United States Nuclear Regulatory Commission - Protecting People and the Environment


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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