ENS 42226
ENS Event | |
|---|---|
19:00 Dec 22, 2005 | |
| Title | Safety Equipment Failure |
| Event Description | While performing semi-annual criticality accident alarm system (CAAS) testing, one unit in a pair of detectors failed to initiate the site wide alarm. Spare unit was immediately installed and all systems successfully tested. Production facility covered by this CAAS [was] in a shutdown status at the time of testing. Subsequent troubleshooting indicated a faulty electronic relay contact in the failed unit.
Testing of CAAS is conducted on a semi-annual basis in accordance with procedure, NFS-HS-A-80, Sections 5.5 & 5.6. [The] Detector pair on 2nd floor of Oxide Conversion Facility did not activate site-wide alarm as expected. Alarm indication did occur as expected at the local read-out panel, and at the central alarm panel located in an adjacent building occupied by security guards. Investigation revealed failed relay contact in Eberline Instruments Model RMS-3 read-out meter. [The] Unit [was] replaced, and [a] subsequent test [was] satisfactory. No actual safety consequences occurred as a result of this event; however, there was a risk of potential health and safety consequence to the occupational workforce, involving significant radiation exposure from accidental criticality event with no warning to initiate prompt site-wide evacuation. The licensee notified the NRC Resident Inspector.
Following evaluation of this event by the licensee's Part 21 review committee, Nuclear Fuel Services has reached the conclusion that this event was the result of a design defect in the relay used in the RMS-3 read-out meter. This event is being updated to reflect the Part 21 reportability conclusion. The Eberline RMS-3 read-out meter is manufactured by Thermo Electron Corporation. Nuclear Fuel Services has been in contact with Eberline during its investigation and Eberline is aware of the conclusions. The defective relay is manufactured by Potter and Brumsfield. Immediate corrective actions included replacement of the defective equipment, and re-testing to ensure operability; long term corrective action includes design and installation of PLC based surveillance equipment to continuously monitor the function of system components by NFS Engineering Department in approximately 3 - 6 months. The licensee notified the NRC Resident Inspector. The R2DO (Bernhard), NMSS EO ( Janosko) and Part 21 coordinator (Markley) have been notified.
This event has been decontrolled to make it publicly available and permit information about this problem to be shared with all affected parties. NRC management has determined that the report does not contain information about sensitive operations at the NFS site. R2DO(Bernhard) and NMSS (Morell) notified. |
| Where | |
|---|---|
| Nuclear Fuel Services Inc. Erwin, Tennessee (NRC Region 2) | |
| License number: | SNM-124 |
| Reporting | |
| 10 CFR 70.50(b)(2) 10 CFR 21.21 | |
| Time - Person (Reporting Time:+18.5 h0.771 days <br />0.11 weeks <br />0.0253 months <br />) | |
| Opened: | Mike C. Tester 13:30 Dec 23, 2005 |
| NRC Officer: | Arlon Costa |
| Last Updated: | Feb 7, 2006 |
| 42226 - NRC Website | |
Nuclear Fuel Services Inc. with 10 CFR 70.50(b)(2), 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | |
WEEKMONTHYEARENS 559022022-05-18T18:50:00018 May 2022 18:50:00
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