05000529/LER-2003-002, Regarding ESF Actuation - Unit 2 Emergency Diesel Generator Actuation
| ML040280432 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 01/16/2004 |
| From: | Danni Smith Arizona Public Service Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 192-01132-DMS/SAB/DJS LER 03-002-00 | |
| Download: ML040280432 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| 5292003002R00 - NRC Website | |
text
10 CFR 50.73 ZAPS Tel: 623-3934116 Mail Station 7602 Palo Verde Nuclear David M. Smith Fax: 623-393-6077 PO Box 52034 Generating Station Plant Manager e-mail:
Phoenix, Arizona 85072-2034 DSMITH10@apsc.com 192-01132-DMS/SAB/DJS January 16, 2004 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Dear Sirs:
Subject:
Palo Verde Nuclear Generating Station (PVNGS) Unit 2 Docket No. STN 50-529 License No. NPF-51 Licensee Event Report 2003-002-00 Attached please find Licensee Event Report (LER) 50-529/2003-002-00 that has been prepared and submitted pursuant to 10CFR 50.73. This LER reports the Engineered Safety Feature Actuation of the "A" train Diesel Generator due to a valid Loss of Power (LOP) on the bus on November 21, 2003.
In accordance with 10 CFR 50.4, a copy of this LER is being forwarded to the NRC Regional Office, NRC Region IV and the Resident Inspector. If you have questions regarding this submittal, please contact Daniel G. Marks, Section Leader, Regulatory Affairs, at (623) 393-6492.
Arizona Public Service Company makes no commitments in this letter. The corrective actions described in this LER are not necessary to maintain compliance with regulations.
Sincerely, DMS/SAB/DJS/kg A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde *-South Texas Project
- Wolf Creek
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Licensee Event Report 50-529/2003-002-00 Page 2 Attachment cc:
B. S. Mallett M. B. Fields N. L. Salgado NRC Region IV Regional Administrator NRC NRR Project Manager + (send electronic and paper)
NRC Senior Resident Inspector for PVNGS
APPROVED BY OMB NO. 3150-0104 EXPIRES 7-31-2004
Abstract
On November 21, 2003, at approximately 22:53 Mountain Standard Time, Palo Verde Nuclear Generating Station Unit 2 experienced a valid Engineered Safety Feature (ESF) actuation of the "A" Emergency Diesel Generator (EDG). Unit 2 had been performing testing of the Gas Turbine Generator #1 (alternate AC Power source for station blackout) in isochronous mode. This testing required GTG #1 to be run in parallel with EDG "A." Upon completion of the paralleled operation, the Train "A" 4.16 kV bus had been successfully transferred to the EDG and loads carried by the EDG for approximately 5 minutes. When the EDG speed control was taken from "droop" mode (load sharing) to "isochronous" mode (fixed frequency,) the EDG output breaker tripped opened, resulting in a valid Loss of Power (LOP) signal based on undervoltage on the Train "A" bus. EDG "A" shifted from the "test run" mode to the "emergency' mode and the output breaker re-closed, re-supplying the train "A" 4.16 KV bus.
Offsite power was available to both safety buses throughout the event. The other (Train "B") safety bus was being supplied by offsite power and its EDG was operable. The offsite electrical grid was stable. Palo Verde Unit 2 was defueled in its 1 1th refueling outage. No other ESF actuations occurred and none were required. There were no structures, systems, or components that were inoperable at the time of discovery that contributed to this condition.
In the past three years, Palo Verde Nuclear Generating Station has not experienced a valid EDG actuation.
NRC FORM 366 (7-2001)
(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 (If more space is required, use additional copies of NRC Form 366A)
Any additional corrective actions taken as a result of the investigation of this event will be implemented in accordance with the APS corrective action program. If information is subsequently developed that would significantly affect a reader's understanding or perception of this event, a supplement to this LER will be submitted.
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PREVIOUS SIMILAR EVENTS
In the past three years, Palo Verde Nuclear Generating Station has not experienced a valid EDG actuation.
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ADDITIONAL INFORMATION
None.