ENS 49326
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ENS Event | |
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21:00 Sep 5, 2013 | |
Title | Loss of Auxiliary Component Cooling Water Systems |
Event Description | This is a non-emergency notification from Waterford 3. Conditions were discovered which appear to require immediate NRC notification per 10CFR50.72(b)(3)(ii)(B) due to both trains of Auxiliary Component Cooling Water [CCW] being inoperable several times since 7/27/2012. A deficiency was identified with Auxiliary Component Cooling Water valve ACCW-126A, which is a part of the ultimate heat sink system, associated with the inability to adequately close this valve manually, locally, in order to preserve Wet Cooling Tower A inventory during an accident. System operability requirements came into question and resulted in Operations declaring the system inoperable on 9/4/2013 at 1509 CDT, and entering Technical Specification (TS) LCO 3.7.3 and associated cascading TS. As part of the review for NRC reporting requirements associated with the inoperable CCW Train A, historical information was discovered that indicated the redundant train of CCW, Train B, was declared inoperable several times, while ACCW-126A was presumably in the degraded or inoperable condition, since ACCW-126A had last been rebuilt on 7/27/2012. This condition requires immediate reporting to NRC under 10CFR50.72(b)(3)(ii)(B), an unanalyzed condition that significantly degrades plant safety. The condition was corrected and the system declared operable on 9/5/2013 at 1231 CDT, exiting the CCW TS LCO and associated cascading TS.
Prior to the condition with ACCW-126A being corrected, a snubber pin (FWSR-60) was found missing on 9/5/2013 at 1228 CDT that could have adversely affected the ability to feed Steam Generator #2 with Emergency Feedwater. Less than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> later, the pin was replaced, which restored the path to operable at 1609 CDT on 9/5/2013. The plant remained stable at 100% during this time. Plant risk index was 10.0 green. The licensee has notified the NRC Resident Inspector. |
Where | |
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Waterford Louisiana (NRC Region 4) | |
Reporting | |
10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
Time - Person (Reporting Time:+3.45 h0.144 days <br />0.0205 weeks <br />0.00473 months <br />) | |
Opened: | Michael Mason 00:27 Sep 6, 2013 |
NRC Officer: | Dong Park |
Last Updated: | Sep 6, 2013 |
49326 - NRC Website | |
Unit 3 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (100 %) |
WEEKMONTHYEARENS 568492023-11-10T21:45:00010 November 2023 21:45:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition ENS 498752014-03-05T15:12:0005 March 2014 15:12:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Impact on Unfused Direct Current Ammeter Circuits in the Main Control Room ENS 493262013-09-05T21:00:0005 September 2013 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Loss of Auxiliary Component Cooling Water Systems ENS 406322004-04-01T01:19:0001 April 2004 01:19:00 Other Unspec Reqmnt, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition New Worst Case Single Failure May Exceed 10 Cfr 50.46 Acceptance Criterion for Sbloca 2023-11-10T21:45:00 | |
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