ML17333A904

Part 21 Rept Re Spacer Missing from Torque Switch Assembly for MOV 2-MMO-421 Which Allows Torque Switch Shaft to Rotate Slightly Along Length of Shaft.Defective Assemblies Replaced or Repaired by Addition of Spacer

ML17333A904
Person / Time
Site:	Cook
Issue date:	03/19/1997
From:	INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	NRC
References
REF-PT21-97-191 NUDOCS 9705300009
Download: ML17333A904 (6)

Text

4, CATEGORY 1 REGULATO . INFORMATION DISTRIBUTION STEM (RIDS)

ACCIESSIEON NBR:9705300009 DOC.DATE: 97/03/19 NOTARIZED: NO DOCKET FACIL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana M 05000315 50-3l6 Donald C. Cook Nuclear Power Plant, Unit 2, Indiana M 05000316

-AUTH. NAME AUTHOR AFFILIATION

• Indiana Michigan Power Co. (fo'rmerly Indiana 6 Michigan Ele RECIP.NAME RECIPIENT AFFII IATION NRC No Detailed Affiliation Given

SUBJECT:

Part 21 rept re spacer missing from torque switch assembly for MOV 2-MMO-421 which allows torque switch shaft to ro',ate slightly along length of shaft. Defective assemblies replaced or repaired by addition of spacer.

DISTRIBUTION CODE: IE19T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: Part 21 Rept (50 DKT) E NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD3-3 PD HICKMANiJ 1 INTERNAL: ILE CgPggR '01 '1 NRR/DISP/PSIB/B NRR DRPM/PECB

" 1 PDR WARD, M.

RES/DET/EIB 1 RGNl RGN2 1 RGN3 RGN4 1 f

EXTERNAL: INPO .RECORD CTR NOAC SILVERgE NRC PDR NUDOCS FULL TXT D

yHls DOCUMENT HAS BEEN SCANNED E

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 NUMBER OF COPIES REQUIRED: LTTR ~ ENCL 15

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')AEw)9'92(KED) 09:19 COOK-+ TEL:612906 P, 002 f'zi VV-tV-i I

l3onald-C. Cook Plant, Units 1 and 2 Docket Numbers 50-315 and 50-316 Operating Licenses DPR-58 and DPR-74 This fax serves as a report of a 10 CFR Part 21 defect, reported under 10 CFR 21.21.d.3.i.

D rii f n On January 8, 1997, while installing a new torque switch assembly for motor operated valve 2-NIN)I0-421, it was noted that a spacer appeared to be missing from the torque switch. An inspection of all the standard SMB-00 torque switches assemblies remaining in stock determined that they were al) missing a spacer. These torque switch assemblies were part of a group of 7 received from Limitorque for general use at DC Cook under ASP 18787. A condition report was written to investigate if this was a new design.

On January 12, 1997, 2-WMO-728, West Essential Service Water (ESN/)

Supply to the 2CD Emergency Diesel Generator (EDG) Heat Exchanger Shutoff Valve, failed to fully close during performance of routine surveillance

• '2 OHP 4030,STP.027CD, "CD Diesel Generator Operability Test".

Investigation of the failure on January 14, 1997 discovered that the torque switch assembly installed on the valve was also missing a spacer. The valve was declared inoperable, however the valve was still capable of performing its design basis function of opening, therefore, the operability of the 2CD Diesel Generator was not affected.

On January 14,1997, in evaluating the failure of 2-WMO-728 and the effects of the missing spacer on the torque switch assembly, it was determined that the lack of the spacer allows the torque switch shaft to rotate slightly along the shaft length. This shaft rotation allowed the torque switch contacts to open. With the closed torque switch contacts open, the actuator control circuit will not allow the actuator to run in the closed direction and therefore will not allow the valve to fully close. The actuator control circuit uses only the closed set of contacts and therefore the open operation is not affected.

In the investigation, it was determined that 2-CMO-415, the Component Cooling Water {CCW) to Miscellaneous Header Shutoff Valve for Train A, had received one of the torque switch assemblies from the lot of 7 which 9705300009 9703i9 PDR S

ADQCK 050003i5 PDR

'IIKP~'-l9'2(VIEDI 09:20 COOK- TEL:6I2906 Part 21 Report DC Cook Plant Page 2 were missing the spacer, Because the operability of the valve could not be assured, it was declared inoperable, As the defective assembly had been installed in September of 1996, it was determined that a 10CFR50.72(b)(1)(ii)(B) ENS call for a condition outside the design basis was appropriate. The ENS call was made on January 14, 1997 at 1650 hours0.0191 days <br />0.458 hours <br />0.00273 weeks <br />6.27825e-4 months <br />.

The fourth defective torque switch assembly was found to have been installed in 1-WMO-754. With the exception of the 2-CMO-415, all the valves in which the defective assemblies had been installed had either an "open" safety function (2-WMO-728 and 1-WMO-724) or were a BOP valve (2-MMO-421), and thus their operability was not in question.

During the investigation of this event, an operability evaluation was performed for 2-CMO-415. The valve was found to have been successfully tested under dynamic conditions during the September 1996 to January 1997 interval and that the defective torque switch assembly would not have kept the valve from performing its design basis function of closing.

Therefore, the valve had never been inoperable. The ENS notification was retracted on February 22, 1997.

f n The defective lot of 7 received from Limitorque apparently resulted from a manufacturing/assembly error at the Limitorque facility.

Eff F il nPI The double pole torque switch is a standard configuration for American Electric power and is used extensively at the DC Cook Plant in SMB-00 actuators. The 7 assemblies supplied under ASP 18787 were placed in open stock for use in the next valve requiring one. Therefore, the 3 torque

'.MAR,.")Ã 97(WED) 09:20 COOK-I~

TEI:61 2905 Part 21 Report DC Cook Plant Page 3 switch assemblies in open stock could have been used in any number of safety related applications with unknown results, The failures in the 4 valves in which they were installed did not result in any safety impact, however, this could not be guaranteed for all other SIVlB-00 valve actuators in the plant due to the large variety of applications for the assembly.

Because it is not possible to definitively evaluate all possible applications for significant safety hazard, it was conservatively decided to submit this event as a Part 21.

i A n All 4 of the defective assemblies which were installed have been either replaced, or repaired by addition of a spacer. All 7 assemblies were returned to Limitorque for evaluation on March 10, 1997. Limitorque has not been able to predict when their evaluation might be complete.