Event Notification Report for April 25, 2012

UNANALYZED CONDITIONS RESULTING FROM A NON-CONSERVATIVE ERROR IN CALCULATIONS

"A non-conservative error was identified in the Proto-Flo input calculation FC06644 for LPSI (Low Pressure Safety Injection) flow post-RAS [recirculation actuation signal]. The calculation used an incorrect (non-conservative) input for LPSI pump performance. Also, the associated procedure (EOP/AOP Attachment 11) as written does not provide adequate direction during the Alternate Hot Leg Injection mode of operation.

"EOP/AOP Attachment 11 (Alternate Hot Leg Injection) used 140 psia as the entry point. The LPSI pumps may not be able to meet minimum flow requirements at this pressure, affecting core cooling and possibly resulting in pump damage. Also the EOP/AOP attachment directs the operator to verify that flow is approximately 400 gpm as indicated on FIC-326. If 400 gpm cannot be achieved the contingency is to open any LPSI loop injection isolation valve. This step would not depressurize the RCS low enough to allow the 400 gpm flow rate to be achieved which would cause insufficient flow.

"Therefore, it is reasonable to conclude that the referenced procedural guidance may not be able to complete the safety function of providing adequate core cooling during the Alternate Hot Leg Injection mode of operation under a worst case scenario.

"Therefore, this condition is an unanalyzed condition and reportable under 10CFR50.72(b)(3)(ii)(B)."

The licensee has notified the NRC Resident Inspector.

ALERT DECLARED DUE TO TOXIC GAS BUILD UP FOLLOWING AN EMERGENCY DIESEL GENERATOR TEST RUN

On April 25, 2012 at 2106 CDT, Point Beach Nuclear Plant declared an Alert under EAL HA3.1 due to toxic gas in a vital area. During a maintenance run on the plant's emergency diesel generator, diesel exhaust caused the concentration of carbon monoxide in an adjacent vital area room (Plant Instrument Air Compressor Room) to exceed OSHA IDLH (Immediately Dangerous to Life and Health) levels. The diesel was immediately secured and the room was ventilated. There were no personnel injuries and no public health and safety issues associated with this event.

The licensee notified the NRC Resident Inspector.

Notified DHS SWO, FEMA, USDA, DOE, DHS NICC, HHS AND EPA.

* * * UPDATE FROM JOHN RODGERS TO JOHN SHOEMAKER AT 0022 EDT ON 04/26/12 * * *

The Alert at Point Beach was terminated at 2314 CDT on 04/25/12.

The licensee notified the NRC Resident Inspector. Notified R3DO (Lara), NRR EO (Lubinski), IRD (Scott via email only).

Notified DHS SWO, FEMA, USDA, DOE, DHS NICC, HHS, EPA, and Nuclear SSA (email only).

* * * RETRACTION FROM MARY SIPIORSKI TO CHARLES TEAL AT 1650 EDT ON 8/2/2012 * * *

"On April 25, 2012, at 2106 CDT, Point Beach Nuclear Plant declared an Alert under EAL HA3.1 (EN #47863) due to toxic gas in a vital area. During a maintenance run on the plant's emergency diesel generator, diesel exhaust caused the concentration of carbon monoxide in an adjacent vital area room (Plant Instrument Air Compressor Room) to exceed OSHA IDLH (Immediately Dangerous to Life and Health) levels. The diesel was immediately secured and the room was ventilated. There were no personnel injuries and no public health and safety issues associated with this event.

"This retraction is based on the fact that station personnel incorrectly used an Alert trigger value for toxic gas concentration that was well below the actual value which would pose an immediate danger to life and health. In a subsequent evaluation, NextEra concluded that the station used the carbon monoxide (CO) OSHA limits (OSHA Permissible Exposure Limit 8-hour time weighted average of 50 ppm to 200 ppm short term exposure limit) that are normally monitored for confined spaces. The recommended CO limit value of 1200 ppm was determined to be the correct IDLH for the plant air compressor room, the actual reading in the room was 124 ppm. The plant air compressor room is not a confined space, and is not required to be monitored to the same limits as a confined space.

"Therefore, the Emergency Notification made on April 25, 2012, documenting an Alert due to toxic gas in a vital area is retracted."

The NRC Resident Inspector has been notified.

Notified R3DO (Kunowski).

NOTIFICATION TO OFFSITE AGENCIES DUE TO OIL SPILL

"At 2246 EDT on April 25, 2012, D.C. Cook notified the State of Michigan and local authorities of an oil spill from the Unit 2 [Main Generator] Seal Oil system at 2110 EDT which resulted in a portion of this oil entering the absorption pond, which is in the owner controlled area. An oil sheen is present on the absorption pond which has a surface area of approximately 2 acres (87,000 square feet) and it is estimated that five to ten gallons of oil are on the absorption pond.

"The NRC Resident Inspector was notified."

The licensee has contained the oil leak and clean up efforts are ongoing.

PRESS RELEASE ISSUED FOR SHUTDOWN OF UNIT 2 DUE TO SALP INFLUX

"On April 25, 2012, at 2227 PDT, Diablo Canyon Power Plant (DCPP) U2 was manually taken offline and the reactor shut down due to an influx of sea salp - a small, jellyfish-like organism - in the intake structure. Operators manually started the auxiliary feedwater pumps in accordance with the plant operating procedures.

"PG&E will not restart Unit 2 until conditions improve at the intake structure. As previously announced, Unit 1 was safely shut down for a planned refueling and maintenance outage.

"All systems operated as designed and no unexpected equipment performance issues were noted.

"The licensee notified the NRC Resident Inspector."

The licensee plans on issuing a press release.