ENS Event | |
|---|---|
10:02 Sep 26, 2011 | |
| Title | Unanalyzed Condition - Appendix R Equipment May Not Have Been Available |
| Event Description | An Appendix R non-compliance issue was identified. When the plant automatically tripped on September 25, 2011, an unexpected automatic trip was identified in DC shunt trip breakers 72-01 and 72-02. This automatic trip function was not considered in the Appendix R electrical coordination evaluation. Preliminary analysis has shown that if the shunt trip breaker would have automatically opened due to fire induced fault currents, then Appendix R credited equipment may have been lost unexpectedly. The operability evaluation performed, resulted in increasing the shunt trip settings to maximum, and implementing compensatory measures to isolate some non-safety related electrical loads, which restored compliance with 10 CFR 50 Appendix R.
The licensee notified the NRC Senior Resident Inspector. CR# PLP2011-04835 |
| Where | |
|---|---|
Palisades  Michigan (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+223.97 h9.332 days <br />1.333 weeks <br />0.307 months <br />) | |
| Opened: | Otto Gustafson 18:00 Oct 5, 2011 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Oct 5, 2011 |
| 47322 - NRC Website
Loading map... | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Standby (0 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 526472017-03-29T19:08:00029 March 2017 19:08:00
[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, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Discovery of Non-Conforming Conditions During Tornado Hazards Analysis ENS 495162013-11-07T20:52:0007 November 2013 20:52:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Postulated Hot Short Fire Event That Could Adversely Impact Safe Shutdown Equipment ENS 473222011-09-26T10:02:00026 September 2011 10:02:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Appendix R Equipment May Not Have Been Available ENS 463022010-10-01T17:25:0001 October 2010 17:25:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Appendix R Non-Compliance Issue Identified ENS 429592006-11-02T19:36:0002 November 2006 19:36:00 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 High Pressure Safety Injection (Hpsi) Pumps Alignment Blocks Improperly Installed ENS 423372006-02-14T21:00:00014 February 2006 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Appendix "R" Related Unanalyzed Condition 2017-03-29T19:08:00 | |