[Federal Register Volume 59, Number 145 (Friday, July 29, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-18507]


[[Page Unknown]]

[Federal Register: July 29, 1994]


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NUCLEAR REGULATORY COMMISSION

 

Commonwealth Edison Co.; Zion Nuclear Power Station, Units 1 and 
2; Environmental Assessment and Finding of No Significant Impact

    The U.S. Nuclear Regulatory Commission (the Commission) is 
considering issuance of an exemption to Facility Operating License Nos. 
DPR-39 and DPR-48, issued to Commonwealth Edison Company (the 
licensee), for operation of the Zion Nuclear Power Station, Units 1 and 
2, located in Lake County, Illinois.

Environmental Assessment

Identification of Proposed Action

    The proposed action would grant an exemption from 10 CFR Part 50, 
Appendix J, Section III.D.3, which requires that Type C tests 
(containment isolation valve leakage rate tests) be performed during 
each reactor shutdown for refueling, but in no case at intervals 
greater than 2 years. This requirement applies to valves 1(2)MOV-CC685, 
the first isolation valves outside containment in the component cooling 
water return line from the reactor coolant pump thermal barriers. It is 
these valves that are the subject of this exemption request. This one-
time exemption will allow the Type C leak rate test on valves 1(2)MOV-
CC685 to be deferred until the next refueling outages (September 1995 
for Unit 1 and January 1995 for Unit 2).
    An amendment request to recognize the exemption was submitted by 
the licensee in another letter, also dated June 16, 1994. Both the 
amendment and exemption requests were preceded by a Notice of 
Enforcement Discretion (NOED) to not enforce compliance with the 
Technical Specification requirement to perform Type C tests of 1(2)MOV-
CC685 in accordance with 10 CFR Part 50, Appendix J. The NOED precluded 
Unit 2 from being shut down and allowed the startup of Unit 1.

The Need for the Proposed Action

    The proposed exemption is needed because valves 1(2)MOV-CC685 have 
never been tested per the requirements of 10 CFR Part 50, Appendix J, 
Section III.D.3. Continued operation of both units until their next 
refueling outage requires the exemption because they will not be in 
compliance with the requirements until the tests are performed. 
Requiring the licensee to place both units in cold shutdown to do the 
tests would result in undue hardship without a compensating increase in 
safety. The scope of the test preparations in significant, requiring 
removal of the reactor coolant pumps (RCP) from service, draining the 
component cooling water (CCW) return line from the RCP thermal 
barriers, uncoupling the flange at the CCW outlet from the RCP thermal 
barrier and opening test valves to provide a vent path. In addition to 
the undesirable thermal cycling of each unit, the licensee estimates 
each unit would be shut down for about three weeks, significant 
planning and maintenance support would be necessary, and significant 
radiation doses to maintenance personnel would be incurred. There would 
not be a compensating increase in level of safety that would justify 
the extensive amount of work and radiation exposure that would be 
incurred by requiring the licensee to perform the Type C leak rate 
testing of these two valves prior the units' next refueling outage. The 
licensee is proposing performance of the tests during the next 
refueling outage for each unit (September 1995 for Unit 1 and January 
1995 for Unit 2) which is a time period that is outside of the 
schedular requirements of 10 CFR Part 50, Appendix J.

