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On 8/28/11 at 0920 hrs. PDT, electrical st … On 8/28/11 at 0920 hrs. PDT, electrical storms in the area caused power surges. The site backup power generators activated as designed. However, it was later discovered that a gamma monitor associated with the waste water treatment process was damaged. When the gamma monitoring system failed, the system interlocks shut the system down as designed. The system has remained down since that time and will remain down until repaired.</br>This report is being made per the requirements of 10 CFR 70, Appendix A(b)(4), (24-hr. report criteria), 'Any natural phenomenon that has affected the availability or reliability of one or more Items Relied On For Safety (IROFS)'.</br>An updated report with additional timeline information will be provided as the information becomes available.</br>SAFETY SIGNIFICANCE OF EVENTS: Low. The waste water treatment system was shut down as designed.</br>POTENTIAL CRITICALITY PATHWAYS INVOLVED: The only potential pathway is gradual accumulation of uranium in the waste water treatment equipment over an extended period of time.</br>CONTROLLED PARAMETERS: Concentration is controlled. Maximum concentration in the equipment is estimated to be less than 1.5 grams of uranium per liter based on gamma monitor reading when the system shut down.</br>ESTIMATED AMOUNT/ENRICHMENT, FORM OF LICENSED MATERIAL: Facility is licensed for 5 wt% U-235. Normal system clean out results in about 120 grams of uranium. A minimum critical mass assuming spherical geometry is (much greater than normal system content).</br>CORRECTIVE ACTIONS: System automatically shut down as designed and will remain down until the equipment is repaired and returned to service.</br>* * * UPDATE AT 1214 EDT ON 09/02/11 FROM CALVIN MANNING TO S. SANDIN * * *</br>The following information was received via email:</br>At approximately 0920 local time, 8/28/2011 and closely associated in time with both a thunderstorm and a test of various internal backup power generators, an operator at the Waste Water Treatment (WWT) facility noticed that the gamma monitors on two sand filters had ceased to function correctly. Apparently as an immediate result of this failure to function, the associated flows to the sand filters shut down automatically (normal fail-safe shutdown). The system has remained down since that time and will remain down until the gamma monitoring system is repaired.</br>This plant condition was brought to the attention of the HRR EHS&L staff on Tuesday 8/30/2011 at 0800 by an engineer responsible for the gamma monitoring system who was soliciting potential options to restore the system to service. </br>At 0901 local time AREVA's HRR EHS&L notified the NRC Operation's Center of this condition per the requirements of 10CFR70 Appendix A criterion (b) (4) (24 hour report) which requires reporting of any natural phenomenon that has or may have affected the intended safety function or availability or reliability of one or more items relied on for safety. </br>Safety Significance of Event: The safety significance of this event is low. The feed and discharge to and from the waste water treatment sand filters were shut down as designed when the gamma detectors failed.</br>Potential Nuclear Criticality Pathways Involved: The only potential pathway is for gradual build up / accumulation of uranium in the WWT equipment over an extended period of time (many years). </br>Controlled Parameters (Mass, Moderation, Geometry, Concentration, Etc.): Uranium concentration is controlled. The maximum concentration of uranium in the equipment is estimated to be less than 1.5 g U/L based on gamma monitor readings just prior to the system being shut down.</br>Estimated Amount, Enrichment, Form of License material (Includes process limit and % worst case critical mass): The facility is licensed for 5 wt.% U-235. Normal system clean out results in about 120 grams of uranium. A minimum critical mass of uranium at 5 wt.% U-235 assuming spherical geometry is about 38,000 grams.</br>Nuclear Criticality Safety Control(s) or Control System(s) and description of the failures or deficiencies: No control system failures occurred.</br>Corrective Actions to Restore Safety Systems and When Each Was Implemented: The system automatically shut down as designed and will remain down until the equipment is repaired, functionally tested, and returned to service.</br>Notified R2DO (Sykes) and NMSS (Pstrak). service.
Notified R2DO (Sykes) and NMSS (Pstrak).
