ENS Event | |
|---|---|
21:00 Dec 12, 2014 | |
| Title | |
| Event Description | Engineering identified fuse and breaker coordination issues with Reactor Core Isolation Cooling (RCIC) valves operated at the Remote Shutdown Panel (RSDP). The coordination issues are such that, given a fire in the main control room, it is possible that RCIC valve power supply breakers could trip prior to tripping control power fuses. Operation of RCIC from the RSDP could be impaired in this scenario without compensatory actions to reset breakers. RCIC is the single credited source of makeup to the reactor pressure vessel during this scenario. The current licensing basis (Fire Protection Report) does not identify the compensatory actions required to reset breakers prior to RCIC operation at the RSDP. This condition is applicable to Unit 1 and Unit 2.
This report is being made pursuant to 10CFR50.72(b)(3)(ii)(B), 'Event or Condition that results in an unanalyzed condition that significantly degrades plant safety'. Actions are being taken to amend the appropriate operating procedures to take the required steps to ensure proper operation of RCIC in the postulated scenario. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
LaSalle  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| LER: | 05000373/LER-2015-002 Regarding Valve Control Power Breaker-Fuse Coordination Issue Results in Unanalyzed Condition |
| Time - Person (Reporting Time:+0.25 h0.0104 days <br />0.00149 weeks <br />3.4245e-4 months <br />) | |
| Opened: | Wayne Clayton 21:15 Dec 12, 2014 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Dec 12, 2014 |
| 50675 - NRC Website
Loading map... | |
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 532132018-02-15T17:00:00015 February 2018 17:00:00
[Table view]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 Notification of Unanalyzed Condition Affecting Accident Mitigation for Tornado Generated Missiles ENS 506752014-12-12T21:00:00012 December 2014 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition with Reactor Core Isolation Cooling ENS 424052006-03-11T06:30:00011 March 2006 06:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition ENS 423482006-02-20T06:23:00020 February 2006 06:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Site Area Emergency - Reactor Scram ENS 418442005-07-14T21:10:00014 July 2005 21:10:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Station Blackout Temperature Analysis Higher than Rcic Governor Documentation ENS 413662005-02-02T21:42:0002 February 2005 21:42:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Single Failure Vulnurability in Ac Auxiliary Power System 2018-02-15T17:00:00 | |