1CAN058304, Discusses 830315 Commitment to Provide Results of B&W Supplemental ECCS Calculations Addressing Impact of Cladding Models Presented in NUREG-0630, Results of Bounding Analysis. Revised NUREG-0630 Being Prepared by B&W

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Discusses 830315 Commitment to Provide Results of B&W Supplemental ECCS Calculations Addressing Impact of Cladding Models Presented in NUREG-0630, Results of Bounding Analysis. Revised NUREG-0630 Being Prepared by B&W
ML20071G822
Person / Time
Site: Arkansas Nuclear Entergy icon.png
Issue date: 05/18/1983
From: John Marshall
ARKANSAS POWER & LIGHT CO.
To: Stolz J
Office of Nuclear Reactor Regulation
References
RTR-NUREG-0630, RTR-NUREG-630 1CAN058304, 1CAN58304, NUDOCS 8305240399
Download: ML20071G822 (2)


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a ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK. ARKANSAS 72203 (501) 371-4000 May 18, 1983 1CAN058304 Director of Nuclear Reactor Regulation ATTN: Mr. J. F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing U. S. Nuclear Regulatory Commission Washington, DC 20555

SUBJECT:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 NUREG 0630 - Results of Bounding Analysis Gentlemen:

By our letter dated March 15, 1983 (1CAN038305), AP&L committed to provide the results of B&W's supplemental emergency core cooling system calculations to address the impact of the cladding models presented by the NRC staff in NUREG 0630. Our letter indicated that problems identified during our review of the previous B&W report needed to be resolved, and also stated that B&W had experienced inconsistencies with the results from a NUREG 0630 analysis of another plant which could affect the validity of the AN0-1 analysis.

These matters have been reviewed by AP&L and discussed with the B&W Owners Group. B&W has verified the validity of the AN0 NUREG 0630 analysis by performing hand calculations to confirm the computer code analysis results.

In addition, B&W has now completed the revision of the bounding analysis report. The report indicates that the bounding analysis assessment, performed without compensating models, resulted in a 0.5 kw/ft. penalty at the 2 ft. elevation for the LOCA kw/ft. limits. This limit was also assigned to the 4 ft. and 6 ft. elevations.

AP&L has no plans for implementation of these penalties at the present time. We do not feel such penalties are appropriate for the following reasons. Firrt, the NUREG 0630 models may be overly conservative. It is  ;

our understanding that this matter is scheduled for discussions before the l ACRS in the near future. Secondly, as you are aware, impending changes are being considered to Appendix K of 10CFR50 that could have beneficial impact on kw/ft limits. Third, the NRC has suggested that compensating models may be allowed in assessing the NUREG 0630 impact. ,

CDI 8305240399 830518 DR ADOCK 05000155 PDR MEMBEA MIDDLE SOUTH UTIUTIES SYSTEM

e-Mr. J. F. Stolz May 18,* 1983 o

AP&L has directed B&W to proceed with an assessment of one such compensating model, the use of the "FLECHT-SEASET" heat transfer correlation. B&W has recently completed the analysis which demonstrates that a 0.5 kw/ft increase in LOCA limits is justified at the 2 ft. and 4 ft. core elevations. The NUREG 0630 related penalty at the 6 ft. elevation would not affect the operating Technical Specification limits. Based on the results of the .

bounding analysis and the compensating model, the NUREG 0630 data will have no net effect. B&W is now preparing a revised NUREG 0630 report which will incorporate the results of the FLECHT-SEASET work. We expect to receive the report shortly, and will submit a copy for your review at that time.

Very truly yours,

(./ S f John R. Marsha Manager, Licensing JRM:CT:s1 4

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