ML17335A382

LER 98-039-01 Re EOP Step Conflicts with Small Break LOCA Analysis.Ler 98-039-00 Has Been Canceled.With 981208 Ltr

ML17335A382
Person / Time
Site:	Cook
Issue date:	12/08/1998
From:	Sampson J, Weber L INDIANA MICHIGAN POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-98-039, LER-98-39, NUDOCS 9812140132
Download: ML17335A382 (5)

Text

~ CA.TE GORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RZDS)

ACCESSION NBR:9812140132 DOC.DATE: 98/12/08 NOTARIZED: NO DOCKET FACIL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana M 05000315 AUTH. NAME AUTHOR AFFILIATION WEBER,L. Indiana Michigan Power Co.

SAMPSON,'J.R. Indiana Michigan Power Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 98-039-01 re EOP step conflicts with small break LOCA analysis.LER 98-039-00 has been canceled. With 981208 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

J SIZE:

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-3 PD 1 1 STANG,J 1 1 INTERNAL: AEOD D RAB 2' AEOD/SPD/RRAB 1 1 FILE CE 1 1 NRR/DE/ECGB 1 1 NRR DE EELB 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 LITCO BRYCE,J H 1 1' NOAC POORE,W. 1 1 NOAC QUEENER,DS 1 D 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 CONTROZ DESK (DCD) ON EXTENSION 415-2083 FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 22 ENCL 22

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616 INDIANA NICHIGAN IaOWKR December 8, 1998 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 LER 315/98-039-01, "Retraction Emergency Operation Procedure Step Conflicts with Small Break LOCA Analysis".

No commitments were identified in this document.

Sincerely, J. R. Sampson Site Vice President Imbd Attachment J. 'L. Caldwell (Acting), Region III R. P. Powers P. A. Barrett J. B. Kingseed R. - Whale D. Hahn Records Center, INPONRC Resident Inspector 9812140132 981208 PDR ADQCK 05000315 S PDR

NRC,Form 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OM8 NO. 31604104 EXPIRES 06/30/2001 (6-1998)

KSTSIATKD BURDEN PKR RESPONSE TO COMPLY WITH TIBS MANDATORY INFORMATlONCOLLKCTCN RKOLJKST'. $ 0.0 HRS. REPORTED LESSONS LEARNED ARE NCORPORATKO erTO THK LJCKNSLNO PROCESS ANO FKO BACK TO INOLJSTRY.

LICENSEE EVENT REPORT (LER)

(See.reverse for required number of COMMISSION. WASH)NOTCH. DC 2055%001, ANO TO THK P~

FCRWARO COMMENTS RKCAROLNO BLIOKN KSTSIATK TO THK ~ORMATION ANO RECORDS IMNACKMKNT BRANCH IT4 FS)). U.S. NUCLEAR RKGLAATORY RKOLJCTNtr PROJECT L5)5001LH). OFFlCK OF IlAWCKMKNT ANO BLJOCKT, WAS)eNOTOJL OC digits/characters for each block)

FACIUTYNAME II) DOCKET NUMBER (2) PAGE P)

Cook Nuclear Plant Unit 1 05000-315 1 of 2 TITLE<<)

Retraction - Emergency Operating Procedure Step Conflicts with Small Break LOCA Analysis EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

A ILI NAM NUMB SEQUENTIAL REVISION MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY Cook Unit 2 05000-316 A ILI D NUM 08 24 1998 1998 039 01 12 08 1998 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR g: (Check one or more) (11)

MODE (9) 20.2201 (b) 20.2203(a)(2)(v) 5o.73(a)(2)(i) 50.73(a)(2)(viii)

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

LEVEL (10) 00 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50.73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50.73(a)(2)(iv) OTHER O'P~P~F%"k~ 'ti45 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(v)

'N E 623 J ( '~8 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii)

SPeoify h Abelracl be)orr or nNRCForllr 368A LICENSEE CONTACT FOR THIS LER (12)

TELEPHONE NUMBER (B)etude Area Code)

Mr. Larry Weber, Operations Manager 616/465-5901 X2443 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 YES X SUBMISSION (IfYes, complete EXPECTED SUBMISSION DATE NO DATE 15 Abstract (Limit to 1400 spaces, l.e., approximately 15 single-spaced typewritten lines) (16)

On August 24, 1998, with both units in Cold Shutdown, a review of the current revision of Emergency Operating Procedure (EOP), "Transfer to Cold Leg Recirculation," identified a step that did not appear to satisfy an assumption in the Westinghouse Small Break Loss of Coolant Accident (SBLOCA) analysis at the point in time when high head safety injection (Sl) pump flow would be delivered to the reactor coolant system (RCS). The EOP step required the Sl pumps to be turned off if RCS pressure exceeded 1250 psig (1000 psig for adverse containment condition) after isolation of the pump minimum flow line returning SI pump flow to the refueling water storage tank (RWST). The Sl pumps would be turned off to prevent pump damage due to inadequate pump minimum flow. This would leave only the centrifugal charging pumps injecting to the RCS during a SBLOCA with high RCS pressure. The Westinghouse analysis assumes SI pump injection to the RCS whenever RCS pressure is less than 1350 psig. When RCS pressure instrument uncertainty was applied, the EOP step to terminate Sl was considered capable of placing the plant in a condition outside of the safety analysis during a SBLOCA that allowed RCS pressure to remain high but less than 1350 psig. An ENS notification was made on August 24, 1998, at 1705 hours0.0197 days <br />0.474 hours <br />0.00282 weeks <br />6.487525e-4 months <br /> EDT in accordance with 10CFR50.72(b)(2)(i). An interim LER was submitted on September 22, 1998, in accordance with 10CFR50.73(a)(2)(ii).

