Event Notification Report for July 13, 2001

THE LICENSEE REPORTED THE RELEASE OF CONTAMINATED MATERIAL

On 7/13/01 two 30 gallon trash cans containing expendable contaminated lab items such as pipette tips, gloves, empty bottles, beakers, etc. were emptied into a dumpster. These items were at very low levels and had been collected in the two trash cans since January. The typical analysis that is done in the laboratory is on nuclear plant effluent samples from which these items received their contamination. Only the items used to handle the effluent sample material were discarded in the two trash cans. The material itself was not disposed in these trash cans. The dumpster was taken to the Hillsboro landfill in Lawrence County, AL this morning.

LOST AM-241 SOURCE

A source purchased from Panametrics (under general license 20-07181-04G) and delivered to the facility in 1977 was inadvertently placed in a scrap metal bin and picked up by a scrap metal dealer in 1997. The device contained a 10 mCi Am-241 source. The scrap metal dealer was contacted, but the whereabouts of the material are unknown.

AUTOMATIC REACTOR TRIP

"On July 13, 2001, at approximately 08:21 MST Palo Verde Unit 2 experienced an automatic reactor trip (RPS actuation) from approximately 100% rated thermal power due to low Departure from Nucleate Boiling Ratio (DNBR) trip generated by the Core Protection Calculators (CPCs). The DNBR trip resulted from the closure of 3 of the 4 main steam isolation valves (MSIVs). Unit 2 was at normal temperature and pressure prior to the trip. All CEAs inserted fully into the reactor core. No ESF actuations occurred and none were required. An investigation of this event has been commenced to determine why the MSIVs closed.

"Due to the MSIV closures, two of twenty main steam safety valves (MSSVs) lifted to relieve secondary pressure. Operators restored reactor coolant system heat removal using atmospheric dump valves and feedwater to the steam generators is being supplied by the B train main feedwater pump.

"Safety related buses remained energized during and following the reactor trip. The offsite power grid is stable. No significant LCOs have been entered as a result of this event. No major equipment was inoperable prior to the event that contributed to the event.

"Unit 2 is stable at normal operating temperature and pressure in Mode 3. The event did not result in any challenges to fission product barriers and there were no adverse safety consequences as a result of this event. The event did not adversely affect the safe operation of the plant or the health and safety of the public."

The NRC resident inspector has been informed of this event by the licensee.

APRM FLOW-BIASED SCRAM SETPOINTS SET NONCONSERVATIVELY

"On July 13, 2001 at 0855 hrs, with the reactor at 100% core thermal power, Pilgrim Station determined the Average Power Range Monitoring (APRM) system flow-biased reactor scram setpoints were non-conservative and potentially exceeded Core Operating Limit Report (COLR) analyses. Programmed Flow Control Trip Reference (FCTR) cards establish the APRM flow-biased scram setpoints. The FCTR cards are a plant enhancement in response to the BWR stability issue. During core flow mapping for FCTR card calibration in accordance with station procedure (9.17.1), it was determined by reactor engineering personnel that the input setting for the FCTR card DIP switches was non-conservative. In response to this event, the APRMs were declared inoperable and Technical Specification 3.1 and the Actions of Table 3.1.1 were initiated. TS Table 3.1.1 requires that reactor trip capability for the given trip function be restored within 1 hour or initiate insertion of operable control rods and complete insertion of all operable control rods within 4 hours. However, Instrumentation and Controls personnel completed FCTR card DIP switch adjustments in accordance with station procedure (3.M.2-5.4.s) within approximately 45 minutes. All APRM RPS functions were declared operable at 0946 hours and TS 3.1 was exited. The reactor remained at 100% core thermal power throughout the event and there were no plant transients as a result of the event.

"The cause of the event appears to [be] a lack of administrative controls to ensure the FCTR card flow mapping be performed when steady-state 100% core thermal power is achieved following refueling outages or significant power maneuvers."

The licensee informed the NRC resident inspector and will inform the Commonwealth of Massachusetts.

* * * UPDATE AT 1221EDT ON 7/27/01 FROM OLSON TO S. SANDIN * * *

The licensee is retracting this report based on the following:

"Pilgrim Station retracts a report made to the NRC Operations Center on July 13, 2001 at 1500 hours. The Event Number was 38139. The report was made pursuant to 10 CFR 50.72(b)(3)(v)(A) when it was determined the Average Power Range Monitoring (APRM) system flow-biased reactor scram setpoints were set non-conservatively.

"Subsequent testing has determined that the setpoints were set conservatively and that the APRM flow-biased reactor scram was operable. Therefore, no situation existed which was reportable pursuant 10 CFR 50.72(b)(3)(v)(A).

"The NRC resident inspector has been informed of this retraction." Notified R1DO(White).

STOLEN MOISTURE/DENSITY GAUGE

A Troxler Model 3440A moisture/density gauge (S/N 14786) was stolen from its locked storage case. The gauge and case were chained to the bed of a pickup truck that was parked in Shelby Township, MI. The licensee has contacted local law enforcement agencies and has already contacted NRC Region III regarding this matter.