ENS 45642
ENS Event | |
|---|---|
00:35 Jan 21, 2010 | |
| Title | Potentially Overpressurized Uf6 Cylinders |
| Event Description | UF6 cylinders are in storage. The cylinders consist of 1s/2s, hoke tubes, and 5A cylinders. The UF6 is contained in the cylinders, which are in DOT shipping containers (20PF1 and 6M containers). Calculations were performed that indicated that the theoretical pressure in some of the cylinders exceeds the service pressure (200psi) and some exceed the hydrostatic test pressure (400psi). DOE literature indicates that the burst pressure for a 5A cylinder is [approximately] 8,000 psi. The age of the cylinders is 1950s [to] 1980s. The potential pressure in the cylinders is estimated to be by liberation of fluorine gas in the cylinders. Access to the areas has been restricted. The path forward consists of further analysis, evaluation, and understanding of the issue. The cylinders potentially contain fluorine gas.
There were no actual safety consequences to workers, the public, or the environment. The potential consequences are minimal due to restricted access to the areas and the stable condition of the cylinders (i.e., cylinders, shipping containers, building containment). UF6 cylinders, shipping containers, building containment provide mitigation. Area sprinklers and smoke detection also provide mitigation. Area security cameras provide assistance for monitoring. Security fire patrols [have been] implemented. Other compensatory measures are being considered that include providing uncharged fire hoses to the areas. Licensee has informed the NRC Resident Inspector.
These are additional compensatory actions that have been and will be put in place: 1. Verified operability of smoke detection 2. Verified operability of sprinkler system 3. Established fire patrol inspection. (minimum of 1 inspection per hour) 4. Restricted access 5. Hot work restriction in the restricted areas 6. Verified Fire Brigade members on each shift. (minimum of 5 members each shift) 7. Staging one (1) 150 pound dry chemical extinguisher 8. Staging a fire response vehicle 9. Briefing plant superintendent on status with a superintendent turnover each shift. The licensee has informed the NRC Resident Inspector. Notified R2DO (Sykes), NMSS EO (Smith), and IRD (Gott).
With regard to the compensatory actions listed in the e-mail dated January 20, 2010, Nuclear Fuel Services, Inc. (NFS) is modifying its commitment to have at least five Fire Brigade members on each shift. Thus, compensatory action No. 6 is being replaced with the following compensatory action: NFS has developed a specific pre-fire response plan for the areas where the UF6 cylinders are stored. This plan has been reviewed with the Erwin City Fire Chief. NFS plans to provide one trained Fire Brigade member on each shift who will coordinate the Erwin Fire Department response to a fire incident involving a UF6 cylinder. Notified R2DO (Sykes), NMSS EO (Smith), and IRD (Gott).
Following an extensive review by both NFS and independent experts, the analysis of the issue of UF6 cylinders in storage is now complete. The analysis concluded that the likelihood of a release from the cylinders is low, but even if a release were to occur, the consequences to workers, the public, and the environment would be low. Therefore, the additional compensatory actions that have been in place since January 20, 2010, are being discontinued. The licensee notified the NRC Resident Inspector. Notified R2DO (Franke), NMSS EO (McCartin), IRD (McDermott), and Fuels OUO Group via E-mail. |
| Where | |
|---|---|
| Nuclear Fuel Services Inc. Erwin, Tennessee (NRC Region 2) | |
| License number: | SNM-124 |
| Reporting | |
| Part 70 App A (A)(4) | |
| Time - Person (Reporting Time:+-4.32 h-0.18 days <br />-0.0257 weeks <br />-0.00592 months <br />) | |
| Opened: | Randy Shackelford 20:16 Jan 20, 2010 |
| NRC Officer: | Dong Park |
| Last Updated: | Mar 18, 2010 |
| 45642 - NRC Website | |
Nuclear Fuel Services Inc. with Part 70 App A (A)(4) | |
WEEKMONTHYEARENS 502082014-06-17T23:00:00017 June 2014 23:00:00
[Table view]Part 70 App A (A)(4) Items Relied on for Safety (Irofs) Bypassed ENS 456422010-01-21T00:35:00021 January 2010 00:35:00 Part 70 App A (A)(4) Potentially Overpressurized Uf6 Cylinders 2014-06-17T23:00:00 | |