ML20203H685
| ML20203H685 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 07/31/1986 |
| From: | Withers B PORTLAND GENERAL ELECTRIC CO. |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| TASK-2.K.3.31, TASK-TM GL-83-35, TAC-48209, NUDOCS 8608050060 | |
| Download: ML20203H685 (2) | |
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Bart D. Wahers Vce Presxtyt July 31, 1986 Trojan Nuclear Plant Docket 50-344 License NPF-1 Director of Nuclear Reactor Regulation ATTN:
Mr. Steven A. Varga Director, PWR-A Project Directorate No. 3 Office of Nuclear Reactor Regulation U.S. Nuclear Reguistory Commission Washington DC 20555
Dear Sir:
Small Break LOCA Plant-Specific Analysis TMI Action Plan Item II.K.3.31
References:
1.
Letter to D. G. Eisenhut, NRC, from C. Goodwin, Jr., PGE Dated June 16, 1980.
2.
NRC Generic Letter 83-35 from D. G. Eisenhut,
" Clarification of TMI Action Plan Item II.K.3.31",
November 2, 1983.
3.
L. D. Butterfield Letter to J. Lyons, " Westinghouse Owners Group Transmittal of WCAP-11145", OG-190, June 11, 1986.
Portland General Electric (PCE) committed to submit a Plant-specific analysis (Reference 1) utilizing the new NRC approved NOTRUMP Small Break LOCA (SBLOCA)
Evaluation Model (EM), as required by TMI Action Plan Item II.K.3.31.
In Reference 2, the NRC staff indicated that the resolution of TMI Action Plan Item II.K.3.31 may be accomplished by generic analyses to demonstrate that the previous NRC approved WFLASH SBLOCA EM results were conse?tvative when compared with the new NOTRUMP SBLOCA EM.
Such generic studies were under-taken by the Westinghouse Owners Group (WOG) of which PCE is a participating member. The WOG has completed these generic studies and has submitted the results of the analyses to the NRC in the topical report WCAP-11145 (Reference 3).
The purpose of this letter is to inform you that PGE is referencing topical report WCAP-11145 in order to satisfy the requirements of TMI Action Item II.K.3.31 for the Trojan Nuclear Plant in a generic fashion, in accordance with Reference 2.
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N Gersercd BectricW Mr. Steven A. Varga July 31, 1986 Page 2 Topical report WCAP-11145 documents the results of a series of SBLOCA analyses performed with the NRC approved NOTRUMP SBLOCA EM.
Cold leg break spectrum analyses were performed for the limiting SBLOCA plant from each of the Westinghouse 4-loop, 4-loop upper head injection (UHI), 3-loop, and 2-loop plant categories. The limiting SBLOCA plant in each category was defined on the basis of previous SBLOCA analyses which were performed with the NRC approtred WFLASH SBLOCA EM.
In addition to the cold leg break spectrums, a hot leg and pump suction break were performed as part of the 4-loop plant analyses, confirming that the cold leg was still the worst break location. Comparison of the NOTRUMP cold leg break spectrum results with the previously generated WFLASH results, showed that the WFLASH results were conservstivo for all plant categories.
In particular, the 4-loop plant category results showed that the NOTRUMP SBLOCA EM calculated a limiting peak clad temperature (PCT) which was 537'F lower than that previously calculated by the WFLASH SBLOCA EM.
The generic results documented in WCAP-11145, demonstrate that a plant-specific reanalysis of the 4-loop Trojan Plant with the NOTRUMP SBLOCA EM would result in the calculation of a limiting PCT which would be signifi-cantly lower than the 1520*F PCT currently calculated with the WFLASH SBLOCA EM.
Hence, the WFLASH SBLOCA EM results which currently form the licensing basis for Trojan are conservative and still valid for demon-strating the adequacy of the Emergency Core Cooling System to mitigate the consequences of a SBLOCA, as required by 10 CFR 50.46.
It is therefore concluded that a plant-specific analysis is not needed in order for Trojan to comply with TMI Action Item II.K.3.31.
Rather, PGE references WCAP-11145 in order to comply with TMI Action Item II.K.3.31 on a generic basis, in accordance with Reference 2.
This should satisfy the commitments of Reference 1.
Sincerely, Bart D. Withers Vice President Nuclear c:
Mr. Lynn Frank, Director State of Oregon Department of Energy Mr. John B. Martin Regional Administrator, Regicn V U.S. Nuclear Regulatory Commission
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