Part 21 Report - 1997-340

LICENSEE: AUTOMATIC SWITCH COMPANY SITE: AUTOMATIC SWITCH COMPANY EN NUMBER:32240 DOCKET: EVENT DATE: 04-29-97 RX TYPE: EVENT TIME: 00:00 VENDORS: NOTIFY DATE: 04-29-97 EMERGENCY CLASS: N/A REGION: 1 STATE: NJ TIME: 15:47 OPS OFFICER: LEIGH TROCINE 10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH AUTOMATIC SWITCH COMPANY (ASCO) 10 CFR PART 21 NOTIFICATION OF A POTENTIAL SAFETY-RELATED PROBLEM WITH ASCO HV-266000-007J SCRAM SOLENOID PILOT VALVES POSSIBLY SUPPLIED TO SEVERAL BOILING WATER REACTOR NUCLEAR POWER PLANTS THROUGH GENERAL ELECTRIC (THIS NOTIFICATION MAY BE RELATED TO THE TECHNICAL SPECIFICATION SHUTDOWN REPORTED BY OYSTER CREEK ON 04/22/97 - EVENT #32196) DURING PERFORMANCE MAINTENANCE TESTING OF SCRAM SOLENOID PILOT VALVES AT OYSTER CREEK NUCLEAR PLANT, 13 OUT OF 36 SCRAM SOLENOID VALVES INSTALLED IN THE PLANT EXHIBITED EXCESSIVE AIR LEAKAGE. AN INVESTIGATION BY THE UTILITY, GENERAL ELECTRIC, AND ASCO CONCLUDED THAT THE LEAKAGE WAS THE RESULT OF HARDENING OF THE CORE DISC IN THE SCRAM SOLENOID PILOT VALVE PILOT HEAD. SUBSEQUENT INVESTIGATION BY ASCO ALSO INDICATED THAT SOME SCRAM SOLENOID PILOT VALVES IN THE OYSTER CREEK PLANT MAY HAVE BEEN SHIPPED WITH CORE DISCS FABRICATED FROM COMMERCIAL GRADE BUNA-N (NITRILE) MATERIAL RATHER THAN THE REQUIRED NUCLEAR GRADE FLUOROCARBON MATERIAL. ASCO IS CONTINUING ITS INVESTIGATION (IN COOPERATION WITH THE UTILITY AND GENERAL ELECTRIC) TO DETERMINE THE ROOT CAUSE OF THIS PROBLEM AND THE POPULATION OF SUSPECT SCRAM SOLENOID PILOT VALVES. THE EVIDENCE CURRENTLY SUGGESTS THAT THE SUBSTITUTION OF THE BUNA-N MATERIAL OCCURRED IN A PORTION OF THE FIRST LOT OF SCRAM SOLENOID PILOT VALVES MANUFACTURED AFTER A 1994 DESIGN CHANGE THAT CHANGED THE CORE DISCS TO THE FLUOROCARBON MATERIAL.

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