ENS 47176
ENS Event | |
|---|---|
13:15 Aug 19, 2011 | |
| Title | 24-Hr Loss of Criticality Control Report Required Under Bulletin 91-01, Supplement 1 |
| Event Description | At 0815 CDT on 08-19-11, a Chemical Operations First Line Manager discovered that during disassembly of a single Seal Exhaust/Wet Air (SX/WA) pump, pump housing subcomponents (i.e. two piston slides and a cam) were placed within 2 feet of the internal oil separators. Nuclear Criticality Safety Approval (NCSA) GEN-011 requires a minimum 2-foot edge-to-edge spacing between pump housing subcomponents and internal oil separators. The purpose of this control is to ensure interaction between grossly contaminated fissile items is minimized during movement and storage. The Plant Shift Superintendent and the NCS group were notified and access to the area was controlled.
Since one leg of double contingency was lost, this is being reported to the NRC as a 24-hour Event Report in accordance with NRC BL 91-01, Supplement 1. The NRC Senior Resident Inspector has been notified of this event. PGDP Problem Report No. ATRC-11-2161 PGDP Event Report No. PAD-2011-13 POTENTIAL CRITICALITY PATHWAYS INVOLVED: In order for a criticality to be possible, the components would have to be grossly contaminated and brought together in a geometry capable of supporting a criticality and an additional spacing violation would have to occur before a criticality is possible. CONTROLLED PARAMETERS: Double contingency is maintained by implementing controls on geometry and interaction. ESTIMATED AMOUNT, ENRICHMENT, FORM OF LICENSED MATERIAL : Uranium contaminated oil. Product withdrawal assay at the time of the event was less than 4.95 wt% U235. The pump components were not grossly contaminated. NUCLEAR CRITICALITY SAFETY CONTROL(S) OR CONTROL SYSTEM(S) AND DESCRIPTION OF THE FAILURES OR DEFICIENCIES: The first leg of double contingency relies on the geometry of the seal exhaust/wet air pump components. The pump components are controlled as safety related items. This control was not violated. Therefore, this leg of double contingency was maintained. The second leg of double contingency relies on minimizing interaction between internal oil separators and pump housing subcomponents. Interaction is controlled by maintaining a minimum 2-foot edge-to-edge spacing between pump internal oil separators and pump housing subcomponents. The pump housing subcomponents were placed within 2 feet of the internal oil separators in violation of this control. The interaction parameter was not maintained; therefore this leg of double contingency was not maintained. Double contingency was not maintained because the interaction parameter was not maintained. CORRECTIVE ACTIONS TO RESTORE SAFETY SYSTEMS AND WHEN EACH WAS IMPLEMENTED: 1. Control Access to the area. This was completed at 0845 CDT on 08/19/11. 2. Move one item at a time such that the spacing between the pump housing subcomponents and the internal oil separators is always increasing until a minimum 2-foot edge-to-edge spacing has been established. This was completed at 1445 CDT on 08/19/11. 3. Upon establishing the proper spacing between the pump housing subcomponents and the internal oil separators, the exclusion zone may be removed. This was accomplished at 1450 CDT on 08/19/11. |
| Where | |
|---|---|
| Paducah Gaseous Diffusion Plant Paducah, Kentucky (NRC Region 2) | |
| License number: | GDP-1 |
| Reporting | |
| Response | |
| Time - Person (Reporting Time:+3.18 h0.133 days <br />0.0189 weeks <br />0.00436 months <br />) | |
| Opened: | Calvin Pittman 16:26 Aug 19, 2011 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Aug 19, 2011 |
| 47176 - NRC Website | |
Paducah Gaseous Diffusion Plant with Response | |
WEEKMONTHYEARENS 483982012-10-10T18:05:00010 October 2012 18:05:00
