05000250/LER-2023-004, Unplanned Automatic Scram During RPS Testing

Unplanned Automatic Scram During RPS Testing

ML23347A130
Person / Time
Site:	Turkey Point
Issue date:	12/13/2023
From:	Strand D Florida Power & Light Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-2023-178 LER 2023-04-00
Download: ML23347A130 (1)

LER-2023-004, Unplanned Automatic Scram During RPS Testing

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation
2502023004R00 - NRC Website

text

U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Re:

Turkey Point Unit 3 Docket No. 50-250 Reportable Event: 2023-04-00 Date of Event: October 24, 2023 Automatic Reactor Trip December 13, 2023 L-2023-178 10 CFR 50.73 The attached Licensee Event Report 2023-04 is being submitted pursuant to the requirements of 10 CFR 50. 73 to provide notification of the subject event.

Respectfully, Dianne Strand General Manager, Regulatory Affairs Florida Power & Light Company Attachment cc:

Turkey Point NRG Senior Resident Inspector Turkey Point Station NRG Program Manager Florida Power & Light Company 9760 SW 344th Street, Homestead, FL 33035

Abstract

On October 24, 2023, with Unit 3 at 100% power, during performance of Reactor Protection System (RPS) [EIIS: JE] logic testing on Unit 4 (U4), instrument and control (l&C) technicians incorrectly initiated a U3 RPS Safety Injection signal creating an automatic trip of U3. The cause of this event was a human performance error by the l&C technicians involved in the RPS testing. The trip was uncomplicated with all systems responding normally post trip, including the actuation of the AFW system [EIIS: BA] to remove decay heat. This is an expected condition after reactor trips. This licensee event report is being reported pursuant of 10 CFR 50.73(a)(2)(iv)(A) for any event or condition that resulted in the manual or automatic actuation of the RPS and AFW. In addition, there were no inoperable Structures, Systems, or Components that contributed to this event.

Description of Event

2. DOCKET NUMBER I

000250

3. LER NUMBER D

NUMBER NO.

I YEAR SEQUENTIAL REV O-,

04 1-0 On October 24, 2023, with Unit 3 at 100% power, during performance of Reactor Protection System (RPS) [EIIS: JE] logic testing on Unit 4 (U4), instrument and control (l&C) technicians incorrectly initiated a U3 RPS Safety Injection signal creating an automatic trip of U3. The cause of this event was a human performance error by the l&C technicians involved in the RPS testing. The trip was uncomplicated with all systems responding normally post trip, including the actuation of the AFW system [EIIS: BA] to remove decay heat. This is an expected condition after reactor trips.

Cause of Event

The direct cause of this event are human performance errors by l&C technicians performing steps in an RPS test procedure on the incorrect unit. In addition, leaders with management responsibilities have not established a culture where all supervisors recognize they are directly responsible for the performance of their direct reports. Contributing to this event was a lack of hard barriers to guard plant equipment associated with the unit not in an outage where both units share the same room.

Safety Significance

The plant trip was uncomplicated with systems responding as expected post-trip. In response to the expected low steam generator level, emergency feedwater actuated as expected. This event did not result in a Safety System Functional Failure. This licensee event report is being reported pursuant of 10 CFR 50.73(a)(2)(iv)(A) for any event or condition that resulted in the manual or automatic actuation of the RPS and AFW. In addition, there were no inoperable Structures, Systems, or Components that contributed to this event.

Corrective Actions

1. A stand down with l&C department personnel was conducted to share learnings.

2. Procedures governing guarding equipment will be revised to include blocking/guarding of equipment in rooms that both units share such as the cable spreading room at Turkey Point.

3. Locks for RPS cabinets will be modified such that the same keys will no longer allow access to either U3 or U4 RPS cabinets. Page 2

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