Semantic search
| Entered date | Event description | |
|---|---|---|
| ENS 55802 | 25 March 2022 20:05:00 | The following information was provided by the licensee via email: As part of the extent of condition review for EN55770, (Urenco USA) UUSA identified historical instances where construction vehicles may have been allowed near buildings of concern and our process failed to identify if controls needed to be established for the activities planned. The hazards associated with those construction vehicles were not properly analyzed. UUSA failed to properly document and require controls and, during those times, available (Item Relied On For Safety) IROFS appear to be insufficient to meet the performance requirements in (10 CFR) 70.61. No unanalyzed vehicles presently exist near buildings of concern. This event has been entered in UUSA's corrective action program as EV 149990. The plant is in a safe configuration. The licensee notified NRC Region 2 personnel. |
| ENS 54492 | 22 January 2020 19:00:00 | Urenco USA is conservatively reporting a condition in that Uranic bearing material was placed into the Small Component Decontamination Train (SCDT) without meeting all conditions of IROFS54a and IROFS54b. IROFS54a and IROFS54b are Mass Controls that ensure the configuration of the SCDT remains sub-critical. Bookkeeping elements of the IROFS were performed correctly and the masses of the components were determined properly. However the visual inspection of the SCDT to ensure it is empty, prior to introducing components, was not performed in accordance with procedure instructions. The components were removed and the visual inspection was performed which confirmed the SCDT was in fact empty. The facility was and remains in a safe and stable configuration. The licensee will notify NRC Region 2 tomorrow.
This event was determined to not be reportable. Consistent with NRC FCSS ISG-12, Rev 1, 10 CFR Part 70, Appendix A - Reportable Safety Events, UUSA has concluded that EN54492 was not reportable. All situations where IROFS have failed or degraded are reportable under Paragraphs (a)(4) or (b)(2), exceptions include the following: The capabilities of the degraded IROFS are still sufficient to meet the performance requirements of 10 CFR 70.61. On 01-17-2020, UUSA completed a discharge of material to the slab tanks in the Liquid Effluent Collection Treatment & Storage (LECTS) Room. Upon completion of decontamination activities in the SCDT, procedurally required actions were performed to ensure all in process uranic material was removed and verification of the uranic material hold-up value was still valid in accordance with IROFS54a&b. IROFS54a&b tags and locks were then installed indicating the IROFS functions had been performed. On 01-22-2020, a new work evolution began which included bookkeeping measurements to ensure the calculated mass of uranium was below the allowable threshold prior to introduction to the SCDT. In summary, all requirements of the IROFS54a&b boundary were functionally complete and the capabilities of the degraded IROFS remained sufficient to meet the performance requirements of 10 CFR 70.61. Notified the R2DO (Coovert) and NMSS Events Notification (email) |
| ENS 53604 | 14 September 2018 11:29:00 | The UUSA (URENCO USA) facility CAAS (Criticality Accident and Alarm System) exists to detect and alarm in the unlikely event of a criticality accident, as required by 10 CFR 70.24, Criticality accident requirements. This monitoring system will be temporarily disabled during planned corrective maintenance activities for approximately thirty minutes, commencing at approximately 0730 MDT, on Saturday, September 15th, 2018. This activity will affect the CAAS in the Separations Building Module (SBM) 1001/1002 and the Cylinder Receipt and Dispatch Building (CRDB). The CAAS in the remaining portions of the facility will be unaffected. Essential personnel will remain inside the controlled access area during the maintenance activities. The populated areas of the facility will be limited to the Security Alarm Station, Operations Control Room, and the Maintenance Area housing the CAAS control cabinets in the Technical Services Building (TSB) where technicians will be needed for this work evolution. CAAS coverage of these populated areas will be provided during the maintenance activity by temporary criticality detection equipment. Compensatory measures will be implemented in accordance with section 3.1.5 of the UUSA Integrated Safety Analysis (ISA) Summary. These measures including evacuation of non-essential personnel from the areas of concern and the Immediate Evacuation Zone (IEZ) before removing the equipment from service, limiting access into facility, and restricting Special Nuclear Material (SNM) movement will be implemented until CAAS coverage is verified operational. UUSA will notify the NRC when CAAS coverage is returned to normal operation. Radiation surveys will be conducted prior to re-entry to confirm acceptable conditions in the area. The licensee has notified the NRC Project Manager.
The Criticality Accident and Alarm System was returned to service at 0930 MDT after the completion of the scheduled maintenance. During the maintenance period, no abnormal radiation readings were observed. Notified R2DO (Ernstes). |