05000352/LER-2024-003, Core Operating Limits Report Thermal Limit Exceeded for Unit 1 Fuel Bundle GGK123
| ML24170A772 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/18/2024 |
| From: | Gillin M Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LG-24-067 LER 2024-003-00 | |
| Download: ML24170A772 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3522024003R00 - NRC Website | |
text
- ~ Constellation 10 CFR 50.73 LG-24-067 June 18, 2024 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 1 Renewed Facility Operating License No. NPF-39 NRC Docket No. 50-352 Subject: LER 2024-003-00 Core Operating Limits Report Thermal Limits Exceeded In accordance with the requirements of 10 CFR 50.73(a)(2)(i)(B), Limerick Generating Station hereby submits the enclosed Licensee Event Report.
There are no commitments contained in this letter.
If you have any questions, please contact Jordan Rajan at (610) 718-3400.
Respectfully, Michael F. Gillin Vice President - Limerick Generating Station Constellation Energy Generation, LLC cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, Limerick Generating Station
Abstract
Limerick Generating Station Unit 1
352 3
Core Operating Limits Report Thermal Limit Exceeded for Unit 1 Fuel Bundle GGK123 04 22 24 2024 003 00 06 18 2024 4
0
Jordan Rajan 610-718-3400 B
AC ROD G080 Yes
On April 12, 2024, while performing a water rod inspection of fuel bundle GGK123 during a planned refuel outage, it was
identified that several fuel spacers had propagated up within the bundle toward the upper tie plate. It was determined through
analysis that spacer positioning had a direct effect on the Minimum Critical Power Ratio (MCPR). On April 22, 2024, an
analysis of the operating conditions by Global Nuclear Fuel (GNF) of fuel bundle GGK123 was reviewed and accepted by the
station. The report confirmed that, during the previous cycle, the Operating Limit MCPR exceeded limits set by Technical
Specifications (TS) 3.2.3. Since the Operating Limit MCPR was exceeded for longer than allowed by TS Limiting Condition for
Operation (LCO) 3.2.3, this event is reportable as a condition prohibited by TS per 10 CFR 50.73(a)(2)(i)(B).
The fuel bundle spacers shifted out of position over the previous operating cycle. This condition was identified during the
inspections in response to GNF 10 CFR Part 21 communication SC 22-04, GNF3 Raised Water Rod. This fuel bundle has
been removed from the reactor core, is currently located in the spent fuel pool, and will not be re-loaded into the core. There
was no impact to the health and safety of the public or plant personnel because the Safety Limit MCPR was not exceeded in
the previous cycle operation
l~\\
"~+.,
+o~
I
- Page of
- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
052 050 Cause of the Condition The cause of the spacer relocation was determined to be the mis-oriented water rod in the fuel bundle GGK123. Mis-orientation of the water rod would have occurred during fuel bundle fabrication. The mis-orientation caused the spacers to not be locked into position, causing them to propagate up the bundle due to hydraulic force during normal operation.
Corrective Actions
Corrective actions taken in response to the conditions were:
v Verified no plant off-gas signatures indicative of leaking fuel rods which verified fuel rod integrity had not been
compromised.
v Performed full length peripheral visual inspection of de-channeled fuel bundle GGK123.
v Evaluated the impact to APLHGR, LHGR, and MCPR limits.
v Permanently discharged fuel bundle GGK123 to the spent fuel pool.
v Completed inspection on the remaining 267 fuel bundles in the Unit 1 susceptible population and confirmed no additionalfuel bundles had a mis-oriented water rod.
v Confirmed no impact to Unit 2 due to no fuel bundles in the susceptible population.
v GNF implemented the following additional checks during the fuel fabrication process:
P An in-process laser check on the orientation of the water rod tabs.
P Removed the Quality at the Source process and reintroduced Qualify Inspectors to the bundle assembly tables
P Added a check for tab orientation at final inspection.
v Constellation Energy Generation, LLC (and Limerick Generating Station) enhanced the new fuel receipt inspectionprocedures to confirm proper water rod orientation on all new GNF3 fuel bundles.
Previous Occurrences
There were no previous occurrences.
Component Failure Data
System: Reactor Core Systems (AC)
Component: Unit 1 Fuel Bundle (ROD)
Manufacturer: Global Nuclear Fuel (G080) 3 3
Limerick Generating Station Unit 1 352 2024 003 00
~¥'
i
<--+_,
~o' I
I~
I I* I I D