ML20029B285
| ML20029B285 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 02/27/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20029A640 | List: |
| References | |
| NUDOCS 9103060386 | |
| Download: ML20029B285 (2) | |
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- NUCLEAR REGULATORY COMMISSION
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yy J ENCLOSURE SUPPLEMENTAL SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO THE USE OF RELAP5YA CODE FOR VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKEE NUCLEAR POWER STATION
-DOCXET NO. 50-271 FACILITY OPERATlHG LICENSE N0 DPR-28
1.0 INTRODUCTION
Dy letter dated January 26, 1988 (Ref. 1) and supplemented by-letter dated June-8.1990 (Ref. 2), Vermont Yankee Nuclear Power Corporation (VYNPC) submitted a request for a Supplemental Safety Evaluation supporting the use of.
the RELAPSYA code-for the Vermont Yankee Nuclear Power Station (VYNPS).
In the request, the licensee provided additional-information in the areas of the valve-subroutines and the HUXY code, which are parts of those certain condi-tions and restrictions delineated in the first staff SER (Ref 3).
The NRC staff was assisted in this review by our consultant, the Idaho National Engineering Laboratory (INEL).
The review covered the VYNPC's submittal (Ref.1)'and the response by VYNPC (Pef. 2) to the April 5,1990 letter'(Ref, 4) requesting additional information on the use of RELAPSYA. The staff has adopted the findings recommended in our consultant's Technical Report, as modified by-this evaluation.
2.0 EVALVATION The evaluation is provided in the enclosed INEL Technical Report EGG-EAST-9403, dated September 1990..
3.0- CONCLUSION On the basis of-the staff review and our consultant's evaluation we have concluded as follows:
(1) The rt.,triction regarding use of the valve components with loss coefficients shall be removed.
The VYNPS licensee has obtained the RELAPS/M001, Cycles 19 and 29 updates from the INEL pertaining to the valve component models and incorporated i,
these updates to REL*PS, which correct errors in the original RELAPSYA code.
The restriction stated in Item 3 of the Pegulatory Position 3 in Section 3.0 and identified in Item 3 of Section 2.3 of the SER (Ref. 3) pertain to these cerors and-is no longer needed.
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.ie for computing radiation view factors for LOCA analyses for
. is acceptable with the following restrictions:
.The use of the HVXY code to compute radiation view factors for the VYNPS shall be limited to the geometry and assumptions for the fuel assembly radiation enclosure model described in Reference 2.
b.
'The use of the HUXY code to compute radiation view factors shall be limited to a calculated fuel clad temperature not exceeding 2000'F.
In addition, the staff noted two typographical errors which were identified in the staf f SER (Ref. 3) (i.e., the number of fuel assentlics is 368, not 348 as typed; and the ruptured nodo length will not be less than 3" for~Ticensing calculations, not more, as typed).
4.0 REFERENCES
1.
Letter from R.W. Capstick (VYNPC) to llSHRC, " Request for Supplemental Safety Evaluation Report Supporting the Use of RELAP5YA for Vermont Yankee Nuclear Power Station," FVY 88-006, January 26, 1988.
2.
Letter, L.A. Tremblay, Jr. (VYMPC) to USNRC, " Response to Second Request for Additional Information on the use of RELAP5YA," BVY 90-067,-June 8, 1990.
3.
Letter, V.L. Pooney (USHRC) to R.W. Capstick (VYHPC), Approval of use of Thermal-Hydraulic Code RELAP5YA (TAC No. 60193), Re:
Vermont Yankee Nuclear Power Station," HVY 87-136, USNRC, dated August 25,1987(Docket Ho.50-271).
4.
Letter, USHRC to VYHPC, HVY 90-068, dated April 5,1990.
(2) The HUXY code for computing radiation view factors for LOCA analyses for the VYNPS is acceptable with the following restrictions:
a.
The use of the HUXY code to compute radiation view factors for the VYNPS shall be limited to the geometry and assumptions for the fuel assembly radiation enclosure model described in Reference 2.
b.
The use of the HUXY code to compute radiation view factors shall be limited to a calculated fuel clad temperature not exceeding 2000'F.
In addition, the staff noted two typographical errors which were identified in the staff SER (Ref. 3) (i.e., the number of fuel assemblies is 368, not 348 as typed; and the ruptured node length will not be less than 3" foFTicensing calculations, not more, as typed).
4.0 REFEREtlCES x
1.
Letter from R.W. Capstick (VYNPC) to USilRC, " Request for Supplemental Safety Evaluation P.eport Supporting the Use of RELAP5YA for Vermont Yankee Nuclear Power Station," FVY 88-006, January 26, 1988.
2.
Letter, L. A. Trertlay, Jr. (VYMPC) to USNRC, " Response to Second Request for Additional Information on the use of RELAP5YA," BVY 90-067, June 8, 1990.
3.
Letter, V.L. Rooney (USNRC) to R.W. Capstick (VYtlPC), Approval of use of Thermal-Hydraulic Code RELAPSYA (TAC Ho, 60193), Re:
Vermont Yankee Nuclear Power Station," NVY 87-136, USNRC, dated August 25, 1987 (Dociet No. 50-271).
4.
Letter, USNRC to VYtiPC, NYY 90-068, dated April 5, 1990.