Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 49233 | 2 August 2013 14:32:00 | 10 CFR 76.120(c)(1) | Contamination Found in Process Building | While Health Physics (HP) technicians were checking radiological control wrapping in the Uncomplicated Handling (UH) waste storage area on the ground floor of the C-337 Process Building, contamination was discovered on the floor around some valve subassemblies. A Contamination Area (CA) was set up to establish contamination boundaries. Due to the contamination spread, access requirements for the area will be increased for more than 24 hours. Decontamination efforts are underway but will not be completed within 24 hours from the time that radiological controls were increased. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(1)(i) 'An unplanned contamination event that: requires access to the contaminated area, by workers or the public, to be restricted for more than 24 hours by imposing additional radiological controls or by prohibiting entry into the area'. The NRC Resident Inspector has been notified of this event. PGDP Problem Report No. ATRC-13-1667: PGDP Event Report No. PAD-2013-06. | ||
| ENS 49165 | 28 June 2013 19:09:00 | 10 CFR 76.120(c)(1) | Unplanned Contamination Event That Restricted Access for Greater than 24 Hours | At 1409 hours (CDT) on 6/28/2013, the Plant Shift Superintendent was notified of an unplanned contamination event that occurred in the C-710 Laboratory building. The controller program for the sample cylinder wash system in room #21 failed, causing supply water to flow out of the system. The water leaked through the floor into room B-23, which is located in the basement, and spread contamination onto the floor and a table. The area of the known water leak was immediately posted as a contamination area. Chemical Operations decontaminated the area that was initially contaminated by the water leak at 1730 hours on 6/28/2013. During follow-up investigative surveys conducted by Health Physics, additional contamination was discovered in other areas of the room causing the entire room to be posted as a contamination area (CA). It was initially thought that the additional contamination which was found was legacy contamination unrelated to the water leak; however, based on further investigation and HP survey results (on 7/1/13), it appears that contamination found elsewhere in the room also came from the water leak event. All contamination related to this event was not cleaned up within 24 hours and the room remains restricted at this time. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(1)(i), 'An unplanned contamination event that: Requires access to the contaminated area, by workers or the public, to be restricted for more than 24 hours by imposing additional radiological controls or by prohibiting entry into the area'. The NRC Resident Inspector has been notified of this event. Room B-23 remained locked over the weekend and was not accessed by plant personnel so the possibility of spreading contamination was minimized. PGDP Problem Report No. ATRC-13-1468: PGDP Event Report No. PAD-2013-05.
Calculations were performed by the Health Physics group of the estimated quantity of material in the release. The estimate was based on: (1) An isotopic analysis of the contamination revealed three predominant isotopes, all Uranium daughters, Pa-234, Thorium-231, and Thorium-234; (2) the estimated water volume 'released' of 8.0 liters; and (3) that the isotopic concentration in the 8.0 liters of water was homogeneous. Based on the calculations, the summation of the mixture of isotopes was 4.52E2 microcuries and is approximately 30 percent of 5 ALI (annual limit on intake) for the most restrictive isotope, Th-234 (1.5E3 microcuries). Therefore part (ii) of 10 CFR 76.120(c)(1) was not met and reporting is not required. Based on the above information the subject notification should be retracted. This retraction has been discussed with the NRC Senior Resident Inspector. R2DO (Nease) and NMSS EO (Benner) notified. | ||
| ENS 48990 | 30 April 2013 18:20:00 | 10 CFR 76.120(c)(1) | Area Access Restricted for More than 24 Hours Due to Increased Radiological Controls | On 04/30/13, while changing the feed from Position 3 East to Position 3 West autoclaves, Operators noticed a pressure spike on the 3 East cylinder to approximately 47 psia. After disconnecting the cylinder in Position 3 East with Health Physics (HP) assistance, HP found a contamination spread on the cylinder, on the grating within the autoclave, and on the autoclave locking ring. Due to the contamination spread, access requirements to the area will be increased for more than 24 hours. Decontamination efforts are underway but will not be completed within 24 hours from the time that radiological controls were increased. This event is reportable as a 24 hour event in accordance with 10 CFR 76.120(c)(1)(i) 'An unplanned contamination event that: Requires access to the contaminated area, by workers or the public, to be restricted for more than 24 hours by imposing additional radiological controls or by prohibiting entry into the area.' The NRC Resident Inspector has been notified of this event. | ||
| ENS 47111 | 31 July 2011 15:30:00 | 10 CFR 76.120(c)(1) | Unplanned Contamination Area | |||
| ENS 45413 | 4 October 2009 20:00:00 | 10 CFR 76.120(c)(1) | Unplanned Contamination During Startup | On 10/04/2009 at 1500 C-331 unit 2 cell 2 was being charged and placed on stream and had just gone above atmospheric pressure when a Maintenance Mechanic observed smoke coming from the cell instrument cubicle and determined it to be UF6 outleakage from cell process instrumentation. To stop the release the cell was immediately taken back below atmospheric pressure. Investigation revealed that a UF6 release had occurred inside the instrument cubicle. The amount of material released has not yet been determined. Decontamination is underway but has not been completed inside the cabinet. The area outside the cabinet has been decontaminated. No injuries or personnel exposure occurred as a result of this event. This is being reported based on 10 CFR 76.120(c)(1)(i) (unplanned contamination event). PGDP Problem Report Nos. ATRC-09-2435; PGDP Event Report No. PAD-2009-016. Responsible Division: Operations PGDP Assessment and Tracking Report No. ATR-09-2435; PGDP Event Report No. PAD-2009-16; Worksheet No. Responsible Division: Operations The NRC Senior Resident Inspector has been notified of this event. Decontamination is expected to be completed on 10/6/2009.
