05000316/LER-1999-001, :on 960610,degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations,Identified on 990226.Caused by Inadequate Understanding of Design Basis.Additional Investigations Ongoing

:on 960610,degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations,Identified on 990226.Caused by Inadequate Understanding of Design Basis.Additional Investigations Ongoing

ML17325B522
Person / Time
Site:	Cook
Issue date:	03/29/1999
From:	Berry L INDIANA MICHIGAN POWER CO.
To:
Shared Package
ML17325B521	List: 05000316/LER-1999-001, :on 960610,degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations,Identified on 990226.Caused by Inadequate Understanding of Design Basis.Additional Investigations Ongoing
References
LER-99-001, LER-99-1, NUDOCS 9904090204
Download: ML17325B522 (1)

LER-1999-001, on 960610,degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations,Identified on 990226.Caused by Inadequate Understanding of Design Basis.Additional Investigations Ongoing

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition
3161999001R00 - NRC Website

text

NRC Forn 366 U.S. NUCLEAR REGULATORY COMMiSSION (6-1998)

LICENSEE EYENT REPORT (LER)

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

APPROVEO BY OMB No. 3160 0104 EXP(RES 06130I2001 fSTSIIATED BURDEN PER

RESPONSE

TO COMPLY WITH T)SS MANDATORY WfORMATIONCOLLECTION REOUESTI 50 0 HRS. REPORTED LESSONS LEARNED ARE WCORPORATED WTO THE LICENSING PROCESS JJIO FEO BACK TO eeUSTRY.

fORWARD COMMENTS REGA)CING BURDEN ESTIMATE TO THE SP'ORMATION ANO RECORDS MANAGEMENT BRANCH ITS F55).

U.S.

NUCLEAR REGIAATORY COMMISSION. WAS)eNGTON. DC 205554ool. At TO THE PAPERWORK RECUCTION PROJECT (M500101), CFFCE Of MANAGEMENT AND BUDGET. WASHINGTON. DC 205OS FACILITYNAME(1)

TITLE(4)

Cook Nuclear Plant Unit 2 DOCKET NUMBER(2) 05000-316 PAGE (3) 1of1 Degraded Component Cooling Water Flow to Containment Main Steam Line Penetrations EVENT DATE (5)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILITIESINVOLVED(8)

MONTH 06 DAY 10 YEAR YEAR SEQUENTIAL NUMBER 1996, 1999

001

'EVISION NUMBER 00 MONTH DAY YEAR 03 29 1999 A ILI NAM Cook Plant Unit 1 A ILI Y HAM 05000-315 K

NUM OPERATING MODE (9)

POWER LEVEL(10) 100 20.2201 (b) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(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)

LICENSEE CONTACT FOR THIS LER (12) 50.73(a)(2)(i) 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) 50.73(a)(2)(x) 73.71 OTHER Speorry in Aberrso( below or n NRC Form 366A TELEPHONE NUMBER(Inc@de Aree Code)

THIS REPORT IS SUBMITTEDPURSUANT TO THE REQUIREMENTS OF 10 CFR (): (Check one or more) (11)

Lyle R. Berry, Regulatory Compliance Engineer (616) 465-5901 x2637 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX PP,,

d.

S

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO EPIX SUPPLEMENTAL REPORT EXPECTED (14)

X YES (IfYes, complete EXPECTED SUBMISSION DATE)

NO EXPECTED SUBMISSION DATE (15 MONTH DAY 06 25 1999 Abstract (Limitto 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (18)

On February 26, 1999, during an engineering review of the Unit 2 Component Cooling Water System (CCW), it was identified that power operation was permitted in June 1996 with degraded CCW flow to the coolers for containment penetrations 2-CPN-3 and 2-CPN-4. The main steam headers for steam generators 22 and 23 pass through these penetrations.

Operating with the degraded CCW to these coolers may have resulted in excessive thermal stress on the penetration sleeves/liners.

The Updated Final Safety Analysis Report (UFSAR) credits the penetration coolers for maintaining the temperature of adjacent concrete less than 150 degrees F. Atthe time of the event, containment exterior surface concrete temperatures were measured at a maximum of 155 degrees F. Operability determinations performed at the time of the event, to justify continued operation with degraded CCW flow to the main steam line penetrations, have been re-evaluated and found to be

, inadequate.

This event was reported via a 4'hour non-emergency Emergency Notification System (ENS) report on February 27, 1999, pursuant to the requirements of 10CFR50.72(b)(2)(i).

This LER is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(ii)(B) as an event or condition that resulted in the nuclear power plant being in a condition that was outside the design basis of the plant.

Initial investigations indicate that the cause for this event was an inadequate understanding of the design basis for the containment penetration coolers.

Additional investigations to assess potential degradation to the concrete, liners and sleeves at these penetrations are ongoing. The results of those investigations, including identified root cause(s),

preventive actions and safety significance willbe provided when completed.

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