ENS 54335
ENS Event | |
|---|---|
04:00 Oct 16, 2019 | |
| Title | an Item Relied on for Safety (Irofs) Determined to Be Inadequate |
| Event Description | The following was reported by Westinghouse Electric Company via email:
As part of a review to revalidate the design of passive safety controls, on October 16, 2019 an engineering calculation was completed which demonstrates that one of two independent and redundant passive overflow devices used in the Solvent Extraction (SOLX) process was undersized for its credited safety function. This passive overflow device is an Item Relied On For Safety (IROFS), designated as SOLX -115. The IROFS prevents the potential backflow of uranium bearing solution from the SOLX process into the commercially-provided, chemical supply drums. These drums are non-favorable geometry (NFG) containers used to add chemicals to the batch process. Upon review of the calculation, the process engineer reported the issue at 3:05 p.m. [EDT] to the Environmental Health and Safety (EH&S) department. The design of the second, redundant passive overflow IROFS in this accident sequence (SOLX-117) has been validated and is available and reliable to perform its safety function. Under the new calculation, with no credit for SOLX-115, the overall likelihood index (OLI) for this scenario increased from -6 to -3. Therefore, the 10CFR70.61 performance requirements (OLI < -4) are not satisfied. The process was shut down, and the NFG chemical drums were isolated from the process until appropriate controls are established. This event has been entered into the facility's Corrective Action Program (CAP). The licensee notified the NRC Region II office (McCurry). |
| 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:+15.08 h0.628 days <br />0.0898 weeks <br />0.0207 months <br />) | |
| Opened: | Gerald Couture 19:05 Oct 16, 2019 |
| NRC Officer: | Brian Lin |
| Last Updated: | Oct 16, 2019 |
| 54335 - 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 | |