05000373/LER-2022-004, Both Trains of Main Control Room and Auxiliary Electric Room HVAC Declared Inoperable Due to Compressor Trips

Both Trains of Main Control Room and Auxiliary Electric Room HVAC Declared Inoperable Due to Compressor Trips

ML22362A015
Person / Time
Site:	LaSalle
Issue date:	12/28/2022
From:	Van Fleet J Constellation Energy Generation, Exelon Generation Co LLC
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
RA22-054 LER 2022-004-00
Download: ML22362A015 (1)

LER-2022-004, Both Trains of Main Control Room and Auxiliary Electric Room HVAC Declared Inoperable Due to Compressor Trips

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2) 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
3732022004R00 - NRC Website

text

LaSalle County Station 2601 North 21 " Road Constellation~ Marseilles. IL 61341 815-415-2000 Telephone

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10 CFR 50.73

RA22-054

December 28, 2022

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

LaSalle County Station, Units 1 and 2 Renewed Facility Operating License No. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374

Subject: Licensee Event Report 2022-004-00, Both Trains of Main Control Room and Auxiliary Electric Room HVAC Declared Inoperable due to Compressor Trips.

In accordance with 10 CFR 50.73(a)(2)(v)(D), Exelon Generation Company, LLC (EGC) is submitting Licensee Event Report (LER) Number 2022-004-00 for LaSalle County Station, Units 1 and 2.

There are no regulatory commitments in this letter. Should you have any questions concerning this report, please contact Mr. Dan Mearhoff, Regulatory Assurance Manager, at (815) 415-2800.

Respectfully, frJ/4~

John Van Fleet Jr Plant Manager LaSalle County Station

Enclosure: Licensee Event Report

cc: Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - LaSalle County Station NRCFORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 08/31/2023 (08-2020) Estimated burden per respon se 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 />. Rep orted LICENSEE EVENT REPORT (LER) lessons leamed are incorporated into the licens ing proce ss and fed back ID industry. Send comments regarding burden estimate ID lhe FOIA, Library, and Information Co llections Branch (T-6 A10M), U.S.

(See Page 3 for required number of digits/characters for each block) Nuclear Regu latory Commission, Wash ington, DC 20555-0001, or by e-mail to (S ee NUREG - 1022, R.3 for instruction and guidance for completing this form lnfocollects.Resource@nrc.gov, and the 0MB reviewer al: 0 MB Office of Information and Regulatory http://www.nrc.gov /reading - rm /do c-collec tions /nuregs /staff/ sr1022/r3/ ) Affairs, (3150-0104), Attn: Desk a il: o ira submission@ o mb.eop.gov. The NRC ""Y not condud or sponsor, and a person is not required ID respond ID, a cdlection of infonnation unless lhe document requesting or requiring lhe collection displays a currenUy valKI 0MB control number.

1. Faclllty Name 2. Docket Number 3. Page LaSalle County Station, Unit 1 05000 - 373 1 OF 5

4. TIiie Both Trains of Main Control Room and Auxiliary Electric Room HVAC Declared Inoperable due to Compressor Trips.

5. Event Date 6. LER Number 7. Report Date 8. Other Facllltles Involved Month Day Year Year Number No. Month Day Year LaSalle County Station, Unit 2 05000-374 Sequential Revision Faclllty Name Docket Number

11 04 2022 2022 004 00 12 21 2022 Faclllty - - NA NA Name Docket Number

9. Operating Mode 1 110. Power Level 100 percent

11. This Report Is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply) 10 CFR Part 20 D 20.2203(a)(2)(vl) D 50.36(c)(2) D 50.73(a)(2)(Iv)(A) D 50.73(a)(2)(x)

~ '

20.2201(b) D 20.2203(a)(3)(I) D 50.46(a)(3)(11) D 50.73(a)(2)(v)(A) 10 CFII Part 73 20.2201(d) D 20.2203(a)(3)(11) 50.69(g) 50.73(a)(2)(v)(B) D 73.71(a)(4)

D 20.2203(a)(1) D 20.2203(a)(4) 50. 73(a)(2)(I)(A) 50.73(a)(2)(v)(C) D 73.71(a)(5)

D 20.2203(a)(2)(I) 10 CFR P11!i1' 21 50.73(a)(2)(I)(B) ~ 50.73(a)(2)(v)(D) D 73.77(a)(1)(I)

D 20.2203(a)(2)(11) D 21.2(c) 50.73(a)(2)(I)(C) 50.73(a)(2)(vll) D 73.77(a)(2)(I)

