05000315/LER-1998-026, :on 980430,TS SR 4.6.5.1.b.2 Was Not Met.Caused by Failure to Accurately Transfer SR Into Plant Procedures. Software Used to Support Ice Condenser Surveillance Program Will Either Be Revised or Replaced

:on 980430,TS SR 4.6.5.1.b.2 Was Not Met.Caused by Failure to Accurately Transfer SR Into Plant Procedures. Software Used to Support Ice Condenser Surveillance Program Will Either Be Revised or Replaced

ML17334A726
Person / Time
Site:	Cook
Issue date:	06/01/1998
From:	Sampson J, Schoepf P AMERICAN ELECTRIC POWER CO., INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-98-026, LER-98-26, NUDOCS 9806100099
Download: ML17334A726 (9)

LER-1998-026, on 980430,TS SR 4.6.5.1.b.2 Was Not Met.Caused by Failure to Accurately Transfer SR Into Plant Procedures. Software Used to Support Ice Condenser Surveillance Program Will Either Be Revised or Replaced

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(1) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(x)
3151998026R00 - NRC Website

text

CATEGORY 3y REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9806100099 DOC.DATE: 98/06/01 NOTARIZED: NO DOCKET FACIL:50-315 Donald C.

Cook Nuclear Power Plant, Unit 1, Indiana M

05000315 AUTH.NAME, AUTHOR AFFILIATION SCHOEPF, P.

American Electric Power Co., Inc.

SAMPSON,J.R.

American Electric Power Co., Inc.

RECIP.NAME RECIPIENT AFFXLIATXON

SUBJECT:

LER 98-026-00:on 980430,TS SR 4.6.5.1.b.2 was not met.Caused by failure to accurately transfer SR into plant procedures.

Software used to support ice condenser surveillance program will either be revised or replaced.W/980601 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL'IZE:

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

NOTES:

E RECIPIENT ID CODE/NAME PD3-3 PD INTERNAL:

i~+/~

NRR/DE/EELB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRZB RGN3 FILE 01 EXTERNAL: L ST LOBBY WARD NOAC POORE,W.

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1 RECIPIENT ID CODE/NAME STANG, J AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DET/EIB LXTCO BRYCE,J H NOAC QUEENER,DS NUDOCS FULL TXT COPIES LTTR ENCL 1

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NOTE TO ALL.nRZDSsi 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 COPXES REQUIRED: LTTR 24 ENCL 24

American Electrfc~

. Cook Nuclear Plant.+

One Cook Place Bndgman, Ml49106 6164655901 AMERICAN

'ELECTRIC POWER June 1, 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 HEBKLBJ 1

f I

i g p

b 1

d:

98-026-00 P

Sincerely, J. R. Sampson Site Vice President

/mbd Attachment C. J.

Paperiello (Acting), Region III R.

Sampson P. A.

Barrett S. J.

Brewer R.

Whale D.

Hahn Records Center, INPO NRC Resident,Inspector 980bi00099 980bOi PDR ADOCK 050003f5 8

PDR

HRC FORH 366 (5-92)

U.S.

NUCLEAR REGULATORY COMHISSION LICENSEE EVENT REPORT (LER)

APPROVED BY OMB NO. 3150-0104 EXP IRES 5/31/95 ESTIMATED BURDEN PER

RESPONSE

TO COMPLY IIITH THI INFORHATION COLLECTION REQUEST: 50.0 HRS.

FORIIAR COMMENTS REGARDING BURDEN ESTIHATE TO TH INFORMATION AND RECORDS MANAGEHENT BRANCH (MNB 7714),

U.S.

NUCLEAR.

REGULATORY COHMISSION, LIASHINGTON, DC 20555-0001, AND TO THE PAPERMOR REDUCTION PROJECT (3150-0104),

OFFICE 0

HANAGEMENT AND BUDGET WASHINGTON DC 20503.

