ML17277B468
| ML17277B468 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 07/26/1984 |
| From: | Eisenhut D Office of Nuclear Reactor Regulation |
| To: | WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| Shared Package | |
| ML17277B469 | List: |
| References | |
| NUDOCS 8408090409 | |
| Download: ML17277B468 (10) | |
Text
7590-01 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of Washington Public Power Supply System (WPPSS Nuclear Project No. 2)
Docket No. 50-397 EXEf1PT ION The Washington Public Power Supply System (WPPSS/the licensee) is the holder of Facility License No. NPF-21 which authorizes operation of WPPSS Nuclear Project No.
2 (WNP-2) at power levels not in excess of 3323 megawatts thermal.
The facility is a Boiling Water Reactor located at the licensee's site in Richland, Washington.
The license provides, among other things, that it is subject to all rules, regulations, and Orders of the Commission now or hereafter in effect.
Inerting the containment for the WNP-2 plant is required by 10 CFR 50.44 (revised) and by the plant's Technical Specifications.
'Standards for combustible gas control system in light-water-cooled power reactors,"
Section 50.44 (c)(3)(i) states that, "Effective May 4, 1982 or 6 months after'nitial criticality, whichever is later, an inerted atmosph'ere shall be provided for each boiling light-water nuclear power reactor with a Mark I or Mark II type containment."
8408090409 840727 PDR ADOCK 05000397 P,
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Since l<NP-2 achieved its initial criticality on January 19, 1984, the plant is required to be inerted by July 19, 1984, per the 10 CFR 50.44 requirement set forth above.
By its letter dated f1ay 11, 1984, the licensee V
requested a temporary exemption from the requirement of 10 CFR 50.44 so that it may continue operating the plant with a non-inerted containment during the balance, of the initial startup test program as originally planned.
The exemption from the regulation is required in order to complete the balance of the power ascension test program (PATP) in accordance with the licensee's test plan.
The licensee's test plan is based on maintaining the containment in a non-inerted condition until after completing the 100% rated thermal trip test, a condition which normally would be expected to occur within about 120 effective full power days of core burn-up.
No changes are being made in the maximum full power days of core burn-up normally expected before inerting is required.
In fact to assure this, the maximum expected value of 120 effective full power days is made part of the proposed action.
The licensee's PATP schedule has not been maintained as originally planned.
This has resulted in a simple stretch out of the time required to complete all post criticality PATP tests.
It is advantageous to operate the reactor without inerting during the PATP, as an uninerted containment would permit unscheduled inspections or identification of possible problems important to safety during this period.
The anticipated high frequency of containment entries during the PATP period
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and the required deinerting and re-inerting time (about 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) would tend to discourage early and frequent containment entries for identifying and correcting any potential safety problems before they become serious safety problems.
We have evaluated the licensee's requested exemption.
The NRC staff believes that to now require inerting before the PATP tests have been com-I pleted could result in less assurance of safety, because of the added time and/or decreased ability to directly examine and evaluate components and-systems i'nside containment while the PATP tests are under way.
Completing the PATP tests with an uninerted containment then would reduce the likeli-,
hood of development of an event requiring protective safety actions both during the period of exemption and later.
Because of the low level of fission product inventory during the PATP period, (less than 10 effective full power days (FPD) at present increasing to the maximum of only 120 FPD) and the short duration anticipated for the exemption (until about September i
1984), there is an extremely low likelihood that the inerting system'ould be required.
The inerting system is now fully operable and ready for service if needed.
Based on the information provided by the licensee and the staff's assurance that the remainder of the PATP tests will be performed in essentially the same manner as originally planned with respect to the magnitude and duration of
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power levels for each remaining PATP test, the NRC staff concludes that there will be no increase in the risks of operation through completion of the PATP tests with the proposed limited exemption regarding initial inerting over the risks that were contemplated for the duration of the PATP tests at the time the plant was licensed.
Therefore, since there is no perceived increased risk by the mere fact of extending the time allowed for completion of the PATP tests under uninerted conditions, the NRC staff finds that operation would be as safe under the conditions propo'sed by the exemption as it would have been had the tests been completed in the shorter calander time of six months after initial criticality.
The inerting requirement resulted from a staff judgement that the safety benefits attributable to having an inerted containment during normal opera-"
tions outweighed the associated disadvantages.
This judgement does not f
prevail during the PATP because of the need for frequent containment entries
,for inspection and surveillance purposes.
The staff has reviewed the licensee's submittals, agrees with the statements, and finds that the proposed exemption from 10 CFR 50.44, paragraph (c)(3)(i) is acceptable.
IV.
Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12, the exemption is authorized by law, will not endanger life or property or the common defense and security and is otherwise in the public interest.
Therefore, the Commission hereby grants the exemption as follows:
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7 "An exemption is granted from the requirements of 10 CFR 50.44 Paragraph (c)(3)(i) until either the required 100 percent rated thermal power trip startup tests have been completed or the reactor I
has operated for 120 effective full power days, whichever is earlier."
Pursuant to 10 CFR 51.32, the Commission has determined that the issuance of the exemption will have no significant impact on the environment (49 FR 29885).
1 A copy of the Commission's Safety Evaluation dated July 27, 1984, related to this action is available for public inspection at the Commissions Public Document
- Room, 1717 H Street, N. W., Washington, D.C., and at the This Exemption is effective upon issuance.
FOR THE NUCLEAR REGULATORY COMMISSION Darrell G. Eisenhut, Director Division of Licensing, NR ck.dh Pt ut e orth ASchwencer WPaton TN yk DElsenhu 7/z¹/84 07/g/84 07/~84
/84 07/A/84 07/
/84 Dated at Bethesda, Maryland this July 27, 1984 L8¹ PD L ¹ L8 2/DL OELD "AD/
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