safety, and is consistent with the common defense and security. The
Commission further determines that special circumstances, as provided
in 10 CFR 50.12(a)(2)(ii), are present justifying the exemption;
namely, that application of the regulation of the particular
circumstances is not necessary to achieve the underlying purpose of the
rule.
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. The NRC staff has noted that the
licensee has a good record of ensuring a leaktight containment. All
Type A tests have passed with significant margin and the licensee has
noted that the results of the Type A testing have been confirmatory of
the Type B and C tests which will continue to be performed. The
licensee has stated to the NRC Project Manager that they 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 also
notes that the unique IP2 Containment Penetration and Weld Channel
Pressurization System provides a means for continuously monitored
potential containment leakage paths.
The NRC staff has also made use of the information in 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 IP2 experience has also been
consistent with these results.
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 these considerations, it is unlikely
that an extension of one cycle for the performance of the Appendix J,
Type A test at IP2 would result in significant degradation of the
overall containment integrity. As a result, the application of the
regulation in these particular circumstances is not necessary 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 12787).
This Exemption is effective upon issuance and shall expire at the
completion of the 1997 refueling outage.
Dated at Rockville, Maryland, this 8th day of March 1995.
For the Nuclear Regulatory Commission.
Steven A. Varga,
Director, Division of Reactor Projects--I/II, Office of Nuclear Reactor
Regulation.
[FR Doc. 95-6483 Filed 3-15-95; 8:45 am]
BILLING CODE 7590-01-M