FACILITY NAHE (1)

Donaid C. Cook Nuciear Plant - Unit 1 DOCKET NUHBER (2) 50-315 Page 1 of4 TITLE (4)

Technical Specification Surveillance Requiement 4.6.5.1.b.2 Not Met Due to Failure to Accurately Transfer Requirments into Plant Procedure EVENT DATE 5

MONTH DAY YEAR YEAR LER NUMBER 6

SEQUENTIAL NUMBER REVISION NUHBER HONTH DAY REPORT DATE 7

FACILITY NAHE Cook - Unit 2 DOCKET NUHBER 50-316 OTHER FACILITIES INVOLVED B

04 30 98 98 026 00 06 01 FACILITY NAHE DOCKET NUMBER OPERATING MODE (9)

POWER LEVEL (10) 0 THIS REPORT IS SUBHITTED PURSUANT 20.2201(b) 20.2203 5

1 20.2203(a)(2)(I) 20.2203 a

2 ii 20 '203(a)(2)(iii) 20'203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)<3)(I) 20.2203 a

3 ii 20.2203(a)(4) 50.36 c 1

50.36(c)(2) 50.73(a)(2)(1) 50.73(a)(2)(ii) 50.73(a)(2)(iii) 50.73 a

2 iv 50.73(a)(2)(v) 50.73 a

2 vii 50.73(a)(2)(viii)(A) 50.73(a)<2)(viii)(B) 50.73(a)(2)(x) 73.71 (b) 73.710 OTHER

<Specify in Abstract below and in TextTO THE REQUIREHEN'TS OF 10 CFR:

Check one or more 11 NAME LICENSEE CONTACT FOR THIS LER 12 Mr. Paul Schoepf, Safety Related Mechanical Engineering Superintendent TELEPHONE NUMBER (Include Area Code) 616/465-5901, x2408 COMPLETE ONE LINE FOR EACH COMPONENT FA LURE DESCRIBED IN THIS REPORT 13

CAUSE

SYSTEH COMPONENI'ANUFACTURER REPORTABLE TO NPRDS

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS SUPPLEMENTAL REPORT EXPECTED 14 YES (If yes, complete EXPECTED SUBHISSION DATE).

X NO EXPECTED SUBHISSION DATE (15)

HONTH DAY YEAR ABSTRACT <Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On April30, 1998, with Unit 1 and Unit 2 in Mode 5, plant personnel determined that the surveillance requirements of Technical Specification (T/S) 4.6.5.1.b.2 were not being met. The surveillance requires, in part, that ifany basket is found to contain less than the T/S required ice weight, then a representative sample of 20 additional baskets from the same bay must be weighed.

The average'weight of these 21 baskets must meet the T/S required ice weight at a 95 percent level of confidence.

Contrary to these requirements, the average weight of the group of 21 baskets was not statistically analyzed separately from the remainder of the basket weight data. This was determined to represent an unanalyzed condition, and in accordance with 10CFR50.72(a)(2)(i) and ENS notification was made at 1838 hours0.0213 days <br />0.511 hours <br />0.00304 weeks <br />6.99359e-4 months <br /> EST that day. This LER is therefore submitted in accordance with 10CFR50.73(a)(2)(ii) for an unanalyzed condition.

The cause of this condition was the failure to accurately transfer the T/S surveillance requirements into the plant surveillance procedures, and the utilization of inadequate software programs.

To correct any potential maldistribution of ice, the ice condensers for both units willbe melted out and reloaded with fresh ice. The basis of the ice condenser surveillance program willbe reconstituted.

The software used to support the ice condenser surveillance program willeither be revised or replaced.

The safety significance of this condition was assessed.

The assessment concluded that the ice mass contained in the ice condenser as a whole was in excess of the amount used in the long term containment'analysis, and that the containment pressure would have remained below the design pressure value of 12 psig. Therefore, this condition was of minimal safety significance.

HRC FORM 366A U.S.

NUCLEAR REGULATORY COMHISSION LICENSEE EVENT CONTINUATION APPROVED BY OHB NO. 3150-0104 EXPIRES 5/31/95 ESTIHATED BURDEN PER

RESPONSE

TO COHPLY WITH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEN ESTIHATE TO THE INFORMATION AND RECORDS HANAGEMENT BRANCH (MNBB 7714), U.S.

NUCLEAR REGULATORY COMMISSIONg WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104),

OFFICE OF MANAGEHENT AND BUDGET WASHINGTON DC 20503.

FACILITY NAME 1

Cook Nuclear Plant - Unit 1 TEXT (ifmore space is required.

use additional NRC Form 3664's)

(17)

Condi ions Prior o Even Unit 1 was in Mode 5, Cold Shutdown Unit 2 was in Mode 5, Cold Shutdown DOCKET NUMBER 2

50-315 YEAR 98 LER NUMBER 6

SEQUENTIAL REVISION 026

00 PAGE 3

2OF4 De I

io f Eve The function of the ice condenser system is dependent upon the quantity and distribution of the ice mass within the ice condenser.

The ice mass is contained within an array of 1944 ice baskets.

Eighty-one ice baskets, arranged in a 9 by 9 grid, are located in each of the 24 bays of the ice condenser.

