Event Notification Report for August 24, 2009

INTERIM REPORT ON THERMOSTATIC VALVE FAILURE ON PALO VERDE EDG

"This interim report is being issued because Engine Systems, Inc. (ESI) is not able to complete an evaluation of an identified deviation within the 60 day requirement of 10CFR21.21. The evaluation is expected to be completed no later than November 30, 2009.

"ESI began an evaluation of a thermostatic valve element failure on August 24, 2009. Palo Verde Nuclear Plant notified ESI of the failure as a result of a failure analysis they were performing on a thermostatic valve that had been removed from the lube oil system of their 2A-EDG. The element was in service since April 2008 and Palo Verde verified operation of the element prior to installation.

"The Palo Verde failure analysis determined that one of two elements within the valve was defective. The element failure was attributed to wax leakage past the diaphragm seal on one of two power pills within the element. Evidence of mechanical binding of the piston is believed to have caused the wax leakage. If the piston was jammed, the expanding wax could have over pressurized the diaphragm seal leading to wax leakage. The failure analysis noted the following to support piston binding:

- The piston was initially difficult to remove from its guide tube.
- A gouge was observed on the piston surface.
- The rubber plug within the power pill exhibited brass machining chip debris.

"ESI has been coordinating with Palo Verde and the manufacturer (AMOT) to complete our evaluation and to determine if this is a generic issue or if it is an isolated incident.

"To date, no other similar failures with AMOT thermostatic valves have been reported to ESI."

Palo Verde has Cooper Bessemer KSV-20T diesel engines that use one 6" thermostatic valve in the engine jacket water system and one in the engine lube oil system to regulate system temperatures during engine operation. The thermostatic valve is an AMOT model 6HAS. The AMOT thermostatic valve element (P/N 9760X) is the defective part. ESI did not provide any information on other nuclear power plants that have EDGs that utilize this model thermostatic valve.

* * * UPDATE RECEIVED VIA EMAIL FROM PAUL STEPANTSCHENKO TO DONG PARK AT 1642 EST ON 12/01/09 * * *

"This report is a follow-up to an interim report (10CFR21-0098-INT) issued by Engine Systems, Inc. (ESI) on 10/23/09 which identified a deviation with an Amot thermostatic valve element. The interim report was issued because ESI was not able to complete the evaluation within the 60 day requirement of 10CFR21. The evaluation was completed on 11/30/09 and the deviation was determined be a reportable defect as by defined by 10CFR21.

"The Exelon analysis also reports that similar brass machining debris was observed on the plugs from the other three power pills to varying degrees. None of the stems of these pills displayed evidence of gouging or binding.

"To date, no other similar failures with Amot thermostatic valves have been reported to ESI.

"ESI has contacted the valve manufacturer (Amot) to discuss these findings. A copy of the Palo Verde failure analysis and eleven (11) element assemblies from ESI inventory were sent to Amot for evaluation. The following elements were sent to Amot for evaluation:

"Qty. 8: PIN 9760 X-170' (CES PIN 2-05V-419-107)
"Qty. 3: PIN 9760 X-160' (CES PIN 2-05V-419-109)

"Both part number elements are the same except for the temperature setting ('-170' indicates 170?F nominal and '-160' indicates 160?F nominal).

"Upon completion of their evaluation, Amot has reported the following:

"Fine shavings/powder of brass was observed in some of the element pills.

"None of the pill stems had any evidence of gouging.

"The pills used in the 9760X elements are made by converting another part number pill. This conversion consists of removing the stem from the pill and performing some machining. Amot believes the brass debris may have entered the pill as a result of this conversion process.

"Amot has not made any changes to this conversion process in recent history and has not had reports of similar problems with these elements.

"Machining debris, while undesirable, was evident in other pills which did not exhibit any operability issues; therefore this is not believed to be the cause of the pill failure.

"The primary cause of the failure is believed to be the gouge found in the pill stem. The gouge could have occurred during the conversion process as the stem is removed and handled at that time.

"As a precaution, Amot has made changes to their conversion process for this pill. The drilling fixture was modified to eliminate the possibility of chips entering the pill during the machining operation. This change was made effective 10/22/09.

"A listing of users with the thermostatic valves that contain the Amot 9760X element is provided in the table below.

