ML20083C206
| ML20083C206 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/19/1991 |
| From: | Shelton D CENTERIOR ENERGY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20083C209 | List: |
| References | |
| NUDOCS 9109260087 | |
| Download: ML20083C206 (2) | |
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l CIEff71ENfH)R-ervanecnr Donald C. Shelton 300 Madison Avenue i
Vice Presdent Nuclear Toledo, OH 43f620001 Dam Besse (419)249 2300 Docket Number 50-346 License Number NPF-3 Serial Number 1977 September 19, 1991 United States Nuclear Regulatory Commission Document Control Deck Washington, D.C. 20555
Subject:
10CFR50.46 Notification of Changes in the Application of the B&W Emergency Core Cooling System Evaluation Model for Davis-Besse Nuclear Power Station, Unit 1 Gentlement The purpose of this letter is to inform the NRC, in accordance with 10CFR50.46, of changes in the application of the Babcock & V11cox Nuclear Technologies Company (BVNf) Emergency Core Cooling System (ECCS) Evaluation Model (EM) for Davis-Besse Nuclear Power Station, Unit 1 (DBNPS). The changes result from the discovery of an error in the input to the EH.
This change is estimated to increase the calculated peak clad temper'ture (PCT) by 90'F at the 2 ft, elevation, 85'F at the 4 ft. elevation, and 50'F at the 8 and 10 ft, elevations.
The error did not apply, and tFerefore had no effect at the 6 ft.
elevation. This constitutes a significant change as defined by 10CFR50.46.
However, based on conservative analysis by BVNT, it is estimated that the use of the revised fuel pin thermal analysis computer code, TACO 3, approved by the NRC far use in generating fuel performance inputs to the EM, would reduce PrT by 350'F at the 4 ft, elevation and by 250'r at the 2. 6, 8, and 10 ft. elevations. The combined effect of correction of the error and use of TACO 3 is expected to be a net reduction of PCT by 160'F at the 2 ft, elevation, with larger net reductions at the 4, 6, 8, and 10 ft. elevations.
Consequently, the current linear heat rate (LER) limits remain velid and the 10CPR50,46 ECCS performance acceptance criteria continue to be satisfied.
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-Docket Number 50-346 license Number NPF,-
. Serial Number 1977 Page 2-i A more detailed discussion of the changes in the application of the EH and the analytical basis for the.above conclusions is provided in the.
BVNT-letter to the NRC dated September 3, 1991 (copy attached).
Based on the information provided by the BVNT letter, Toledo Edison considers that no additional actions are required to satisfy the requirements of' 10CFR50.46.
If you have any questions regarding this matter, please contact Mr. R. V. Schrauder, Manager - Nuclear Licensing at (419) 249-2366.
Ver:r truly yours,
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-FVS/dlm Enclosure cci P. H. Byron, NRC Region III, DB-1 Senior Resident Inspector A. B. Davis, Regional Administrator, NRC Region III J. B. Hopkins, NRC/NRR DB-1 Senior Project Manager Utility Radiological Safety Board
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