The ice baskets are 48 feet tall with an approximate diameter of 12 inches.

The vertical portion of the basket is substantially open to accommodate heat transfer.

The ice mass provides sufficient heat removal capability to condense the reactor coolant system volume released during a Loss of Coolant Accident (LOCA) or a Main Steam Line Break (MSLB) event.

The T/S ice bed weight surveillance provides assurance that the required ice inventory willbe resident in an adequate distribution in the ice condenser.

The surveillance is accomplished through a statistical analysis of a representative sample of individual ice basket weights in lieu of a 100 percent ice basket weight surveillance.

During the investigation of another condition related to the ice condenser, plant personnel determined that the requirements ofTechnical Specification surveillance 4.6.5.1.b.2 were not being met. The surveillance requirement states, in part, that the operability of the ice condenser shall be verified at least once per 18 months by:

Weighing a representative sample of at least 144 ice baskets and verifying each basket contains at least 1333 pounds of ice. The representative sample shall include 6 baskets from each of the 24 ice condenser bays and shall be constituted of one basket each from Radial Rows 1, 2, 4, 6, 8, and 9 (or from the same row of an adjacent bay ifa basket from a designated row cannot be obtained forweighing) within each bay. Ifany basket iffound to contain less than 1333 pounds of ice, a representative sample of 20 additional baskets from the same bay shall be weighed.

The minimum average weight of the ice from the 20 additional baskets and the discrepant basket shall not be less than 1333 pounds per basket at a 95 percent level of confidence.

The investigation revealed that implementation of the ice bed weight surveillance is accomplished by **12 EHP 4030.STP.211, "Ice Condenser Surveillance". The guidance provided in this procedure deals mainly with the physical work methods to be used for ice basket weighing and maintenance activities. The procedure does not provide guidance on the selection of baskets to be weighed or on the statistical analysis of the data.

During performance of this surveillance, random selection of the initial 144 ice baskets to be weighed is accomplished by computer program.

The software program used is not referenced in the procedure.

Statistical analysis of the individual ice basket weight data is performed using the NSLICE software program.

Input for NSLICE is from data gathered from the weighing of ice baskets in accordance with **12 EHP 4030.STP.211.

The data represents weights collected during the as-found weighing, the after mass addition weighing, and the as left weighing. No procedural guidance is provided for the input of data, or the use of the output tables from the NSLICE program. The output tables depict individual ice basket ice mass, average ice mass for individual radial rows, each bay within the ice bed, each rowgroup average, and for the total ice bed mass at the 95% confidence factor. No provisions exist in NSLICE for averaging the expanded sample weights of the discrepant basket plus 20 as required by T/S.U.s.

NUCLEAR REGULATORY COMMISSION LICENSEE EVENT CONTINUATION APPROVED BY OMB No. 3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEH PER

RESPONSE

TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COHMEHTS REGARDING BURDEN ESTIMATE To THE INFORHATIOH AND RECORDS HANAGEMENT BRANCH (HNBB 7714), U.S.

NUCLEAR REGULATORY COMMISSION, WASHINGTON, Dc 20555-0001, AND To THE PAPERWORK REDUCTION PROJECT (3150 0104),

OFFICE OF HANAGEHENT AHD BUDGET WASHINGTON Dc 20503.

FACILITY NAME 1

Cook Nuclear Plant - Unit 1 TEXT (If more space ss required.

use additional HRC Fom 366A's) (17)

DOCKET HUHBER 2

50-315 LER NUMBER 6

YEAR SEQUENI'IAL REVISION 98

026

00 PAGE 3

3OF4 Descri tio of Eve co The minimum 144 ice basket sample is required to be expanded for 20 additional ice baskets for each ice basket determined to be below the T/S average weight. The expanded sample is performed in the same bay as the discrepant basket and is considered to be representative of the ice baskets.

ICEPICK, a computer software random number generator, is utilized to pick the initial 144 ice basket sample.

The 20 baskets, however, are selected by the lead test engineer, as ICEPICK has no capability to perform the sample expansion of 20 additional ice baskets.

The acceptance criteria in the plant surveillance procedure requires the completion of the 20 ice basket sample expansion required by T/S, but does not require the confirmation of acceptable average weight of the 21 basket group.

No record of the 21 basket group average being calculated could be retrieved.

The current T/S surveillance requirements for the ice basket weights evolved from a requirement to weigh a sample of 60 baskets to a requirement to weigh 96 representative baskets due to weighing results which indicated non-uniform sublimation rates in the ice condenser.

