Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 55902 | 18 May 2022 18:50:00 | 10 CFR 70.50(b)(2) | Criticality Accident Alarm System Speakers Disabled | The following information was provided by the licensee via email: On May 18, 2022, at approximately 1450 (EDT), an electrical switch for the Criticality Accident Alarm System (CAAS) legacy speakers was noted to be out of its normal position. A functional redundant speaker system is installed in the main processing plant and laboratory. As a consequence of the switch being out of position, in the highly unlikely event that the CAAS had actuated, the alarm would not have been annunciated in areas outside of the main processing area and laboratory where there are no redundant speakers. Compliance was restored at approximately 1500 (EDT) when the switch was placed back in its normal position. The system was subsequently tested and confirmed to be operational. The most recent audibility test of the speaker system had been performed on May 13, 2022, at approximately 1100 (EDT). The licensee notified the NRC Resident Inspector on May 18, 2022, at approximately 1625 (EDT). There were no actual nuclear safety consequences. The potential consequence was that, in the event of a nuclear criticality accident, evacuation could have been delayed for those personnel outside of the main processing area where redundant speakers have not been installed. | ||
| ENS 54218 | 13 August 2019 20:00:00 | 10 CFR 70.50(b)(2) | Criticality Accident Alarm System Speaker Failure | At approximately 1320 (EDT) one speaker in the Low Enriched Uranium (LEU) area was identified as not operating when a series of Public Address (PA) announcements were made. Strobe lights, however, were functioning in the area. At 1430 compensatory measures were established to limit access in the affected area to only those personnel with radio communication with the alarm room. At 1600 the system was tested and it was confirmed that the Criticality Accident Alarm System (CAAS) was not audible in the LEU area. No other areas were effected. On August 13, 2019 at approximately 1726, full compliance was restored when the speaker was replaced and satisfactorily retested. The most recent audibility test of this area had been satisfactorily performed on August 6, 2019 at approximately 1100. The licensee notified the NRC Resident Inspector on August 13, 2019 at approximately 1653. | ||
| ENS 52404 | 1 December 2016 15:14:00 | 10 CFR 70.50(b)(2) | Office Area Alarm Audibility Disabled | On December 1, 2016, at 1014 hours (EST), the speakers for a portion of the bottom floor of Building 305, office and lunch room areas, were inadvertently disabled during construction activities to remove obsolete equipment. Special Nuclear Material (SNM) is not processed, handled, or stored within the areas where the speaker system was disabled; however, these areas require evacuation in the unlikely event of a nuclear criticality accident as described in the NFS (Nuclear Fuel Services) Emergency Plan. There were no actual radiological or other nuclear safety consequences. The potential consequence was that in the event of a nuclear criticality accident, evacuation could have been delayed for those personnel within these areas with a resultant increase of postulated doses. Additionally, awareness of a fire event could have been delayed for these same personnel. A series of compensatory actions were taken including restricting access to the affected areas to essential personnel, and establishing radio communications between the personnel in these areas and the personnel continuously monitoring the alarm station panel. On December 1, 2016, at approximately 1159 hours (EST), full compliance was restored by repairing a disabled cable in the speaker circuit and by successfully performing a speaker system test in the affected areas. The licensee notified the NRC Resident Inspector on. December 1, 2016. | ||
| ENS 52358 | 9 November 2016 16:15:00 | 10 CFR 70.50(b)(2) | Insufficient Alarm Audibility | On November 9, 2016, at approximately 1115 hours (EST), the speaker system in Buildings 302, 303, and 306 West was identified as non-operational while performing a functional test of the system. This speaker system is designed to annunciate alarms generated from the Criticality Accident Alarm System (CAAS) required by 10CFR70.24, alarms generated from the Fire Alarm Control Panel and Public Address System announcements. Additional functional testing identified that no redundant speakers could adequately provide speaker coverage for all affected areas of these buildings. Special Nuclear Material (SNM) is processed, handled, or stored within the areas where the speaker system failed; these areas require evacuation in the unlikely event of a nuclear criticality accident as described in the NFS Emergency Plan. There were no actual radiological or other nuclear safety consequences. The potential consequence was that in the event of a nuclear criticality accident, evacuation could have been delayed for those personnel within these areas with a resultant increase of postulated doses. Additionally, awareness of a fire event could have been delayed for these same personnel. A series of compensatory actions were taken including implementing a plant-wide stop-movement of SNM, limiting access to the affected areas to essential personnel, and establishing radio communications between the personnel in these areas and the personnel continuously monitoring the alarm station panel. On November 9, 2016, at approximately 1725 hours (EST), full compliance was restored by repairing a damaged cable and by successfully performing a speaker system test in the affected areas. The licensee notified the NRC Resident Inspector on November 9, 2016. NFS Event Number: 55579 | ||
| ENS 52190 | 17 August 2016 21:39:00 | 10 CFR 70.50(b)(2) | Failure of a Speaker in an Area Potentially Requiring Personnel Evacuation | On August 17, 2016 at approximately 1739 hours (EDT), one speaker in Building 120 was identified as non-operational while performing a functional test of the system. This speaker is designed to annunciate alarms generated from the Criticality Accident Alarm System (CAAS) required by 10CFR70.24, alarms generated from the Fire Alarm Control Panel, and Public Address System announcements. Additional functional testing identified that no redundant speaker could adequately provide speaker coverage for all affected areas of this building. Special Nuclear Materials are not processed, handled, or stored within the area where the speaker failed; however, this area requires evacuation in the unlikely event of a nuclear criticality accident as described in the NFS Emergency Plan. There were no actual radiological or other nuclear safety consequences. The potential consequence was that in the event of a nuclear criticality accident, evacuation could have been delayed for those personnel within Building 120 with a resultant increase of postulated doses. A series of compensatory actions were taken to restore compliance including installation of a temporary speaker and limiting equipment operation to limit background noise. On August 18, 2016, at approximately 1100 hours (EDT), full compliance was restored as demonstrated by successfully performing a speaker test in the affected area. The licensee notified the NRC Resident Inspector on August 18, 2016. | ||
