05000315/LER-1998-015, :on 980312,ice Weight Requirements Potentially Were Not Met Due to Nonconservative Assumption in Software Program.Update to Interim LER Will Be Issued by 980513

:on 980312,ice Weight Requirements Potentially Were Not Met Due to Nonconservative Assumption in Software Program.Update to Interim LER Will Be Issued by 980513

ML17334B730
Person / Time
Site:	Cook
Issue date:	04/13/1998
From:	Sampson J, Schoepf P INDIANA MICHIGAN POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-98-015, LER-98-15, NUDOCS 9804200534
Download: ML17334B730 (5)

LER-1998-015, on 980312,ice Weight Requirements Potentially Were Not Met Due to Nonconservative Assumption in Software Program.Update to Interim LER Will Be Issued by 980513

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(s)(2) 10 CFR 50.73(a)(2)(x)
3151998015R00 - NRC Website

text

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CATEGORY 1 REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9804200534 DOC.DATE: 98/04/13 NOTARIZED: NO DOCKET ¹ FACIL:$0-315 Donald C.

Cook Nuclear Power Plant, Unit 1, Indiana M

05000315 AUTH.NAME AUTHOR AFFILIATION SCHOEPF,P.

Indiana Michigan Po~er Co.

SAMPSON,J.R.

Indiana Michigan Power Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 98-015-00:on 980312,ice weight requirements potentially were not met due to nonconservative assumption in software program. Update to interim LER will be issued by 980513.

W/980413 ltr.

DISTRIBUTION CODE:

IE22T COPIES RECEIVED:LTR I

ENCL

(

SIZE:

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

NOTES:

INTERNAL:

RECIPIENT ID CODE/NAME PD3-3 PD B

ILE CENTER NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN3 FILE 01 COPIES LTTR ENCL 1

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1 RECZPZENT ID CODE/NAME STANG, J AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HZCB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DET/EIB COPIES LTTR ENCL 1

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D EXTERNAL: L ST LOBBY WARD NOAC POORE,W.

NRC PDR 1

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1 LITCO BRYCE, J H NOAC QUEENER,DS NUDOCS FULL TXT 1

1 1

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1 0

E N

NOTE,TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRZBUTION LISTS OR REDUCE THE NUMBER OF COPZES 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 24 ENCL 24

indiana Michigan Power Company Cock Mriear Peer Cce Cook Piace Bnrrgman, MI49l06 INOIANA NICHIGAN IaOH%R April 13, 1998 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Operating Licenses DPR-58 Docket No. 50-315 Document Control Manager:

In accordance with the criteria established by 10 CFR 50.73 entitled WHISRSQK 98-015-00 Sincerely, J. R. Sampson Site Vice President Imbd Attachment A. B.

Beach, Region III E. E.

Fitzpatrick P. A.

Barrett S. J.

Brewer R.

Whale D.

Kahn Records Center, INPO NRC Resident Inspector

'rr804200534 980413 PDR ADOCK 050003i5 S

PDR

0

NRC FORH 366 (5.92)

.S.

HUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

ROVED BY OMB No. 3150.0104 ExPIREs 5/31/95 ESTIMATED BURDEN PER

RESPONSE

TO COMPLY MITH THI INFORMATION COLLECTIOH REOUEST t 50.0 HRS.

FORNAR COMMENTS REGARDING BURDEN ESTIMATE TO TH IHFORMATION AND RECORDS MANAGEMENT BRANCH (MNB 7714),

U.S.

NUCLEAR REGULATORY COHHISSION, NASHINGTOHg DC 20555 0001 'ND TO THE PAPERNOR REDUCTION PROJECT (3150 0104),

OFFICE 0

HANAGEHENT AND BUDGEt IIASHINGTOH DC 20503.