"Site - Thermostatic Valve - System:
"Braidwood - 6HAS - Lube
"Byron - 6HAS - Lube
"Nine Mile Point - 6HAS- Lube
"Oconee - 4HAS & 6HAS - Water
"Palo Verde - 6HAS - Lube & Water
"South Texas Project - 6HAS - Lube & Water
"Susquehanna - 6HAS - Lube & Water
"Waterford - 5HAS & 6HAS - Lube & Water

"Corrective Action: The element failure at Palo Verde is considered to be an isolated incident related to a gouge in the pill stem. Thus, there is no recommended corrective action for users of the Amot 9760X element. The evaluation also indicated a weakness in Amot's manufacturing process for the element pill which introduced machining debris. While not believed to be the cause of the Palo Verde element failure, machining debris within the element pill is undesirable and increases the potential for failure in the future. Users with thermostatic valves containing Amot PIN 9760X elements should be aware of this issue so that they can monitor their systems for any indications of thermostat element problems.

Notified R1DO (Holody), R2DO (Guthrie), R3DO (Riemer), R4DO (Deese), NRR (Thorp) via e-mail, NRO (Tabatabai) via email.

* * * UPDATE RECEIVED VIA FAX FROM TOM HORNER TO DONG PARK AT 1613 EST ON 04/01/11 * * *

Two sentences were added to address the safety hazard which is created or could be created by this defect.

"This defect could affect operability of the thermostatic valve within the diesel engine cooling water and/or lube oil system, resulting in elevated fluid system temperatures during engine operation. Engine performance and/or load carrying capability could be impacted with the possibility of eventual engine failure, thereby preventing the emergency diesel generator from performing its safety related function."

Notified R1DO (Powell), R2DO (Sykes), R3DO (Peterson), R4DO (Lantz), PART 21 GROUP via e-mail.

* * * UPDATE RECEIVED VIA FAX FROM TOM HORNER TO VINCE KLCO AT 1611 EST ON 12/01/11 * * *

The report was updated to revise part numbers for Oconee, Waterford and Laguna Verde (Mexico). Affected users added include the following: Susquehanna 5th EDG and Ergytech/Iberdroia (Spain).

Notified R1DO (Schmidt), R2DO (Desai), R3DO (Riemer), R4DO (Farnholtz) and PART 21 GROUP via e-mail.

TSC AIR FILTRATION SYSTEM INOPERABLE DUE TO PLANNED MAINTENANCE

"Planned maintenance activities will commence today (August 24, 2009) on the Quad Cities Station Technical Support Center (TSC) ventilation air filtration system. The maintenance will be completed in approximately 36 hours, and is scheduled to be worked continuously to minimize out-of-service time.

"If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing procedures; contingency plans are in place to expeditiously restore the TSC ventilation to an operable status. If TSC evacuation is warranted due to radiological conditions, the facility will be relocated in accordance with existing procedures.

"This event is reportable per 10CFR50.72(b)(3)(xiii) since the scheduled maintenance affects an emergency response facility.

"The NRC Resident Inspector has been notified."

* * * UPDATE FROM KEVIN O'SHEA TO CHARLES TEAL AT 1858 ON 8/25/09 * * *

The TSC air filtration system maintenance has been completed. The TSC has been returned to normal operation.

Notified R3DO (Orth).

MANUAL TRIP DUE TO LOSS OF POWER TO CONTROL RODS

"Following completion of surveillance testing for the electrical checks of the Control Rod Drive power train, the operating crew observed that Group 7 regulating control rods unexpectedly lost power and inserted into the core. The Operators manually tripped the reactor prior to exceeding any RPS trip set point. There were no other safety system actuations and the plant is stable at normal post-trip temperature and pressure."

There are seven rods in Group 7. Operators tripped the unit within 7 seconds.

All rods fully inserted on the trip. The plant is removing decay heat through the main condenser and feeding generators with auxiliary feed.

The licensee notified the NRC Resident Inspector.

EOF BACKUP DIESEL FAILURE AND EOF OUTAGE

"On August 24, 2009 at 0900 EDT the Fermi 2 Emergency Operations Facility (EOF) was declared unavailable due to failure of the EOF backup diesel generator to start during weekly testing. Fermi 2 is making this notification in accordance with 10 CFR 50.72(b)(3)(xiii). In the event that EOF activation is necessary, the alternate EOF will be utilized. Activation and use of the alternate EOF is included in Fermi's Radiological Emergency Response Preparedness Plan. The alternate EOF has been verified available. Investigation into the failure of the EOF backup diesel generator start failure is in progress. Fermi will notify the NRC when EOF availability is restored. "

The licensee notified the NRC Resident Inspector.

