ENS 49678
ENS Event | |
|---|---|
12:44 Dec 29, 2013 | |
| Title | Switchgear Room Door Discovered Unlatched |
| Event Description | A condition was discovered on December 29, 2013 that could have prevented the fulfillment of safety functions to shutdown the reactor and maintain it in a safe shutdown condition and mitigate the consequences of an accident.
On December 29, 2013, a water tight door between the East Switchgear and Service Building was discovered not dogged (unlatched). Upon discovery, the safety function was immediately restored by properly dogging (latching) the subject door. The subject door between the East Switchgear and Service Building protects both trains' of safety related switchgears. The access Key Log indicates the door was in the condition for approximately 60 minutes. If the door is inoperable, then T.S. 3.0.3 applies. This condition is being reported pursuant to 10CFR50.72(b)(3)(v)(A) and 10CFR50.72(b)(3))(v)(D). The NRC Resident lnspector has been notified [by the licensee]. The licensee has notified state and local authorities. The door is required to be properly secured to protect the East Switchgear from a potential High Energy Line Break and was left improperly dogged by a security officer while making rounds. Millstone Unit 3 did not enter T.S.3.0.3 and continues to operate at 100%.
Upon further review the fact that the switchgear room door was closed but not latched did not render the switchgear within the room inoperable, and therefore, there was no loss of safety function. The engineering evaluation determined the switchgear would have been protected for high energy line break, flooding, and tornado pressure drop events. Additionally, the carbon dioxide fire suppression capability would have also been maintained. The details of the engineering review will be provided to the NRC Senior Resident Inspector. Notified R1DO (DeFrancisco). |
| Where | |
|---|---|
Millstone  Connecticut (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+2.68 h0.112 days <br />0.016 weeks <br />0.00367 months <br />) | |
| Opened: | Michael Socha 15:25 Dec 29, 2013 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Feb 27, 2014 |
| 49678 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |