Event Notification Report for July 20, 2004

POSSIBLE RADIATION EXPOSURE FROM A LEVEL DETECTION DEVICE

It has been determined that during a painting and insulation replacement: job on the exterior of the D-15 vessel at the Solvents Plant at Dow's Plaquemine manufacturing complex, a radiation shield was not locked out on a 500 mCi Cs-137 radiation source used for level detection. The zone of potential exposure was approximately 3 inches wide by 14 inches long on the external top of the tank. The work that was being performed was in such a manner that there could have been a possibility of hand or arm exposure. During the six day period it was determined that up to 16 persons had the potential to be exposed while completing the insulation replacement. A conservative estimate of 5 minutes total continuous exposure time over this period at a distance of 5 inches from the source yield a potential exposure of 421 mrems. A two minute total continuous exposure at a distance of 14 inches would yield a potential exposure of 31 mrems. The cause of the incident was failure to lock out a radiation shield prior to commencement of work. Lock out procedures for the facility have been reviewed and strengthened to prevent reoccurrence. Medical screening was performed on all potentially exposed personnel and the results were reviewed with the personnel. No effects were observed.

4-HOUR NOTIFICATION REQUIRED BY TECHNICAL SPECIFICATIONS

"At 1818 the predicted post trip voltage on the 161 KV incoming line went into alarm on the PCM MINT program. The alarm was validated using OI-EG-3 and by conversation with the system operator. The predicted voltage was 160.4 KV. AOP-31 Section 1 'grid instability' was entered. Per the AOP, at less that 160.7 KV, the incoming line and T1A3 and T1A4 are considered inoperable. Technical Specification 2.7(2)c was entered. This is a 72 hour LCO and requires a 4 hour notification to the NRC. Both diesel generators are operable.

"The system operator took actions to raise the 161 KV system voltage. At 1831, the predicted post trip voltage was 160.9 KV and the LCO was exited. The line was inoperable for 13 minutes.

"At 1834 the voltage was 161.1 KV and AOP-31 was exited."

The licensee attributes the dip in line voltage due to heavy demand. The licensee informed the NRC Resident Inspector.

ALERT DECLARED DUE TO HIGH OFFGAS EFFLUENT ALARM PEGGED HIGH AND UNABLE TO CONFIRM WITHIN 15 MINUTES

At 0344 hrs. EDT, the licensee declared an Alert under Emergency Action Level HA.1. The initiating event was a pegged high off gas ventilation effluent radiation monitor and inability to obtain a confirmatory sample within 15 minutes. Only the gaseous channel failed high. The particulate and iodine channels remained reading normally.

When plant chemistry technicians were able to obtain samples (an initial and back-up), they were negative with no activity greater than background detected. The plant management and operations team is currently evaluating their exit strategy for the Alert. The plant remains stable at 100% power, operating at normal operating parameters.

The NRC entered monitoring mode at 0438 hrs. in response to this event.

Notified DOC (Outlaw), DOE (Wyatt), USDA (Brzostek), EPA(NRC) (Baumgartner), and HHS (Phillips).

The NRC Resident Inspector was notified and is present in the control room.

* * * UPDATE FROM RALPH DAVIS TO JEFF ROTTON AT 0907 HRS ON 07/20/04 * * *

The licensee terminated the Alert at 0901 hrs. EDT. The basis for the termination was that samples taken at the site boundary were negative, samples taken locally at the skid indicated no activity, and the licensee determined that the radiation monitor equipment was faulted.

The NRC Resident Inspector was notified by the licensee.

The licensee notified the State of Ohio (Collins), Ashtabula County, OH, Geauga County, OH and Lake County, OH.

The NRC exited monitoring mode at 0914 hrs. EDT.

The NRC Operations Center notified DHS (Everett), FEMA (Biscoe), DOE (Smith), EPA(NRC) (Jones), USDA (Comeau), HHS (Molina), HQPAO (Brenner), DOC (Outlaw) and RIVDO (Farnholtz).

* * * RETRACTION FROM MEADE TO CROUCH AT 1637 EDT ON 9/10/04 * * *

The following retraction was received from the licensee via facsimile:

"Update to Emergency Plan Alert Event Notification 40882 Retraction

"This is a follow-up notification to inform the NRC that Perry Nuclear Power Plant (PNPP) is retracting an Alert Emergency Declaration reported on July 20, 2004. Emergency Action Level HA.1, 'Any unplanned release of gaseous radioactivity to the environment that exceeds 200 times the ODCM [Offsite Dose Calculation Manual] Control limit for 15 minutes or greater', was entered based on an invalid reading due to a failed instrument.

"The Offgas Vent Pipe Gaseous Radiation Monitor had pegged offscale high. The post-accident high range Offgas Vent Pipe Gaseous Radiation Monitor, which monitors the same process stream, had started in response to the offscale reading and was indicating low, which did not correspond to the offscale readings. The radiation monitors for Offgas pre-treatment and post treatment process streams were both reading normally for the plant conditions. Other plant and process radiation monitors, post accident high range monitors, and area radiation monitors did not indicate increased radiation levels to support the off-scale Offgas Vent Pipe Gaseous Radiation Monitor. Aside from the one offscale radiation monitor, there were no corresponding indications that there was a release in progress.

"The Shift Manager took actions based on the offscale reading. In addition to the radiation monitor reading, the entry criteria for the Emergency Action Level (EAL) required entry into an Alert, unless gaseous effluent levels were verified by chemistry sample analysis methods to be less than the ODCM limits within 15 minutes. These results were not provided within 15 minutes, therefore the Shift Manager declared the Alert.

"Troubleshooting confirmed that the Offgas Vent Pipe Gas instrument reading was invalid. The Emergency Plan directs classification of events based on valid indications. At no time was there any unplanned release that would have required taking any emergency plan actions.

"Therefore, the entry criteria in the EAL were not met and the Alert emergency classification is being retracted."

The licensee notified the NRC Resident Inspector of this retraction.

Notified NRREO (Reis), R3DO (Hills) and IRD (Nieh).

LOSS OF EMERGENCY ASSESSMENT CAPABILITY EXCEEDING 8 HOURS

"Scheduled work activity on Plant Computer System resulted in loss of emergency assessment capability exceeding 8 hours."

The licensee informed the NRC Resident Inspector.