ML18016A951

Submits Info Re Estimated Effect of Change to ECCS Evaluation Model,As Required by 10CFR50.46

ML18016A951
Person / Time
Site:	Harris
Issue date:	05/13/1999
From:	Alexander D CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HNP-99-088, HNP-99-88, NUDOCS 9905190300
Download: ML18016A951 (3)

Text

CATEGORY REGULAT ICY INFORMATION DISTRIBUTIOh YSTEM (RIDS)

ACCESSION NBR:9905190300 DOC.DATE: 99/05/13 NOTARIZED: NO DOCKET FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTH.NAME AUTHOR AFFILIATION ALEXANDER,D.B. Carolina Power 6 Light Co.

RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control Desk)

SUBJECT:

Submits info re estimated effect of change to ECCS evaluation model, as required by 10CFR50.46.

DISTRIBUTION CODE: AOOID TITLE: OR COPIES RECEIVED:LTR Submittal: General Distribution I ENCL 0 SIZE:

T NOTES:Application for permit renewal filed. 05000400 E

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL LPD2-2 LA LPD2-2 PD 0 LAUFER,R.

INTERNAL: ACRS 1 P- E C E~RO 1 NRR/DE/EMCB 1 RR DE/EMEB 1 NRR/DSSA/SPLB 1 NRR/DSSA/SRXB 1 NRR/SPSB JUNG,I 1 NUDOCS-ABSTRACT 1 OGC/RP 1 EXTERNAL: NOAC NRC PDR D

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NOTE TO ALL "RIDS" RECZPIENTS:

PLEASE HELP US TO REDUCE WASTE.'TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPZES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED: LTTR 14 ENCL

Carolina Power & Ught Company Harris Nuclear Plant P.O. Box 165 New Hill NC 27562 SERIAL: HNP-99-088 MAY 13 1999 10 CFR 50.46 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 EMERGENCY CORE COOLING SYSTEM EVALUATIONCHANGES

Dear Sir or Madam:

This letter submits information required by 10 CFR 50A6 for Carolina Power & Light Company's (CP&L's) Harris Nuclear Plant (HNP), regarding the estimated effect of a change to the Emergency Core Cooling System (ECCS) evaluation model. The model change results in a reduction of the fuel Peak Clad Temperature (PCT) for the Small Break Loss of Coolant Accident (SBLOCA) analysis by an amount greater than 50 'F. Thus, this letter fulfillsthe requirement for a 30-day report in accordance with 10 CFR 50.46(a)(3)(ii).

The HNP ECCS performance following a SBLOCA is calculated by HNP's fuel vendor, Siemens Power Corporation (SPC), using the EXEM PWR Small Break LOCA Model for SBLOCAs. By letter dated April 20, 1999, SPC provided information to CP&L regarding a core nodalization non-convergence problem. The resulting model change to correct this problem was estimated by SPC to reduce the HNP SBLOCA PCT by approximately 158 'F.

The previous SBLOCA PCT reported for HNP was 1986 'F, as documented by letter dated October 1, 1998 to the NRC. Since that time, there have been two additional minor changes to the SBLOCA PCT. These changes were an increase of 2'F and a decrease of 3 'F, reported to CP&L by SPC letters dated April 14, 1999 and April 15, 1999, respectively. The cumulative impact of the 158 'F and 3 'F reductions, and the 2 'F increase, is a SBLOCA PCT decrease of 159 'F . Since this cumulative impact on PCT is in the conservative direction, HNP will not incorporate the changes into the existing PCT value at this time. Therefore, the SBLOCA PCT for HNP will remain as 1986 'F. Because this PCT value is less than 2200'F for the SBLOCA analysis, HNP remains in compliance with the requirements specified in 10 CFR 50.46(b).

9905i90300 9905iS PDR ADOCK 05000400 P PDR 5413 Shearon Harris Road New Hill NC

Document Control Desk SERIAL: HNP-99-088 Page 2 Questions regarding this matter may be referred to Mr. J. H. Eads at (919) 362-2646.

Sincerely, D. B. Alexander Manager, Regulatory Affairs Harris Plant AEC c: Mr. J. B. Brady (NRC Senior Resident Inspector, HNP)

Mr. L. A. Reyes (NRC Regional Administrator, Region II)

Mr. R. J. Laufer (NRR Project Manager, HNP)