ML19257D787
| ML19257D787 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/31/1980 |
| From: | Lundval A BALTIMORE GAS & ELECTRIC CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19257D788 | List: |
| References | |
| NUDOCS 8002060470 | |
| Download: ML19257D787 (2) | |
Text
'
'g B ALTIMORE G AS AND ELECTRIC COMPANY P.O. B O X 14 7 5 B A LTIM O R E. M A R YL A N D 2120 3 Antteum C. Lu*eovaLL..JR.
' 5I. ~
January 31, 1980 s
Mr. D. G. Eisenhut, Acting Director Division of Operating Reactors Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No. 1, Docket 50-317 Unit No. 2, Docket 50-318 ECCS Flow Blockage Model
REFERENCES:
(A) NRC Letter from D. G. Eisenhut to-All Operating Light Water Reactors, dated November 9, 1979.
(B) BG&E letter from A. E. Lundvall, Jr. to D. G. Eisenhut, da u d December 27, 1979.
(C) Enclosure 1-P of C-E Letter LD-78-069, A. E. Scherer to D. F. Ross, dated September 18, 1978
Dear Mr. Eisenhut:
Reference A required confirmation of information presented by the fuel vendors regarding fuel cladding strain and assembly flow blockage modeling in our ECCS analyses. Confirmation of our continued compliance with the Appendix K requirements was provided in Reference B.
Reference B also stated that regions exist where the fuel cladding strain and assembly flow blockage models used in the ECCS analysis for Calvert Cliffs Unit 1 and 2 are less conservative than the new NRC models. As requested, further calculations were initiated to demonstrate continued compliance with the ECCS Acceptance Criteria of 10 CFR 50.45.
In order to respond to the NRC concern in a timely manner, Combustior Engineering (C-E), our fuel vendor, performed an analysis for the operating plants with C-E fuel. The attached analysis was performed for the plant most limited by the new NRC models for the previously determined limiting break size. The C-E ECCS Evaluation Model of Reference C was used for this Aw!
1928 328 s
///
4'90 8002060 4-
Mr. D. G. Eisenhut, Acting Director January 31, 1980 Page 2 analysis. The method for including the new NRC rupture strain and blockage models is described in detail in Section III of the attached report. Results of the analysis are summarized in Section IV of the report. With higher (more conservative) strain and blockage, a lower peak cladding temperature than calculated for the reference cycle was obtained. The applicability of the analysis to Calvert Cliffs Unit 1 and 2 is provided in Sections V and VI.
As a result of the analysis documented in the attached report, we believe that the ECCS analyses performed for our plant (s) by C-E continue to be in compliance with the limits of 10 CFR 50.46.
Very truly yours, N
/
_/
jo n
A. E. Lundvall,' Jr.
Vice President - Supply AEL/ JAM /mrc Copy To:
J. A. Biddison, Esquire G. F. Trowbridge, Esquire Mr. E. L. Conner - NRC Mr. P. W. Kruse - C-E 1928 329