05000368/LER-2020-001, Loss of Feedwater Control System Power for Train a Feedwater That Resulted in Plant Trip
| ML21039A557 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/08/2021 |
| From: | Dinelli J Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 2CAN022102 LER 2020-001-00 | |
| Download: ML21039A557 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| 3682020001R00 - NRC Website | |
text
2CAN022102 February 8, 2021 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Licensee Event Report 50-368/2020-001-00, Loss of Feedwater Control System Power for Train 'A' Feedwater that Resulted in Plant Trip Arkansas Nuclear One - Unit 2 NRC Docket No. 50-368 Renewed Facility Operating License No. NPF-6 Pursuant to the reporting requirements of 10 CFR 50.73, attached is the subject Licensee Event Report concerning the Loss of Feedwater Control System Power for Train A Feedwater that Resulted in Plant Trip for Arkansas Nuclear One, Unit 2 which occurred on December 10, 2020.
There are no new commitments contained in this submittal. Should you have any questions concerning this issue, please contact Riley D. Keele Jr., Manager, Regulatory Assurance, at 479-858-7826.
Respectfully, John C. Dinelli JCD/mar Attachment: Licensee Event Report 50-368/2020-001-00 Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 John C. Dinelli Site Vice President Arkansas Nuclear One John Dinelli Digitally signed by John Dinelli Date: 2021.02.08 10:04:08 -06'00'
2CAN022102 Page 2 of 2 cc:
NRC Region IV Regional Administrator NRC Senior Resident Inspector - Arkansas Nuclear One NRC Project Manager - Arkansas Nuclear One Designated State Official Arkansas
to 2CAN022102 Licensee Event Report 50-368/2020-001-00
Abstract
Arkansas Nuclear One Unit 2 368 4
Loss of Feedwater Control System Power for Train 'A' Feedwater that Resulted in Plant Trip 12 10 2020 2020 001 00 02 08 2021 N/A N/A N/A N/A 1
100
Riley D. Keele / Manager, Regulatory Assurance (479)858-7826 B
JB UJX TDW120 Yes
On December 10, 2020, at 1608 CST, while in MODE 1 at 100 percent power, Arkansas Nuclear One, Unit 2 (ANO-2) experienced an automatic reactor scram due to low steam generator water level in the 'A' Steam Generator (SG). The low SG water level was caused by loss of power to the 'A' Feedwater Control System (FWCS) due to power supply failures in the 'A' FWCS cabinet. This resulted in main feedwater flow demand to the 'A' Main Feedwater Pump (MFP) and associated feedwater regulating valves to fail to minimum. Emergency Feedwater (EFW) actuated automatically due to low water level in the 'A' SG.
The failure of the 'A' FWCS power supplies affected post-trip response of the 'B' FWCS, which resulted in water level in the 'B' SG rising to a level requiring manual trip of the 'B' MFP. EFW responded as designed to feed both steam generators automatically. The plant was stabilized in MODE 3.
The other safety systems responded as designed. Electrical power was supplied from offsite power and maintained unit electrical loads as designed. The 'B' MFP remained available using approved plant procedures.
There were no consequences to the general safety of the public, nuclear safety, industrial safety, or radiological safety. No radiological releases have occurred due to this event.Page of 05000-
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5. Previous Similar Events
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