05000352/LER-2013-001, Regarding High Pressure Coolant Injection System Pressure Switch Lubricating Oil Leak
| ML13140A323 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 05/20/2013 |
| From: | Dougherty T Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 13-001-00 | |
| Download: ML13140A323 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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) 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)(i)(B), Prohibited by Technical Specifications |
| 3522013001R00 - NRC Website | |
text
10CFR50.73 May 20, 2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 1 Facility Operating License No. NPF-39 NRC Docket No. 50-352
Subject:
LER 2013-001-00, Condition That Could Have Prevented the Fulfillment of the High Pressure Coolant Injection System Safety Function This Licensee Event Report (LER) addresses a condition that could have prevented the fulfillment of the High Pressure Coolant Injection (HPCI) system safety function due to the failure of a turbine lube oil system pressure switch.
This LER is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(v)(D).
There are no commitments contained in this letter.
If you have any questions, please contact Robert B. Dickinson at (610) 718-3400.
Respectfully, Original signed by Thomas J. Dougherty Vice President - Limerick Generating Station Exelon Generation Company, LLC cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, LGS
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (10-2010)
LICENSEE EVENT REPORT (LER)
(See reverse for required number of digits/characters for each block)
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME Limerick Generating Station, Unit 1
- 2. DOCKET NUMBER 05000352
- 3. PAGE 1 OF 3
- 4. TITLE High Pressure Coolant Injection System Pressure Switch Lubricating Oil Leak
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO.
MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 03 20 2013 2013 - 001 -
00 05 20 2013 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERATING MODE 1
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b) 20.2203(a)(3)(i) 50.73(a)(2)(i)(C) 50.73(a)(2)(vii) 20.2201(d) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A) 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(x) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specify in Abstract below or in LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET The affected pressure switch is calibrated on a 6-year frequency.
There is no preventive maintenance task that performs periodic replacement of the switch. The failed switch had been in service since initial plant operation.
Failure analysis concluded that the observed oil leak resulted from a crack in the pressure sensing bellows of the pressure switch. The failure mechanism of the brass bellows was determined to be consistent with corrosion fatigue, which results from the combined action of corrosion and cyclic stresses.
Cause of the Event
The cause of the HPCI inoperability was a failure of a bellows actuated pressure switch which resulted in a significant turbine oil system leak. The apparent cause of the pressure switch bellows failure was corrosion fatigue.
Corrective Action Completed The failed pressure switch was replaced and the HPCI system tested successfully.
Corrective Action Planned A similar service pressure switch, Unit 1 HPCI oil filter differential pressure switch, will be replaced as an extent of condition action.
A review of HPCI and RCIC (EIIS:BN) turbine lube oil system components will be performed to determine if any additional components are potentially susceptible to failure as a result of historical exposure to oil with high moisture content.
Previous Similar Occurrences There were no previous similar occurrences of unplanned HPCI system inoperability due to oil leakage in the past 5 years.
Component data:
System:
High Pressure Coolant Injection System Component:
HPCI Turbine Bearing Low Oil Pressure Alarm Switch (PSL-056-160)
Manufacturer:
S345 Square D Company Model Number:
9012-ACW-3 Serial Number:
None