ENS 45099
ENS Event | |
|---|---|
17:52 May 6, 2009 | |
| Title | Automatic Actuation of Rps, Eccs and Edg Generated by an Invalid Actuation Signal |
| Event Description | On May 6, 2009, Beaver Valley Power Station Unit 1 was in Mode 5 during a refueling outage. At 1352, a Low Steam Line Pressure Reactor Trip and Safety Injection (SI) signal was unexpectedly received on Train A. The Train A Emergency Diesel Generator started upon the SI signal, as designed, but did not load since there was no actual emergency bus low voltage condition. The Train A Charging pump (Emergency Core Cooling Pump) was in service and operating before the generation of the SI signal, and continued to operate following the SI signal. Other plant components not isolated for plant outage conditions properly actuated in response to the generated SI signal.
A SI Block must be inserted whenever the Solid State Protection System (SSPS) is operating in Mode 5 to prevent a SI signal from being generated on low steam line pressure since steam line pressure will be below the low steam line pressure setpoint. Since the plant was in Mode 5 (temperature less than 200F), there can be no steam in the steam lines. Thus, the receipt of a Low Steam Line Pressure Safety Injection signal while the plant was in Mode 5 was invalid. It was determined that the SI Block was removed due to a degraded Steam Line Pressure SI Block/Reset switch on the control room benchboard. Further troubleshooting detected a similar erratic type degradation on the Train A Pressurizer SI Block switch. Both switches were replaced. This event is reportable pursuant to 10 CFR 50.73(a)(2)(iv)(A) since it involved an actuation of the Reactor Protection System (RPS) per 10 CFR 50.73(a)(2)(iv)(B)(1), an Emergency Core Cooling System (ECCS) pump per 10 CFR 50.73(a)(2)(iv)(B)(3), and an Emergency Diesel Generator (EDG) per 10 CFR 50.73(a)(2)(iv)(B)(8). 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 automatic actuation of the RPS, ECCS Pump and EDG 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:+519.12 h21.63 days <br />3.09 weeks <br />0.711 months <br />) | |
| Opened: | Brian Matty 08:59 May 28, 2009 |
| NRC Officer: | Vince Klco |
| Last Updated: | May 28, 2009 |
| 45099 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
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 | |