ENS Event | |
|---|---|
22:22 Sep 13, 2021 | |
| Title | Unanalyzed Condition of Fire Safe Shutdown Equipment |
| Event Description | On September 13, 2021, at 1822 EDT, an apparent non-compliance with 10 CFR 50, Appendix R, section III.G.2 (separation of redundant fire safe shutdown equipment) was identified. Specifically, it was determined that some Emergency Diesel Generator (EDG) cables may be susceptible to a hot short/spurious operation to the close circuit. A spurious closure of the emergency bus normal supply breakers after the EDG is powering the bus could result in non-synchronous paralleling, EDG overloading, or EDG output breaker tripping due to faulted power cable from normal supply breaker. The spurious closure of the normal supply breakers is not currently addressed in the Appendix R Report or previous Multiple Spurious Operations (MSO) analysis.
This condition is associated with the Appendix R safe-shutdown function of the Emergency Power System. The Emergency Power System is considered operable but not fully qualified for its safety-related design function. The following fire areas are impacted: 1) Fire Area 13, Unit 1 Normal Switchgear Room 2) Fire Area 46, Unit 1 Cable Tray Room 3) Fire Area 3, Unit 1 Emergency Switchgear and Relay Room 4) Fire Area 2, Unit 2 Cable Vault and Tunnel Until this condition is analyzed, Surry has implemented mitigating actions in the above fire areas. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B). This is also reportable as a 60-day written report pursuant to 10 CFR 50.73(a)(2)(ii)(B). This event was entered into the licensee's Corrective Action Program as CR [condition report] 1180502. The NRC Resident Inspector has been notified of this event. Mitigating actions include posting fire watches in the affected areas. |
| Where | |
|---|---|
Surry  Virginia (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+1.42 h0.0592 days <br />0.00845 weeks <br />0.00195 months <br />) | |
| Opened: | Ken Wagar 23:47 Sep 13, 2021 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Sep 14, 2021 |
| 55459 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 554592021-09-13T22:22:00013 September 2021 22:22:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition of Fire Safe Shutdown Equipment ENS 544372019-12-11T18:56:00011 December 2019 18:56:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Tornado Missile Vulnerabilities ENS 407702004-05-22T01:46:00022 May 2004 01:46:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Due to Auxiliary Feedwater Not Being in Compliance with Justification for Continued Operation (Jco). ENS 403892003-12-12T16:19:00012 December 2003 16:19:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Both Trains of Auxiliary Feewater Were Declared Inoperable for One Hour and 22 Minutes. ENS 402922003-11-03T22:20:0003 November 2003 22:20:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Non-Conservatism in Design Methodology for Loss of Rcp (Reactor Coolant Pump) Seal Cooling 2021-09-13T22:22:00 | |