FACTLltY NAME (1)

Donald C. Cook Nudesr Plant - Unit 1 DOCKET NUMBER (2) 50-315 Page 1 of 1 TITLE (4)

Ice Weight Requirements Potentially Not Met Due to Nonconservative Assumption In Software Program MONTH DAY YEAR YEAR EVEN'I DATE 5

LER NUMBER 6

SEOUEHTIAL NUMBER REVISION NUMBER REPORT DATE 7

MONTH DAY OTHER FACILITIES INVOLVED 8

FACILITY NAHE YEAR Cook - Unit 2 DOCKET NUHBER 50-316 03 12 98 98 015 00 04 13 FACILITY NAME DOCKET NUHBER OPERATING MODE (9)

PONER LEVEL (10) 0 TH S REPORT IS SUBMITTED PURSUANT 20.2201(b) 20.2203 0

1 20.2203(a)(2)(I) 50.73(a)(2)(iii) 5073 s

2 iv 20.2203(s)(3)(I) 20.2203 s 3 ii 50.73(a)(2)(v) 20.2203(o)(4)

To THE REOUIREMENTS OF 10 CFR Check one or mo e 11 73.71(b) 73.71o OTHER 20.2203 s

2 ii 20.2203(a)(2)(ii I>

20.2203(s)(2)( Iv) 20.2203(a)(2)(v)

X 50.36 c 1

50.36(c)(2) 50.73(a)(2)(I>

50.73(a)(2)(ii) 50.73 s 2 vii 50.73(s)(2)(vlii)(A) 50'3(a)(2)(vi Ii)(B) 50.73(a)(2)(x)

(Specify in Abstract below and in Text,LICENSEE CONTACT FOR THIS LER 12 HAHE

, Mr. Paul Schoepf, Safety Related Mechanical Engineering Superintendent TELEPHONE NUHBER (Include Ares Code) 616/465-5901, x2408 COMP ETE ONE LINE FOR EACH COMPONENT FA LURE DESCR HIS REPORT IBED IN T

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE To NPRDS

CAUSE

SYSTEH COMPONENT MANUFAC'TURER REPORTABLE To NPRDS SUPPLEMENTAL REPORT EXPECTED 14 X YEs (If yes, complete EXPECTED SUBMISSIOH DAlE).

No EXPECTED SUBH IS SION DATE (15)

MONTH DAY YEAR 05 13 98 ABSTRACT (Limit to 1400 spaces, I.e., spproximstcty 15 single-spaced typewritten lines) (16)

On March 12, 1998, an ENS notification was made in accordance with 10CFR50.72(b)(2)(l), for a condition found while the reactor was shutdovm, which, ifit had been found during operation, may have resulted in the plant being in an unanalyzed condition. The ice condenser consists of 24 bays, each of which contain 81 ice baskets for a total of 1,944 ice baskets per unit.

Technical Specifications in effect duri(ig operation required that the ice condenser be divided into three groups ofbaskets and that the average ice weight of baskets from radial rows 1, 2, 4, 6, 8, and 9 in each group contain at least 1220 Ibs/basket at a 95 percent confidence level. The weight requirement was subsequently raised to 1333 Ibs/basket during the current outage.

Compliance with the Technical Specifications (T/S) is demonstrated by use of an in-house soibvare package, NSLICE2, to perform a statistical analysis of ice basket weight samples.

The NSLICE2 program performs a pre-processing step which rejects weights less than 800 pounds as invalid data.

It has been learned that this pre-processing step was not understood by plant staff using the program, and this resulted in some light ice basket data not being Included in the NSLICE2 statistical analysis.

A preliminary evaluation was performed to determine the effect the low weight data points would have had on the previous statistical analysis results. The evaluation indicates that the T/S row group minimum ice weight limitmay have been violated with respect to the 95% confidence requirement.

This appears to have been made possible by the combination of the NSLICE2 pre-processing step and performance of non-representative ice basket weight sampling as described in LER 315/98-007-00.

The investigation into this event continues, along evaluation of the significance of the low basket weights with regard to ice maldistribution analyses.

An update to this interim LER willbe issued by May 13, 1998.