ML17333B111

LER 97-026-00:on 970925,determined Potential Failure of Control Air Headers Due to Overpressurization.Installed Safety Valves on All Regulated Air Headers & Continuing Analysis on RHR Heat Exchanger valves.W/971027 Ltr

ML17333B111
Person / Time
Site:	Cook
Issue date:	10/27/1997
From:	Benes J, Blind A INDIANA MICHIGAN POWER CO., INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-97-026, LER-97-26, NUDOCS 9711040027
Download: ML17333B111 (5)

Text

~ CATEGORY REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9711040027 DOC.DATE: 97/10/27 NOTARIZED: NO DOCKET g FACIL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana M 05000315 AUTH. NAME AUTHOR AFFILIATION BENESgJ. Indiana Michigan Power Co. (formerly Indiana & Michigan Ele BLIND,A.A. Indiana Michigan Power Co. (formerly Indiana a Michigan Ele RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 97-027-00:on 970925,determined potential failure of control air headers due to overpressurization.Installed safety valves on all regulated air headers a continuing analysis on RHR heat exchanger valves.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

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

El NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-3 PD 1 1 HICKMAN,J 1 1 INTERNAL: AB 2 2 AEOD/SPD/RRAB 1 1 FILE CEN 1 1 NRR/DE/ECGB 1 1 ELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/PECB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DET/EIB 1 1 RGN3 FILE 01 1 1 D

EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 1 1 NOAC POORE,W. 1 1 NOAC QUEENER,DS 1 1 0

'NRC PDR 1 1 NUDOCS FULL TXT 1 1 N

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 NUMB::R OF COPIES REQUIRED: LTTR 24 ENCL 24

Indiana Iiichlgan Power Company CocKMvctear PanI Ore Coorr Pace Bridgman. MI49)C6 October 27, 1997 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Operating Licenses DPR-58 Docket No. 50-315 Document Control Manager:

97-027-00 Sincerely, A. A. Blind Site Vice President Il

/mbd Attachment A. B. Beach, Region III E. E. Fitzpatrick P. A. Barrett S. J. Brewer J. R. Padgett D. Hahn Records Center, INPO NRC Resident Inspector

~ ~ ~

H!ffff!fffl!fillllfllfllfllllf Ifffffff 97i1040027 97i027 PDR ADGCK 050003i5 S PDR

1 NRC FORH 366 U.s. NUCLEAR REGULA'TORY COMHISSION APPROVED BY OMB No. 3150-0104 (5.92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE To COMPLY 'WITH THI INFORHATION COLLECTION REQUEST: 50.0 HRS ~ FORWAR LICENSEE EVENT REPORT (LER) COMHENTS REGARDING BURDEN ESTIMATE TO TH INFORHATION AND RECORDS HANAGEMENT BRANCH (MNB 7714), U.S. NUCLEAR REGULATORY COMHISSION, WASHINGTON, DC 20555.0001, AND To THE PAPERWOR REDUCTION PROJECT (3150-0104), OFFICE 0 HANAGEHENT AND BUDGET WASHINGTON DC 20503.

FACILITY NAHE (1) DOCKET NUHBER (2) Page 1 of1 Donald C. Cook Nuclear Plant - Unit 1 50.315 TITLE (4)

Interim LER - Potential for Overpressurization of the Control Air Headers Determined to be Unanalyzed Condition SEQUENTIAL REVISION FACILITY NAHE DOCKET HUHBER HOHTH DAY YEAR YEAR MONTH DAY NUMBER NUHBER Cook Unit 2 50-316 FACILITY NAME DOCKET NUHBER 09 25 97 97 026 00 10 27 OPERATING HOOE (9) 20.2201(b) 20.2203(a)(3)(I) 50.73(a)(2)(iii) 73.71(b)

POWER 0

LEVEL (10) 20.2203(a)(2)(I) 20.2203(a)(4) 50.73(a)(2)(v) OTHER (Specify in 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(viii)(A) Abstract below 20.2203(a)(2)(iv) 50.73(a)(2)(I) 50.73(a)(2)(viii)(B) and in Text, 20.2203(a)(2)(v) X 50.73(a)(2)(ii) 50.73(a)(2)(x) NRC Form 366A)

NAHE TELEPHONE NUMBER (Include Area Code Mr. James Benes, Mechanical Systems 616/465-5901, X2862 REPORTABLE REPORTABLE CAUSE SYSTEH COMPONENT MANUFACTURER CAUSE SYSTEH COMPONENT MANUFACTURER To NPRDS TO NPRDS EXPECTED X SUBHISSION YEs No DATE 15 11 17 97 ABSTRACT ~

(Limit to 1400 spaces,'.e., approximately 15 single-spaced typewritten lines) (16)

On September 25, 1997 it was determined that the potential failure of the control air headers due to overpressure constituted an unanalyzed condition. This was determined reportable under 10CFR50.72(b)(2)(i), and an ENS notification was made at 1011 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.846855e-4 months <br /> on September 25, 1997. This interim LER is being submitted under 10CFR 50.73(a)(2)(ii), as an unanalyzed condition.

During the recent Architectural Engineering inspection a question was raised regarding the lack of overpressure protection on the 20, 50, & 85 psig control air headers. The specific concern is that there may be the potential for common mode failure of both trains of safety related equipment served by the headers should an overpressure condition occur due to a regulator failure.

C Analysis of the 20, 50 and 85 psig headers has been completed. The results of the analysis indicate that overpressurization of the 50 and 85 psig headers would not have had any safety significance. Overpressurization of valves on these headers fell into the following categories: 1) the valves are normally in the vented position and would not have seen the excessive air pressure, 2) the valves are allowed a one-time pressure excursion to 125 psig by the manufacturer, and 3) the diaphragm of the valve actuator would have failed resulting in the valve going to its safe position. Some valves going to their safe position may have resulted in a unit trip similar to the loss of control air. Overpressurization of the 20 psig header could have resulted in safety significant consequences. A unit trip would have been likely and there would be the potential for partial mispositioning of both trains of the RHR heat exchanger outlet valves, resulting in degradation of the RHR system for the duration of the overpressure event.

In conclusion, it was determined that the potential overpressurization of the 50 and 85 psig headers would have resulted in no safety significance. Overpressurization of the 20 psig header would have been safety significant due to the potential degradation of both trains of RHR for the overpressure event duration. Safety valves have been installed on all regulated air headers.

Analysis is continuing to determine the effect on the RHR heat exchanger valves, including expected operator response. An update to this interim LER will be issued by November 17, 1997.

1 4