| ENS 49998 | 4 April 2014 17:15:00 | 10 CFR 70.50(b)(2) | Criticality Accident Evacuation Alarm Not Audible in Certain Areas Outside the Material Handling Area | At approximately 1315 hours (Eastern Daylight Time) on April 4, 2014, while testing the audibility of the criticality accident evacuation alarm in the Building locker room, a report was made that the alarm could not be heard in an office trailer restroom. Subsequent testing confirmed the evacuation alarm could not be heard in the office trailer restroom when the fan was running. Safety management personnel were notified of the problem and other restrooms were tested. Testing revealed that the alarm was not able to be heard in three (3) additional office trailer restrooms. All affected restrooms were posted with signs indicating the areas are not to be occupied pending resolution of the audibility issue. It should be noted that the restrooms are located outside of the material processing areas. The licensee notified the NRC Resident Inspector. See similar event EN #49848. | ||
| ENS 49848 | 21 February 2014 13:39:00 | 10 CFR 70.50(b)(2) | Audibility of Alarm System | A report was made to the facility Corrective Action Program (PIRCS) at 0839 (EST) on 2/21/2014 regarding difficulty hearing plant announcements and alarms in the recently renovated Building 110B restroom. Testing of the Public Address (PA) system confirmed that the PA system was difficult to hear. The speakers associated with the PA system are also used for annunciating the site criticality accident alarm evacuation warning. Subsequent testing of the criticality evacuation alarm indicated the alarm was difficult to hear as well. Safety management personnel were notified of the problem and the restroom was locked and posted with signs indicating the area was not to be occupied, pending resolution of the audibility issue. The licensee notified the NRC Resident Inspector. | ||
| ENS 46086 | 12 July 2010 16:00:00 | 10 CFR 70.50(b)(2) | Electrical Fault Disabled Public Address System Which Supports Various Alarm Annunciators | At approximately 1200 hours (EST) on 7/12/2010, an electrical fault was identified in the fire alarm system. This fault disabled the public address portion of the system which supports annunciation of plant alarms including the following: fire alarm, criticality alarm, take-cover alarm, (carbon dioxide) discharge alarms. Trouble shooting of the problem is continuing. There is no impact to actual detection, suppression, etc. systems. Compensatory measures include the following: stop SNM handling and movement, fire patrols, restriction of hot work, notification to facility personnel, evacuation of nonessential personnel from production areas, fire brigade on standby and radios provided to fire brigade officers and some fire brigade members. It is believed that the condition was associated with heavy rainfall and possible water intrusion. There were no actual safety consequences to workers, the public, or the environment associated with the event. Potential consequences to workers, the public, or the environment are mitigated by compensatory measures. The licensee notified the NRC Resident Inspector.
The public address portion of the plant alarm system was restored on 7/13/2010. It appears that recent rain storms caused some wiring to develop short circuits. These short circuits were corrected. The system is continuing to be monitored and wiring may be identified that requires replacement. It was confirmed that the criticality alarm portion of the plant alarm system was not impacted during the recent outage. The licensee notified the NRC Resident Inspector. Notified R2 DO (Seymour), NMSS EO (Hiltz) , Fuels Grp (Email) | ||
| ENS 45179 | 30 June 2009 20:00:00 | 10 CFR 70.50(b)(2) | Safety Equipment Failure of the Criticality Alarm System | The public address system (criticality accident alarm) was impaired for a portion of the Building 310 warehouse and a subcontractor trailer. The cause of the impairment was determined to be the result of a contractor drilling into a public address system speaker wire while installing fire protection components in the Building 310 warehouse. This created an electrical short which rendered the speakers inoperable for a portion of the Building 310 warehouse and a subcontractor trailer. The speaker wire was obscured from view by a structural beam. The system was repaired, tested, and placed back into service by 1721 hours (EDT) on 6/30/2009. The NRC Resident Inspector was notified. | ||
| ENS 43883 | 5 January 2008 14:00:00 | 10 CFR 70.50(b)(2) | Safety Equipment Failure of the Criticality Alarm System | SNM-124 Section 12.6.4 requires that criticality alarm system detector pairs must generate an alarm signal when both detectors in a pair exceed their trip point, or when one detector is in a fault condition while the other exceeds the alarm trip point. During testing, 2 of 18 detector pairs did not generate an alarm signal in all modes as discussed above. In the event of a criticality, 2 detector pairs may not have generated an alarm signal. During 27 December 2007 through 29 December 2007, a programmable logic controller (PLC) monitoring system was attached to the critical alarm system components. On 29 December 2007, all detector pairs were satisfactorily tested that they would generate an alarm signal when required. During 31 December 2007 until 5 January 2008, limited SNM operations were conducted at the plant. Suspect equipment faults occurred during the time frame from 29 December 2007 to 5 January 2008 due to unknown cause. Troubleshooting revealed an equipment fault in each detector pair that failed during testing. These faults have been corrected and the detector pairs satisfactorily retested. The two (2) affected detector pairs are located in the NDA North & South and Building 311 North & South. There were no recorded trouble alarms generated by the operable detector in the affected areas during the week when the system was not functioning properly. Also, there is no indication of tampering in that the fault was identified as loose wiring/connections inside locked cabinets accessible to authorized personnel only. The licensee informed the NRC Resident Inspector. | ||
| ENS 42226 | 22 December 2005 19:00:00 | 10 CFR 70.50(b)(2) 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | Safety Equipment Failure | 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. |