05000272/LER-2024-001, Pressure Boundary Leakage Through a Reactor Coolant Pump Thermal Barrier Heat Exchanger
| ML24130A090 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 05/09/2024 |
| From: | Desanctis R Public Service Enterprise Group |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LR-N24-0038 LER 2024-001-00 | |
| Download: ML24130A090 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2722024001R00 - NRC Website | |
text
Richard J. Desanctis, Jr.
Plant Manager, Salem Generating Station, PSEG Nuclear LLC o PSEG I NUCLEAR
PO Box 236
- Hancocks Bridge, New Jersey 08038-0221
10 CFR 50.73 LR-N24-0038
May 9, 2024
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Salem Generating Station, Unit 1 Renewed Facility Operating License No. DPR-70 Docket No. 50-272
Subject: Licensee Event Report 2024 -001-00, Pressure Boundary Leakage through a Reactor Coolant Pump Thermal Barrier Heat Exchanger
PSEG Nuclear LLC submits the attached licensee event report (LER) per 10 CFR
- 50. 73(a)(2)(i)(B).
There are no regulatory commitments contained in this letter.
- Please contact Mr. Harry Balian at (856) 339 - 2173 if you have questions.
Sincerely,
Richard J. Desanctis, Jr.
Plant Manager, Salem Generating Station
Attachment: Licensee Event Report
cc: USNRC Regional Administrator - Region 1 USNRC NRR Project Manager-Salem USN RC Senior Resident Inspector - Salem NJ Department of Environmental Protection, Bureau of Nuclear Engineering
Abstract
PSEG Nuclear LLC (PSEG) confirmed that Salem Generating Station, Unit 1 operated with reactor coolant PRESSURE BOUNDARY LEAKAGE through a reactor coolant pump (RCP) thermal barrier heat exchanger (TBHX) into the component cooling water (CCW) system. PSEG previously identified a TBHX as a possible leakage source and replaced the associated RCP during the fall 2023 refueling outage.
Limiting condition for operation (LCO) 3.4.6.2 prohibits operation with PRESSURE BOUNDARY LEAKAGE. It was determined that the plant operated with in-leakage to the CCW system from December 2022 to October 2023.
Vendor testing confirmed the leakage from the TBHX into CCW. Engineering subsequently determined this was PRESSURE BOUNDARY LEAKAGE. 10 CFR 50.73(a)(2)(i)(B) requires this report. (04-02-202A) Estimated b u rden per response.to comply with this mandatory co llectton requ est: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reponed lessons learned are inco rporated into lhe licensing pro cess and fed bac k lo Industry. Send comment5 LICENSEE EVENT REPORT (LER) regarding b u rden estlmale lo the FOIA, Library, and lnfo11n a ~on Collections Branch (T-6 A1QM), U, S, Nuc lear Regulalory Commlss loo, Washfnglon, DC 20555-0001, or by email to CONTINUATION SHEET lnfocollects.Resou rce@nr c. gov, and lhe 0MB reviewer a t 0MB Office of lnformalion and Reg u latory Affairs, (3150-0104), Attn: Desk Officer for the Nuclear Regulaloiy Comm ission. 725 171h Street NW.
(See NUREG -1 022, R.3 fo r instruction and guidance for completing thfs form Washingto n, DC '20503, Tile NRC may n ot conducl or sponsor, -and a person is not required lo http* llwww nrc _govlreading-un/doc--collectionslnuregs/staff/sr1022/r3Q respond to, a co Uec tion of lnfo11na tion u nless the document requesting or requiring the oo llectfon displays a currendy valid 0MB contro l number.
,---------------, ~ 1. FACILITY NAME 050 2. DOCKET NUMBER 3. LER NUMBER NUMBER NO.
Salem Generating Station. Unit 1 052 I 05000272 I
- - 1 001 1-0
~ARRAT IVE
PLANT AND SYSTEM IDENTIFICATION
Westinghouse - Pressurized Water Reactor (PWR/4)
Reactor Coolant System - EIIS' Identifier {AB}
Pump - EIIS Identifier {P}
IDENTI FICATION OF OCCURRENCE
Discovery Date : April 18, 2024
Following receipt of a vendor testing report, Salem Generating Station, Unit 1 (Salem) confirmed there was leakage from the reactor coolant system (RCS), through the reactor coolant pump (RCP) thermal barrier heat exchanger (TBHX) into the component coo ling water (CCW) system. Engineering determined this was PRESSURE BOUNDARY LEAKAGE.
CONDITIONS PRIOR TO OCCURRENCE
MODE 1, POWER OPERATION.
No other structures, systems, or components (SSC) that could contribute to the event were inoperable during the event.
DESCRIPTION OF OCCURRENCE
In January 2023, PSEG identified higher than normal tritium in the CCW system and found that counts on the respective radiation mon itor had slowly begun rising in December 2022.
PSEG adapted chemistry methods used to mon itor primary-to-secondary leakage to identify a TBHX as a poss ible source of radioactivity in the CCW system ; however, this could not be confirmed while the plant was operating. Conservatively, PSE!3 replaced the associated RCP during the fall 2023 refuelin,g outage and radioactivity levels in the CCW system have returned to n ormal levels.
