LR-N24-0027, Inadvertent Main Turbine Control Valve Closure Caused Reactor Scram

Inadvertent Main Turbine Control Valve Closure Caused Reactor Scram

ML24079A283
Person / Time
Site:	Hope Creek
Issue date:	03/19/2024
From:	Mclaughlin R Public Service Enterprise Group
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
LR-N24-0027 LER 2023-003-01
Download: ML24079A283 (4)

Text

Robert D. McLaughlin Plant Manager, Hope Creek Generating Station, PSEG Nuclear LLC o PSEG I NUCLEAR

PO Box 236 Hancocks Bridge, New Jersey 0 8038- 0221

10 CFR 50.73 LR-N24-0 027

March 19, 2024

U.S. Nuclear Re gulatory Co mmission ATTN: Document C ontrol D esk Washington, D C 2 0555- 001

Hope Creek G enerating Station Renewed F acility O perating License No. N PF-57 Docket No. 50-3 54

Subject:

Licensee Event Report 2023-0 03-01, Inadvertent Main Turbine Control Valve Closur e Caused Reactor Scram

PSEG Nuclear LLC submits the attached licensee event report supplement per 10 CFR 50.73(a)(2)(iv)(A).

There are no regulatory commitments contained in this submittal.

Please contact Ms. Bernadette Humphrey at (856) 339 - 1308 if you have questions.

Sincerely,

Robert D. McLaughlin Plant Manager, Hope Creek Generating Station

Attachment:

Licensee Event Report

cc: USNRC Regional Administrator Region 1 USNRC NRR Project Manager - Hope Creek USNRC Senior Resident Inspector - Hope Creek NJ Department of Environmental Protection, Bureau of Nuclear Engineering NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2024 (10-01-2023) Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons

~./;(,-,>" ~£<111,.,,.0._ learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden

! ~ LICENSEE EVENT REPORT (LER) estimate to the FOIA, Library, and Information Collections Branch (T-6 A10M), U. S. Nuclear Regulatory

~ : (See Page 2 for required number of digits/characters for each block) Commission, Washington, DC 20555-0001, or by email 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

~+-?,..,.11**._o' (See NUREG-1022, R.3 for instruction and guidance for completing this form Commission, 725 17th Street NW, Washington, DC 20503; email: oira_submission@omb.eop.gov. The NRC may http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/) 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.

1. Facility Name 050 2. Docket Number 3. Page Hope Creek Generating Station 00 00354 31 OF 052

4. Title Inadvertent Main Turbine Control Valve Closure Caused Reactor Scram

5. Event Date 6. LER Number 7. Report Date 8. Other Facilities Involved

Month Day Year Year Sequential Revision Month Day Year Facility Name Docket Number Number No. 050 12 14 2023 2023 003- - 01 03 19 2024 Facility Name 052 Docket Number

9. Operating Mode 10. Power Level 1 88I

11.This Report is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply) 10 CFR Part 20 20.2203(a)(2)(vi)10 CFR Part 5050.73(a)(2)(ii)(A)50.73(a)(2)(viii)(A)73.1200(a) 20.2201(b)20.2203(a)(3)(i)50.36(c)(1)(i)(A)50.73(a)(2)(ii)(B)50.73(a)(2)(viii)(B)73.1200(b) 20.2201(d)20.2203(a)(3)(ii)50.36(c)(1)(ii)(A)50.73(a)(2)(iii)50.73(a)(2)(ix)(A)73.1200(c)

[{] 20.2203(a)(1)20.2203(a)(4)50.36(c)(2)50.73(a)(2)(iv)(A)50.73(a)(2)(x)73.1200(d) 20.2203(a)(2)(i)10 CFR Part 2150.46(a)(3)(ii)50.73(a)(2)(v)(A)10 CFR Part 7373.1200(e) 20.2203(a)(2)(ii)21.2(c)50.69(g)50.73(a)(2)(v)(B)73.77(a)(1)73.1200(f) 20.2203(a)(2)(iii)50.73(a)(2)(i)(A)50.73(a)(2)(v)(C)73.77(a)(2)(i)73.1200(g) 20.2203(a)(2)(iv)50.73(a)(2)(i)(B)50.73(a)(2)(v)(D)73.77(a)(2)(ii)73.1200(h) 20.2203(a)(2)(v)50.73(a)(2)(i)(C)50.73(a)(2)(vii)

OTHER (Specify here, in abstract, or NRC 366A).

12.Licensee Contact for this LER

Licensee Contact Phone Number (Include area code)

Bernadette Humphrey (856)339 - 1308

13.Complete One Line for each Component Failure Described in this Report

Cause System Component Manufacturer Reportable to IRIS Cause System Component Manufacturer Reportable to IRIS

14. Supplemental Report Expected Month Day Year

15. Expected Submission Date

[{] No Yes (If yes, complete 15. Expected Submission Date)

16. Abstract (Limit to 1326 spaces, i.e., approximately 13 single-spaced typewritten lines)

On December 14, 2023, at 1939 EST, while attempting to manually close a failed open #4 turbine control valve (TCV), the #4 TCV closed rapidly. This caused a scram on average power range monitor (APRM) high neutron flux due to a rise in reactor pressure.

Hope Creek Generating Station (HCGS) repaired the #4 TCV by replacing the servo valve. In addition, the fast-acting solenoid (FAS) valve and the shutoff valve were replaced. HCGS synchronized the Main Generator to the grid on December 17, 2023, at 1537 EST.

