ML17335A469

LER 98-056-00:on 981211,hot Leg Nozzle Gaps Resulted in Plant Being in Unanalyzed Condition.Analyses Are Being Performed by W to Resolve Problem.Updated LER Will Be Submitted by 990211.With 990106 Ltr

ML17335A469
Person / Time
Site:	Cook
Issue date:	01/06/1999
From:	Brassart G, Sampson J INDIANA MICHIGAN POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-98-056, LER-98-56, NUDOCS 9901130007
Download: ML17335A469 (5)

Text

CATEGORY 1 4 REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9901130007 DOC.DATE: 99/01/06 NOTARIZED: NO DOCKET FACIL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana M 05000315 AUTH.NAME BRASSART,G:A.

'UTHOR AFFILIATION Indiana Michigan Power Co.

SAMPSON,J.R. Indiana Michigan Power Co.

RECZP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 98-056-00:on 981211,hot leg nozzle gaps resulted in plant in being in unanalyzed condition. Analyses are being performed by W to resolve problem. Updated LER will be submitted by 990211.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT C COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL

'PD3-3 PD 1 1 STANG', J 1 1 INTERNAL: .S RAB 2 2 AEOD/SPD/RRAB 1 1 ILE CENTER 1 1 NRR/DE/ECGB 1 1

/EE 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOHB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 RES/DET/EIB 1 1 RGN3 FILE 01 1 1 EXTERNAL: L ST LOBBY WARD 1 1 LZTCO BRYCE,J H 1 1 0 NOAC POORE,W. 1 1 NOAC QUEENER,DS 1 1 NRC PDR 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED- LTTR 22 ENCL 22

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616465 5901 INDIANA NlOIIOiAN Pal/IRR January 6, 1999 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Operating License DPR-58 Docket No. 50-315 Document Control Manager:

In accordance with the criteria established by 10 CFR 50.73 entitled Licensee Event fll i i i ~

LER 315/98-056-00, "Interim LER Hot Leg Nozzle Gaps".

No commitments were identified in this submittal.

Sincerely, J. R. Sampson Site Vice President

/mbd Attachment J. L. Caldwell (Acting), Region III R. P. Powers P. A. Barrett D. F. Kunsemiller R. Whale D. Hahn Records Center, INPO NRC Resident Inspector 9eosisooov WVOiOe, PDR ADQCK 050003i5 8 PDR

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Pvrm 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED 8Y OM8 NO. 31504104 EXPIRES 06/30/2001 (6-1998) ESTSIATEO BURDEN PKR RESPONSE TO COMPLY WIIH TISS MAINATORY INFORMAT)ON COLLECTK)N REQUEST: 50.0 HRS. REPORTED lESSONS lEARNED ARE WCORPORATEO Brro THE LICENSWO PROCESS AIE) FED BACK TO IIE)USTRY, LICENSEE EVENT REPORT (LER) FORWARD CCIMKNTS RECARcrNO BURDOI ESTSIATE TO THE PP'ORMATION Are)

REcoRD$ MANAGEMENT BRANcH Iro F55L IAB. NUclEAR RKOIAATDRY COMISSSION, WASHINOTON. DC 20$ 5$ ocot. AM) TO THE PAPERWORK RKDUCTION PROJECT ISI500IOI). OFFCE OF MANAGEMENT ANO BUDGET, WASICNCTOIL DC

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(See reverse for required number of 20505 digits/characters for each block)

FACIUTYNAME I1) DOCKET NUMBER IE) PAGE IS)

Cook Nuclear Plant Unit 1 05000-315 1 of1 TITLE IS)

Interim LER - Hot Leg Nozzle Gaps EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

I SEQUENTIAL REVISION DC Cook- Unit 2 05000-316 MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY YEAR 12 11 1998 1998 056 00 01 06 1999 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR Ii: (Check one or moro) (11)

MODE (9) 20.2201 (b) 20.2203(a)(2)(v) M.73(a)(2)(i) 50.73(a)(2)(viii)

POWER 20.2203(a)(1) 20.2203(a)(3)(l) 50.73(a)(2)(ii) 50.73(a)(2)(x)

LEVEL (10) 00 20.2203(a)(3)(il) 50.73(a)(2)(iii) 73.71 20.2203(a)(2)(l) 20.2203(a)(2)(ii) 20.2203(a)(4) 50.73(a)(2)(iv) OTHER 20.2203(a)(2)(ill) 50.36(c)(1) 50.73(a)(2)(v)

Speci/r tn Abttrect be)INr 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii) or nNRCForm366A UCENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (Indude Ares Code)

Mr. Gary A. Brassart- Nuclear Safety and Analysis Acting Supervisor 616497-5631 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

REPORTABLE REPORTABLE TO CAUSE SYSTEM COMPONENT MANUFACTURER TO EPIX CAUSE SYSTEM COMPONENT MANUFACTURER EPIX SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED MONTH DAY X YES SUBMISSION 02 11 1999 If Yes, corn lete EXPECTED SUBMISSION DATE DATE 15 Abstract (Limitto 1400 spaces, I.e. approximately 15 single-spaced typewritten lines) (16)

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On October 23, 1998, the Westinghouse Owners Group (WOG) withdrew from consideration by the Staff WCAP-14486, "ECCS Hot Leg Recirculation Elimination for Westinghouse 3 and 4 Loop Design NSSS". The WCAP included analyses which showed that criticality would not occur on switchover to hot leg recirculation if credit was taken for the flow path of borated liquid through the reactor vessel hot leg nozzle gap. Recriticality resulting from switchover to hot recirculation was identified by Westinghouse during a review of the hot leg switchover methodology in the 1993 time frame, therefore analysis of recriticality on hot leg switchover was not part of the original Cook Plant license basis. During the fall of 1997 it was identified that issues regarding the Cook sump design would impact the existing hot Ieg switchover criticality calculation. The loss of margin that resulted from the partitioning of fluid between the active and inactive sump volumes was offset by taking credit for the WOG hot Ieg nozzle gap analysis. After the withdrawal of WCAP-14486, Westinghouse undertook studies to assess whether subcriticality on switchover to hot leg recirculation could be assured without taking credit for the hot leg nozzle gap. A successful result has been obtained for Unit 1 for the current fuel cycle by taking credit for existing bumup. However, an acceptable analysis for Unit 2 (or Unit 1 with a fresh core) is not available. As such, this condition was reported on December 11, 1998 under 10CFR50.72(b)(2)(i), a condition which was found while the reactor was shutdown, which had it been found while the reactor was operating, would have resulted in the nuclear power plant being in an unanalyzed condition. This LER is therefore submitted in accordance with 10 CFR 50.73(a)(2)(ii)(A) for an unanalyzed condition.

Analyses are currently being performed by Westinghouse to resolve this problem. A root cause investigation is underway, and is expected to be complete by January 28, 1999. An update to this interim LER will be submitted by February 11, 1999.

NRC FORM 366 (6-1998)