ENS 45316
ENS Event | |
|---|---|
15:14 Aug 31, 2009 | |
| Title | Secondary Containment Boundary Door Inoperable |
| Event Description | During normal entry / exit through secondary containment boundary door 1A401, it was discovered that the door would not latch closed due to interferences between the door and its frame. The door was unable to be latched closed for approximately 5 minutes which represented a possible path for uncontrolled release of radioactive material. No release of radioactive material occurred as a result of this event.
The time during which the door would not latch was spent diligently troubleshooting to determine why the door would not secure. When discovered, the interference was immediately removed and the door was secured (latched). Door 1A401 is now operable as a secondary containment boundary but is currently deactivated and posted by security to prevent use as a conservative measure until further inspection and maintenance can be preformed on the door to prevent this issue from reoccurring. At this time secondary containment is operable with boundary door 1A401 closed and latched. The licensee has notified the NRC Resident Inspector.
Retraction of Notification EN# 45316. The event was reported by Grand Gulf Nuclear Station on 08/31/2009 at 1014 CDT. This update is being provided for the purpose of retracting that notification. On August 31, 2009, during normal entry/exit through secondary containment boundary door 1A401, it was discovered that the door would not latch closed due to interferences between the door and its frame. The door was unable to be latched closed for approximately 5 minutes which represented a possible loss of safety function since it could have provided a path for uncontrolled release of radioactive material. No release of radioactive material occurred as a result of this event. As part of the event investigation, the malfunction (inability to close and latch) of door 1A401 was simulated under controlled conditions. Data was obtained under normal ventilation conditions and under the condition with one train of Standby Gas Treatment System (SGT) operating. Analysis of the data determined that the SGT system was able to drawdown the secondary containment enclosure building pressure to greater than 0.311 inch of vacuum water gauge (for no assumed failures) which is above the Technical Specification (TS) 3.6.4.1 surveillance minimum requirement of 0.266 inch of vacuum water gauge (following a postulated accident with assumed failures) using one SGT subsystem. Therefore, this event did not constitute a loss of the safety function of secondary containment and this event is not reportable. The licensee notified the NRC Resident Inspector. Notified R4DO (Powers). |
| Where | |
|---|---|
Grand Gulf  Mississippi (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material | |
| Time - Person (Reporting Time:+3.03 h0.126 days <br />0.018 weeks <br />0.00415 months <br />) | |
| Opened: | Terry Holcombe 18:16 Aug 31, 2009 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Oct 30, 2009 |
| 45316 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |