05000412/LER-2021-005, Manual Reactor Trip and Auxiliary Feedwater Actuation Due to Trip of a Main Feedwater Pump
| ML22017A001 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 01/17/2022 |
| From: | Grabnar J Energy Harbor Nuclear Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-21-294 LER 2021-005-00 | |
| Download: ML22017A001 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(iv)(B)(1) 10 CFR 50.73(a)(2)(iv)(B)(6) |
| 4122021005R00 - NRC Website | |
text
John J. Grabnar 724-682-5234 Site Vice President Fax: 724-643-8069 January 17, 2022 L-21-294 10 CFR 50.73 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 LER 2021-005-00 Enclosed is Licensee Event Report (LER) 2021-005-00, Manual Reactor Trip and Auxiliary Feedwater Actuation due to trip of a Main Feedwater Pump. This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A).
There are no regulatory commitments contained in this submittal. Any actions described in this document represent intended or planned actions and are described for information only.
If there are any questions or if additional information is required, please contact Mr. Steve Sawtschenko, Manager, Regulatory Compliance and Emergency Response, at 724-682-4284.
Sincerely, John J. Grabnar Enclosure: Beaver Valley Power Station, Unit 2 LER 2021-005-00 cc: Mr. D. C. Lew, NRC Region I Administrator NRC Senior Resident Inspector Ms. S. Goetz, NRC Project Manager INPO Records Center (via INPO Industry Reporting and Information System)
Mr. L. Winker (BRP/DEP)
Beaver Valley Power Station P.O. Box 4 Shippingport, PA 15077
Enclosure L-21-294 Beaver Valley Power Station, Unit 2 LER 2021-005-00
Abstract
Beaver Valley Power Station, Unit 2 412 3
Manual Reactor Trip and Auxiliary Feedwater Actuation due to trip of a Main Feedwater Pump 11 17 2021 2021 005 00 01 17 2022 1
100 Steve Sawtschenko, Manager, Regulatory Compliance and Emergency Response 724-682-4284 At 1313 on November 17, 2021, the Beaver Valley Power Station, Unit No. 2 (BVPS-2) reactor was manually tripped while at approximately 100 percent power following a trip of a main feedwater pump (MFP) caused by a loss of adequate suction pressure. A transient in the Heater Drain System occurred from a level increase in a Second Point Heater Drain Receiver Tank.
The level fluctuation resulted in an unexpected actuation of the tank's low-low level switch, which tripped the Train A Heater Drain and Separator Drain Receiver Drain Pumps. The trip of these pumps reduced flow and lowered MFP suction pressure. The standby condensate pump was not available to automatically start on low MFP pressure. When the MFP tripped, operators manually tripped the reactor per procedure. With the spare condensate pump unavailable, MFP suction pressure was unable to be restored and the manual reactor trip was procedurally required.
This event is being reported pursuant to 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in a manual actuation of the Reactor Protection System, 10 CFR 50.73(a)(2)(iv)(B)(1), and an automatic actuation of the Auxiliary Feedwater System, 10 CFR 50.73(a)(2)(iv)(B)(6). Corrective actions include changes to procedural controls for conditional single point vulnerabilities and condensate pump alignments above 40% power.Page of 05000-
- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
ANALYSIS OF EVENT
The event was reported per Event Notification 55586 as an event that resulted in the actuation of the reactor protection system, 10 CFR 50.72(b)(2)(iv)(B), and a specific system actuation, 10 CFR 50.72(B)(3)(iv)(A). This event is reportable pursuant to 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in a manual actuation of the Reactor Protection System, 10 CFR 50.73(a)(2)(iv)(B)(1), and the automatic actuation of the Auxiliary Feedwater System, 10 CFR 50.73(a)(2)(iv)(B)(6).
The plant risk associated with the BVPS-2 reactor trip on November 17, 2021, is considered to be very low. This is based on the change in average core damage frequency derived using the conditional core damage probability and change in average large early release frequency derived using conditional large early release probability for the event. Therefore, this event had very low safety significance.
CORRECTIVE ACTIONS
Completed Actions:
- 1) The standby third condensate pump was returned to service on November 20, 2021.
Planned Actions:
- 1) Revise the risk management procedure to require additional risk management actions and to reassess conditional single point vulnerabilities that remain out of service when exiting an outage.
- 2) Revise the maintenance notification screening procedure to incorporate conditional single point vulnerability screening guidance.
- 3) Verify that planned maintenance strategies for the Unit 2 condensate pumps minimize out of service time when greater than 40 percent power.
- 4) Revise the startup procedure that if the standby condensate pump is not available, enter an evaluation process prior to power ascension above 40 percent power.
PREVIOUS SIMILAR EVENTS
A review of the previous three years identified that no similar events have occurred at BVPS.
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Beaver Valley Power Station, Unit 2 412 2021 005 00