PY-CEI-NRR-1281, Part 21 Rept Re Failure of Several Asco Scram Solenoid Pilot Valves.Initially Reported on 901211.Faulty Valves Limited to Single Production Run.Installed Valves from Subj Production Run Replaced

Part 21 Rept Re Failure of Several Asco Scram Solenoid Pilot Valves.Initially Reported on 901211.Faulty Valves Limited to Single Production Run.Installed Valves from Subj Production Run Replaced

ML20065R165
Person / Time
Site:	Perry
Issue date:	12/14/1990
From:	Lyster M CENTERIOR ENERGY
To:	Office of Nuclear Reactor Regulation
References
REF-PT21-90 PY-CEI-NRR-1281, NUDOCS 9012180248
Download: ML20065R165 (4)

Text

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CENTERIOR ENERGY PERRY NUCLEAR POWER PLANT M . sacress:

O C'_NTER ROAD PC. BOX 97 ,nwheel D. Lyster c PERRY, OHIO 44081 PERRY. OHIO 44081 he President Nucint (216)259 3737 December 14, 1990 PY-CEI/NRR-1281 L I

Director, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C. 20555 Perry Nucione Power Plant Docket ;io. 50-440 10 CFR Part 21 Notification -

ASCO Scram Solenoid Pilot Valves Gentlemen:

Pursuant to the requirements of 10CFR21.21(b)(2), the NRC was notifled on December 11, 1990 of a 10CFR21 reportable condition identified at the Perry Nuclear Power Plant (PNPP). The condition involved the failure of several ASCO acram solenoid pilot valves Irom a single production run of these valven.

Enclosed are three copies of the written report which is being submitted in accordance with 10CFR21.21(b)(2) and (b)(3).

If you have any questions, please feel free to call.

Sincerely,

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t /n % 7 Mich e D. Lyster HDL GSanje Attachment cc A. B. Davis, Region 111 USNRC Project Manager USNRC Resident Office USNRC Document Control Desk 901218024G 901214 (CI PDR ADOCK 0S000440 J l

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Attachment PY-CEI/NRR-1281 L Page 1 of 3 10CFR21 Report - ASCO Scram Solenoid Pilot Valves 10CFR21.21(b)(3}

-1. Name of Person Notifying the Commission E. Riley - Director, Perry Nuclear Assurance Department / V. Concel -

Acting Mgr., System Engineering Section

11. Identification of Facility and-Basic Component Perry Nuclear Power Plant - Unit #1 3-vay Dual Scram Solenoid Pilot Valve (SSPV)

Model EP-139 GE Part #9?20138P001 ASCO Part #HV.176-816-1 PNPP Stock Code 1579947 Application IC11D0001 - Control Rod Drive Hydraulic Control Unit 111. Identification of Firm Supplying the Basic Component Valves were furnished by GE Nuclear Energy under PNPP P.O. #S-121462, Material Receipt #MR-96472. Production Run NF61191A. Valves vere manufactured by Automatic Svitch Company (ASCO).

iv. tature j of the Defect and the Safety Hazard Created The SSPV's are used in the Control Rod Drive System to cause the

- insertion of control rods into the reactor core. By design, the SSPV changes position upon deenergization permitting the venting of all air pressute from the Scram Valve Actuators. This in turn opens the Scram Valves. This opening results in a differential pressure across the Control Rod-Drive mechanism causing rod insertion.

. Contrary to the Design Criteria, 6 of the 41 installed SSPV's from this production run failed to operate properly. No SPPV's from other production ans experienced failures during this period. The types of

-failure were as follows:

SSPV Number Type of Failure F61191A-82 Slov valve shift F61191A-87 Premature exhaust F61191A-33 Prematuie exhaust F61191A-20 Valve failed to shift F61191A-41 Valve failed to shift F61191A-67 Possible valve failure to shift In addition to these 6 failures, several unused valves from this production run vero returned to ASCO for tss'ing. One of these returned valves fnlled to meet the basic ASCO production test standards by displaying premature exhaust.

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- Attachment PY-CEl/NRR-1281 L Page 2 of 3 These deficiencies could cause a delay in control rod insertion resulting in higher peak reactor power levels being attained during certain transient /accioent sequences,

v. Date Information was Ontained The failures occurred during the period July 27, 1990 through October 28, 1990. An evaluation of the failures was conducted and the decision that the def ect., were reportable under 10CFR21 vas made on December 10, 1990, vi. The Number and Location of Basic Components GE Mieleat Energy informed us that production run F61191A consisted of 100 valves. PNPP putchased 70 of these valves on P.O. 3-121462. Of these 70, only 41 vete ever installed. All 41 have been replaced with valves from other production runs. Controls are in place to prevent the use of F61191A valves in th future.

The remaining 30 SSPV's from F61191A vere purchased for use at the Hope Creek Plant. It is believed that these valves are currently located at ilope Creek.

vii. Corrective Action All 41 installed valves from the identified production run have been temoved and replaced with valves from other production runs. Controls are in place to prevent the future use of these valves. Efforts to determine the cause of the failures ir.cluded the return of four of the six failed valves to GE/ASCO for analysis. Independent of this action, three of the six failed valves vere also evaluated by a laboratory contracted by PNPP. In addition to evaluating the failed valves, several unused valves were teturned to ASCO for standard production testing.

Although one of these unused valves exhibited premature exhaust, no concL ive evidence could be found to explain the difference between this production run of valves and other production runs. No root cause for the individual ot the collective failures could be conclusively determined.

An evaluation of the receipt, storage, hand;'ng and installation conditions at PN0P was also performed. The SSPV's from all production runs purchased by PNPP vete essentially treated the same. There was nothing identified at Perry concerning pre-installation, installation or operation that was unique to production run F61191A. The same receipt, storage, handling and installation conditions and personnel vere utilized for the valves from all production runs. Local ambient conditions during operation vould not adversely affect only the va19 ; f rom one production run because the valves are installed in a staggered pattern with_ valves f rom other pr oduction runs.

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. *- Attachment

- PY-CEI/NRR-1281'L

• Page 3 of 3 Because no conclusive root cause could be determined for the-individual or the' collective failures and because the valves from several other production runs installed and in operation during this period did not experience any -f ailures, i t was concluded that the faulty valves were limited to this single production run. The corrective action therefore was to replace all of the installed valves from this production run and to prevent their future use. These actions have been completed.

viii. Advice Related to the Defect

- Concurrent with our investigation, it was determined that the Hope Creek Station received 30 valves from production run F61191A. Ve have notified them of our decision to replace the vales installed at Perry.

NJC/ CODED /4267' s

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