ENS 54487: Difference between revisions
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| unit = 1 | | unit = 1 | ||
| utype = W-4-LP, W-4-LP | | utype = W-4-LP, W-4-LP | ||
| cfr = 10 CFR 50.72(b)(3)( | | cfr = 10 CFR 50.72(b)(3)(ii)(B) | ||
| emergency class = Non Emergency | |||
| emergency class = | |||
| notification date = 01/22/2020 04:34 | | notification date = 01/22/2020 04:34 | ||
| notification by = John Alexander | | notification by = John Alexander | ||
| NRC officer = Brian P. Smith | | NRC officer = Brian P. Smith | ||
| event date = 01/21/2020 22:18 EST | | event date = 01/21/2020 22:18 EST | ||
| last update date = | | last update date = 02/20/2020 | ||
| title = | | title = | ||
| event text = | | event text = EN Revision Imported Date : 2/21/2020 | ||
CONTAINMENT RELIEF VALVES INOPERABLE | |||
At 22:18 (EST) on 1/21/20, it was discovered that all Unit 1 containment vacuum relief isolation valves were closed and all vacuum relief lines were simultaneously inoperable; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). The isolation valves were opened and the vacuum relief valves were restored to operable. | |||
| URL = https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2020/ | There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. | ||
* * * UPDATE ON 02/20/2020 AT 1626 EST FROM FRANK SCHULTE TO BRIAN P. SMITH * * * | |||
At 1549 (EST), February 20, 2020, a completed engineering evaluation of the condition initially reported on January 22, 2020 determined that the inoperability of the Sequoyah Unit 1 Containment Vacuum Relief System affected the ability to protect containment against an external pressure event. This condition is not bounded by existing design and licensing documents; however, it poses no impact to the health and safety of the public or plant personnel. The condition was resolved when isolation valves were opened on January 21, 2020 and the vacuum relief lines were restored to an operable status. Therefore, this event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(B), "an unanalyzed condition that significantly degrades plant safety. | |||
Subsequent to the initial notification, continued evaluation of the reported condition has concluded that the isolation of the containment vacuum relief function did not prevent the fulfillment of a safety function that is needed to control the release of radioactive material; nor mitigate the consequences of an accident therefore this event is not reportable under 10 CFR 50.72(b)(3)(v), "Event or Condition that could have prevented fulfillment of a safety function. | |||
The NRC Resident has been notified. | |||
Notified R2DO (Musser) | |||
| URL = https://www.nrc.gov/reading-rm/doc-collections/event-status/event/2020/20200221en.html#en54487 | |||
}} | }} | ||
{{ENS-Nav}}[[Category:Power Reactor]] | {{ENS-Nav}}[[Category:Power Reactor]] | ||
Latest revision as of 12:54, 15 January 2021
| Where | |
|---|---|
Sequoyah  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+1.27 h0.0529 days <br />0.00756 weeks <br />0.00174 months <br />) | |
| Opened: | John Alexander 04:34 Jan 22, 2020 |
| NRC Officer: | Brian P. Smith |
| Last Updated: | Feb 20, 2020 |
| 54487 - NRC Website | |