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2024 (10-01-2023) Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported

~c,J> P. REGt,(,.>O lessons learned are incorporated into the licensing process and fed back to industry. Send comments LICENSEE EVENT REPORT (LER) regarding burden estimate to the FOIA, Library, and Information Collections Branch (T-6 A10M), U. S.

~. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by email to f~t? ~,i CONTINUATION SHEETInfocollects.Resource@nrc.gov, and the OMB reviewer at: OMB Office of Information and Regulatory

..;.+-, +O'

• • 11t** Affairs, (3150-0104), Attn: Desk Officer for the Nuclear Regulatory Commission, 725 17th Street NW, (See NUREG-1022, R.3 for instruction and guidance for completing this form Washington, DC 20503; email: oira_submission@omb.eop.gov. The NRC may not conduct or http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/) 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.

1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER

~ 050 YEAR SEQUENTIAL REV NUMBER NO.

Hope Creek Generating Station 00354 2023 003 01052 - -

I I D I I NARRATIVE

ABSTRACT (continued)

A Root Cause Evaluation (RCE) was performed. The root cause of this event was inadequate adherence to applicable administrative tools and processes. Corrective actions include procedure revisions and reinforcement of expectations regarding procedure adherence.

HCGS reported this per 10 CFR 50.72(b)(2)(iv)(B) as event notification 56889 and now reports this event per 10 CFR 50.73(a)(2)(iv)(A).

PLANT AND SYSTEM IDENTIFICATION

General Electric - Boiling Water Reactor (BWR/4)

Turbine Control Valve/ Electro-Hydraulic Control System (EHC) - TG

IDENTIFICATION OF OCCURRENCE

Event Date: December 14, 2023 Discovery Date: December 14, 2023

CONDITIONS PRIOR TO OCCURRENCE

OPCON 1, POWER OPERATION. Reactor power was at 88 percent.

No other structures, systems or components that could have contributed to the event were inoperable during the event.

DESCRIPTION OF OCCURRENCE

On December 11, 2023, an EHC leak was discovered on the #4 turbine control valve (TCV). Reactor power was reduced to 90 percent, the #4 TCV was closed, and EHC was isolated to stop the leak while the plant was at 90 percent power.

HCGS further lowered power to 70% to facilitate conditions for repairs.

On December 14, 2023, HCGS was at 88 percent power after #4 TCV FAS oil supply tubing repairs. During restoration, foreign material that entered and damaged the servo o-rings during the leak repair caused the #4 TCV to go full open despite having a closed demand signal. While taking action to manually close the #4 TCV, the valve unexpectedly closed in approximately one second causing an automatic actuation of the reactor protection system (RPS) due to high average power range monitor (APRM) high neutron flux.

All control rods fully inserted into the core. All safety systems responded as designed and expected. There were no emergency core cooling system actuations during the event.

NRC FORM 366A (10-01-2023) Page 2 3of NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2024 (10-01-2023) Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported

~c,J> P. REGt,(,.>O lessons learned are incorporated into the licensing process and fed back to industry. Send comments LICENSEE EVENT REPORT (LER) regarding burden estimate to the FOIA, Library, and Information Collections Branch (T-6 A10M), U. S.

~. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by email to f~t? ~,i CONTINUATION SHEETInfocollects.Resource@nrc.gov, and the OMB reviewer at: OMB Office of Information and Regulatory

..;.+-, +O'

• • 11t** Affairs, (3150-0104), Attn: Desk Officer for the Nuclear Regulatory Commission, 725 17th Street NW, (See NUREG-1022, R.3 for instruction and guidance for completing this form Washington, DC 20503; email: oira_submission@omb.eop.gov. The NRC may not conduct or http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/) 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.

1. FACILITY NAME 2. DOCKET NUMBER 3. LER NUMBER

~ 050 YEAR SEQUENTIAL REV NUMBER NO.

Hope Creek Generating Station 00354 2023 003 01052 - -

I I D I I NARRATIVE

CAUSE OF EVENT

Rapid closure of the #4 TCV caused a scram on APRM high neutron flux.

The direct cause of the full open #4 TCV was foreign material exclusion (FME) practices were not implemented correctly by the work groups. Decision makers believed manually operating the FAS could be done in a controlled manner; however, the subsequent fast closure of the #4 TCV resulted in the reactor scram.

The human performance related cause of this event was inadequate adherence to applicable administrative tools and processes. Vendor information was acted upon without employing a formal decision-making process.

SAFETY CONSEQUENCES AND IMPLICATIONS

There were no safety consequences because of this event. There was no radiological release. All safety equipment functioned as designed.

PREVIOUS EVENTS

There have been no previous events at HCGS in the last three years where the #4 TCV caused a reactor scram.

CORRECTIVE ACTIONS

1.Hope Creek Generating Station (HCGS) repaired the #4 TCV by replacing the servo valve, the fast-acting solenoid valve, and shutoff valve. HCGS synchronized the Main Generator to the grid on December 17, 2023, at 1537 EST.

2.Revise applicable EHC procedures which involve manual FAS valve manipulations while on-line.

3.Conduct training to review roles and responsibilities of the station duty team during the response to emergent issues.

Additional actions are being tracked in the licensees Corrective Action Program.

COMMITMENTS

There are no regulatory commitments in this LER.

NRC FORM 366A (10-01-2023) Page 3 3of