05000269/LER-2005-001, Re Exceeded Tech Spec: Emergency Power Path Aux Power Source Inoperable
| ML052080156 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/21/2005 |
| From: | Rosalyn Jones Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 05-001-00 | |
| Download: ML052080156 (14) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 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) 10 CFR 50.73(a)(2)(viii)(B) 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)(v), Loss of Safety Function |
| 2692005001R00 - NRC Website | |
text
Duke RONALD A JONES e Duker-Vice President PokyPowere
- - Oconee Nuclear Site Duke Power ONOI VP / 7800 Rochester Hwy.
Seneca, SC 29672 864 885 3158 864 885 3564 fax July 21, 2005 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555
Subject:
Oconee Nuclear Station Docket Nos. 50-269,-270, -287 Licensee Event Report 269/2005-01, Revision 0 Problem Investigation Process No.: 0-05-3599 Gentlemen:
Pursuant to 10 CFR 50.73 Sections (a)(1) and (d), attached is Licensee Event Report 269/2005-01, Revision 0, regarding an inoperable Emergency Power Path due to a failed electrical contactor.
This report is being submitted in accordance with 10CFR 50.73(a)(2)(i)(B) as operation in a condition prohibited by Technical Specifications and 50.73(a)(2)(ii)(B) as an unanalyzed condition.
This event is considered to be of no significance with respect to the health and safety of the public.
Very truly yours, R. A. Jones Attachment www.dukepower. corn
Document Control Desk Date: July 21, 2005 Page 2 cc:
Mr. William D. Travers Administrator, Region II U.S. Nuclear Regulatory Commission 61 Forsyth Street, S. W., Suite 23T85 Atlanta, GA 30303 Mr. L. N. Olshan Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C.
20555 Mr. S. E. Peters Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D.C.
20555 Mr. M. C. Shannon NRC Senior Resident Inspector Oconee Nuclear Station INPO (via E-mail)
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U.S. Nuclar Regulatory Commission, Washington. DC 20555-0001. or by internet e-mail to infocollects@nrc.gov. and to the Desk Officer. Office of Information and Regulatory Affairs, NEOB-10202. (3150-0104). Office of Managesnent and Budget. Washington. DC 20503. If a (See reverse for required number of means used to impose an information collection does not display a currently valid 0MB control digits/characters for each block) number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME
- 2. DOCKETNUMBER3.PAGE Oconee Nuclear Station, Unit 1 05000-0269 1 OF 11
- 4. TITLE Exceeded Tech Spec: Emergency Power Path Aux Power Source Inoperable
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED 1
C FACILITY NAME DOCKET NUMBER MO DAY YEAR YEAR NI MO DAY YEAR Unit 2 05000 0270 I
FACILITY NAME DOCKET NUMBER 05 24 2005 2005 -
01 00 07 21 2005 Unit 3 05000 0287
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CF F (Check A/7 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)(vlii)(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)(ili) 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 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) 100 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)
X 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D)
Specify in Abstract below or In
Abstract
On 5/24/2005, with all three Oconee Units at 100% power in Mode 1, Oconee Operations and Engineering concluded that both Keowee Emergency Power Paths could be lost following certain single failures.
An electrical contactor failed in the "Normal" supply to the cooling system of the Main Transformer, which is in the Overhead Path.
The "Back up" supply from the redundant Underground Path closed automatically. This line up would allow loss of both Emergency Power Paths on certain single failures.
At 1350 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.13675e-4 months <br /> TS 3.8.1 condition C was entered.
The system was realigned and the TS condition was exited at 1540 hours0.0178 days <br />0.428 hours <br />0.00255 weeks <br />5.8597e-4 months <br />.
An investigation determined that the unacceptable alignment had existed since 0820 on 4/21/2005.
Operations personnel found parts from the contactor on 5/3/2005, notified their supervision but it was assumed the parts were from a different component with a known problem and did not take further action.
Root Causes are 1) the operability assessment failed to detect inadequate train separation 2) failure of the operator to verify his assumption.
The component failed primarily due to age.
It is obsolete and a suitable replacement is on order.
This event is considered to have no significance with respect to the health and safety of the public.
NRC FORM 366 (7-2001)
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- 2. a Loss of Off site Power (LOOP) event where the 230 Kv switchyard is separated from the grid,
- 3. a fault within the 2XA motor control center.
Due to the low probability of the simultaneous occurrence of these three conditions, and due to the time available, and high probability and ease of performing the mitigating operator actions, the risk associated with this Design Basis Event scenario is considered low.
In terms of the Probabilistic Risk Assessment results, the principle scenarios are:
- 1. A Loss of Off site Power (LOOP) event occurs,
- 2. Recovery of offsite power is unsuccessful,
- 3. A fault disables the 2XA motor control center, and 4a. The SSF is unavailable, which leads to a Reactor Coolant Pump seal LOCA.
OR 4b. The emergency feedwater system [EIIS:BA] fails, resulting in a loss of all secondary side heat removal.
A risk assessment of this event determined that the impacts on the estimated Core Damage Frequency (CDF) and Large Early Release Frequency (LERF) were not significant.
Therefore, the event described in this LER was not significant with respect to the health and safety of the public.
ADDITIONAL INFORMATION
There have been no similar failures of contactors at Oconee Nuclear Station.
A data base search was performed for similar events with similar root causes within the previous three years.
None were found; therefore this is not a recurring event.
There were no releases of radioactive materials, radiation exposures or personnel injuries associated with this event.
This event is considered reportable under the Equipment Performance and Information Exchange (EPIX) program.
The failed component is a contactor, Part Number CR109EOOOALD, made by General Electric.
(If more space is required, use additional copies of NRC Form 366A)
Energy Industry Identification System (EIIS) codes are identified in the Text within brackets [EIIS:xx].