ENS 55480
ENS Event | |
|---|---|
20:01 Jul 20, 2021 | |
| Title | CAAS Alarm Not Clearly Audible |
| Event Description | During routine Criticality Accident Alarm System (CAAS) maintenance on July 20, 2021, UUSA [(URENCO USA)] staff identified an area in which the CAAS alarm was not clearly audible. The alarm was (and is) functioning, but not at an adequate level of sound pressure to meet the acceptance criteria. UUSA arranged compensatory measures which achieve an equivalent safety function within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in the affected area. The affected area was in the Immediate Evacuation Zone (IEZ), outside of the area in which licensed special nuclear material is handled, used, or stored.
On September 16, 2021, an NRC inspector conducting an onsite inspection informed UUSA staff that given the potential that the alarm had not been clearly audible for a period of time between surveillances, this event should have been reported within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to the NRC in accordance with 10 CFR 70.50(b)(2) in which equipment is disabled or fails to function as designed when required by regulation (10 CFR 70.24). The licensee will notify the NRC Region 2.
During the Apparent Cause Evaluation related to Event Notification 55480, an extent of condition was performed. This extent of condition revealed three historical examples of inaudible CAAS alarms that were not reported under 10 CFR 70.50(b)(2) as required by regulation. These conditions occurred on April 12th, 2014, August 15th, 2014, and August 20th, 2015. Corrective actions were implemented for these deficiencies during the approximate time period in which they were identified. The affected systems are currently compliant with 10 CFR 70.24 regulations. Details of this extent of condition are documented in UUSA's Corrective Action Program, EV 148663. The licensee notified NRC Region 2 personnel. Notified R2DO (Miller) and NMSS Event Notifications via email. |
| Where | |
|---|---|
| Louisiana Energy Services Eunice, New Mexico (NRC Region 2) | |
| License number: | SNM-2010 |
| Reporting | |
| 10 CFR 70.50(b)(2) | |
| Time - Person (Reporting Time:+1412.9 h58.871 days <br />8.41 weeks <br />1.935 months <br />) | |
| Opened: | Blake Bixenman 16:55 Sep 17, 2021 |
| NRC Officer: | Ossy Font |
| Last Updated: | Nov 8, 2021 |
| 55480 - NRC Website | |
Louisiana Energy Services with 10 CFR 70.50(b)(2) | |
WEEKMONTHYEARENS 565502023-06-01T08:39:0001 June 2023 08:39:00
[Table view]10 CFR 70.50(b)(2) Partial Loss of Criticality Accident Alarm System ENS 555642021-11-05T18:07:0005 November 2021 18:07:00 10 CFR 70.50(b)(2) Loss of High Radiation Audible Alarm ENS 554802021-07-20T20:01:00020 July 2021 20:01:00 10 CFR 70.50(b)(2) CAAS Alarm Not Clearly Audible ENS 536042018-09-15T06:00:00015 September 2018 06:00:00 Information Only, 10 CFR 70.50(b)(2) Preplanned Outage of a Required Safety Monitoring System ENS 530462017-09-07T06:00:0007 September 2017 06:00:00 10 CFR 70.50(b)(2) Wrong Irofs Procedure Followed Prior to Filling Cylinder ENS 515932015-12-07T23:00:0007 December 2015 23:00:00 10 CFR 70.50(b)(2) Crane Item Relied Upon for Safety Never Installed 2023-06-01T08:39:00 | |