05000335/LER-2021-001, Manual Reactor Trip Due to Insufficient Feed Flow to Steam Generators

Manual Reactor Trip Due to Insufficient Feed Flow to Steam Generators

ML22035A033
Person / Time
Site:	Saint Lucie
Issue date:	02/04/2022
From:	Deboer D Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L -2022-019 LER 2021-001-00
Download: ML22035A033 (4)

LER-2021-001, Manual Reactor Trip Due to Insufficient Feed Flow to Steam Generators

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A)
3352021001R00 - NRC Website

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February 4, 2022 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Re:

St. Lucie Unit 1 Docket No. 50-335 Reportable Event:

2021-001-00 Date of Event: December 10, 2021 L -2022-019 10CFR 50.73 Manual Reactor Trip Due to Insufficient Feed Flow to Steam Generators The attached Licensee Event Report 2021-001 is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Respectfully, Daniel DeBoer Site Vice President St. Lucie Plant DD/tf Attachment cc:

St. Lucie NRC Senior Resident Inspector St. Lucie NRC Program Manager Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (08-2020)

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 St. Lucie Unit 1

2. Docket Number 05000335

3. Page 1 of 3

4. Title Manual Reactor Trip Due to Insufficient Feed Flow to Steam Generators

5. Event Date

6. LER Number

7. Report Date

8. Other Facilities Involved Month Day Year Year Sequential Number Revision Number Month Day Year Facility Name n/a Docket Number 05000 12 10 2021 2021 -

001 - 00 02 04 2022 Facility Name n/a Docket Number 05000

9. Operating Mode 1

10. Power Level 100

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) 50.36(c)(2) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 20.2201(b) 20.2203(a)(3)(i) 50.46(a)(3)(ii) 50.73(a)(2)(v)(A) 10 CFR Part 73 20.2201(d) 20.2203(a)(3)(ii) 50.69(g) 50.73(a)(2)(v)(B) 73.71(a)(4) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C) 73.71(a)(5) 20.2203(a)(2)(i) 10 CFR Part 21 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D) 73.77(a)(1) 20.2203(a)(2)(ii) 21.2(c) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 73.77(a)(2)(i) 20.2203(a)(2)(iii) 10 CFR Part 50 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 73.77(a)(2)(ii) 20.2203(a)(2)(iv) 50.36(c)(1)(i)(A) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(v) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A)

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

12. Licensee Contact for this LER Licensee Contact Timothy Falkiewicz, Licensing Engineer Telephone Number (Include area code)

(772) 429-3756 Cause System Component Manufacturer Reportable To IRIS

Cause

System Component Manufacturer Reportable To IRIS A

SN PDIS I204 Y

14. Supplemental Report Expected YES (If yes, complete 15. Expected Submission Date)

NO

15. Expected Submission Date Month Day Year Abstract (Limit to 1560 spaces, i.e., approximately 15 single-spaced typewritten lines)

On December 10, 2021 at 1024 EST with Unit 1 in Mode 1 at 100% power, the reactor was manually tripped due to lowering level in the steam generators. The trip was uncomplicated with all systems responding normally post trip.

Operators restored steam generator level utilizing main feedwater and stabilized the reactor in Mode 3.

The event occurred while replacing a feedwater heater control Pressure Differential Indicating Switch (PDIS). In the process of landing the wires from the new PDIS on the terminal strip, the technician made inadvertent contact with the enclosure housing resulting in a blown supply fuse which caused a loss of high pressure heater level control and a reduction of Steam Generator feedwater flow.

Due to the emergent nature of this work, some of the normal preplanned mitigation measures were not in place.

Corrective actions include maintenance procedure revisions.

Manual reactor trips are analyzed events in the Updated Final Safety Analysis Report. The trip was uncomplicated.

Therefore, this event had no impact on the health and safety of the public.

Page 3 of 3 Failed Components Identified

1) PDIS-11-30D1

Description

PDIS between the HP heater 5A and the 1D MSR Part Number: 288A (0-100 psig)

Manufacturer: ITT - Barton Instrument

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