ML20096E308

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Part 21 Rept Re Problems in Operation of Valve Operator Sys. Caused by Pressure Drop of Hydraulic Oil Pump Resulting from Leakage of Either Solenoid Valves,Actuators or Accumulators. Corrective Actions Being Developed
ML20096E308
Person / Time
Site: Limerick  Constellation icon.png
Issue date: 08/29/1984
From: Erlach F
PAUL-MUNROE HYDRAULICS, INC.
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
REF-PT21-84-430-000 PT21-84-430, PT21-84-430-000, NUDOCS 8409070008
Download: ML20096E308 (1)


Text

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DESIGNATED ORIGINAL i A PAUL-A4UNROE -

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AUGUST 29, 1984 '#"* '"

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c UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT, REGION 1

SUBJECT:

INITIAL NOTIFICATION OF "10CFR21" REPORT PAUL-MUNROE WAS ADVISED BY BECHTEL POWER CORPORATION AND PHILADELPHIA ELECTRIC COMPANY OF PROBLEMS IN THE OPERATION OF THE VALVE OPERATOR SYSTEMS AS APPLIED IN THE LIMERICK GENERATING STATION. SPECIFICALLY, ON SEVERAL Of THE VALVE OPERATORS, IT WAS OBSERVED THAT THE HYDRAYLIC OIL PUMP WHICH MAINTAINS ACCUMULATOR PRESSURE WAS FUNCTIONING MORE FREQUENTLY THAN CALLED FOR IN THE OPERATING AND MAINTENANCE MANUAL.

AS A RESULT OF PAUL-MUNR0E'S INVESTIGATION OF THIS PROBLEM TO DATE, IT HAS BEEN DETERMINED AT THIS TIME THAT THE FREQUENT CYCLING IS CAUSED BY A PRESSURE DROP RESULTING FROM LEAKAGE OCCURRING ON ANY ONE OF THREE COMP 0NENTS:

- SOLEN 0ID VALVES THE VALVE SEATS ON THESE "ZER0 LEAKS" SOLEN 0ID OPERATED, DIRECTIONAL CONTROL VALVES WERE DAMAGED THROUGH MICROSCOPIC ABRASION OR EROSION WITH THE RESULT THAT LEAKAGE WAS OBSERVED.

- ACTUATORS PREMATURE ABRASION AND FAILURE OF THE PISTON SEAL ALLOWED LEAKAGE PAST THE PISTON.

- ACCUMULATORS LEAKAGE HAS BEEN OBSERVED IN THE END CAP AREA.

ALTHOUGH THE AB0VE FINDINGS ARE THE RESULT OF CONSIDERABLE INVESTIGATION, CONTINUING ANALYSIS IS UNDERWAY TO DETERMINE IF THERE ARE ADDITIONAL

' CONTRIBUTING FACTORS FROM ENVIRONMENTAL CONDITIONS, INSTALLATION PROCEDURES OR MAINTENANCE PROCEDURES.

TECHNICA OLUTION TO THESE LEAKAGE PROBLEMS ARE PRESENTLY BEING DEVELOPED AND PAU .UNR0E I NT NUING TO SUPPORT BECHTEL ANi PHILADELPHIA ELECTRIC IN THIS E T. AS R IR BY REGULATION, A FULL WRITTEN REPORT WILL FOLLOW.

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