* * * UPDATE FROM GREG MILLER TO HOWIE CROUCH @ 1534 ON 8/25/09 * * *

"Repairs have been made to the EOF backup diesel generator and it was successfully tested. The EOF is now available for use. The NRC Resident Inspector has been notified."

Notified R3DO (Orth).

STATION SAFETY GRADE PNEUMATIC SUPPLY ISSUE

"This event is being reported pursuant to the requirements of 10 CFR 50.72(b)(3)(v) as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of systems supplied by the station safety-grade pneumatic supply. The systems affected include the primary containment isolation valves (i.e., large primary containment isolation valve boot seals) and the reactor-building to suppression pool vacuum breakers.

"On 8/24/09 at 1330, while troubleshooting the receipt of unexpected alarms during containment valve stroking the previous week, Exelon personnel discovered a valve closed instead of the expected open position. Licensed personnel concluded at 1415 that the out of position valve was restricting the Containment Atmospheric Dilution tank from supplying operating nitrogen to the Safety Grade Instrument Gas (SGIG) system headers for Peach Bottom Units 2 and 3. The valve was re-opened at 1445 (within the one hour action time required by Technical Specifications) and other system valves were verified to be in the required positions."

The licensee notified the NRC Resident Inspector.

CONDENSATE BOOSTER PUMP TRIP RESULTING IN A MANUAL REACTOR SCRAM

"On 8/24/09, at 18:50 Unit 3 was manually scrammed due to loss of 2 of the 3 Condensate Booster Pumps due to low pump suction pressure. The cause for the Condensate Booster Pump low suction pressures is unknown at this time, but is under investigation. After the reactor was scrammed manually, reactor water level lowered below the automatic scram set point (+2 inches) and below the automatic start for HPCI and RCIC (-45 inches). All expected Primary and Secondary Containment isolation valves operated as required, isolation groups 2,3,6 and 8 were actuated. Both reactor recirculation pumps tripped due to the low reactor water level. HPCI and RCIC actuated as expected to restore reactor water level. Reactor pressure control was maintained on the turbine bypass valves, and no Main Steam Relief Valves (MSRVs) were opened as a result of the transient.

"At this time the unit is stable in mode 3. Reactor water level is being controlled using one Reactor Feedwater pump, HPCI and RCIC have been returned to standby readiness. The 3B Reactor Recirculation Pump has been returned to service. Reactor pressure is being automatically maintained by the main turbine bypass valves.

"This event is reportable as a 4 hour non-emergency report due to 10CFR 50.72(b)(2)(iv)(A) and (B) (ECCS discharge to the reactor and Reactor Protection System (RPS) actuation) and as an 8 hour non-emergency report due to 10CFR50.72(b)(3)(iv)(A) (specified system actuations)."

All rods fully inserted on the SCRAM. The plant is in its normal shutdown lineup.

The licensee notified the NRC Resident Inspector.

MEDICAL EVENT - ACTUAL DOSE LESS THAN SCHEDULED DOSE

Two patients were scheduled for treatment using Tc-99m. One patient was scheduled to receive a dosage of 8 mCi and the other patient a 25 mCi dose of a different Tc-99m chemical make-up. However, the wrong patient was given the 8 mCi (versus the 25 mCi). Both the patient and physician were notified of the wrong dosage. The critical organ of concern is the upper intestine and the exposure is calculated to be 1.44 Rem which is below the administrative limit.

There is no expected medical effects to the patient.

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

MEDICAL EVENT - D90 DOSE LESS THAN PRESCRIBED DOSE

On April 16, 2009, a patient received a permanent prostate implant of I-125 seeds. On August 24, 2009, post-implant dosimetry analysis, performed multiple times using multiple modalities, determined the D90 dose was 76.3% of prescribed dose. The prescribed dose was 145 Gy using 0.679u/seed and 54 seeds.

The referring physician and patient have been notified.

The licensee is conducting an investigation and will be determining corrective actions.

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

POTENTIAL MEDICAL EVENT - D90 DOSE LESS THAN PRESCRIBED DOSE

On April 16, 2009, a patient received a permanent prostate implant of I-125 seeds. On August 24, 2009, post-implant dosimetry analysis, performed multiple times using multiple modalities, determined the D90 dose was 46.8% of prescribed dose. The prescribed dose was 145 Gy using 0.577 u/seed and 57 seeds.

The referring physician and patient have been notified. The physician will be conducting a corrective implant.

The licensee is conducting an investigation and will be determining corrective actions.

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.