ML19345B735
| ML19345B735 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 11/28/1980 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8012020438 | |
| Download: ML19345B735 (3) | |
Text
W BALTIMORE G AS AND ELECTRIC COMPANY P.O. BOX 1475 B ALTIMOR E. M ARYLAN D 21203 Am7 Hum c.LUNDVALL,Jm.
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November 28, 1980 Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 ATTENTION:
Mr. R. A. Clark, Chief Operating Reactors Branch #3 s
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cn Division of Licensing E, _,
LN 5
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'?:SOBJECT:
Calvert Cliffs Nuclear Power Plant EE' Unit No.1, Docket No. 50-317
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Amendment to Operating License DPR-53 2-
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B Fifth Cycle License Application Responses to NRC Staff Questic.ns f.
Gentlem'en:
Enclosed are our reponses to questions posed by NRC staff on the subject application.
Very truly yours, BALTIMORE GAS ND..EL'ECTRIC COMP NY A. N. I Vice President - Supply AEL/W3L/mit Copy To:
- 3. A. Biddison, Esquire (w/out Encl.)
G. F. Trowbridge, Esquire (w/out Encl.)
Messrs.
E. L. Conner, Jr., NRC P. W. Kruse, CE Enclosure (40 copies)
D
-8012020 @
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ENCLOSURE QUESTION The reload safety analysis (1) provides an insufficient discussion on fuel rod bowing and its effect on DNBR margin. The two sentences that are pro-vided do not identify the bow-magnitude and reduction-in-DNBR correlations used for the Calvert Cliffs Unit 1 analysis. Neither is there any information given on the input parameters used for the calculations.
Furthermore, the BG&?
discussion of fuel rod bowing references the Combustion Engineering generic topical report CENPD-225, " Fuel & Poison Rod Bowing" that has not been approved for licensing applications.
Please identify the correlations that were used and cite their NRC approval.
Provide the input that was used for the Cycle 5 analysis.
Describe any generic or plant specific DNBR margins that were required to offset fuel rod bowing effects.
RESPONSE
The following supplements cur response (Reference 1) to the above question as per our discussion with D. H. Powers on Novemt.er 25, 1980:
The fuel rod bowing effects on DNB margin for Calvert Cliffs Unit I have been evaluated within the guidelines set forth in Reference 2.
A total of 63 fuel assemblies will exceed the NRC-specified DNB penalty threshold burnup of 24,000 MWD /T, as established in Reference 2, during Cycle 5.
At the end of Cycle 5, the maximum burnup attained by any of these assemblies will be 42,700 MWD /T.
From Reference 2, the correspond-ing DNB penalty for 42,700 MWD /T is 6.2 percent.
An examination of power distributions for Cycle 5 shows that there exists at least 15.3 percent DNB margin for assemblies exceeding 24,000 MWD /T relative to the DNB limits established by other assemblies in the core.
This margin is considerably greater than the Reference 2 reduction penalty of 6.2 percent imposed upon fuel assemblies exceeding 24,000 MWD /T in Cycle 5.
Therefore, no power penalty for fuel rod bowing is required in Cycle 5.
(
Enclosure Page 2 REFERENCES 1.
Letter A. E. Lundvall to R. A. Clark, November 20, 1980, "Fifth Cycle License Application.
Response to NRC Staff Questions."
2.
"Tb: Interim SER on Effects of Fuel Rod Bowing in Thermal Margin Calculations for Light Water Reactors", Rev. 1, February 16, 1977.