ENS 40882
ENS Event | |
|---|---|
07:44 Jul 20, 2004 | |
| Title | Alert Declared Due to High Offgas Effluent Alarm Pegged High and Unable to Confirm within 15 Minutes |
| Event Description | 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.
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).
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). |
| Where | |
|---|---|
Perry  Ohio (NRC Region 3) | |
| Reporting | |
| Emergency class: | Alert |
| 10 CFR 50.72(a) (1) (i), Emergency Class Declaration | |
| Time - Person (Reporting Time:+-3.67 h-0.153 days <br />-0.0218 weeks <br />-0.00503 months <br />) | |
| Opened: | James Judd 04:04 Jul 20, 2004 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Sep 10, 2004 |
| 40882 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 499872014-04-02T18:01:0002 April 2014 18:01:00
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