ENS 44740
ENS Event | |
|---|---|
12:49 Dec 23, 2008 | |
| Title | Degraded Safety Equipment |
| Event Description | Area 600 uses a flammable gas as part of its operation. IROFS [Items Relied On For Safety] FIRE6-6 is a control that prevents the flammable gas from exiting the main process equipment and being released into an attached glovebox. FIRE6-6 makes use of a dual door system in which only one (1) door is allowed to be open at a time and the chamber between the doors is purged when both doors are closed. The accident scenario of concern is release of the flammable gas into the glovebox where it could mix with oxygen, creating a potential for an explosion inside Building 302. Additionally, IROFS FIRE6-8, 6-1 and 6-9 ensure an inert gas purge occurs prior to opening the main process equipment to the glovebox and are also credited as IROFS.
The equipment associated with FIRE6-6 is designated as Safety Related Equipment (SRE) and is functionally tested annually. The regularly scheduled SRE Test was performed on December 23, 2008, and the purpose of the test is to demonstrate that each door remains closed while the other door is opened. The test failed because when the first door was opened, the second door also opened slightly (approximately one (1) inch). Though there are mitigating factors such as potential dilution of the flammable gas through the glovebox ventilation system, it was determined that IROFS FIRE6-6 was degraded and that the performance criteria of 10CFR70.61 were not met. A similar event was reported to the NRC (#44584) on October 21, 2008 for similar equipment in Bldg 302. However, the cause of the previous IROFS failure was due to a blocked speed controller which failed to bleed off air. The blocked speed controlled is unrelated to the current IROFS failure. POTENTIAL CONSEQUENCES: Potential explosion in a glovebox and release of radiological material and exposure to the worker. No actual explosion or radiological exposure occurred. SEQUENCE OF OCCURRENCES: The event occurred due a degraded IROFS that was discovered during a periodic functional test. Initial investigation indicates an airline solenoid valve is leaking by. ACTIONS TAKEN: Operations has closed the flammable gas supply for Area 600 Bldg 303 until the equipment associated with FIRE6-6 is fixed and the SRE test passes. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
| Nuclear Fuel Services Inc. Erwin, Tennessee (NRC Region 2) | |
| License number: | SNM-124 |
| Reporting | |
| Part 70 App A (B)(2) | |
| Time - Person (Reporting Time:+-2.22 h-0.0925 days <br />-0.0132 weeks <br />-0.00304 months <br />) | |
| Opened: | Mike Tester 10:36 Dec 23, 2008 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Dec 23, 2008 |
| 44740 - NRC Website | |
Nuclear Fuel Services Inc. with Part 70 App A (B)(2) | |
WEEKMONTHYEARENS 561492022-10-05T19:00:0005 October 2022 19:00:00
[Table view]Part 70 App A (B)(2) Degradation of Safety Items ENS 448872009-03-03T05:00:0003 March 2009 05:00:00 Part 70 App A (B)(2) Degradation of Item Relied on for Safety (Irofs) ENS 447402008-12-23T12:49:00023 December 2008 12:49:00 Part 70 App A (B)(2) Degraded Safety Equipment ENS 445842008-10-21T17:02:00021 October 2008 17:02:00 Part 70 App A (B)(2) Irofs Failure in Area 600 ENS 441042008-03-28T14:00:00028 March 2008 14:00:00 Part 70 App A (B)(2) Filters Not Scanned Properly for Activity Prior to Packaging ENS 415232005-03-24T19:00:00024 March 2005 19:00:00 Part 70 App A (B)(2)
2022-10-05T19:00:00 | |