ENS 51440
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ENS Event | |
|---|---|
12:25 Oct 2, 2015 | |
| Title | Loose Safety Relief Valve Discharge Flange Bolts |
| Event Description | On October 2nd, at approximately 0825 EDT, maintenance technicians were performing as-found torque checks on the discharge flange of the 'B' Safety Relief Valve (SRV). 12 of the 16 bolts were not adequately torqued. The 'B' Safety Relief Valve is credited for Remote Shutdown. The as-found condition of inadequate torque potentially impacts the seismic qualification of the 'B' SRV.
An investigation and extent of condition review is ongoing. The NRC Resident Inspector has been notified. Before the outage, there were no abnormal indications of leakage as indicated by a rise in drywell temperature or pressure. The SRVs had been cycled under pressure with no abnormal indications. The four bolts that were tight were in a diagonal pattern. The looses bolts were described as "finger tight." The licensee is determining the actions to take regarding the remaining 14 SRVs.
As part of the event investigation and extent of condition review, the as-found torque values of the inlet and outlet Safety Relief Valve (SRV) flange connections were measured and an engineering evaluation of the as-found condition was performed. The evaluation confirmed that all 15 SRVs would have remained operable during a design basis earthquake. Any potential discharge flange connection leakage during SRV operation would be bounded by the design basis Loss of Coolant Accident analysis described in the UFSAR. Subsequent investigation activities of the as-found condition of SRV 'B' determined that the four tight bolts were not oriented in a diagonal pattern across the discharge flange as originally reported. This information is provided only to clarify previously reported information and does not affect the original basis for reporting or the current basis for retraction. The licensee notified the NRC Resident Inspector. Notified R3DO (McCraw). |
| Where | |
|---|---|
Fermi  Michigan (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor | |
| Time - Person (Reporting Time:+2.42 h0.101 days <br />0.0144 weeks <br />0.00331 months <br />) | |
| Opened: | Chris Robinson 14:50 Oct 2, 2015 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Nov 20, 2015 |
| 51440 - NRC Website
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Fermi with 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
WEEKMONTHYEARENS 564292023-03-23T15:45:00023 March 2023 15:45:00
[Table view]10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Design Flaw Discovered in Mechanical Draft Cooling Tower Fan Brakes ENS 552312021-05-03T13:30:0003 May 2021 13:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition ENS 537122018-11-01T04:00:0001 November 2018 04:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition En Revision Imported Date 12/31/2018 ENS 536742018-10-19T04:00:00019 October 2018 04:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Low Pressure Core Injection Pumps Incapable of Automatic Startup ENS 527242017-05-02T21:00:0002 May 2017 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition for Combustion Turbine Generator Configuration ENS 523422016-11-02T14:34:0002 November 2016 14:34:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition for Control Rod Drop Accident at Low Power ENS 523312016-10-28T19:00:00028 October 2016 19:00:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Standby Liquid Control Technical Specification Not Met ENS 522142016-08-31T23:50:00031 August 2016 23:50:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition with a Potential Tornado ENS 522022016-08-25T20:29:00025 August 2016 20:29:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Mechanical Draft Cooling Tower Declared Inoperable ENS 517552016-01-06T20:14:0006 January 2016 20:14:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Power Reduction Due to Automatic Opening of the Turbine Bypass Valves ENS 514402015-10-02T12:25:0002 October 2015 12:25:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Loose Safety Relief Valve Discharge Flange Bolts ENS 517562015-02-21T05:30:00021 February 2015 05:30:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident Power Reduction Due to Automatic Opening of a Turbine Bypass Valve ENS 468742011-05-22T18:44:00022 May 2011 18:44:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor Safe Shutdown Operability Concern Associated with Offsite Power Circuits ENS 427832006-08-17T23:00:00017 August 2006 23:00:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Emergency Diesel Generators Inoperable Due to Undersized Breaker Control Transformers ENS 422242005-12-23T03:25:00023 December 2005 03:25:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Eecw Temperature Control Valve Not Fully Open ENS 418472005-07-18T02:31:00018 July 2005 02:31:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition of Maintenance Bus Tie Breakers ENS 418162005-06-30T23:31:00030 June 2005 23:31:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Related to the Standby Feedwater Pumps and Control Circuits ENS 417142005-05-18T22:50:00018 May 2005 22:50:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Identification of Design and Operating Procedure Deficiencies Related to Appendix R Events ENS 415512005-03-30T21:00:00030 March 2005 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Identification of Design and Operating Procedure Deficiencies ENS 402152003-10-02T19:00:0002 October 2003 19:00:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor Loss of Safe Shutdown Capability Due to All Oprm Channels Being Declared Inoperable. 2023-03-23T15:45:00 | |
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