[Federal Register Volume 59, Number 151 (Monday, August 8, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-19264]


[[Page Unknown]]

[Federal Register: August 8, 1994]


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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-295 and 50-304]

 

Commonwealth Edison Co. (Zion Nuclear Power Station, Units 1 and 
2); Exemption

I

    The Commonwealth Edison Company (the licensee), is the holder of 
Facility Operating License Nos. DPR-39 and DPR-48 which authorize 
operation of the Zion Nuclear Power Station, Units 1 and 2 (the 
facility), at a steady-state power level not in excess of 3250 
megawatts thermal. The facility consists of two pressurized water 
reactors located at the licensee's site in Lake County, Illinois. The 
licenses provide, among other things, that they are subject to all 
rules, regulations and orders of the Nuclear Regulatory Commission (the 
Commission) now and hereafter in effect.

II

    In a letter dated June 16, 1994, the licensee requested an 
exemption from the requirement in 10 CFR 50, Appendix J, to perform 
Type C leak rate testing of 1(9992) MOV-CC685 during each refueling 
outage, but at an interval not to exceed 2 years. This scheduler 
exemption will defer the Type C leak rate testing requirements to 
refueling outage Z1R14 for 1MOV-CC685 and to Z2R13 for 2MOV-CC685.

III

    Appendix J of 10 CFR Part 50, requires that a program consisting of 
a schedule for conducting Type A, B, and C tests be developed for leak 
testing the primary reactor containment, and related systems and 
components penetrating the primary containment pressure boundary. In 
addition, prior to any reactor operating period, periodic leak rate 
tests are required to be conducted in accordance with the schedule 
specified by 10 CFR Part 50, Appendix J, Section III.D.3. Type C tests 
are intended to measure containment isolation valve leakage rates and 
are performed by local pressurization in the accident direction, using 
either air or nitrogen. The acceptance criterion for the tests is that 
the combined leakage rate for all penetrations and valves subject to 
Type B and C tests shall be less than 0.60 La, where La is 
the maximum allowable leakage rate. Type C tests are required to be 
performed during each reactor refueling outage, but in no case at an 
interval greater than 2 years.
    The licensee requested that Type C leak rate testing in accordance 
with 10 CFR Part 50, Appendix J, for valves 1(2)MOV-CC685 be deferred 
until the next scheduled refueling outage for each unit. Valve IMOV-
CC685 would be Type C tested in accordance with 10 CFR Part 50, 
Appendix J, during refueling outage Z1R14 which is scheduled to begin 
on September 9, 1995, and valve 2MOV-CC685 would be Type C tested in 
accordance with 10 CFR Part 50, Appendix J, during refueling outage 
Z2R13 which is scheduled to begin on January 5, 1995.
    One of the conditions of all operating licenses is that primary 
reactor containments shall meet the containment leakage test 
requirements set forth in 10 CFR Part 50, Appendix J. These test 
requirements provide for preoperational and periodic verification tests 
of the leak tight integrity of the primary reactor containment, and 
systems and components which penetrate containment and established the 
acceptance criteria for such tests. The purposes of the tests are to 
ensure that (a) leakage through the primary reactor containment, and 
systems and components penetrating primary containment, does not exceed 
allowable leakage rate values as specified in the Technical 
Specifications (TS) or associated bases, and (b) periodic surveillance 
of reactor containment penetrations and isolation valves is performed 
so that proper maintenance and repairs are made during the service 
lives of the containment and systems and components penetrating the 
containment. Type C tests are tests intended to measure containment 
isolation valve leakage rates.
    All remaining leak rate tests, including those on the valves in 
series with 1(2)MOV-CC685 have been performed in full compliance with 
TS requirements and 10 CFR Part 50, Appendix J. To provide an 
additional margin of safety and to account for possible leakage through 
the subject valves, Zion will impose an administrative limit for 
maximum pathway leakage of 0.4La for the remaining operating cycle 
for both units. In addition, periodic visual inspections of the piping 
from the containment wall to the subject valves will provide further 
assurance that no external leakage exists from 1(2)MOV-CC685. The self-
imposed limit for maximum pathway leakage along with the visual 
inspection of 1(2) MOV-CC685 and its piping provide a basis for showing 
that the probability of exceeding off-site dose rates established in 10 
CFR Part 100 will not be increased by deferring completion of the Type 
C leak rate testing of the subject valves to the next refueling outage. 
Accordingly, the staff finds, for the reasons set forth above, that the 
subject exemption request will not present an undue risk to the public 
health and safety [10 CFR 50.12(a)(1)].
    Special circumstances are present or required by 10 CFR 50.12(a)(2) 
in that the requested exemption is temporary and schedular in nature 
and would provide only temporary relief from the applicable regulation 
and the licensee has made good faith efforts to comply with the 
regulation. Type C testing of the valve will only be deferred until the 
next refueling outage. This delay will be 15 months for 1MOV-CC685 and 
6 months for 2MOV-CC685. Following completion of the testing of the 
valves during the next refueling outage, subsequent testing will be 
performed in accordance with the schedule prescribed in 10 CFR Part 50, 
Appendix J. The licensee made a good faith effort to comply with the 
regulations in that in 1991, valves that had never been tested per the 
regulations were identified and modifications and testing scheduled. 
The licensee is conducting a root cause investigation to determine the 
systematic breakdown that resulted in the modifications and testing of 
these valves being missed. On this basis, the staff finds that the 
licensee has demonstrated that there are special circumstances present 
as required by 10 CFR 50.12(a)(2)(v).
    The staff has reviewed the licensee's exemption request and finds 
that it meets the underlying purpose of the rule, special circumstances 
exist, and it will not present an undue risk to the public health and 
safety. Since the licensee has justified the integrity of the 
containment based on previous leakage test results, the staff concludes 
that a one-time deferral of the Type C leak rate testing of 1(2)MOV-
CC685 will not have a significant safety impact.

IV

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), this exemption is authorized by law and will not endanger 
life or property and is consistent with the common defense and security 
and is otherwise in the public interest and hereby grants the following 
exemption with respect to requirements of 10 CFR Part 50, Appendix J, 
Section III.D.3:
    For the Zion Nuclear Power Station, Unit 1, the leak rate testing 
of 1MOV-CC685 may be deferred until refueling outage Z1R14 and for Zion 
Nuclear Power Station, Unit 2, the leak rate testing of 2MOV-CC685 may 
be deferred until refueling outage Z2R13.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will have no significant impact on the 
environment (59 FR 38646).

    Dated at Rockville, Maryland, this 1st day of August 1994.

    For the Nuclear Regulatory Commission.
Jack W. Roe,
Director, Division of Reactor Projects III/IV, Office of Nuclear 
Reactor Regulation.
[FR Doc. 94-19264 Filed 8-5-94; 8:45 am]
BILLING CODE 7590-01-M