D 20.2203(a)(2)(111) 10 Cfll Pi tt. SO 50.73(a)(2)(11)(A) D 50.73(a)(2)(vlil)(A) D 73.77(a)(2)(11)

D 20.2203(a)(2)(Iv) 50.36(c)(1)(I)(A) 50.73(a)(2)(11)(B) D 50.73(a)(2)(vlil)(B)

D 20.2203(a)(2)(v) 50.36(c)(1)(1i)(A) D 50.73(a)(2)(111) D 50.73(a)(2)(Ix)(A)

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

12. Licensee Contact for this LER Licensee Contact Phone Number (Include area code)

CJ Smith, Operations Director I(815) 415-2200

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 B VI COMP C147 y I 14. Supplemental Report Expected Month Day Year

15. Expecte t Submission Date

[81 No I D Yes (If yes, complete 15. Expected Submission Date)

6. Abstract (Limit to 1560 spaces, i.e., approximately 15 single-spaced typewritten lines)

On November 3, 2022, both Units 1 and 2 were in Mode 1 and at 100% power. At 2308 CDT the A Main Control Room Ventilation (VC) Compressor tripped on low oil pressure. The A train of the Main Control Room Ventilation (VC) was declared inoperable. The station swapped to the B VCNE train.

On November 4 at 0006 CDT, the B Auxiliary Electric Room Ventilation (VE) compressor tripped on high oil temperature and the B VE train was declared inoperable. With both the A and B control room area ventilation air conditioning (CRAC) trains inoperable, the system was in a condition that could have prevented fulfillment of a safety function.

The cause of the A VC Compressor trip was a leak on an oil pressure switch sensing line and the cause of the B VE compressor trip was high oil temperature due to slugging.

5

Corrective Actions

Corrective actions taken in response to the conditions were:

• Oil was added to the B VE compressor and the compressor was restarted.

• Repairs were made to the A VC compressor oil pressure switch sensing lines.

Previous Occurrences

LER 373-2022-003

On May 20, 2022, both Units 1 and 2 were in Mode 1 and at 100% power. The B train of the Main Control Room Ventilation (VC) and Auxiliary Electric Room Ventilation (VE) was inoperable due to a planned maintenance window. At 0905 and again on 5/23/22 at 1256, various equipment on the A VCNE train tripped following train swaps to support ongoing maintenance activities. This resulted in the A VCNE train being declared inoperable.

With both the A and B trains being simultaneously inoperable, the system was in a condition that could have prevented fulfillment of a safety function. The cause of the event was inadequate breaker settings.

LER 373-2014-004

On August 28, 2014, both Units 1 and 2 were in Mode 1 at 100% power. The 'B' train of Auxiliary Electric Equipment Room ventilation (VE) was inoperable due to a planned repair of an oil leak. At 1227 hours0.0142 days <br />0.341 hours <br />0.00203 weeks <br />4.668735e-4 months <br /> CDT, the A VE compressor was not found to be cycling on and off resulting in the 'A' train of VCNE being declared inoperable. With both trains of VCNE inoperable, this resulted in an event or condition that could have prevented the fulfillment of a safety function. The cause of the event was a shorted wire on liquid line solenoid valve 0RG053A that caused the solenoid valve to close, resulting in the compressor shutting down on low suction pressure. The corrective action was to repair the wiring problem and return the compressor to service.

LER 373-2013-008

On November 22, 2013, both Units 1 and 2 were in Mode 1 at 100% power. The 'A' train of Main Control Room ventilation (VC) was inoperable due to an emergent repair of a Freon leak. At 1920 hours0.0222 days <br />0.533 hours <br />0.00317 weeks <br />7.3056e-4 months <br /> CST, the 'B' AEER Cooler Condenser Fan tripped. An acrid mell was detected coming from the fan motor breaker comp~rtment. The 'B' train of VC and VE was declared inope able. With both trains of VCNE inoperable, this resulted in ~n event or condition that could have prevented the fulfillment of a safety function. The cause of the event was a winding failure of the 'B' AEER Cooler Condenser fan motor. Corrective actions included replacing the failed fan motor and performing a failure analysis to determine the cause of the winding failure.

5

Component Failure Data

Manufacturer: Carrier Corp.

Device: A Control Room HVAC Refrigeration Compressor (Model 5H80)

Component ID: 0VC0SCA

Manufacturer: Carrier Corp.

Device: B Aux Electric Equipment Room HVAC Refrigeration Compressor (Model 5H86)

Component ID: 0VE04CB

SNRC FORM 366A (08-2020) Page_5_ of..i_