ENS 53266
ENS Event | |
|---|---|
15:30 Mar 15, 2018 | |
| Title | Unanalyzed Scenario Associated with Uranium Recovery and Recycle System |
| Event Description | On March 15, 2018 during an NRC inspection of the Solvent Extraction area, an inspector identified a potential credible scenario which is not adequately addressed in the applicable Criticality Safety Evaluation (CSE). Plant Environmental Health and Safety (EH&S) staff reviewed the issue and at 1130 [EDT] determined that, based on the available information, the scenario did not appear to be properly analyzed in the CSE and thus the Integrated Safety Analysis (ISA). The scenario is associated with the Uranium Recovery and Recycle System (URRS) 706 hood operation. The process performed in the 706 hood is the transfer of low concentration residues into a container for disposal at a Low Level Radioactive Waste (LLRW) facility. There was no actual event, and no impact to public health and safety, the workers, or the environment.
The issue revolves around the lack of a specific analysis controlling the handling, transport and replacement of the container, a 55 gallon drum, used in that process. A criticality event for the scenario of an inadvertent container handling upset was identified as incredible in the safety basis documents. However, the accident sequence does not meet the definition of incredible as defined in the license application, and thus appears to be an improperly analyzed scenario. While not properly documented, unlikely, independent, and concurrent changes in process conditions would have to occur to result in a criticality accident. Procedural controls and process barriers which are in place were not identified as Items Relied On For Safety (IROFS) for this scenario. There are, however, passive and administrative IROFS in place for other chemical, fire and criticality safety accident sequences that can be applied to this scenario. These IROFS include requirements for mechanical integrity and spill protection techniques to preclude significant loss of uranium bearing liquid material that would have to accumulate in an improperly handled container. Examples of existing IROFS that control process leaks include SOLX-903 and WASH-119, degradation resistant design to prevent leakage from tanks/vessels; SOLX-503, structural integrity of piping; ADUHNP-901, flange guards; ADUHFS-507 and SOLX-505, valve alignments to prevent spills; and DPH-104, piping integrity. In addition, there is annual training and testing on the proper handling of non-favorable geometry containers. The hood and associated container were removed from service while the scenario is being evaluated. Issue Report 2018-7306 was entered into our Corrective Action Program, and an extent of condition was performed. Based on the extent of condition, the cylinder wash area has been identified for additional evaluation.
Based on evaluation of the extent of condition, a similar scenario was identified with the wet combustible trash system in the Uranium Recovery and Recycle System (URRS) area. This event report is updated to include a 24 Hour Event Notification for the wet combustible trash system based on 10 CFR 70 Appendix A(b)(1) 'Any event or condition that results in the facility being in a state that was not analyzed, was improperly analyzed, or is different from that analyzed in the Integrated Safety Analysis, and which results in failure to meet the performance requirements of 10 CFR 70.61.' The issue revolves around the lack of a specific analysis controlling the handling and transport of containers, 55 gallon drums, used in the wet combustible trash process. A cylinder wash operation is in the area where the wet combustible trash drums are used. Cylinder wash operations were shutdown to preclude significant loss of uranium bearing liquid material that would have to accumulate in an improperly handled drum. Similar procedural controls, process barriers and IROFS from other accident sequences can be applied to this scenario. Wet combustible trash collection may continue since the potential source of liquid material (cylinder wash) has been shut down. Notified R2DO (Nease) and NMSS (via email). |
| Where | |
|---|---|
| Westinghouse Electric Corporation Columbia, South Carolina (NRC Region 2) | |
| License number: | SNM-1107 |
| Reporting | |
| Part 70 App A (B)(1) | |
| Time - Person (Reporting Time:+19.77 h0.824 days <br />0.118 weeks <br />0.0271 months <br />) | |
| Opened: | Nancy Parr 11:16 Mar 16, 2018 |
| NRC Officer: | Thomas Kendzia |
| Last Updated: | Mar 16, 2018 |
| 53266 - NRC Website | |
Westinghouse Electric Corporation with Part 70 App A (B)(1) | |
WEEKMONTHYEARENS 561992022-11-01T15:29:0001 November 2022 15:29:00
[Table view]Part 70 App A (B)(1) Unanalyzed Condition - Nuclear Material Received in Excess of License Limits ENS 543352019-10-16T04:00:00016 October 2019 04:00:00 Part 70 App A (B)(1) an Item Relied on for Safety (Irofs) Determined to Be Inadequate ENS 532662018-03-15T15:30:00015 March 2018 15:30:00 Part 70 App A (B)(1) Unanalyzed Scenario Associated with Uranium Recovery and Recycle System ENS 520902016-07-13T04:00:00013 July 2016 04:00:00 Part 70 App A (B)(1), Part 70 App A (A)(4) Degraded Safety Items Caused by Uranium Buildup ENS 483752012-10-04T14:00:0004 October 2012 14:00:00 Part 70 App A (B)(1) Unanalyzed Accident Scenarios for Certain Consequences of Concern ENS 473302011-10-07T20:15:0007 October 2011 20:15:00 Part 70 App A (B)(1) Dimension of Snm Carrying Pails Different from Value in Safety Analysis ENS 461382010-07-28T18:00:00028 July 2010 18:00:00 Part 70 App A (B)(1) Incorporation of 'Incredible' Criticality Sequences Into Integrated Safety Analysis ENS 456552010-01-25T16:30:00025 January 2010 16:30:00 Part 70 App A (B)(1) Unanalyzed Condition - Overflow of Uranium Bearing Ammoniated Wastewater 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 2022-11-01T15:29:00 | |