05000416/LER-2020-004-01, Automatic Reactor Scram Due to Reactor Feed Pump Trip

Automatic Reactor Scram Due to Reactor Feed Pump Trip

ML21231A137
Person / Time
Site:	Grand Gulf
Issue date:	08/19/2021
From:	Hardy J Entergy Operations
To:	Office of Nuclear Reactor Regulation
Shared Package
ML21231A134	List: 05000416/LER-2020-002-02, Reactor Scram Due to Main Turbine Trip 05000416/LER-2020-003-01, Manual Reactor Scram Due to Turbine High Pressure Control Valve Malfunction and Automatic Reactor Water Level Scram 05000416/LER-2020-004-01, Automatic Reactor Scram Due to Reactor Feed Pump Trip 05000416/LER-2020-005-02, Primarv Water Svstem Flow Lowered Causinc Turbine Trio and Subseauent Reactor Scram 05000416/LER-2020-006-02, Primary Water Tank Low Level Causing Turbine Trip and Subsequent Reactor Scram
References
GNRO-2021/00021 LER 2020-004-01
Download: ML21231A137 (6)

LER-2020-004, Automatic Reactor Scram Due to Reactor Feed Pump Trip

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation
4162020004R01 - NRC Website

text

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"'='Entergy G N RO-2021 /00021 August19,2021 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Entergy Operations, Inc.

P.O. Box 756 Port Gibson, Mississippi 39150 Jeff A. Hardy Regulatory Assurance Manager Grand Gulf Nuclear Station Tel: 601-437-7500 10 CFR 50.73

SUBJECT:

Grand Gulf Nuclear Station, Unit 1 Revised Licensee Event Report 2020-004-01 Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 Renewed License No. NPF-29 Attached is revised Licensee Event Report 2020-004-01, Automatic Reactor Scram Due to Reactor Feed Pump Trip. This report is being submitted in accordance with 10 CFR 50.73(a)(2)(iv)(A), for any event or condition that resulted in manual or automatic actuation of the Reactor Protection System (RPS).

This letter contains no new Regulatory Commitments. Should you have any questions concerning the content of this letter, please contact Jeff Hardy, Regulatory Assurance Manager at 269-764-2011.

Sincerely, (JA~\\~:

Jeff A. Hardy JAH/fas Attachments: Revised Licensee Event Report 2020-004-01

GNRO-2021/00021 Page 2 of 3 cc:

NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 U.S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

G N RO-2021 /00021 Page 3 of 3 Attachment Revised Licensee Event Report 2020-004-01

NRC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-01 04 EXPIRES: 08/31/2023 (08-2020)

I3.Page Grand Gulf Nuclear Station, Unit 1 05000 416 1 OF3

4. Title A, "',.;,., ;, RP.;:ir.tnr ~ccarn Due Io Beactor FP.P.rl Pt Jmn Trin

5. Event Date

6. LER Number

7. Report Date

8. Other Facilities Involved Sequential Rev Facility Name Docket Number Month Day Year Year Month Day Year N/A Number No.

05000 N/A 08 24 2020 2020

- 004 -

01 08 19 2021 Facility Name Docket Number N/A 05000 N/A

9. Operatrg Mode 1 10. Pov.erlewl 1

14 Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to lnfocollects.Resource@nrc.gov, and the 0MB reviewer at: 0MB Office of Information and Regulatory Affairs, (3150-0104), Attn: Desk Officer for the Nuclear Regulatory Commission, 725 17th Street NW, Washington, DC 20503; e-mail: oira submission@omb.eop.gov. The NRG may not conduct or sponsor, and a person is not required lo respond to, a collection of information unless the document requesting or requiring the collection displays a currently valid 0MB control number.

3. LER NUMBER YEAR Grand Gulf Nuclear Station, Unit 1 05000-416 2020 SEQUENT IA NUMBER

- 004 REV NO

- 01 The root cause of the event was that the Reactor Feed Pump "B" Minimum Flow Valve positioner installed during Preventive Maintenance activities failed due to infant mortality within approximately 29 hours3.356481e-4 days <br />0.00806 hours <br />4.794974e-5 weeks <br />1.10345e-5 months <br /> of service. This caused the malfunctioning pilot valve condition, resulting in the minimum flow valve going closed and tripping RFP B on low suction flow. The condition was a latent issue (manufacturer defect) not identified by functional testing at the time the part was received.

Corrective Actions

The failed positioner for the RFP "B" Minimum Flow Valve was replaced and tested satisfactorily prior to unit restart.

Additionally, the positioner for the RFP "A" Minimum Flow Valve was also replaced as part of the initial extent of condition review. These actions were completed.

The corrective action to Preclude Repetition was to develop work instructions for those Air Operated Valves (AOV) using ABB/Bailey AV1 or AV2 series positioners to inspect the positioners prior to installation. This action has been completed.

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