ENS 45001
ENS Event | |
|---|---|
05:53 Apr 20, 2009 | |
| Title | Unexpected Start of the Steam Driven Auxiliary Feedwater Pump During Plant Cooldown |
| Event Description | On 4/20/09 at 0153 hours0.00177 days <br />0.0425 hours <br />2.529762e-4 weeks <br />5.82165e-5 months <br />, while in Mode 3 performing a plant cooldown for a refueling outage, a control room operator noted that the 'B' train steam supply (TV-1MS-105B) to the steam driven auxiliary feedwater pump, FW-P-2, was open. This caused the steam driven auxiliary feedwater pump to start and inject auxiliary feedwater into the steam generators. This was an unexpected condition. The start of the FW-P-2 auxiliary turbine driven feedwater pump is reportable under 10CFR50.72(b)(3)(iv)(A).
At 0209, TV-1MS-105B was closed. The steam driven auxiliary feedwater pump was declared inoperable and Technical Specification action statements were entered. Technical Specification 3.7.5 Condition B requires the pump to be restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in Mode 4 within the following 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />. Mode 4 was entered on 4/20/09 at 0347 hours0.00402 days <br />0.0964 hours <br />5.737434e-4 weeks <br />1.320335e-4 months <br />. The steam drive auxiliary feedwater pump is not required to be operable in Mode 4. Technical Specification 3.7.5 Condition B was exited on 4/20/09 at 0347. Investigation is in progress to determine the cause of TV-1MS-105B opening. The licensee notified the NRC Resident Inspector.
This notification retracts 10 CFR 50.72 Event Notification No. 45001 since the actuation that was reported has subsequently been determined to be invalid. On April 20, 2009, Beaver Valley Power Station Unit 1 (BVPS-1) was in Mode 3 and being shutdown in preparation for a refueling outage. At 0153 hours0.00177 days <br />0.0425 hours <br />2.529762e-4 weeks <br />5.82165e-5 months <br />, one steam supply isolation valve (TV-1 MS-105B) to the steam-driven Auxiliary Feedwater System Pump (FW-P-2) unexpectedly opened at BVPS-1, causing this pump to commence feeding all three steam generators. FW-P-2 functioned as designed with steam being supplied to the pump's steam-driven turbine. This actuation was reported in NRC Event Notification No. 45001. This start of the steam-driven Auxiliary Feedwater Pump was not valid. There was no adverse Steam Generator water levels, no Safety Injection signal, and no Reactor Coolant Pump undervoltage condition which could have caused an Auxiliary Feedwater Pump start. No maintenance or tests were ongoing with the Auxiliary Feedwater System at the time. After observing that there was no demand for this Auxiliary Feedwater System pump to be operating, the control room crew closed the steam supply isolation valve from the control room at 0209 hours0.00242 days <br />0.0581 hours <br />3.455688e-4 weeks <br />7.95245e-5 months <br />, terminating operation of this auxiliary feedwater pump. A follow-up problem solving team investigation did not identify any deficiencies within the solid state protection system. The most likely cause involved a degraded control room benchboard switch for TV-1 MS-105B. The physical degradation of the control switch would have allowed for the unplanned opening of the steam supply to the Auxiliary Feedwater Pump. This benchboard switch has been replaced and satisfactorily tested. This event is being retracted since the Auxiliary Feedwater Pump actuation was not valid and therefore not reportable pursuant to 10 CFR 50.72(b)(3)(iv)(A) as previously reported. This event is, however, reportable pursuant to 10 CFR 50.73(a)(2)(iv)(A) since it involved an actuation of a PWR Auxiliary Feedwater system train as listed per 10 CFR 50.73(a)(2)(iv)(B)(6). 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 Auxiliary Feedwater System pump was not generated by a valid actuation. The licensee has notified the NRC Resident Inspector. R1DO (Holody) notified. |
| Where | |
|---|---|
Beaver Valley  Pennsylvania (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+-0.73 h-0.0304 days <br />-0.00435 weeks <br />-9.99954e-4 months <br />) | |
| Opened: | George E. Storolis 05:09 Apr 20, 2009 |
| NRC Officer: | Steve Sandin |
| Last Updated: | May 14, 2009 |
| 45001 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Standby (0 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 556022021-09-30T14:07:00030 September 2021 14:07:00
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