ML20071P892
| ML20071P892 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/27/1982 |
| From: | Lippold W BALTIMORE GAS & ELECTRIC CO. |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8212290122 | |
| Download: ML20071P892 (2) | |
Text
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4-B ALTIMORE G AS AND ELECTRIC COMPANY P.O. BO X 14 7 5 B A LTI M O R E*.
M A R YL A N D 21203 LvERT CL FFS NUCLEAR power PL ANT LUSBY, M ARYLAND 20657 December 27,1982 Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 ATTENTION: MR. R. A. Clark, Chief Operating Reactors Branch #3 Division of Licensing
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit 2, Docket No. 50-318, DPR-69 Response to NRC Question on l
Application of FATES 3 to Cycle 5 Gentlemen:
NRC staff posed a verbal question relative to the impact of an NRC imposed restriction to the FATES 3 grain size on the Cycle 5 operating limits. The attachment is a response to that question.
Should you have any questions, please contact us.
Very truly yours, I
W. J. Lippold Nuclear Fuel Management WJL:fld Attachment ec: J. A. Biddison, Esquire yf G. F. Trowbridge, Esquire D.11. Jaffe - N RC R. R. Mills - CE R. E. Architzel-NRC/CC 0212290122 821227 PDR ADOOK 05000318 P
\\
December 22,1982 ATI'ACHMENT Impact of NRC Imposed FATES 3 Grain Size Restriction on Calvert Cliffs 2 Cycle 5 Operating Limits A burnup dependent restriction on UO2 grain size for use in the FATES 3 (CEN-161) fission gas release model has been assessed with respect to its impact on FATES 3 results and the FATES 3 dependent safety analyses of Calvert Cliffs 2 Cycle 5. The purpose of this assessment was only to determine the validity of the as-submitted operationallimits of Unit 2 Cycle 5 with the restriction imposed. The restriction is stated as follows:
G gg MIN Ginit, MAX (1.0, G )
=
e b
where G
=
effective grain size to be used for the analysis of st*e dy-state fission gas release and as the starting point for transient grain-boundary-sweeping calculations, um Ginit the initial as-fabricated (design) grain size, um
=
G 15.0 1.0 - B/55.0
=
b and where Gb burnup dependent grain size limit, um
=
B local burnup, GWD/MTU
=
MIN
=
minimum function i
MAX maximum function
=
The restriction was incorporated into FATES 3 and an evaluation performed for the Calvert Cliffs 2 Cycle 5 reload. Results show that the only change in Unit 2 Cycle 5 of any significance is that the end-of-cycle fission gas release and rod internal gas pressure is increased in the lead burnup rod (a maximum of 40.0 GWD/MTU rod average and 44.0 GWD/MTU local burnup). However, the maximum internal pressure remains below the nominal reactor coolant system pressure throughout Cycle 5. Further, the higher end-of-cycle fission gas release and internal gas pressure was evaluated for its impact on the FATES 3 dependent safety analyses and found to have either no impact or to be ron-limiting. The established as-submitted operating limits for Calvert Cliffs 2 Cycle 5, therefore, remain valid.
WJL:fld i
i
,