ML20101H929
| ML20101H929 | |
| Person / Time | |
|---|---|
| Site: | 05200001 |
| Issue date: | 06/26/1992 |
| From: | Stark S GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| MFN-058-92, MFN-58-92, PWM-92-051, PWM-92-51, NUDOCS 9206300260 | |
| Download: ML20101H929 (2) | |
Text
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GI Nuclear Ennoy June 26,1992 h1FN 058-92 PWM 92-051 Of0ce of Nuclear Reactor Regulation US Nuclear Regulatory Commission Mail Station PI 137 Washington, DC 20555 ATTENTION:
Document Control Desk SUlHECT:
REPORTING OF CllANGES AND ERRORS IN ECCS EVALUATION MODELS
REFERENCE:
1.
Letter, PW Marriott to the Director of Nuclear Reactor Regulation,
" Reporting of Changes and Errors in ECCS Evaluation Models",
March 12,1991.
The purpose of this letter is to report, in accordance with 10CFR50.46(a)(3)(ii), the impact of changes and errors in the Emergency Core Cooling System (ECCS) evaluation methodology used by GE. This report covers the period from the last report (Reference 1) to the present. It is noted that peak cladding temperature (PCT) variations resulting from plant specific system or fuel changes are not addressed in this letter. These should be treated, as appropriate, on a plant specific basis in accordance with other sections of 10CFR50, i
There have been no changes or errors identified for the S AFE/REFLOOD model described in l
NEDE 20566 P-A, " Analytical Model for Loss-of-Coolant Analysis in Accordance with 10CFR50 Appendix K" or the SAFER /GESTR methodology described in NEDE 23785-1 P-A, "The GESTR-LOCA and S AFER Models for the Evaluation of Loss-of-Coolant Accidents", and NEDE 30996-P-A, "S AFER Model for Evaluation of Loss-of Coolant Accident; for Jet Pump and Nondet Pump Plants".
It has been observed that ECCS evaluation model results can be sensitive to changes in the computer operating system or small changes in input parameters. Test cases have been run for a change in the operating system and procedure for de0ning jet-pump loss coefficients for cases analyzed to be less than i 50' pet of these changes on the predicted PCT was fou SAFER /GESTR. The range ofimp i
F. Similarly, a change in the computer system for part of the l
S AFE/REFLgOD package (CH ASTE) resulted in an estimated range of impact on predicted PCT of + 10 F and - 25' F. Potential PCT variations of this magnitude should be anticipated when future ECCS analyses are performed on the new computer system; however, existing PCT predictions are valid and no change to any plant specific evaluation is required.
9206300260 920626 p1 PDR ADOCK 05200001 A
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by copy of this letter, licensees utilizing the GE ECCS methodology in their plant licensing are informed of the status of changes in the evaluation methodology. Since no reanalysis or technical
, specification modifications are required, this submittalis believed to satisfy 10CFil50,46(a)(3)(li) for evaluation model changes without further reporting on the part ofindividual utilities, if you have any questions or comments, please call me or 11C Pfefferlen at (408) 925 3392.
Sincerely.
h O. (6 S.J. Stark Acting Manager Regulatory & Analysis Services Mail Code 482 Phone (408) 925-6948 PWM:jz
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