ENS Event | |
|---|---|
05:00 Dec 20, 2011 | |
| Title | Part 21 - Uf6 Accumulator Tank Had Through Wall Cracks That Caused Leakage |
| Event Description | The following information was received via facsimile:
On October 26, 2011, the discovery of two (2) defects (cracks) was identified on the north head of the Building C-310A side accumulator vessel. The accumulator is a tank used to provide a storage volume for liquid Uranium Hexafluoride (UF6) during the product withdrawal process, and it can hold up to 20,000 pounds of UF6 liquid. The defects in the 48" UF6 side accumulator allowed a small release of material which produced a process gas leak detection alarm on October 21, 2011 Investigation to determine the cause of the cracks has revealed that the base metal contained stress defects which allowed multiple cracks to form with some of the cracks penetrating through the outer wall causing the vessel to leak. These cracks were a result of fabrication deficiencies and not the use of the vessel. There are nine (9) similar basic components used in Buildings C-310 and C-315. However, the other nine (9) vessels were not manufactured by Westerman Companies, the firm which designed and fabricated the defective vessel. The C-310A side accumulator has been repaired by cutting out the area of the defect extending into the unaffected areas of the base metal in accordance with ASME Boiler and Pressure Vessel Code,Section VIII, Division 1. USEC held a meeting with a representative of Westerman Companies on November 22. 2011, to discuss the defect. |
| Where | |
|---|---|
| Westerman Companies Bethesda, Maryland (NRC Region 1) | |
| Organization: | Usec |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+9.37 h0.39 days <br />0.0558 weeks <br />0.0128 months <br />) | |
| Opened: | Steven Penrod 14:22 Dec 20, 2011 |
| NRC Officer: | John Knoke |
| Last Updated: | Dec 20, 2011 |
| 47537 - NRC Website | |
Westerman Companies with 10 CFR 21.21 | |
WEEKMONTHYEARENS 475372011-12-20T05:00:00020 December 2011 05:00:00
[Table view]10 CFR 21.21 Part 21 - Uf6 Accumulator Tank Had Through Wall Cracks That Caused Leakage 2011-12-20T05:00:00 | |