ENS 44661
ENS Event | |
|---|---|
14:07 Oct 16, 2008 | |
| Title | Invalid Actuation of Steam Driven Aux Feed Pump |
| Event Description | On October 16, 2008 during a routine clearance restoration activity, two solenoid-operated steam supply isolation valves on one of the three steam lines to the steam-driven Auxiliary Feedwater Pump (2FWE-P22) unexpectedly opened at Beaver Valley Power Station (BVPS) Unit No.2, admitting steam to and causing this pump to commence rotating. The control room operator monitoring the plant quickly recognized the unwarranted system response and attempted to terminate steam flow to the auxiliary feedwater pump by re-closing the two unexpectedly open steam supply isolation valves from the control room. At the same time, the local operator performing the restoration activity of opening a separate manual upstream steam isolation valve also recognized the unwarranted system response (by hearing too much steam flow through the manual valve) and also terminated steam flow to the pump by re-closing the upstream manual isolation valve. The total time that this pump rotated was less than approximately 30 seconds and the plant computer indicated that no auxiliary feedwater was actually pumped into any of the steam generators. Neither of the other two Auxiliary Feedwater System motor-driven pumps were actuated at BVPS Unit No.2.
The design for these two solenoid-operated isolation valves are susceptible to briefly popping open if steam is initially introduced too rapidly. These valves fail open with no power and are pilot-operated solenoid-actuated to close. An initial large steam rush can briefly overcome the solenoid force holding the valve shut. This is what occurred on October 16, 2008. Therefore, this brief rotation of the steam-driven Auxiliary Feedwater Pump was not initiated by a valid actuation signal. This event is reportable pursuant to 10 CFR 50.73(a)(2)(iv)(A) since it involved a train-level actuation of the PWR auxiliary feedwater system as listed in 10 CFR 50.73(a)(2)(iv)(B)(6). This actuation was not part of a pre-planned sequence and did not occur with system properly removed from service. However, pursuant to 10 CFR 50.73(a)(1), this event is being reported via this telephone notification instead of submitting a written Licensee Event Report since the actuation of the Auxiliary Feedwater System train was not generated by a valid actuation. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
| Beaver Valley Pennsylvania (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+763.32 h31.805 days <br />4.544 weeks <br />1.046 months <br />) | |
| Opened: | R. G. Loose 10:26 Nov 17, 2008 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Nov 17, 2008 |
| 44661 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Beaver Valley with 10 CFR 50.73(a)(1), Submit an LER | |
WEEKMONTHYEARENS 556022021-09-30T14:07:00030 September 2021 14:07:00
[Table view]10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification for an Invalid Emergency Diesel Generator Actuation ENS 468172011-03-15T21:16:00015 March 2011 21:16:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of the Standby Service Water Pump ENS 468162011-03-07T15:18:0007 March 2011 15:18:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of the Auxiliary Feedwater System ENS 450992009-05-06T17:52:0006 May 2009 17:52:00 10 CFR 50.73(a)(1), Submit an LER Automatic Actuation of Rps, Eccs and Edg Generated by an Invalid Actuation Signal ENS 450012009-04-20T05:53:00020 April 2009 05:53:00 10 CFR 50.73(a)(1), Submit an LER Unexpected Start of the Steam Driven Auxiliary Feedwater Pump During Plant Cooldown ENS 446612008-10-16T14:07:00016 October 2008 14:07:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Steam Driven Aux Feed Pump ENS 411192004-09-10T21:30:00010 September 2004 21:30:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Steam Driven Auxiliary Feedwater Pump 2021-09-30T14:07:00 | |