ENS 49165
ENS Event | |
|---|---|
19:09 Jun 28, 2013 | |
| Title | Unplanned Contamination Event That Restricted Access for Greater than 24 Hours |
| Event Description | At 1409 hours0.0163 days <br />0.391 hours <br />0.00233 weeks <br />5.361245e-4 months <br /> [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 hours0.02 days <br />0.481 hours <br />0.00286 weeks <br />6.58265e-4 months <br /> 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 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and the room remains restricted at this time.
This event is reportable as a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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. |
| Where | |
|---|---|
| Paducah Gaseous Diffusion Plant Paducah, Kentucky (NRC Region 2) | |
| License number: | GDP-1 |
| Reporting | |
| 10 CFR 76.120(c)(1) | |
| Time - Person (Reporting Time:+70.73 h2.947 days <br />0.421 weeks <br />0.0969 months <br />) | |
| Opened: | Kevin Beasley 17:53 Jul 1, 2013 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Jul 14, 2013 |
| 49165 - NRC Website | |
Paducah Gaseous Diffusion Plant with 10 CFR 76.120(c)(1) | |
WEEKMONTHYEARENS 492332013-08-02T14:32:0002 August 2013 14:32:00
[Table view]10 CFR 76.120(c)(1) Contamination Found in Process Building ENS 491652013-06-28T19:09:00028 June 2013 19:09:00 10 CFR 76.120(c)(1) Unplanned Contamination Event That Restricted Access for Greater than 24 Hours ENS 489902013-04-30T18:20:00030 April 2013 18:20:00 10 CFR 76.120(c)(1) Area Access Restricted for More than 24 Hours Due to Increased Radiological Controls ENS 471112011-07-31T15:30:00031 July 2011 15:30:00 10 CFR 76.120(c)(1) Unplanned Contamination Area ENS 454132009-10-04T20:00:0004 October 2009 20:00:00 10 CFR 76.120(c)(1) Unplanned Contamination During Startup ENS 438642007-12-23T09:58:00023 December 2007 09:58:00 Other Unspec Reqmnt, 10 CFR 76.120(c)(1) Small Uf6 Process Leak ENS 438292007-12-07T02:44:0007 December 2007 02:44:00 Other Unspec Reqmnt, 10 CFR 76.120(c)(1) Unplanned Safety System Actuation and Contamination Event ENS 438282007-12-06T21:50:0006 December 2007 21:50:00 Other Unspec Reqmnt, 10 CFR 76.120(c)(1) Unplanned Safety System Actuation and Contamination Event 2013-08-02T14:32:00 | |