After further review, it was determined that the amount of contamination was significantly less than five times the lowest annual limit on intake specified in Appendix B to Section 20.1001-20.2402 of 10CFR20 for the material. The licensee notified the NRC Resident Inspector. Notified the R2DO (Guthrie) and NMSS (Whaley). | ||
| ENS 43864 | 23 December 2007 09:58:00 | Other Unspec Reqmnt 10 CFR 76.120(c)(1) | Small Uf6 Process Leak | On 12/23/2007 at 0358 the C-333 unit 3 cell 1 PGLD (process gas leak detection) head (YE-5) at stage 5 actuated. Along with the PGLD actuation a seal alarm and a vibration alarm on stage 7 were received. A nearby operator on the cell floor responded to the alarm and observed a small UF6 release from the stage 7A seal cavity. To stop the release the cell was immediately shut down from the ACR which lowered the cell's pressure to below atmospheric pressure. The exact amount of material released has not been determined. Checks by health physics personnel found the actual amount of UF6 released was not significant and resulted in a relatively small area of contamination on the end of the compressor near the seal that failed and on the floor immediately around the end of the compressor. The actuated PGLD head is a Q safety system component. At the time of the incident the cell was operating in a mode which required the system to be operational. This is being reported based on SAR 6.9 Table 1, J2 (unplanned actuation of a Q safety system) and 10 CFR 76.120(c)(1)(i) (unplanned contamination event). The NRC Resident Inspector has been notified of this event. PGLD Problem Report Nos. ATRC-07-3433; PGLD Event Report No. PAD-2007-022; NRC Event Number 43864 | ||
| ENS 43829 | 7 December 2007 02:44:00 | Other Unspec Reqmnt 10 CFR 76.120(c)(1) | Unplanned Safety System Actuation and Contamination Event | On 12/06/2007 at 2042 (CST) C-337 unit 5 cell 5 was being charged and placed on stream and had just gone above atmospheric pressure. At 2044 hours two PGLD (process gas leak detection) heads in the C-337 unit 5 cell 5 actuated and would not clear indicating a potential UF6 release. To stop the release the cell was immediately taken back below atmospheric pressure. Investigation revealed that a UF6 release had occurred causing the PGLD actuation. The amount of material released has not yet been determined. The PGLD heads are Q safety system components. At the time of the incident the cell was operating in a mode which required the system to be operational. This is being reported based on SAR 6.9 Table 1, J2 (unplanned actuation of a Q safety system) and 10 CFR 76.120 (c) (1) (i) (unplanned contamination event). The NRC Resident Inspector has been notified of this event. There was no release to the environment and no personnel contaminations reported. | ||
| ENS 43828 | 6 December 2007 21:50:00 | Other Unspec Reqmnt 10 CFR 76.120(c)(1) | Unplanned Safety System Actuation and Contamination Event | On 12/06/2007 at 1550 (CST) the C-337 unit 5 cell 3 PGLD (process gas leak detection) head in the C-337 unit 5 cell 3 housing actuated and would not clear. Response to the alarm by operators revealed a haze above the cell indicating a UF6 release inside the cell housing. While the operators were responding to the unit 5 Cell 3 alarm, two other PGLD heads actuated in C-337 unit 5 cell 5. To stop the release both cells 3 and 5 were taken below atmospheric pressure. Investigation indicated that a UF6 release had occurred. The amount of material released has not been determined. The actuated PGLD heads are Q safety system components. At the time of the incident the cell was operating in a mode which required the system to be operational. This is being reported based on SAR 6.9 Table 1, J2 (unplanned actuation of a Q safety system) and 10 CFR 76.120 (c) (1) (i) (unplanned contamination event). The NRC Resident Inspector has been notified of this event. There was no release to the environment and no personnel contaminations reported. |