RCS leakage to CCW was immeasurable by rout ine methods. No changes to the RCS water inventory balance nor the CCW surge tank level were observed. RCS leakage into the CCW system was detected o nly because a slight increase that stabilized was identified on the CCW process radiation monitors as part of routine equipment performance monitoring. The leakage was not detectable via normal mass balance or online leak rate methods but has been estimated as 0.2 gallons per day or less.(04-02-202A) U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0M B: NO. 3150-0104 EXPIRES: 04/30/2027 NRC FORM 366A Estimated burden per response.to comply with this mandatory collectton request: 80 ho urs. Reponed
..,,,.. " lessons learned are incorporated into the licensing process and fed back lo Industry. Send comment5 l LICENSEE EVENT REPORT (LER) regarding burden estlmale lo the FOIA, Library, and lnfo11na on Collections Branch (T-6 A1QM), U, S, Nuc lear Regulalory Comml ssloo, Wash fnglon, QC 20555-0001, or by email lo
. *,,.I CONTINUATION SHEET lnfocollects.Resoorce@ nrc. gov, and lhe 0MB reviewer at 0MB Office of lnforma1i on and Regulatory
........ Affairs, (3150-0104), Attn: Desk Officer for the Nuclear Regulaloiy Commi ssion. 725 17th Street NW *
(See NUREG-1022, R.3 for instruction and guidance for completing thfs form Washlnglon, DC '20503, Tile NRC may not conducl or sp onsor,.and a person is not required lo bttp* llwww nr c_ gov/ read ing -lTTl/d oc-co llectionslnure gslstaff/sr 1022/r 3I) respond to, a coUection of lnf o11nation unless the document requesting or requiring the oollectfon displays a currentty valid 0MB con trol number.
- 1. FACILITY NAME 050 2. DOCKET NUMBER 3. LER NUMBER
.--------------, NUMBER NO. Salem Generating Stati on. Unit 1 052 I 05000272 I -1 001 1-G ARRATIVE
The removed RCP was sent to the vendor where pressure drop testing confirmed that leakage from the RCS side to the CCW side of the TBHX occurred.. Helium was used to pressurize the CCW side of the TBHX.
Once the CCW side of the TBHX was pressurized, a small pressure drop occurred, and helium was detected.
This confirmed that the TBHX had a small leak.
Subsequently, Engineering determined that leakage through the TBHX is PRESSURE BOUNDARY LE AKAGE.
CAUSE OF EVENT
Unknown. Leakage through the 12 RCP TBHX allowed radioactivity to enter the CCW. system, but the cause of the leak *is not known.
SAFETY CONSEQUENCES AND IMPLICATIONS
There were no safety consequences because of this event. The leakage was not detectable via normal mass balance or on-line leak rate methods but has been estimated as 0.2 gallons per day or less. A flaw in the TBHX can be isolated within the confines of CCW piping rated to 2,485 psig which is above normal operating pressure and prevents release of reactor coolant to the containment atmosphere. A relief valve protects this segment of CCW piping against over pressurization.
In the event of catastrophic TBHX failure, reactor coolant release outside of containment is prevented by check valves at the CCW inlet to the TBHX and a motor operated valve (MOV) at the combined CCW outlet from the TBHXs which automatically closes on high CCW flow-rate. Automatic closure of the CCW expansion tank vent valve prevents release of radioactivity from CCW to the Auxiliary Building when the CCW process radiation monitors detect excessive radioactivity.
With CCW to a TBHX isolated, the plant can continue operating and operators can complete an orderly shutdown if required. Operating procedures currently in effect guide operator response to CCW abnormalities, RCP abnormalities, and radiation abnormalities.
PREVIOUS EVENTS
There were no similar events in the past three years. NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 04/30/2027 (04-02-202A) Estimated b u rden per response.to comply with this mandato ry co llectton requ est: 80 hour9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br /> s. Reponed
- .t>""' "'.:\\ lessons learned are incorporated into lhe licens in g process and fed bac k lo Industry. Send comment5 i 'l. LICENSEE EVENT REPORT (LER) regarding b u rden estlmale lo the FOIA, Library, and lnfo11n a ~on Collection s Branch (T-6 A1QM), U, S,
'; r/: CONTINUATION SHEET Nuc lear Regulalory Commlssloo, Washfng lon, QC 20555-0001, or by email to lnfocollects.Resource@nrc.gov, and lhe 0MB reviewer at 0MB Office of lnformalion and Reg u latory 3/4, *"..... Affairs, (3150-0104), Attn: Desk Officer for the Nu clear Regulal.oiy Commiss ion. 725 171h Street NW *
(See NUREG - 1022, R.3 for instruction and guidance for completing thfs form W as hingto n, DC '20503, The NRC may not con du c l or sponso r, -and a person is not required lo htto*UWWW nrc _govlreading-an/doc--collectionslnuregs/staff/sr1022/r3Q respond to, a co Dection of fnfo11na tion u nless the document requestin g or requiring the oo llectfon displays a currendy vajfd 0MB contro l number.
- 1. FACILITY NAME 050 2. DOCKET NUMBER 3. LER NUMBER NUMBER NO.
Salem Generating Station. Uni t 1 I 05000272 I 052 - 1 001 1-0
~ARRATIVE
CORRECTIVE ACTIONS
Salem replaced the affected RCP.
COMMITMENTS
There a re no regulatory commitments in this
LER.
l'IRC FORM 366A (04-02-2024) Page 4 of 4