ENS 42165
ENS Event | |
|---|---|
18:05 Nov 22, 2005 | |
| Title | Improper Criticality Spacing for Waste Drum |
| Event Description | At 1205 CST, on 11-22-05 the Plant Shift Superintendent was notified that during waste drum remediation activities, a drum was discovered that was in violation of one leg of double contingency. Drum #39666W has been determined to contain up to (deleted) g (grams) U235 exceeding the allowed (deleted) gram limit for NCS Spacing Exempt drums. This drum was previously located in an NCS (Nuclear Criticality Safety) Spacing Exempt storage area in violation of NCSA WMO-001 requirements. The drum was moved to the C-335 storage area under an approved Remediation Guide which established a safety basis for the movement of drums that had been roped off and posted per earlier direction. This drum is currently stored in a Temporary Fissile Storage Area maintaining a minimum 2 foot edge-to-edge spacing under NCSA WMO-001, which maintains double contingency.
SAFETY SIGNIFICANCE OF EVENTS While the (deleted) gram U235 limit was exceeded for this drum; DAC-832-2A1280-0001 demonstrates that drums containing less than (deleted) grams U235 in an NCS Spacing Exempt array are subcritical. The storage area is roped off and posted to prevent the addition of fissile material to the area; therefore another upset would be required before a criticality is possible. POTENTIAL CRITICALITY PATHWAYS INVOLVED (BRIEF SCENARIO(S) OF HOW CRITICALITY COULD OCCUR) This drum is currently stored in the Temporary Fissile Storage Area under NCSA WMO-001, meeting double contingency. In order for a criticality to occur, two independent, unlikely, and concurrent events would have to occur. CONTROLLED PARAMETERS (MASS, MODERATION, GEOMETRY, CONCENTRATION, ETC.) Double contingency is maintained by implementing two controls on mass. ESTIMATED AMOUNT, ENRICHMENT, FORM OF LICENSED MATERIAL (INCLUDE PROCESS LIMIT AND % WORST CASE CRITICAL MASS) The drum has been determined to contain (deleted) grams U235. Calculations performed demonstrate that drums containing less than (deleted) grams U235 each, in an NCS Spacing Exempt array are subcritical. NUCLEAR CRITICALITY SAFETY CONTROL(S) OR CONTROL SYSTEM(S) AND DESCRIPTION OF THE FAILURES OR DEFICIENCIES Although the drum contains greater than the WMO-001 limit of (deleted) grams U235 for NCS Spacing Exempt drums, it has been shown to be less than (deleted) grams U235 based on independent sample results. Calculations performed demonstrate that drums containing less than (deleted) grams U235 each, in an NCS Spacing Exempt array, are subcritical. Therefore, an additional process upset (i.e., spacing upset) would be necessary in order to have a criticality. Therefore, while the drum contained greater than (deleted) grams U235 in the spacing exempt array, the array has been shown to be subcritical for drums containing less than (deleted) grams U235 thus maintaining one leg of double contingency. CORRECTIVE ACTIONS TO RESTORE SAFETY SYSTEMS AND WHEN EACH WAS IMPLEMENTED At the time of discovery, the drum was being stored according to NCS approved spacing controls. The drum will continue to be handled according to approved controls until the U235 mass can be reduced to meet the NCS Spacing Exempt criteria per NCSA WMO-001. The NRC Senior Resident Inspector has been notified of this event. See Related Event Report #40700.
At 1100 [CST], on 02-13-06 the Plant Shift Superintendent was notified that two additional waste drums were discovered that exceed the allowed [deleted] gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drums are currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The NRC Senior Resident Inspector has been notified of this event. Notified R2DO(Ayres) and NMSS (Camper).
At 1430, on 03-20-06, the Plant Shift Superintendent was notified that an additional waste drum has been discovered that exceeds the allowed (deleted) gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drums are currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The additional drum was determined to contain (deleted) grams U235. Calculations performed demonstrate that drums containing less than (deleted) grams U235 each, in an NCS Spacing Exempt array are subcritical. The licensee notified the NRC Resident Inspector. R2DO (Ernstes) and NMSS EO (Pierson) notified.
