05000416/LER-2020-005, Re Primary Water System Flow Lowered Causing Turbine Trip and Subsequent Reactor Scram

Re Primary Water System Flow Lowered Causing Turbine Trip and Subsequent Reactor Scram

ML21005A071
Person / Time
Site:	Grand Gulf
Issue date:	01/02/2021
From:	Franssen R Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GNRO-2020/00047 LER 2020-005-00
Download: ML21005A071 (6)

LER-2020-005, Re Primary Water System Flow Lowered Causing Turbine Trip and Subsequent Reactor Scram

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(B), System Actuation
4162020005R00 - NRC Website

text

GNRO-2020/00047 January 2, 2021 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Grand Gulf Nuclear Station, Unit 1 Licensee Event Report 2020-005-00, Primary Water System Flow Lowered Causing Turbine Trip and Subsequent Reactor SCRAM.

Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 Renewed License No. NPF-29 Attached is Licensee Event Report 2020-005-00, Primary Water System Flow Lowered Causing Turbine Trip and Subsequent Reactor SCRAM. This report is being submitted in accordance with 10 CFR 50.73(a)(2)(iv)(B), for any event or condition that resulted in manual or automatic actuation of the Reactor Protection System.

This letter contains no new Regulatory Commitments. Should you have any questions concerning the content of this letter, please contact Jim Shaw, Manager Regulatory Assurance at 601-437-2103.

Sincerely, Robert Franssen RF/fas Attachments: Licensee Event Report 2020-005-00 Robert Franssen Site Vice President Grand Gulf Nuclear Station Tel: 601-437-7500 Entergy Operations, Inc.

P.O. Box 756 Port Gibson, Mississippi 39150 10 CFR 50.73

GNRO-2020/00047 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

GNRO-2020/00047 Page 3 of 3 Attachment Licensee Event Report 2020-005-00

NRC FORM 366 (08-2020)

U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2023

LICENSEE EVENT REPORT (LER)

(See Page 3 for required number of digits/characters for each block)

(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)

1. Facility Name Grand Gulf Nuclear Station, Unit 1

2. Docket Number 05000416

3. Page 1 OF 3

4. Title Primary Water System Flow Lowered Causing Turbine Trip and Subsequent Reactor SCRAM

5. Event Date

6. LER Number

7. Report Date

8. Other Facilities Involved Month Day Year Year Sequential Number Rev No.

Month Day Year Facility Name N/A Docket Number 05000 N/A 11 06 2020 2020

- 005 -

00 01 02 2021 Facility Name Docket Number N/A 05000 N/A

9. Operating Mode 1

10. Power Level 84 Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nrc.gov, and the OMB reviewer at: OMB 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 NRC may not conduct or sponsor, and a person is not required to respond to, a collection of information unless the document requesting or requiring the collection displays a currently valid OMB control number.

LICENSEE EVENT REPORT (LER)

CONTINUATION SHEET (See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)

3. LER NUMBER Grand Gulf Nuclear Station, Unit 1 05000416 YEAR SEQUENTIAL NUMBER REV NO.

2020

- 005

- 00 the appropriate parameters until the condition can be corrected (04-1-02-1H13-P680 Rev. 256).

ARI for the Primary Water Tank low level alarm has been enhanced with directions to bypass the primary water flow trips and vent the primary water coolers after restoring proper tank level (04-1-02-1H13-P680 Rev. 256).

The Primary Water Tank low level alarm setpoint was raised to prevent gas entrainment within instrument tubing.

Temporary modification to allow bypassing the Primary Water low flow trip functions to mitigate the effects of a spurious signal.

Corrective action(s) to prevent reoccurrence to be determined upon completion of the causal investigation.

Previous Similar Events

Entergy conducted a three-year review of the relevant licensee event reports and determined that there were no similar events.

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