05000353/LER-2004-001, Re Automatic Scram Due to 500 Kv Switchvard Faults
| ML042440696 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 08/23/2004 |
| From: | Degregorio R Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 04-001-00 | |
| Download: ML042440696 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iii) 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)(v), Loss of Safety Function |
| 3532004001R00 - NRC Website | |
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Exeklnsm Exelon Nuclear Limerick Generating Station P.O. Box 2300 Pottstown, PA 19464 www.exeloncorp.com Nuclear 1 OCFR50.73 August 23, 2004 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 2 Facility Operating License Nos. NPF-85
- --- NRC-Docket.Nos.--50-353
Subject:
LER 2-04-001, Unit 2 Scram due to 500 kV Switchyard Faults This Licensee Event Report (LER) addresses a Limerick Unit 2 valid automatic actuation of the reactor protection system that occurred when the reactor was critical. This actuation was caused by a main turbine trip due to a power / load unbalance condition. The initiating event was an internal fault on a 500 KV circuit breaker during switching.
Report Number:
Revision:
Event Date:
Discovered Date:
Report Date:
2-04-001 00 June 22, 2004 June 22,2004 August 23, 2004 This LER is being submitted pursuant to the requirements of 1 OCFR50.73(a)(2)(iv)(A).
If you have any questions or require additional information, please do not hesitate to contact us.
Sincerely, cc: S. J. Collins, Administrator Region I, USNRC S. L. Hansell, USNRC Senior Resident Inspector, LGS
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SUMMARY OF EXELON NUCLEAR COMMITMENTS LS-AA-1 17-1003 Rev.1 The following table identifies commitments made in this document by Exelon Nuclear.
(Any other actions discussed in the submittal represent intended or planned actions by Exelon Nuclear. They are described to the NRC for the NRC's information and are not regulatory commitments.)
Commitment #1 Committed date (or "outage"):
6/1/05 Complete the switchyard maintenance project, which will evaluate switchyard components and establish the scope of maintenance tasks required to address known and potential failure modes for the components. This evaluation will be complete by 6/1/05.
Commitment #2 Committed date (or "outage"):
5/1/05 Change the design for the protection of the CT secondary circuit in the 500 kV switchyard. This design change will be implemented by 5/1/05.
NRC'FORM`366 U.S. NUCLEAR REGULATORY APPROVED BY OMB NO. 3150.0104 EXPIRES 6-30-2001 (1-2001)
COMMISSION Estimated burden per response to comply with this mandatory informaton collection request:
50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />. Reported lessons learned are Incorporated Into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records Management Branch (TO 6).U.S Nulea ReulaoryComisson.Washington. DC 20555-0001. or by Internet e LICENSEEEVENTREPORT(LER)
DeskOffice fice of Information and Regulato Affairs, LICENSEE EVEN Rb 50-0104? Office of Management and Budget, Washington. DC 23503. It a (See reverse for required number of means used to Impose in omaton collection does not display a currently valid OMB control digitstcharacters for each block) number, the NRC may not conduct or sponsor. and a person Is not required to respond to, the FACII ITY NAMF 11 nCn§.KFT NI IMRFR (97 PAr.F t1 Limerick Generating Station, Unit 2 05000 353 1 OF 4
TIm F (Al Automatic Scram Due to 500 kV Switchvard Faults l
EVENT DATE (5)
LER NUMBER (6) j REPORT DATE (7) l OTHER FACILITIES INVOLVED (8)
FACILITY NAME DOCKET NUMBER SEOUENTIAL REVl MO DAY YEAR YEA NUMBER NO DAY YEAR 05000 Z FACILITY NAME DOCKET NUMBER 6
22 2004 2004 -
001 00 8
23 2004 05000 OPERATING
)4q lRFPflRTlq l RTMrrTFfl P IRIIIAr TTnT4 RrFniilFUFNT.CnFInrCRgS 1C.h.v't kaIthAtxnnrJ.111 MODE (9) 1 20.2201 (b)
_ 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(B)
_ 50.73(a)(2)(ix)(A)
POWER
_ 20.2201 (d) 20.2203(a)(4)
_ 50.73(a)(2)(iii) 50.73(a)(2)(x)
- - LEVEL (10)
- - 1 00 20.2203(a)(1) 50.36(c)(1)(1)(A) x-50.73(a)(2)(iv)(A)-_ 73.71(a)(4) 20.2203(a)(2)(i) 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71 (a)(5) 20.2203(a)(2)(iH) 50.36(c)(2)
_ 50.73(a)(2)(v)(B)
O THE 20.2203(a)(2)(iii)
_ 50.46(a)(3)(ii) 50.73(a)(2)(v)(C) blC (If more space Is required, use additional copies of (Ifmore space Is required, useadditionalcopies of NRCForm 366A) (17)
Corrective Action Planned Complete the switchyard maintenance project, which will evaluate switchyard components and establish the scope of maintenance tasks required to address known and potential failure modes for the components. This evaluation will be complete by 6/1105.
Change the design for the protection of the CT secondary circuit in the 500 kV switchyard. This design change will be imletedtby5/1/05 Previous Similar Occurrences There were no previous occurrences of a fault within a high voltage circuit breaker that resulted in a main turbine trip and subsequent automatic RPS actuation.
Component data:
System:
Component:
Manufacturer:
Model number:
System:
Component:
Manufacturer:
Model number:
FK (Switchyard System) 52 (Circuit Breaker, AC) 1005 (ITE Circuit Breaker LTD) 550GA40-30C FK (Switchyard System)
XCT (Transformer, Current)
T389 (Trench)
OSKF-1 800