At 1130, on 04-20-06 the Plant Shift Superintendent was notified that an additional waste drum has been discovered that exceeds the allowed (deleted) gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drums are currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The additional drum (#41663) was determined to contain (deleted) grams of U235. The licensee notified the NRC Resident Inspector. R2DO (Lesser) and NMSS EO (Janosko) notified.
At 1333, on 4-21-06 the Plant Shift Superintendent was notified that seven additional waste drums had been discovered that exceed the allowed (deleted) gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drums are currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. Seven additional drums (41160W,41161W,41162W,41158W,41159W,40605W.41681W) were determined to contain in excess of the (deleted) gram limit of U235 but less than the (deleted) gram safety limit. The licensee notified the NRC Resident Inspector. R2DO (Lesser) and NMSS EO (Janosko) notified.
At 1430, on 04-28-06 the Plant Shift Superintendent was notified that an additional waste drum has been discovered that exceeds the allowed [DELETED] gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drum is currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. [This] one additional drum, # 43170W was determined to contain in excess of the [DELETED] gram limit of U235 but less than the [DELETED] gram safety limit. The licensee notified the NRC Resident Inspector. Notified R2DO (Landis) and NMSS EO (Giitter).
At 0900, on 10-11-06 the Plant Shift Superintendent was notified that an additional waste drum (#41470W) has been discovered that exceeds the allowed limit (but less than the safety limit) for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drum is currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The licensee notified the NRC Resident Inspector. Notified R2DO (Decker) and NMSS EO (Essig).
At 1000, on 10/24/06 the Plant Shift Superintendent was notified that an additional waste drum has been discovered that exceeds the allowed [Deleted] gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drum is currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The NRC Senior Resident Inspector has been notified of this event. Notified R2DO (Brain Bonser) and NMSS (Sandra Wastler).
At 1140 on 12/08/06 the Plant Shift Superintendent was notified that an additional waste drum (42171W) has been discovered that exceeds the allowed [Deleted] gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NSCA WMO-001. The drum is currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The licensee notified the NRC Resident Inspector. Notified R2RDO (Lesser) and NMSS EO (Janosko).
At 1250 on 12/18/06 the Plant Shift Superintendent was notified that 4 additional waste drums (39639W, 42118W, 42488W, & 43521W) had been discovered that exceeds the allowed [Deleted] gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NSCA WMO-001. The drum is currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The licensee notified the NRC Resident Inspector. Notified R2RDO (Moorman) and NMSS EO (Ruland).
At 1345 on 3/23/07 the Plant Shift Superintendent was notified that an additional waste drum (43561W) had been discovered that exceeds the allowed [Deleted] gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NSCA WMO-001. The drum is currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The licensee notified the NRC Resident Inspector. Notified R2RDO (Lesser) and FSME EO (Brach).
The following information was received as an update: UPDATE 4/02/07 at 0845, on 4/02/07 the Plant Shift Superintendent was notified that an additional waste drum (43557W) has been discovered that exceed the allowed [Deleted] gram limit for NCS Spacing Exempt drums and had previously been located in an NCS Spacing Exempt storage area in violation of NCSA WMO-001. The drum is currently stored in a Temporary Fissile Storage Area under NCSA WMO-001, which maintains double contingency. The licensee informed the NRC Resident Inspector. Notified R2DO(Henson) and FSME(Wastler). |
| Where | |
|---|---|
| Paducah Gaseous Diffusion Plant Paducah, Kentucky (NRC Region 2) | |
| License number: | GDP-1 |
| Reporting | |
| Response | |
| Time - Person (Reporting Time:+-2.18 h-0.0908 days <br />-0.013 weeks <br />-0.00299 months <br />) | |
| Opened: | Kevin Beasley 15:54 Nov 22, 2005 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Apr 2, 2007 |
| 42165 - 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 | |