ENS 40567
ENS Event | |
|---|---|
20:00 Mar 4, 2004 | |
| Title | 24-Hour Notification - Bulletin 91-01 Criticality Control |
| Event Description | A review of incinerator data indicated higher than expected accumulations and concentrations of uranium bearing material in the incinerator off-gas system. Criticality was not possible because the mass corresponding to each concentration was below the minimum critical mass.
Controlled Parameters: The safety basis for the incinerator off gas-system states that criticality is not credible. This was based on minimal expected carryover and low concentrations of uranium from the incinerator to the off -gas system. The uranium concentrations in the off-gas system were expected to be well below the [deleted] concentration criticality limit for an infinite mass. A criticality would be possible in the off-gas system only if a minimum critical mass for a corresponding uranium concentration accumulated in a critical configuration with sufficient moderator. Because higher than expected accumulation and concentration of uranium bearing material was detected in the incinerator off gas system, this 24-hour notification is being made. Summary of Activity: 1) Incinerator was shut down; 2) The off-gas system is being inspected; 3) Samples from the off-gas system are being obtained for analysis. Conclusions: 1). The bounding assumptions for concentration and carryover were exceeded; 2). At no time was there any risk to the health or safety of any employee or member of the public. No exposure to hazardous material was involved & 3). The Incident Review Committee (IRC) determined that this is a safety significant incident in accordance with governing procedures. A formal causal analysis will be performed. The licensee will be notifying NRC Region III.
The licensee sent the following addendum via facsimile: Reason for Addendum: Higher than expected concentration of uranium bearing material detected in the incinerator ash. The ash from the lower chamber of the incinerator is lifted via a bucket elevator and dumped into a mill feed hopper and then into a fitzmill. As Found Condition: A review of incinerator data indicated higher than expected concentrations of uranium in the incinerator ash. Controlled Parameters: The safety basis for the ash handling system (elevator and fitzmill) states that criticality is not credible based on the ash remaining below 21.6 weight percent uranium. Summary of Activity: -In addition to the previous activities, the formal root cause team has initiated their investigation. -The incinerator ash elevator and fitzmill safety basis is being re-evaluated. Conclusions: -The bounding assumption for concentration was exceeded. -At no time was there any risk to the health or safety of any employee or member of the public. -No exposure to hazardous material was involved. -The ash handling aspect will be incorporated into the formal causal analysis. Notified NMSS (Psyk) and R2D) (Ayres). |
| Where | |
|---|---|
| Westinghouse Electric Corporation Columbia, South Carolina (NRC Region 2) | |
| License number: | SNM-1107 |
| Reporting | |
| Response | |
| Time - Person (Reporting Time:+16.13 h0.672 days <br />0.096 weeks <br />0.0221 months <br />) | |
| Opened: | Carl Snyder 12:08 Mar 5, 2004 |
| NRC Officer: | Mike Ripley |
| Last Updated: | Mar 9, 2004 |
| 40567 - NRC Website | |
Westinghouse Electric Corporation with Response | |
WEEKMONTHYEARENS 419332005-08-19T19:30:00019 August 2005 19:30:00
[Table view]Response Nrc Bulletin 91-01 Violation of Criticality Spacing Requirements ENS 417232005-05-20T22:40:00020 May 2005 22:40:00 Response, Part 70 App A (B)(5) Deviation from Integrated Safety Analysis, and a 24 Hour Notification - Bulletin 91-01 Criticality Control ENS 414182005-02-17T17:00:00017 February 2005 17:00:00 Response, Part 70 App A (B)(1) 24 Hour 91-01 Response Bulletin and Part 70 App a Unanalyzed Condition ENS 413722005-02-04T14:00:0004 February 2005 14:00:00 Response 24-Hour Notification-Bulletin 91-01 Criticality Control ENS 409852004-08-24T14:05:00024 August 2004 14:05:00 Response 24 Hour 91-01 Response Bulletin ENS 408882004-07-21T13:00:00021 July 2004 13:00:00 Response 4-Hour 91-01 Nrc Bulletin Notification Due to Adu in Non-Favorable Geometry Nitrogen Accumulator Tank ENS 408552004-07-07T21:00:0007 July 2004 21:00:00 Response Nrc Bulletin 91-01 - 4 Hour Report ENS 407932004-06-04T22:00:0004 June 2004 22:00:00 Response Licensee Reported a 4 Hour 91-01 Response Bulletin ENS 405672004-03-04T20:00:0004 March 2004 20:00:00 Response 24-Hour Notification - Bulletin 91-01 Criticality Control ENS 404402004-01-12T20:45:00012 January 2004 20:45:00 Response 24 Hour Notification Bulletin 91-01 Criticality Control ENS 402552003-10-16T19:30:00016 October 2003 19:30:00 Response 24 Hour Bulletin 91-01 Notification from Westinghouse Columbia Fuel Facility ENS 402462003-10-14T11:30:00014 October 2003 11:30:00 Response 24-Hour Nrc 91-01 Bulletin Report Involving Improper Mass Control ENS 401522003-09-12T14:32:00012 September 2003 14:32:00 Response Improper Scanning of Lead Rods for the Product Engineering Laboratory 2005-08-19T19:30:00 | |