ML20059F167
| ML20059F167 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 10/27/1993 |
| From: | Roe J Office of Nuclear Reactor Regulation |
| To: | COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML20059F142 | List: |
| References | |
| NUDOCS 9311040159 | |
| Download: ML20059F167 (5) | |
Text
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of
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COMMONWEALTH EDISON COMPANY
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Docket No. 50-304
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(Zion Station, Unit No. 2)
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EXEMPTION 1.
The Commonwealth Ediron Company (the licensee), is the holder of Facility Operating License No. DPR-48 which authorizes operation of Zion Station, Unit No. 2, at a steady-state power level not in excess of 3250 megawatts thermal. The facility consists of a pressurized water reactor located at the licensee's site in Lake County, Illinois. The license provides, among other things, that it is subject to all rules, regulations and orders of the Nuclear Regulatory Commission (the Commission) now and hereafter in effect.
II.
In its letter dated August 23, 1993, Commonwealth Edison Company (the licensee) applied for an exemption from the Commission's regulations. The subject exemption is from the requirements in Appendix J to 10 CFR Part 50 that a set of three Type A tests (Containment Integrated Leak Rate Tests or CILRT) be conducted, at approximately equal intervals during each 10-year service period and that the third of these tests be performed when the plant is shut down for the 10-year plant inservice inspections required by 10 CFR 50.55a.
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' III.
The staff notes that the first Type A test of the second 10-year service period was conducted in October 1988. The second Type A test was conducted in November 1992, 49 months after the first, due to the extended lengths of the controlling refueling outage and fuel cycle. The next refueling outage, which is also the 10-year plant inservice inspection outage, is scheduled for-January.995.
Since the interval between the last Type A test and the scheduled refueling outage date is only 26 months, the licensee proposes to move the next scheduled Type A test to the Cycle 14 refueling outage currently scheduled to start in September 1996. The interval between the two successive Type A tests on Unit 2 would then be 46 months.
The time interval between Type A tests should be about 40 months based on performing three such tests at approximately equal intervals during each 10-year service period.
Since refueling outages do not necessarily occur coincident with a 40-month interval, a permissible variation of 10 months (25 percent variation) is typically authorized to permit flexibility in scheduling the Type A tests.
For the purpose of performing Type A tests, this one-time exemption extends the current service period by approximately 21 months beyond the normal 10-year service period. The staff concludes that the deviation from the scheduling requirements of Section III.D.I.(a) to conduct three Type A tests during each 10-year service period is not significant since the interval between the second and third successive tests will be 46 months.
Accordingly, the staff finds, for the reasons set forth above, that the subject exemption request meets the underlying purpose of the rule ([10 CFR
' 50.12(a)(2)(ii)] to ensure containment integrity, which requires three Type A tests be conducted in a 10-year period, at approximately equal intervals.
The licensee also requested an exemption from the requirement of 10 CFR Part 50, Appendix J, Section III.D.I.(a) that the third Type A test of the second 10-year service period be conducted during the shutdown for the 10-year plant inservice inspections. The requested exemption would permit performance of Type A testing at a 40 10-month interval. This one-time exemption allows the facility to conduct the third Type A test of the second 10-year service period during the outage after the one for the 10-year plant inservice inspections. The staff concludes that the deviation from the scheduling requirement of Section III.D.I.(a) to conduct the third Type A test during the shutdown for the 10-year plant inservice inspections is not significant since I
it will be conducted during the succeeding refueling outage.
The Commission's regulations in 10 CFR 50.12 require special circumstances to be present to grant exemptions from the requirements of the regulations. According to 10 CFR 50.12(a)(2)(ii), special circumstances are present whenever application of the regulation in the particular circumstances would not serve the underlying purpose of the rule.
In the subject exemption request, the underlying purpose of the rule is to ensure containment integrity by performing the tests at approximately equal intervals of about a third of a ten-year service period. The staff finds that the current schedule would allow only 26 months between the last Type A test and the next test.
Therefore, the underlying purpose of the rule would not be served without the granting of an exemption to extend the testing interval. Special 1
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_4-circumstances are, therefore, present with respect to the subject exemption request.
Further, the staff finds that extending the service period and conducting the third Type A test during the refueling outage after the one for the 10-year plant inservice inspections will not present an undue risk to the public health and safety. Since the licensee has justified the leaktight integrity of the containment based on previous leakage test results, the staff concludes that a one-time extension of approximately 21 months beyond the 10-year service period 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, will not present an undue risk to the public health and safety, and is consistent with the common defense and security. Accordingly, the Commission hereby grants the exemption with respect to the requirements of 10 CFR Part 50, Appendix J, Section III.D.l.(a):
For Zion Nuclear Power Station, Unit 2, the current service period ending September 18, 1994, may be extended by approximately 24 months so that the third periodic Type A test may be performed during the Cycle 14 refueling outage.
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- Pursuant to 10 CFR 51.32, the Commission has determined that the granting of the subject exemption will not have a significant effect on the quality of the human environment (58 FR 57635 ).
FOR THE NUCLEAR REGULATORY COMMISSION L5) lkm, i
ack W. Roe, Director Director of Reactor Projects III/IV/V Office of Nuclear Reactor Regulation Dated at Rockville, Maryland this 27th day of October.
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