The 96 sample weights were to be collected from radial rows 2, 4, 6 and 8 in each of the 24 bays.

During the early weighing program, attempts at weighing the baskets in radial rows 1 and 9, the wall baskets, proved unsuccessful.

Later, improvements in weighing methods resulted in the acquisition of wall basket ice weights.

Evaluation of this additional data revealed that the adjacent radial row ice basket weights were not representative of the wall ice basket weights due to sublimation. This resulted in radial rows 1 and 9 sample ice weights being added to the T/S surveillance.

This change resulted in the ice basket weighing program requirements embodied in the current requirements of T/S 4.6,5.1.b.2.

The as-found weighing program and the expanded weighing program have evolved as advances in weighing methods have occurred.

Additional ice basket weights were acquired and added to the NSLICE input data sets,

. which represented baskets from all rows, including baskets with structural interferences from the intermediate deck structure.

A review of past correspondence to and from the NRC relating to the ice basket weighing program shows that bay averages were frequently presented, however, the 21 basket group averages were not. The average ice basket weight on a bay basis has never been required by the T/S. Ifonly the minimum ice basket sample weights required by the T/S had been analyzed separately by NSLICE without the inclusion of the additional sample weights collected during the expanded weighing program, the bay average would represent a 21 ice basket group.

However, as more ice basket weights were collected during the expanded weighing program and added to the NSLICE input data, the bay average was no longer representative of a 21 basket group.

Based on historical information, it appears that originally the bay average was considered to be equivalent to the 21 basket group. The original ice weight surveillance practices and the bases of the statistical analysis depicted in the NSLICE program were closely aligned. As a result of changes in maintenance and surveillance practices related to the ice basket mass, the statistical analyses were no longer aligned.

The cause of this condition was the failure to accurately transfer the T/S surveillance requirements into the plant surveillance procedures, and the utilization of inadequate software programs, NSLICE and ICEPICK.

This condition was determined to represent an unanalyzed condition, and in accordance with 10CFR50.72(b)(2)(i) and ENS notification was made.

This LER is therefore submitted in accordance with 10CFR50.73(a)(2)(ii) for an unanalyzed condition.

HRC FORM 366A U.S.

NUCLEAR REGULATORY COMMISSION LICENSEE EVENT CONTINUATION APPROVED BY OMB.NO. 3150-0104" EXP IRES 5/31/95 ESTIMATED BURDEN PER RESPOHSE To COMPLY WITH THIS IHFORHATION COLLECTION REQUEST: 50.0 HRS.

FORWARD COMMENTS REGARDING BURDEH ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MHBB 7714), U.S.

NUCLEAR REGULATORY COMMISSIONS WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150 0104),

OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503.

FACILITY NAHE 1

DOCKET NUMBER 2

LER NUMBER 6

YEAR SEQUENTIAL REVISION PAGE 3

Cook Nuclear Plant - Unit 1.

TEXT (if cere space is required.

use additional NRC Fora 366A's) (17) 50-315 98 026 00 4OF4 Anal sis of Event con 'd The safety significance of this condition was assessed by Westinghouse.

The assessment concluded that the ice

'ass contained in the ice condenser as a whole was in excess of the amount used in the Iong term containment analysis, and that containment pressure would have remained below the design basis value. Therefore, any potential maldistribution of ice, which may not have been discovered due to the failure to perform the 21 basket average, was determined to be of minimal safety significance.

Corrective Action

To correct any potential maldistribution of ice, the ice condensers for both units willbe melted out and reloaded with fresh ice. The melt out of Unit 1 is complete, and the production of fresh ice is in progress.

The melt out of Unit 2 will commence in the near future.

The basis of the ice condenser surveillance program willbe reconstituted and incorporated into the Design Basis Documents.

Utilizing the reconstituted surveillance basis, all ice condenser surveillance procedures willeither be revised or completely rewritten. As part of the reconstitution process, the surveillance methodology as well as the selection and acceptance criteria for individual ice basket and various basket groupings willbe reviewed for compliance with both the T/S and the analytical basis of the ice condenser system.

The software used to support the ice condenser surveillance program willeither be revised or replaced.

The selection process for all ice baskets to be weighed willbe established and incorporated into procedures, as well as the acceptance criteria for individual baskets and basket groupings.

II A comprehensive assessment of the plant surveillance program is being performed as part of the Restart Plan. This assessment willbe completed prior to restart of either unit. Specific actions that arise from this assessment willbe communicated to the NRC during the restart process.

Fal ed Com onen dentiflc Not Applicable ev us lar Eve s

315/98-025-00