ENS 43814
ENS Event | |
|---|---|
16:00 Nov 30, 2007 | |
| Title | Potential Loss of Item Relied on for Safety (Irofs) |
| Event Description | Reason for Notification: On 11/30/07, during a routine NCS facility walkthrough assessment performed by a qualified NCS Engineer, it was discovered that the SNM mass balance maintained for the Chemical Process Development Laboratory (CPD Lab) had been performed incorrectly. Specifically, although the applicable inventory form and associated mass limit for the lab was in terms of grams of SNM (i.e., grams of UO2), cans of archive pellets brought into the lab had been recorded in terms of grams of 235U (underestimating the total lab mass).
As a result, the total inventory of the lab was actually at approximately 39 kg UO2 (assuming the 2007 annual nominal plant enrichment of 4.38 wt%). This value exceeds the lab mass limit of 15.9 kg UO2, designated an Item Relied on for Safety (IROFS) in the Laboratory ISA Summary (CHMDEV-101). Notification is being made based on the potential for Loss or degradation of IROFS that result in failure to meet the performance requirements of 10CFR70.61, reference Appendix A, Section (b)(2) to Part 70 of 10CFR70. Safety Basis: The total inventory of the lab was at approximately 39 kg UO2 (assuming the 2007 annual nominal plant enrichment of 4.38 wt%). This value exceeds the lab mass balance limit of 15.9 kg UO2 (based on the single parameter mass limit for UO2 and water). Although criticality in the lab is judged to be incredible, a mass limit was established for the lab, and a mass balance was initiated to enforce it. This mass balance was designated an IROFS in the Laboratory ISA Summary (CHMDEV-101). Criticality in the CPD Lab is judged to be an incredible event because no routine process operations are performed in the lab, and special evolutions (for testing or product development) require explicit Criticality Safety Evaluations. The vast majority of SNM currently in the lab is in the form of mounted archive pellets in small (~1 gallon) metals cans stored on the floor of the lab. These cans are being stored there temporarily until a new grinder can be installed to dispose of them. Although the mass limit was exceeded in the lab, no potential for criticality existed, as the SNM was stored in sealed metal cans with limited moderation (provided by plastic mounting material). In addition, per CN-CRI-06-30, it requires more than 27 fully loaded and optimally moderated pellet cans to challenge the CFFF acceptance criterion of 0.98, even with multiple stacked cans and optimal spacing. In reality, there are only 15 pellet cans in the lab, and these are stored in a single planar array with 12 inch surface-to-surface spacing. Summary of Activity: The archive pellet cans have been removed from the lab, such that the total mass balance in the lab is now below the mass limit for the lab. The event was documented in the plant Corrective Action Process (CAPs #07-334-C025). A new Criticality Safety Evaluation for the CPD Lab (CSE-18-D) was issued on October 16, 2007, and is scheduled for implementation during December 2007. Although this new CSE still concludes that criticality in the lab is incredible, it established additional controls on maintaining the mass balance and special periodic Assessments of the mass balance by the NCS Function. Conclusions: Problem was self identified by Westinghouse personnel during a scheduled NCS Facility Walkthrough Assessment. At no time was the health or safety to any employee or member of the public in jeopardy. No exposure to hazardous material was involved. A causal analysis will be performed. The licensee will notify the NRC Resident Inspector. |
| Where | |
|---|---|
| Westinghouse Electric Corporation Columbia, South Carolina (NRC Region 2) | |
| License number: | SNM-1107 |
| Reporting | |
| Part 70 App A (B)(2) | |
| Time - Person (Reporting Time:+-1.67 h-0.0696 days <br />-0.00994 weeks <br />-0.00229 months <br />) | |
| Opened: | Sean Gough 14:20 Nov 30, 2007 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Nov 30, 2007 |
| 43814 - NRC Website | |
Westinghouse Electric Corporation with Part 70 App A (B)(2) | |
WEEKMONTHYEARENS 574722024-12-12T15:30:00012 December 2024 15:30:00
[Table view]Part 70 App A (B)(2) Degradation of Safety Item ENS 542982019-09-27T19:15:00027 September 2019 19:15:00 Part 70 App A (B)(2) Procedural Noncompliance with Administrative Item Relied on for Safety ENS 519742016-06-02T16:45:0002 June 2016 16:45:00 Part 70 App A (B)(2) Administrative Verifications of Ventilation Clean-Out Containers Were Not Performed ENS 510242015-04-29T14:00:00029 April 2015 14:00:00 Part 70 App A (B)(2) Valve Classified as Item Relied on for Safety Failed to Operate as Designed ENS 459262010-05-13T16:33:00013 May 2010 16:33:00 Part 70 App A (B)(2) a Valve Classified as an Item Relied on for Safety Found Closed While Position Indicator Showed Open ENS 458842010-04-29T17:04:00029 April 2010 17:04:00 Part 70 App A (B)(2) Hot Oil System Emergency Shutdown Fails Annual Preventative Maintenance Check ENS 449282009-03-23T11:30:00023 March 2009 11:30:00 Part 70 App A (B)(2) Degraded Item Required for Safety in the Pelleting Area ENS 438142007-11-30T16:00:00030 November 2007 16:00:00 Part 70 App A (B)(2) Potential Loss of Item Relied on for Safety (Irofs) ENS 414242005-02-19T21:04:00019 February 2005 21:04:00 Part 70 App A (B)(2) 24-Hour Criticality Control Report - Failure to Obtain Required Powder Samples 2024-12-12T15:30:00 | |