ML19261B581
| ML19261B581 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 02/22/1979 |
| From: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| TAC-11203, NUDOCS 7902280232 | |
| Download: ML19261B581 (2) | |
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Portland General BectricCompany fq E
c Chres Gacdon a ss s:rt Vce P= Jm' Feb aary 22, 1979 Trojan Nuclear Plant Docket 50-344 License NPF-1 Director of Nuclear Reactor Regulation ATTN:
Mr. A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Sir:
Following are responses to the Requests for Additional Information dated February 26, 1979 in connection with your review of our License Change Application 49, involving the use of the Westinghouse Improved Thermal Design Procedure and the WRB-1 critical heat flut correlation for the Trojan Nuclear Plant.
Request 1.
Submit the sensitivity factors, S, used for the i
Trojan analysis as required by the staff Safety Evaluation Report on WCAP-8567/3568, " Improved Thermal Design Procedure" (April 10, 1978).
Response: Sensitivity factors used for the Trojan analysis are the same as those previously submitted for the D. C. Cook 2 application (American Electric Power Co.
letter to E. G. Case, NRC, dated July 11, 1977; Docket 50-344).
Request 2.
If these sensitivity factors have changed from those previously approved by the staff, then a linearity test is required by the same staff Safety Evaluation Report. Please either reference previous staff approval for the sensitivity factors you are using or provide the results of such a linearity test.
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Portland General BechicCorpnv Mr. A. Schwencer February 22, 1979 Page two Response: The D. C. Cook 2 sensitivity factors and the asso-ciated linearity test have been previously approved by the NRC, as noted in the response to Request 1.
Request 3.
According to the staff Safety Evaluation Report on WCAP-8567 (referenced in Request 1), sensitivity factors are also required for 3-loop operating conditions. Please provide these and also the results of the corresponding linearity tests.
Response: The sensitivity factors referenced in the responses to Requests 1 and 2 are applicable to 3-loop opera-tions. This is true because parameter ranges large enough to encompass 3-loop operating conditions were considered in developing the sensitivity factors.
Request 4.
Describe how the ef fect of fuel rod bowing on DNBR was included in the proposed Technical Specifica-tions changes.
Response: The effect of fuel rod bowing was not incorporated in the Improved Thermal Design Procedure analysis for Trojan. Rather, rod bowing was treated separ-ately, in accordance with the conclusions of the staff Safety Evaluation Report on WCAP-8567/8568.
Specifically, the DNBR penalty due to rod bowing was calculated as 10.6 percent, and this penalty was noted to be more than offset by the 20.2 percent margin included in the Trojan analyses (refer to LCA 49, Page 94). The 10.6 percent DNBR penalty for rod bowing is the magnitude identified by Westinghouse with the partial bow DNB test results submitted to the NRC on October 24, 1977 (Westing-house letter to Denwood F. Ross, Jr., NRC).
Sincerely, pM
/
C. Goodwin, Jr.
Assistant Vfce President Thermal Plant Operation and Maintenance c:
Dr. W. Kelly Woods, Acting Director State of Oregon Department of Energy