ML20057D624

Responds to GL 89-10,Suppl 5, Inaccuracy of MOV Diagnostic Equipment

ML20057D624
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	09/27/1993
From:	Donnelly P CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-10, NUDOCS 9310050085
Download: ML20057D624 (4)

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. Plant Manager POWERING AtlCHIGAN'S PROGRESS Big Rock Pomt Nuclear Plant.10269 US-31 North. Charlovom. MI 49720 September 27, 1993 B

Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - RESPONSE TO GENERIC LETTER 89-10, SUPPLEMENT 5, " INACCURACY OF MOTOR-OPERATED VALVE DIAGNOSTIC EQUIPMENT" By means of a letter dated June 28, 1993, the Nuclear Regulatory Commission.

requested that certain information be submitted within 90 days of receipt under oath or affirmation, pursuant to section 182a of the Atomic Energy Act

~i of 1954, as amended,10 CFR 50.54(f) and 10 CFR 2.204 (the letter was received by the Plant Manager July 2,1993).

1 The requested information concerning the Big Rock Point Facility hae been i

provided in the enclosed attachment.

&LA Patrick M Donnelly Plant Manager CC: Administrator, Region III, USNRC NRC Resident Inspector - Big Rock Point ATTACHMENT 0411')?

q KfY I 9310050085 930927 h

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CONSUMERS POWER COMPANY Big Rock Point Plant Docket 50-155 License DPR-06 Response to Generic Letter 89-10; Supplement 5 dated June 28, 1993 At the request of the Commission and pursuant to the Atomic Energy Act of 1954 and the Energy Reorganization Act of 1974, as amended, and the Commission's Rules and Regulations thereunder, Consumers Power Company submits our response to NRC letter dated June 28, 1993; entitled, " Generic Letter 89-10, Supplement 5, Inaccuracy of Motor-0perated Valve-Diagnostic Equipment".

Consumers Power Company's response is dated September 27, 1993.

CONSUMERS POWER COMPANY To the best of my knowledge, information and belief, the contents of this submittal are truthful and complete.

By David P Hof ice President Nuclear ations Sworn and subscribed to before me this 27th day of September 1993.

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Jackson County, Michigan My Commission expires December 3, 1996.

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ATTACHMENT Consumers Power Company Big Rock Point Plant Docket 50-155 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - RESPONSE TO GENERIC LETTER 89-10, SUPPLEMENT 5, " INACCURACY OF MOTOR-OPERATED VALVE DIAGNOSTIC EQUIPMENT" Dated September 27, 1993 T

e' ATTACHMENT TO RESPONSE-TO GENERIC LETTER 89-10, SUPPLEMENT 5 REPORTING RE0VIREMENTS j

Within 90 days of the receipt of this letter, all licensees are required to 1

notify the NRC staff of the diagnostic equipment used to confirm the proper size, or to establish settings, for MOVs within the scope of 89-10.

LICENSEE RESPONSE 1

The Big Rock Point facility employs V0TES (Valve Operation and Test Evaluation System) diagnostic equipment manufactured by Liberty Technologies.

REPORTING RE0VIREMENT Within 90 days of the receipt of this letter, licensees are required to report whether they have taken actionc or plan to take actions (including schedule and summary of actions taken or planned) to address the information on the accuracy of MOV diagnostic equipment.

LICENSEE RESPONSE i

I Big Rock Point received Liberty Technologies' 10 CFR 21 Notification and the guidance for correcting the thrust data by hand calculations. The Big Rock staff concluded that twelve MOVs had been statically tested using the errant software; six MOVs remained within the scope of GL 89-10 and six were determined to be outside the scope of the generic letter.

In addition to the above, an evaluation was performed on the measured data for all twelve MOVs. Corrections were made for material properties, effective diameter of valve stems and torque effects on valve stems, as well as overall system inaccuracies. Four cases were identified where the corrected maximum thrust exceeded the actuators rated thrust. These cases were analyzed and a j

determination made that no immediate corrective action was required. However, during the 1993 Refueling Outage, an opportunity existed to take planned corrective action on two of the operators.

Limitorque Model SMA actuator This actuator had been scheduled for replacement during the 1993 Refueling Outage, and was replaced with a Model SMB. The torque switch was then set using VOTES diagnostic equipment with the latest version (2.31) of the

software, Rotork actuator Although the amount of overthrust (approximately 13%) was of no concern to Rotork, scheduled maintenance performed during the 1993 Refueling Outage included VOTES testing. Therefore the torque switch was reset to be within the actuators rated thrust.

1 No actions were taken on the remaining two actuators. Both are manufactured by Limitorque and the amount of overthrusting (over actuator rated thrust) was 2%

and 3% respectively. These values are within the 10% margin defined by Limitorque and no corrective actions are planned.