[Table view]Response Double Contingency Control for Empty Cylinders Not Maintained ENS 479112012-05-08T21:16:0008 May 2012 21:16:00 10 CFR 76.120(c)(2), Response Autoclave High Pressure Isolation System Failure ENS 474832011-11-28T15:30:00028 November 2011 15:30:00 Response 24-Hour Report Concerning a Localized Loss of a Geometry Criticality Control Contingency ENS 473102011-09-30T13:54:00030 September 2011 13:54:00 Response 24-Hour Nrc Bulletin 91-01 Report Involving a Loss of One Leg of Double Contingency ENS 471762011-08-19T13:15:00019 August 2011 13:15:00 Response 24-Hr Loss of Criticality Control Report Required Under Bulletin 91-01, Supplement 1 ENS 465922011-02-03T15:30:0003 February 2011 15:30:00 Response 24 Hour Notification Under Bulletin 91-01 Concerning Leakage of Moderating Liquid ENS 463122010-10-06T16:06:0006 October 2010 16:06:00 Response 24 Hour Notification Under Bulletin 91-01 Concerning Cooldown Verification of Uf6 Cylinders ENS 461052010-07-17T19:07:00017 July 2010 19:07:00 Response 24 Hour 91-01 Bulletin Report on Loss of One of Two Criticality Control Contingencies ENS 454922009-11-12T17:15:00012 November 2009 17:15:00 Response Violation of a Nuclear Criticality Safety Control ENS 450422009-05-04T10:07:0004 May 2009 10:07:00 Response 24 Hour 91-01 Bulletin Report on Loss of One of Two Criticality Control Contingencies ENS 445582008-10-09T20:37:0009 October 2008 20:37:00 Response 24-Hours Bulletin 91-01 Report Involving Failure to Visually Inspect Storage Cylinders ENS 442232008-05-18T22:21:00018 May 2008 22:21:00 Response Violation of a Nuclear Criticality Safety Approval - 24-Hour Report ENS 441512008-04-17T21:44:00017 April 2008 21:44:00 Response 24-Hour Nrc Bulletin 91-01 Report Involving an Excessively Large Container Found in a Fissile Control Area ENS 441002008-03-26T19:57:00026 March 2008 19:57:00 Response 24 Hour Report of Degraded Criticality Control ENS 440562008-03-11T19:57:00011 March 2008 19:57:00 Response Two Cylinders Identified with Weight Change Prior to Wash ENS 432322006-09-23T03:00:00023 September 2006 03:00:00 Response Reported Under Nrc Bulletin 91-01 24 Hour Notification ENS 421652005-11-22T18:05:00022 November 2005 18:05:00 Response Improper Criticality Spacing for Waste Drum ENS 411582004-10-29T14:45:00029 October 2004 14:45:00 Response Criticality Control Report ENS 410202004-09-04T18:45:0004 September 2004 18:45:00 Response Violation of Nuclear Criticality Safety Control in the Process Building ENS 408732004-07-14T18:00:00014 July 2004 18:00:00 Response Criticality Control 24-Hour (Bulletin 91-01) Report ENS 408602004-07-08T20:50:0008 July 2004 20:50:00 Response 24 Hour Nrc Bulletin 91-01 Loss of Criticality Control ENS 407232004-05-03T21:00:0003 May 2004 21:00:00 Response Criticality Control 24-Hour (Bulletin 91-01) Report ENS 407002004-04-23T13:45:00023 April 2004 13:45:00 Response Criticality Control 24-Hour (Bulletin 91-01) Report ENS 408052004-04-23T10:53:00023 April 2004 10:53:00 Response Paducah Gaseous Diffussion Plant - Response Bulletin 91-01 24 - Hour Report ENS 406412004-04-04T19:30:0004 April 2004 19:30:00 Response 24-Hour Nrc Bulletin 91-01 Loss of Criticality Control Notification ENS 404552004-01-16T21:27:00016 January 2004 21:27:00 Response 24 Hour Notification for Bulletin 91-01 Loss of Criticality Safety Controls Involving Waste Drum ENS 404472004-01-13T19:00:00013 January 2004 19:00:00 Response 24 Hour Notification for Bulletin 91-01 Loss of Criticality Safety Controls Involving Waste Drum ENS 403562003-11-25T09:45:00025 November 2003 09:45:00 Response 24 Hour Nrc Bulletin 91-01 Notification Regarding Loss of Double Contingency Protection ENS 401512003-09-11T13:45:00011 September 2003 13:45:00 Response Double Contingency Was Not Maintained for Non-Fissile Nams. ENS 401392003-09-07T12:50:0007 September 2003 12:50:00 Response Criticality Controls Degradation at Paducah ENS 401092003-08-27T14:00:00027 August 2003 14:00:00 Response Procedural Deficiency Omission 2012-05-08T21:16:00 | |