Operations provided Westinghouse with details of the use of the EOP step and requested an analysis of the significance of the condition. On November 4, 1998, Westinghouse provided an assessment based on its analysis. Our review of the assessment confirmed that by use of the EOPs the plant would not have been placed in a condition where the Sl pump termination criterion would have been reached. Therefore, the plant was within its analyzed basis, and LER 315/98-039-00 is being retracted.

NRC FORM 366 (6-1998)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (6-1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITYNAME (1) DOCKET NUMBER(2) LER NUMBER (6) PAGE (3)

YEAR SEQUENTIAL REVISION Cook Nuclear Plant Unit 1 05000-315 NUMBER NUMBER 2of2 1998 039 01 TEXT (lfmoro speceis required, use eddiiional copies or NRC Form (366A) (17)

On August 24, 1998, with both units in Cold Shutdown, a review of the current revision, Revision 5, of Emergency Operating Procedure (EOP) 01/02-OHP 4023.ES-1.3, "Transfer to Cold Leg Recirculation," identified a step that did not appear to satisfy an assumption in the Westinghouse Small Break Loss of Coolant Accident (SBLOCA) analysis at the time when high head safety injection (Sl) pump flow would be delivered to the reactor coolant system (RCS). The EOP step required the Sl pumps to be turned off if RCS pressure exceeded 1250 pounds per square inch gage (psig), 1000 psig for adverse containment conditions, after isolation of the pump minimum flow line returning Sl pump flow to the refueling water storage tank (RWST). The Sl pumps would be turned off to prevent pump damage due to inadequate pump minimum flow.

The normal minimum flow path to the RWST cannot be used during a LOCA because it is undesirable to pump radioactively contaminated water from the containment sump to the RWST. Therefore, prior to switching SI pump suction from the RWST to the containment sump, as directed by the EOP, the Sl pump minimum flow lines to the RWST would be isolated. The Sl pumps would then have to rely on RCS injection flow to satisfy the requirement for adequate pump minimum flow of approximately 70 gallons per minute. This flow rate is determined by actual RCS pressure and the physical characteristics of the pumps.

Indicated RCS pressure was chosen as the procedural criterion for operators to determine if the Sl pumps needed to be stopped. Earlier revisions of the procedure had directed the pumps to be stopped at various indicated RCS pressures between 1000 psig and 1630 psig. Some revisions of the procedure also used indicated low Sl flow to direct stopping the pumps. Due to instrument uncertainty the indicated values could have represented higher or lower actual values. During a SBLOCA, pressure in containment could be high enough to have an adverse effect on RCS pressure instruments. In such an adverse containment condition, instrument uncertainty could be greater.

Turning off the high head Sl pumps would leave only the centrifugal charging pumps injecting to the RCS during a SBLOCA with persistent high RCS pressure. The Westinghouse SBLOCA analysis assumes high head Sl pump injection to the RCS whenever RCS pressure is less than approximately 1350 psig during a SBLOCA. When instrument uncertainty was applied, the EOP step to terminate high head Sl was considered capable of placing the plant in a condition outside of the safety analysis during a SBLOCA that allowed RCS pressure to remain high, but less than 1350 psig. An ENS notification was made on August 24, 1998, at 1705 hours0.0197 days <br />0.474 hours <br />0.00282 weeks <br />6.487525e-4 months <br /> EDT in accordance with 10CFR50.72(b)(2)(i). An interim LER was submitted on September 22, 1998, in accordance with 10CFR50.73 (a)(2)(ii).

Operations provided Westinghouse with details on the use of the EOP step and requested an analysis of the significance of the condition. On November 4, 1998, Westinghouse provided its assessment of the condition based on its analysis.

The Westinghouse assessment examines whether a design basis SBLOCA for the Cook Nuclear Plant would lead to conditions required by the various revisions of the procedure for Sl termination. To assess the conditions that could be presented by control room indications following a postulated SBLOCA, design basis simulations using the MAAP4 computer code were used. The effects of plant specific uncertainties were included in the assessment. A range of SBLOCA sizes, down to very small breaks that would result in RCS repressurization, was considered. The potential for operation without Sl flow, with RCS pressures as low as 835 pounds per square inch absolute, was considered. This.

represents the lowest adverse containment RCS pressure when instrument error is considered, without the error due to excess radiation exposure. Excess radiation was not an expected condition. The assessment concludes that no design basis SBLOCA, requiring one or more Sl pumps, would be deprived of flow as a result of a SBLOCA. The conclusion is cited as applicable for all past operation and also as applying to a proposed future revision of the EOP which would call for stopping the SI pumps when the indicated RCS pressure is 1250 psig (1200 psig for adverse containment). Therefore, the

'plant was within its analyzed condition of operation, and LER 315/98-039-00 is being retracted.

NRC FORM 366A (6-1998)