ENS 43161
ENS Event | |
|---|---|
16:52 Feb 12, 2007 | |
| Title | Both Standby Filter Units Inoperable |
| Event Description | {{#Wiki_filter:While performing core alterations and moving irradiated fuel assemblies in the secondary containment, both Standby Filter Units (SFUs) have been declared inoperable per Technical Specification 3.7.4 Condition F. This represents a loss of safety function during the mode of applicability. Core alterations and movement of irradiated fuel assemblies in the secondary containment have been suspended. Movement of irradiated fuel assemblies in the secondary containment, core alterations, and operations with a potential for draining the reactor vessel (OPDRVs) have all been prohibited. As a result of the actions taken, the mode of applicability for Technical Specification 3.7.4 Condition F has been exited.
The A SFU became inoperable per Technical Specification 3.7.4 Condition A due to being unable to meet surveillance requirement 3.7.4.4: -verify each SFU subsystem can maintain a positive pressure of >= 0.1 inches water gauge relative to the outside atmosphere during the isolation mode of operation. This was discovered at 10:52 on 2/12/07. The B SFU was inoperable due to loss of control power from preplanned maintenance per Technical Specification 3.7.4 Condition A. This occurred on 2/9/07 at 00:45. DAEC continues to investigate [the cause of the inoperability of the A SFU]. This event is reportable under � 50.72(b)(3)(v) (D), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (D) Mitigate the consequences of an accident'. The licensee notified the NRC Resident Inspector. }}[[Event description::Description::{{#Regex_clear:While performing core alterations and moving irradiated fuel assemblies in the secondary containment, both Standby Filter Units (SFUs) have been declared inoperable per Technical Specification 3.7.4 Condition F. This represents a loss of safety function during the mode of applicability. Core alterations and movement of irradiated fuel assemblies in the secondary containment have been suspended. Movement of irradiated fuel assemblies in the secondary containment, core alterations, and operations with a potential for draining the reactor vessel (OPDRVs) have all been prohibited. As a result of the actions taken, the mode of applicability for Technical Specification 3.7.4 Condition F has been exited. The A SFU became inoperable per Technical Specification 3.7.4 Condition A due to being unable to meet surveillance requirement 3.7.4.4: -verify each SFU subsystem can maintain a positive pressure of >= 0.1 inches water gauge relative to the outside atmosphere during the isolation mode of operation. This was discovered at 10:52 on 2/12/07. The B SFU was inoperable due to loss of control power from preplanned maintenance per Technical Specification 3.7.4 Condition A. This occurred on 2/9/07 at 00:45. DAEC continues to investigate [the cause of the inoperability of the A SFU]. This event is reportable under � 50.72(b)(3)(v) (D), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (D) Mitigate the consequences of an accident'. The licensee notified the NRC Resident Inspector. }}| ]] |
| Where | |
|---|---|
Duane Arnold  Iowa (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-1.9 h-0.0792 days <br />-0.0113 weeks <br />-0.0026 months <br />) | |
| Opened: | Ellis Vann 14:58 Feb 12, 2007 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Feb 12, 2007 |
| 43161 - NRC Website | |
Duane Arnold with 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
WEEKMONTHYEARENS 528812017-08-01T14:34:0001 August 2017 14:34:00
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