Event Notification Report for March 09, 2010

POTENTIAL LOSS OF 1E PUMPS DUE TO DEGRADED VOLTAGE DURING POSTULATED ACCIDENTS

"While attempting to analyze the consequences of scenarios (loss of coolant accident (LOCA) and loss of offsite power (LOOP)) postulated during the Component Design Basis Inspection (CDBI), PG&E concluded both units were in an Unanalyzed Condition that significantly degrades plant safety, and therefore, reportable under 10 CFR 50.72(b)(3)(ii)(B).

"The postulated scenario could result in permanently connected class 1E pump motors tripping over current relays due to sustained degraded voltage on the startup offsite power source.

"The scenario starts with a safety injection (SI) signal transferring 4160 volt vital buses from auxiliary power to the startup offsite power source. Following bus transfer, the startup source is postulated to degrade to a level above the first level under voltage relay (FLUR) setting of equal to or greater than 2583 volts and below the second level under voltage relay (SLUR) setting of equal to or greater than 3785 volts. Permanently connected class 1E pump motors would experience this degraded voltage for up to the SLUR time delay relay setting of equal to or less than 20 seconds. Prior to reaching the SLUR time delay relay setpoint and transferring loads to the onsite emergency diesel generators (EDGs), operating motors (e.g. auxiliary saltwater (ASW) pump and component cooling water (CCW) pumps) could trip on over current. Operators would be directed by procedures to re-start these motors on an operable power source (EDG). However, since this scenario has not been previously analyzed and could reasonably challenge containment pressure or peak clad temperature limits, it is considered unanalyzed.

"The postulated scenario had previously been considered non-credible, and therefore, had not been analyzed.

"PG&E considers this a nonconservative technical specification (TS) since the values in TS surveillance requirement (SR) 3.3.5.3 would not protect permanently connected class 1E loads from damage during degraded voltage conditions."

The licensee has notified the NRC Resident Inspector. The condition was discovered by NRC inspectors while performing a CDBI inspection.

LOST METALLURGY LABORATORY SAMPLE

"A metallurgy laboratory (Met Lab) sample was determined to be missing from its prescribed location on March 9, 2010. A search for the item was immediately initiated per requirements. As of 10:00am March 12, 2010, the item has not been located and as a result, formal notification of a missing item is being made to the NRC per 10 CFR 74.11. To date, no other indicator of intentional theft or diversion has been found. Both the search and the investigation are still underway. The missing item contains approximately 0.67 grams U and 0.65 grams U-235."

The material was last accounted for on 10/26/2009. The licensee has notified the NRC Resident Inspector and will notify the state.

FAULTY MODULATION INDEX CONTROL CIRCUIT BOARD USED IN A POWER SUPPLY

The following is a summary of information received via fax:

"UCI [United Controls International] personnel witnessed system level functional testing of three [Modulation Index Control] MIC circuit boards in a spare unit on March 9-10, 2010 at the PSEG Nuclear LLC training center as part of the dedication process. Initially, the boards were accepted based on the test results but later irregularities were noticed on the output side of another card (reference oscillator) in the system. The Original Equipment Manufacture (Thomas & Betts) began troubleshooting the issue and determined that two resistors (R336 and R347) had one leg each terminated in the wrong location. Subsequent repair and testing confirmed this to be the issue and that once corrected, the irregularities were gone.

"The affected licensees are PSEG Nuclear LLC - Salem and Hope Creek Nuclear Generating Stations."