[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 
1.0L<INF>a. 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 2L<INF>a; in one case the leakage 
was found to be approximately 2L<INF>a; in one case the as-found 
leakage was less than 3L<INF>a; one case approached 10L<INF>a; and in 
one case the leakage was found to be approximately 21L<INF>a. 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 L<INF>a (approximately 200L<INF>a, 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]
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