ENS Event | |
|---|---|
01:30 Mar 23, 2012 | |
| Title | Potential Fire Induced Spurious Operation of Steam Generator Block Valves |
| Event Description | On February 28, 2005, Duke Energy notified the NRC of McGuire Nuclear Station's (MNS) intent to adopt NFPA 805 in accordance with 10 CFR 50.48(c). On April 18, 2006, Duke Energy notified the NRC that MNS had begun the process of transitioning to NFPA 805. For licensees transitioning to NFPA 805, assuming specific criteria are met, the NRC will exercise enforcement discretion for Appendix R non-compliances identified during the transition process and for existing Appendix R non-compliances that could reasonably be corrected under 10 CFR 50.48(c). As per NRC guidance and policy, enforcement discretion does not relieve the licensee of the requirement to make a required report to the NRC.
As part of the NFPA 805 transition process, MNS has identified Appendix R related noncompliances which are being evaluated for appropriate dispositioning under NFPA 805. The evaluation of the non-compliances has recently identified a condition which could result in fire induced spurious operation of the block valves for the Unit 2 Steam Generator (SG) Power Operated Relief Valves (PORVs). This spurious operation could potentially damage these valves and render them inoperable. Since these valves are unisolable, they could not be repaired to allow the Unit 2 SGs to be used for Unit cool down if needed. This potential condition could adversely affect the ability of the plant to achieve and maintain a cold shutdown of Unit 2. This represents a condition reportable as per the requirements of 10 CFR 50.72(b)(3)(ii)(B). This potential condition is mitigated by existing compensatory measures (i.e. fire watches) which have been in place as part of the NFPA 805 transition. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
McGuire  North Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+-2.62 h-0.109 days <br />-0.0156 weeks <br />-0.00359 months <br />) | |
| Opened: | Scott Warren 22:53 Mar 22, 2012 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Mar 22, 2012 |
| 47764 - NRC Website
Loading map... | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 478542012-04-19T21:45:00019 April 2012 21:45:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Fire Induced Spurious Operation of Steam Generator Porv Block Valves ENS 477642012-03-23T01:30:00023 March 2012 01:30:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Fire Induced Spurious Operation of Steam Generator Block Valves 2012-04-19T21:45:00 | |