Part 21 Report - 1995-173
SAN ONOFRE 2 3 29096 07-21-95 POW LICENSEE: SOUTHERN CALIFORNIA EDISON & SAN DI SITE: .SAN ONOFRE 2 3 . EN NUMBER:29096 DOCKET: 05000361 05000362 EVENT DATE: 07-21-95 RX TYPE: PWR PWR EVENT TIME: 00:00 VENDORS: CE CE NOTIFY DATE: 07-21-95 EMERGENCY CLASS: N/A REGION: 4 STATE: CA TIME: 20:45 OPS OFFICER: TIM McGINTY 10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH UNIT SCRAM RX INIT INITIAL MODE CURR CURRENT MODE CODE CRIT PWR PWR 2 N Y 100 POWER OPERATION 100 POWER OPERATION 3 N Y 83 POWER OPERATION 83 POWER OPERATION SAN ONOFRE PROVIDED A PART 21 REPORT REGARDING POTTER & BRUMFIELD (P&B) MODEL-5095 MOTOR-DRIVEN RELAYS (MDR). SAN ONOFRE WAS NOTIFIED BY P&B OF POSSIBLE IMPROPER RE-ASSEMBLY OF SEVERAL DIFFERENT MODELS OF P&B RELAYS. THE IMPROPER RE-ASSEMBLY INVOLVES INTERNALLY DAMAGED (BENT) CONTACT ARMS THAT COULD ADVERSELY EFFECT RELAY INTERRUPT CAPABILITY, DIELECTRIC CAPABILITY, RELIABILITY, AND LIFE EXPECTANCY. THE PROBLEM IS POTENTIALLY APPLICABLE TO ANY MDR RELAY RETURNED TO P&B FOR REWORK OR DISASSEMBLY BETWEEN MARCH 1993 AND MARCH 1995. POTTER & BRUMFIELD INC. (A SEIMENS CO.) IS LOCATED IN MARION, KY. SEVEN OF EIGHTEEN RELAYS RETURNED FROM P&B TO SONGS WERE SUBSEQUENTLY INSTALLED IN SAFETY-RELATED SYSTEMS OF THE SONGS PLANTS. THE MOST LIMITING APPLICATION OF THESE SEVEN MDR RELAYS IS IN THE CONTROL CIRCUITS OF VALCOR SOLENOID VALVES WHICH ISOLATE CONTAINMENT PRESSURE TRANSMITTER SENSING LINES AT UNITS 2 AND 3. THE SOLENOID VALVES ARE NORMALLY OPEN AND REMAIN OPEN DURING ACCIDENT CONDITIONS INSIDE THE CONTAINMENT. THESE VALVES ARE ONLY REQUIRED TO CLOSE IN ORDER TO ISOLATE A SENSING LINE FAILURE OR LOSS OF PRESSURE BOUNDARY IN THE TRANSMITTER. THE SEVEN INSTALLED RELAYS WILL BE REPLACED AT THE EARLIEST OPPORTUNITY FOLLOWING PROCUREMENT OF REPLACEMENTS. THE SEVEN INSTALLED P&B MDR RELAYS AT SONGS REMAIN OPERABLE AT THIS TIME BASED ON POSITIVE DEDICATION TESTING RESPONSE, SYSTEM DESIGN USE, SUCCESSFUL INSTALLATION POST-MAINTENANCE TESTING, AND PAST OPERATING EXPERIENCE WITH OTHER RELAYS USED IN THIS TYPE APPLICATION. THE HOO FORWARDED THE PART 21 NOTIFICATION TO VERN HODGE.
Page Last Reviewed/Updated Wednesday, March 24, 2021
Page Last Reviewed/Updated Wednesday, March 24, 2021