05000352/LER-2010-001, Regarding Valid Actuation of the Reactor Protection System with the Reactor Critical
| ML102350464 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 08/23/2010 |
| From: | Maguire W Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 10-001-00 | |
| Download: ML102350464 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(iii) 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x) |
| 3522010001R00 - NRC Website | |
text
10CFR50.73 August 23, 2010 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 2010-001-00, Valid Actuation of the Reactor Protection System With the Reactor Critical This Licensee Event Report (LER) addresses a valid actuation of the reactor protection system when the reactor was critical. The event was due to a failure of a 13 kV cable, failure of an undervoltage auxiliary relay, and a failure of a reactor recirculation pump M-G set standby lube oil pump relay that resulted in a trip of both reactor recirculation pumps which required a manual initiation of the reactor protection system. The north stack ventilation exhaust wide range accident monitor also failed during the initial electrical distribution voltage transient which later resulted in a condition prohibited by Technical Specifications.
This LER is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(iv)(A) and 10CFR50.73(a)(2)(i)(B).
There are no commitments contained in this letter.
If you have any questions, please contact John Hunter III at (610) 718-3400.
Respectfully, Original signed by William F. Maguire Vice President - Limerick Exelon Generation Company, LLC cc: Administrator Region I, USNRC E. M. DiPaolo, USNRC Senior Resident Inspector, LGS
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (9-2007)
LICENSEE EVENT REPORT (LER)
(See reverse for required number of digits/characters for each block)
APPROVED BY OMB NO. 3150-0104 EXPIRES 08/31/2010
, 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 5
- 4. TITLE:
Valid Actuation of the Reactor Protection System With the Reactor Critical
- 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 06 23 2010 2010 - 001 - 00 08 23 2010 FACILITY NAME DOCKET NUMBER 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1
- 10. POWER LEVEL 100 20.2201(b) 20.2201(d) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)(2)(vi) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1)(i)(A) 50.36(c)(1)(ii)(A) 50.36(c)(2) 50.46(a)(3)(ii) 50.73(a)(2)(i)(A) 50.73(a)(2)(i)(B) 50.73(a)(2)(i)(C) 50.73(a)(2)(ii)(A) 50.73(a)(2)(ii)(B) 50.73(a)(2)(iii) 50.73(a)(2)(iv)(A) 50.73(a)(2)(v)(A) 50.73(a)(2)(v)(B) 50.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(ix)(A) 50.73(a)(2)(x) 73.71(a)(4) 73.71(a)(5)
OTHER Specify in Abstract below or in (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
Corrective Action Planned The other non-safeguard load centers with the same relay for control power undervoltage automatic transfer will be tested.
Preventive maintenance will be implemented on the non-safeguard load center control power undervoltage automatic transfer equipment.
Previous Similar Occurrences There were no previous similar occurrences in the prior five years due to an electrical distribution failure.
Component data:
Cause
B (Design, Manufacturing, Construction/Installation)
System:
EA (Medium Voltage Power System)
Component:
CBL5 (Cable, Medium-Voltage Power)
Manufacturer:
A385 (Anaconda Company)
Cause
B (Design, Manufacturing, Construction/Installation)
System:
EA (Medium Voltage Power System)
Component:
27 (Relay, Undervoltage)
Manufacturer:
W120 (Westinghouse)
Part#:
289B363A13
Cause
B (Design, Manufacturing, Construction/Installation)
System:
AD (Reactor Recirculation System)
Component:
RLY (Relay)
Manufacturer:
T009 (Tyco)
Part#:
1423165-2