ENS 41274
ENS Event | |
|---|---|
03:30 Dec 18, 2004 | |
| Title |
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| Event Description | THIS IS NOT A NEW REPORT.
This event report was originally withheld from public release under the NRC's policy for protecting sensitive unclassified information. The NRC has reevaluated this policy and is now making this event report available to the public with suitable redactions.
CRITICALITY CONTROL Sequence of occurrences: On December 17, 2004, materials were transferred to a storage area without being transferred thru a particular device as required by the Standard Operating Procedure (SOP). This device prevents a more reactive/incorrect material type from being transferred. Prior to the addition of materials to the system, operations personnel verify that the correct materials are added to the system. The device prevents a more reactive/incorrect material type from entering the storage area. Remaining activities relied on: The remaining activities relied on to prevent potential accidents are available and reliable to perform their function. Operations personnel verified that the correct material type was added to the system. Also, the addition of a more reactive/incorrect material type was specifically evaluated and determined to be subcritical. Actions taken in response to the event: A root cause investigation was initiated as a result of the event. Transfers were suspended until compensatory measures can be put in place. Safety significance of event: The safety significance was low for the event given the very low likelihood of adding a more reactive/incorrect material type to the system. A more reactive/incorrect material type was not added to the system and the addition of a more reactive/incorrect material type was specifically evaluated and determined to be subcritical. Brief scenario of how a criticality could occur: In order for a criticality to occur, multiple occurrences of an excessive amount of a more reactive/incorrect material type would have to be added to the system; and, the material would have to be transferred without use of the particular device. What are the controls or control systems and the failures or deficiencies? The controls were limitations on material types input into the system and the use of a particular device when transferring materials to a storage area. Materials were transferred to the storage area without being transferred thru the particular device as required by the Standard Operating Procedure (SOP). The Nuclear Criticality Safety Evaluation (NCSE) for the area credited the device as a passive control device. The act of transferring the materials thru the device should have been credited as an administrative control since operations personnel have the ability to bypass the device if the procedure is not followed correctly. What are the corrective actions taken and when was each implemented? A root cause investigation was initiated on December 21, 2004 after discovery of the event. Material transfers were suspended on December 21, 2004 until compensatory measures can be implemented. Actual or potential health and safety consequences: There were no actual health and safety consequences to workers, the public, or the environment. There were also no personnel exposures to radiation, radioactive materials, or hazardous chemicals produced from licensed materials. The potential Nuclear Criticality Safety (NCS) consequences for workers were low given the actual materials involved and the very low likelihood of adding a more reactive/incorrect material type to the system. A more reactive/incorrect material type was not added to the system and the addition of a more reactive/incorrect material type was specifically evaluated and determined to be subcritical. The licensee notified the NRC Resident Inspector.
THIS IS NOT A NEW REPORT. This event report was originally withheld from public release under the NRC's policy for protecting sensitive unclassified information. The NRC has reevaluated this policy and is now making this event report available to the public with suitable redactions. |
| Where | |
|---|---|
| Nuclear Fuel Services Inc. Erwin, Tennessee (NRC Region 2) | |
| License number: | SNM-124 |
| Reporting | |
| 10 CFR 70.74 APP. A | |
| Time - Person (Reporting Time:+80.67 h3.361 days <br />0.48 weeks <br />0.111 months <br />) | |
| Opened: | Randy Shackelford 12:10 Dec 21, 2004 |
| NRC Officer: | Mike Ripley |
| Last Updated: | May 11, 2008 |
| 41274 - NRC Website | |
Nuclear Fuel Services Inc. with 10 CFR 70.74 APP. A | |
WEEKMONTHYEARENS 448902009-03-04T19:40:0004 March 2009 19:40:00
[Table view]Part 70 App A (C), 10 CFR 70.74 APP. A Glovebox Overflow Drains May Be Inadequate to Perform Their Safety Function ENS 445792008-10-17T20:15:00017 October 2008 20:15:00 10 CFR 70.74 APP. A Inadvertent Transfer of Unsampled Discard Solution ENS 412742004-12-18T03:30:00018 December 2004 03:30:00 10 CFR 70.74 APP. A
2009-03-04T19:40:00 | |