05000382/LER-2024-003, Automatic EFAS Actuation During Surveillance Test

Automatic EFAS Actuation During Surveillance Test

ML24192A173
Person / Time
Site:	Waterford
Issue date:	07/10/2024
From:	Twarog J Entergy Operations
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
W3F1-2024-0025 LER 2024-003-00
Download: ML24192A173 (1)

LER-2024-003, Automatic EFAS Actuation During Surveillance Test

Event date:
Report date:
3822024003R00 - NRC Website

text

) entergy John Twarog Manager Regulatory Assurance 504-739-67 4 7

W3F1 -2024-0025 10 CFR 50.73

July 10, 2024

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject: Licensee Event Report 50-382/2024-003-00, Automatic EFAS Actuation During Surveillance Test Waterford Steam Electric Station, Unit 3 NRC Docket No. 50-382 Renewed Facility Operating License No. NPF-38

Entergy Operations, Inc. (Entergy) submits the enclosed Licensee Event Report (LER) 50-382/2024-003-00 for Waterford Steam Electric Station, Unit 3. The events reported herein are reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A), Any event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B);

Reactor protection system (RPS) including: reactor scram or reactor trip and emergency feedwater system.

The LER describes the valid, automatic actuation of Emergency Feedwater Actuation Signal and a RPS reactor trip during emergency feedwater flow verification test.

This letter contains no new commitments.

Should you have any questions concerning this issue, please contact me at 504-739-6747.

Respectfully,

John Twarog

JRT/ahv

Entergy Operations, Inc., 17265 River Road, Killona, LA 70057 W3F1 -2024-0025 Page 2 of 2

Enclosure: Licensee Event Report 50-382/2024-003-00

cc: NRC Region IV Regional Administrator NRC Senior Resident Inspector - Waterford Steam Electric Station, Unit 3 NRC Project Manager - Waterford Steam Electric Station, Unit 3 Louisiana Department of Environmental Quality Enclosure

W3F1-2024-0025

Licensee Event Report 50-382/2024-003-00

Abstract

At 1655 on 5/11/2024, during performance of Emergency Feedwater Pump AB (EFW AB) flow verification surveillance test, Steam Generator (SG) #1 level unexpectedly dropped from approximately 30% Narrow Range (NR) to 26.83% NR after emergency feedwater flow was initiated. At 27.4% NR in SG #1, a valid Emergency Feedwater Actuation Signal (EFAS) 1 Train A and B, and Reactor Protection Signal (RPS) reactor trip signal was generated. At the time of this event, the plant was in Mode 3 with all Control Element Assemblies (CEAs) fully inserted, Reactor Trip Circuit Breakers (RTCB) closed and individual CEA disconnects open for plant startup.

The causes of the unexpected EFAS 1 and RPS reactor trip signals was procedural guidance allowed the test to start with SG level close to the actuation setpoint and the operators did not consider the magnitude of the SG level shrink when feeding the SG with colder feedwater. Corrective actions include revising the test procedure to raise the minimum level from 30% to 40% and completion of a performance analysis.

This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A), any event or condition that resulted in manual or automatic actuation of any of the systems listed in 10 CFR 50.73(a)(2)(iv)(B).

U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 04/30/2027 050 Waterford Steam Electric Station, Unit 3 NUMBER 052 00382 2024 003 00

Safety Assessment

There were no safety consequences because of this event. The operators performed all actions in accordance with procedures and training. All CEAs were previously, fully inserted into the core and no control rod movement occurred due to the actuation. EFAS was reset after SG #1 level was raised above the reset setpoint. The event did not affect the availability of systems needed to maintain safe shutdown conditions, control the release of radioactivity, or mitigate the consequences of an accident.

Corrective Actions

(1) Revise OP-903-014 to raise the level band to 40% to 70% NR.

(2) Perform a review of Operations evolutions and surveillance tests that could result in an automatic actuation setpoint being reached due to a change in system inventory during the evolution or test.

(3) Reviewed event with the responsible individuals.

(4) Created a standing order that requires each crew member to participate in a Post-Job Brief at the end of each shift. The standing order also requires work preparation to include an intentional review of procedural guidance to determine if inadequate margin could exist during the activity and to establish additional controls, when necessary, to ensure undesired actuation setpoints are not challenged.

(5) Perform a training needs analysis based on the results from the performance analysis.

Previous Similar Occurrences None