Environmental Impacts of the Proposed Action

    The Commission has completed its evaluation and determined that 
granting the proposed exemption would not significantly increase the 
probability or amount of expected primary containment leakage and that 
containment integrity would, thus, be maintained. Although granting the 
exemption would mean that the schedular requirements for Type C leak 
rate testing in 10 CFR Part 50, Appendix J, would not be met, the 
intent of leak rate testing (which is to (1) ensure that the leakage 
through the primary containment, and systems and components that 
penetrate the primary containment does not exceed the leakage rate 
allowed by the Technical Specifications (TS) and associated basis, and 
(2) ensure that proper maintenance and repair are being performed 
throughout the service life of the containment boundary components) 
would still be met due to the substantial barriers to fission product 
release which are provided by the intact system piping and associated 
valves. In addition, 1(2)MOV-CC9438, which are the valves outside 
containment immediately downstream of 1(2)MOV-CC685, have been 
satisfactorily tested in accordance with the applicable requirements of 
10 CFR Part 50, Appendix J.
    The requested schedular exemption is a one time request of short 
duration for valves 1(2)MOV-CC685. All other required leak rate tests 
have been performed in accordance with the TS and 10 CFR Part 50, 
Appendix J. To provide an additional margin of safety during the 
upcoming operating cycles and to account for possible leakage through 
the valves, Zion will impose an administrative limit for maximum 
pathway leakage of 0.4La for both units. The licensee will also 
perform periodic visual inspections of the piping from the containment 
wall to the subject valves to provide further assurance that no 
external leakage exists. The administrative limit for maximum pathway 
leakage coupled with the visual inspections of the valves and their 
associated piping provide a basis for showing that the probability of 
exceeding the off-site does rate limits of 10 CFR Part 100 will not be 
increased by deferring completion of the Type C leak rate testing of 
1(2)MOV-CC685. In addition, testing has been performed on the valves 
that provides a high degree of confidence that leakage through 1(2)MOV-
CC685 would be well within Type C testing limits. This testing 
consisted of pressurized air tests of the piping between 1(2)MOV-CC685 
and 1(2)MOV-CC9483 and water leakage tests on 1(2)MOV-CC685 in the 
accident direction. In both tests, no leakage was observed. Therefore, 
the staff has determined that the exemption will not present an undue 
risk to the public health and safety.
    Consequently, the probability of accidents would not be increased, 
nor would the post-accident radiological releases be greater than 
previously determined. Neither would the proposed exemption otherwise 
affect radiological plant effluents. Therefore, the Commission's staff 
concludes that there are no significant radiological environmental 
impacts associated with the proposed exemption.
    With regard to potential nonradiological impacts, the proposed 
exemption involves a change to surveillance and testing requirements. 
It does not affect nonradiological plant effluents and has no other 
environmental impact. Therefore, the Commission's staff concludes that 
there are no significant nonradiological environmental impacts 
associated with the proposed exemption.

Alternative to the Proposed Action

    Since the Commission has concluded that there are no significant 
environmental impacts associated with the proposed action, any 
alternatives would have either no or greater environmental impact.
    The principal alternative would be to deny the requested exemption. 
This would not reduce the environmental impacts attributed to the 
facility and would result in a costly shut down of the units for the 
purpose of performing the tests.

Alternate Use of Resources

    This action does not involve the use of any resources not 
previously considered in connection with the Nuclear Regulatory 
Commission's Final Environmental Statement, dated December 1972, 
related to the operation of the Zion Nuclear Power Station, Units 1 and 
2.

Agencies and Persons Consulted

    The NRC staff consulted with the Illinois State official regarding 
the environmental impact of the proposed action. The State official had 
no comments.

Finding of No Significant Impact

    The Commission staff has determined not to prepare an environmental 
impact statement for the proposed license exemption. Based upon the 
foregoing environmental assessment, we conclude that the proposed 
action will not have a significant effect on the quality of the human 
environment.
    For further details with respect to this action, see the request 
for exemption dated June 16, 1994, which is available for public 
inspection at the Commission's Public Document Room, The Gelman 
Building, 2120 L Street, NW., Washington, DC 20555, and at the local 
public document room located at Waukegan Public Library, 128 North 
County Street, Waukegan, Illinois 60085.

    Dated at Rockville, Maryland, this 25th day of July 1994.

    For the Nuclear Regulatory Commission.
Robert A. Capra,
Director, Project Directorate III-2, Division of Reactor Projects--III/
IV, Office of Nuclear Reactor Regulation.
[FR Doc. 94-18507 Filed 7-28-94; 8:45 am]
BILLING CODE 7590-01-M