[Federal Register Volume 60, Number 156 (Monday, August 14, 1995)]
[Notices]
[Pages 41903-41904]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-20027]




[[Page 41903]]


NUCLEAR REGULATORY COMMISSION

[Docket No. 50-382]


Entergy Operations, Inc. (Waterford Steam Electric Station, Unit 
No. 3); Exemption

I

    Entergy Operations, Inc., (the licensee) is the holder of Facility 
Operating License No. NPF-38, which authorizes operation of Waterford 
Steam Electric Station Unit No. 3 (the facility, Waterford 3). The 
operating license provides among other things, that it is subject to 
all rules, regulations, and orders of the Commission now or hereafter 
in effect. The facility is a pressurized water reactor located at the 
licensee's site in St. Charles Parish, Louisiana.

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.

III

    By letter dated November 16, 1993, as supplemented by letters dated 
August 19, 1994, March 30, and June 19, 1995, the licensee 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 
18 months (from the 1995 refueling outage, currently scheduled to begin 
in September 1995, to the 1997 refueling outage).

    The licensee's request primarily 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. The licensee 
also indicated that the testing history, structural capability of the 
containment, and the risk assessment has established that Waterford 3 
has a low leakage containment, the structural integrity of the 
containment is assured, and that there is a neglible risk impact in 
changing the Type A test schedule. 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 18 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 in 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 leak-tight containment. All 
Type A tests have passed with significant margin and the licensee will 
continue to perform the existing Type B and C testing to detect 
containment leakage caused by the degradation of active containment 
isolation components as well as containment penetrations. 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 has also made use of the information in a draft staff 
report, NUREG-1493 ``Performance-Based Containment Leak-Test Program,'' 
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 these considerations, it is unlikely 
that an extension of one cycle for the performance of the Appendix J, 
Type A test at Waterford 3 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 

[[Page 41904]]
test to be acceptable provided the general containment inspection (10 
CFR Part 50, Appendix J, Section V.A.) is performed.

    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 39020).

    This Exemption is effective upon issuance and shall expire after 
March 31, 1997, or at the completion of the 1997 refueling outage 
whichever comes first.

    Dated at Rockville, Maryland, this 3rd day of August 1995.

    For the Nuclear Regulatory Commission.

Elinor G. Adensam,

Deputy Director, Division of Reactor Projects III/IV, Office of Nuclear 
Reactor Regulation.

[FR Doc. 95-20027 Filed 8-11-95; 8:45 am]

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