16:20:00, 29 August 2011 +
47,219 +
12:01:00, 30 August 2011 +
16:20:00, 29 August 2011 +
On 8/28/11 at 0920 hrs. PDT, electrical st … On 8/28/11 at 0920 hrs. PDT, electrical storms in the area caused power surges. The site backup power generators activated as designed. However, it was later discovered that a gamma monitor associated with the waste water treatment process was damaged. When the gamma monitoring system failed, the system interlocks shut the system down as designed. The system has remained down since that time and will remain down until repaired.</br>This report is being made per the requirements of 10 CFR 70, Appendix A(b)(4), (24-hr. report criteria), 'Any natural phenomenon that has affected the availability or reliability of one or more Items Relied On For Safety (IROFS)'.</br>An updated report with additional timeline information will be provided as the information becomes available.</br>SAFETY SIGNIFICANCE OF EVENTS: Low. The waste water treatment system was shut down as designed.</br>POTENTIAL CRITICALITY PATHWAYS INVOLVED: The only potential pathway is gradual accumulation of uranium in the waste water treatment equipment over an extended period of time.</br>CONTROLLED PARAMETERS: Concentration is controlled. Maximum concentration in the equipment is estimated to be less than 1.5 grams of uranium per liter based on gamma monitor reading when the system shut down.</br>ESTIMATED AMOUNT/ENRICHMENT, FORM OF LICENSED MATERIAL: Facility is licensed for 5 wt% U-235. Normal system clean out results in about 120 grams of uranium. A minimum critical mass assuming spherical geometry is (much greater than normal system content).</br>CORRECTIVE ACTIONS: System automatically shut down as designed and will remain down until the equipment is repaired and returned to service.</br>* * * UPDATE AT 1214 EDT ON 09/02/11 FROM CALVIN MANNING TO S. SANDIN * * *</br>The following information was received via email:</br>At approximately 0920 local time, 8/28/2011 and closely associated in time with both a thunderstorm and a test of various internal backup power generators, an operator at the Waste Water Treatment (WWT) facility noticed that the gamma monitors on two sand filters had ceased to function correctly. Apparently as an immediate result of this failure to function, the associated flows to the sand filters shut down automatically (normal fail-safe shutdown). The system has remained down since that time and will remain down until the gamma monitoring system is repaired.</br>This plant condition was brought to the attention of the HRR EHS&L staff on Tuesday 8/30/2011 at 0800 by an engineer responsible for the gamma monitoring system who was soliciting potential options to restore the system to service. </br>At 0901 local time AREVA's HRR EHS&L notified the NRC Operation's Center of this condition per the requirements of 10CFR70 Appendix A criterion (b) (4) (24 hour report) which requires reporting of any natural phenomenon that has or may have affected the intended safety function or availability or reliability of one or more items relied on for safety. </br>Safety Significance of Event: The safety significance of this event is low. The feed and discharge to and from the waste water treatment sand filters were shut down as designed when the gamma detectors failed.</br>Potential Nuclear Criticality Pathways Involved: The only potential pathway is for gradual build up / accumulation of uranium in the WWT equipment over an extended period of time (many years). </br>Controlled Parameters (Mass, Moderation, Geometry, Concentration, Etc.): Uranium concentration is controlled. The maximum concentration of uranium in the equipment is estimated to be less than 1.5 g U/L based on gamma monitor readings just prior to the system being shut down.</br>Estimated Amount, Enrichment, Form of License material (Includes process limit and % worst case critical mass): The facility is licensed for 5 wt.% U-235. Normal system clean out results in about 120 grams of uranium. A minimum critical mass of uranium at 5 wt.% U-235 assuming spherical geometry is about 38,000 grams.</br>Nuclear Criticality Safety Control(s) or Control System(s) and description of the failures or deficiencies: No control system failures occurred.</br>Corrective Actions to Restore Safety Systems and When Each Was Implemented: The system automatically shut down as designed and will remain down until the equipment is repaired, functionally tested, and returned to service.</br>Notified R2DO (Sykes) and NMSS (Pstrak). service.
Notified R2DO (Sykes) and NMSS (Pstrak).
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00:00:00, 2 September 2011 +
SNM-1227 +
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23:19:03, 24 November 2018 +
12:01:00, 30 August 2011 +
0.82 d (19.68 hours, 0.117 weeks, 0.027 months) +
16:20:00, 29 August 2011 +
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