ENS 46923
ENS Event | |
|---|---|
05:00 Apr 12, 2011 | |
| Title | Potential Defect in Certain Velan Supplied Globe Valves |
| Event Description | The following is a summary of a Part 21 e-mail notification received from Velan Inc:
Velan Inc., a valve vendor, has identified a potential defect in certain lots of 0.5, 0.75 and 1 inch NPS globe valves sold to Areva and Fenoc. The failure could result in the valve travelling into the bonnet cavity and became jammed between body and bonnet. The analysis revealed that the failure was caused by the wrong bonnet being installed on the valve which ultimately allowed the disc to travel too far into the bonnet cavity and consequently the disc dropped into the body-bonnet gap. This prevented the valve from being closed during manual operation. Internal analysis also determined that this failure mode is very plausible in valves installed with the stem in a horizontal orientation. Valves installed with the stem in vertical orientation are far less likely to fail but we cannot guarantee that; on valves that are normally fully open certain flow conditions may cause the disc to tilt and jam between body and bonnet. Nevertheless, operational history seems to suggest that valves installed with the stem in vertical orientation have not experienced this type of failure. Velan has requested that each affected utility reviews the individual applications for the specific valves identified in this notification; in the event of any application where the valves inability to close will impact significantly the safe operation of the plant. Velan will work with the utility towards reaching a suitable solution. Velan does not have specific information concerning the specific system and function applicable to these globe valves and therefore we cannot assess whether a substantial safety hazard exists as a result of their inability to close after falling as described above. Velan's investigation and review of the available manufacturing records revealed that the same bonnet, with an oversized lift, was installed in all valves identified hereunder. CUSTOMER ORDER QTY. VALVE FIGURE No. VALVE SERIAL No. AREVA NP 8 W04-2074B-02AA 971022-1 to-8 AREVA NP 12 W03-2074B-02AA 971042-1 to -12 AREVA NP 27 W04-2074B-02AA 971048-1 to -27 AREVA NP 5 W03-2074B-02AA 981028-1 to-5 AREVA NP 5 W03-20748-02AA 981030-1 to-5 AREVA NP 10 W05-20748-02AA 001012-1 to-10 AREVA NP 13 W03-20748-02AA 001029 -1 to -13 AREVA NP 26 W04 20748-02AA 001056 -1 to -26 ARE VA NP 10 W04-20748-02AA 011035-1 to-10 FENOC 4 W05-2074B 02AA 001033 -1 to-4 |
| Where | |
|---|---|
| Velan Inc Quebec, (NRC Region) | |
| Organization: | Velan Inc |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+1259.5 h52.479 days <br />7.497 weeks <br />1.725 months <br />) | |
| Opened: | Victor Apostolescu 16:30 Jun 3, 2011 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Jun 3, 2011 |
| 46923 - NRC Website | |
Velan Inc with 10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation | |
WEEKMONTHYEARENS 469232011-04-12T05:00:00012 April 2011 05:00:00
[Table view]10 CFR 21.21, Notification of failure to comply or existence of a defect and its evaluation Potential Defect in Certain Velan Supplied Globe Valves 2011-04-12T05:00:00 | |