ML20205F605

Safety Evaluation Supporting Amend 81 to License DPR-6

ML20205F605
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	11/01/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20205F597	List: ML20205F592 ML20205F600 ML20205F605
References
NUDOCS 8511120322
Download: ML20205F605 (3)

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+ oq[3, ' UNITED STATES 1 [ ), NUCLEAR REGULATORY COMMISSION i

s r. 8 WASHINGTON, D. C. 20655

'+,*....,o SAFETY EVALUATION I Y THE OFFICE OF NUCLFAR REACTOR REGULATION

SUPPORTING AMEl$NEP

T FO. 81 TO FACILITY OPEPAT!!!G LICENSE NO. DPR-6 CONSUMERS POWER COMPANY BIG ROCK POINT PLANT DOCKET NO. 50-155

1.0 INTRODUCTION

Py letter dated August 16, 1985 as revised by letter dated Septerber 24,

! 1985, Censurers Power Company (CPC, the licensee) requested changes to the Big Rock Point (the facility) Technical Specifications (TS) related to i'

the upcorning fuel reloading. Specifically, the changes wculd incorporate' Maximum Average Planar Linear Heat Generation Rate (P/PLHGP) and Pinimum Critical Power Petic (f:CFR) limits for the reload 11 fuel supplied by j Exxon Nuclear Company (ENC) into the facility TS.

Netices of Consideration of Issuance of Amendment to License and Prepcted Fo Sienificant Hazards Consideration Determination and Opportunity fer Heartre refeted to the requested action were published in the Federal Reaf ster on Septertber 11,1985 (50 FR 37078) and on Cctrber 1,1985 (50 FR 40076). P.o public coments or requests for hearing were received.

j 2.0 EVALUATION o >

2.1 PAPLHGR Limits 4

The proposed P)PLHGR limits are based on the loss-of-coolcnt eccident (LOCA) arelysis required by 10 CFR 50.46. In support of this application, the licensen made reference to Exxon reports XN-NF-78-53 erd 7F-FF-79-?I, Revision 1, which describe the LOCA analysis methods presently used for ,

Exxon fuel reloads at Big Rock Point. On the basis of these two reports, the staff previcusly issued Amendment 44 to the Big Rock Point operating license. That arrer.dment revised MAPLHGR limits for gli feel supplied by Exxon te thet reint in time including the Exxon Reload G3/G4 fuel. .

The present reload !! fuel is identical to the previous G3/Gd fuel in all respects, except as described below:

1. In reload II, the fuel has a smaller pellet-to-clad gap than previous fuels, and

2. The funi red is prepressurfred while the previously used fuel rods were non-prepressurized.

' B511120322 B51101 PDR ADOCK 05000155 Y PDR

m These two differences cause an improved heat transfer in the fuel gap, which results in lower stored energy. The MAPLHGR limits maintain the peak cladding temperatures (PCT) less than 2200'F during LOCA. Since the methods used by the licensee to analyze the behavior of the core remain valid for the reload Il fuel and since PCT remain below 2200*F, we conclude that the MAPLHGR limits for the reload Il fuel are acceptable.

Previous safety evaluations for Big Rock Point fuel reloadings described a reduction in the MAPLHGR limits for General Electric fuel for burnups beyond 30,000 MWD /t to account for the effects of enhanced fission gas release.

This limitation was imposed as part of the staff's approval of Amendment 44 for General Electric Type F and Modified Type F fuel. Since none of the GE fuel will reside in the core (i.e., the core now contains only ENC fuel which is covered by ENC analyses), this reduction in the MAPLHGR limits is no longer applicable.

2.2 MCPR Limits The operating limit MCPR is established to protect the fuel from damage during any limiting transient. In the September 24, 1985 submittal, the licensee indicates that the gap conductance increases by about 50% compared with the existing fuel designs. The increase results from the smaller gap distance and prepressurized fuel design for the reload Il fuel. Based on the results of a sensitivity study performed by the licensee, MCPR increases by 0.012 and 0.022 for cases with increases in gap conductance of 25% and 300%, respectively.

The licensee proposes an increase of 0.02 from the existing operating MCPR limit of 1.59 to conservatively account for an increased conductance of 50%

in the reload II fuel.

, The staff has reviewed the proposed operating MCPR limit and has found that the analytical results support the proposed MCPR limit. This new MCPR limit provides sufficient margin for the Ifmiting transient. On this basis, the staff concludes the proposed MCPR limit is acceptable.

2.3 Summary Based on our review of the licensee's proposed TS changes for the reload Il fuel, the staff finds the MAPLHGR and MCPR limits to be acceptable. We also find that the proposed TS changes correctly reflect the analytical results for the proposed MAPLHGR and MCPR limits and, therefore, are acceptable.

3.0 ENVIRONMENTAL CONSIDERATION

This amendment involves a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The staff has detennined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational J

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radiation exposure. The Commission has previcusly issued a proposed finding that this amendment involves no significant hazards censideration and there has been no public comment on such finding. Accordirgly, this anendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or envirenrental assessment need be prepared in connection with the issuarre of this amendment.

4.0 CONCLUSION

, The staff has concluded, based on the consideratior.s discussed above, that: (1) there is reasonable assurance that the Fealth and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 ACKNOWLEDGEMENT This evaluatien was prepared by S. B. Sun and T. S. Potella.

Dated: November 1,1985 4

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