05000298/LER-2007-001, Regarding High Pressure Coolant Injection Inverter Circuit Failure Results in Loss of Safety Function
| ML071000226 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 04/05/2007 |
| From: | Michael Colomb Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, NRC/NRR/ADRO |
| References | |
| NLS2007025 LER 07-001-00 | |
| Download: ML071000226 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 2982007001R00 - NRC Website | |
text
N Nebraska Public Power District Always there when you need us NLS2007025 April 5, 2007 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001
Subject:
Licensee Event Report No. 2007-001-00 Cooper Nuclear Station, NRC Docket 50-298, DPR-46 The purpose of this correspondence is to forward a Licensee Event Report.
Sincerel Michael J. Colomb General Manager of Plant Operations
/jf Enclosure cc:
Regional Administrator w/enclosure USNRC - Region IV Cooper Project Manager w/enclosure USNRC - NRR Project Directorate IV-1 Senior Resident Inspector w/enclosure USNRC - CNS NPG Distribution w/enclosure INPO Records Center w/enclosure SORC Administrator w/enclosure SRAB Administrator w/enclosure CNS Records w/enclosure COOPER NUCLEAR STATION P.0. Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www.nppd.com
ATTACHMENT 3 LIST OF REGULATORY COMMITMENTS@
ATTACHMENT 3 LIST OF REGULATORY COMMITMENTS© Correspondence Number: NLS2007025 The following table identifies those actions committed to by Nebraska Public Power District (NPPD) in this document. Any other actions discussed in the submittal represent intended or planned actions by NPPD. They are described for information only and are not regulatory
commitments
Please notify the Licensing Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.
COMMITMENT
COMMITTED DATE
COMMITMENT
NUMBER OR OUTAGE None 4
PROCEDURE 0.42 REVISION 20 PAGE 18 OF 25
Abstract
Between 0430 and 0457 Central Standard Time (CST) on February 7, 2007 High Pressure Coolant Injection (HPCI) inverter circuit failure alarms were received intermittently indicating a loss of the inverter output. HPCI was in a standby status at the time of the alarms. The loss of inverter output was confirmed by the HPCI flow controller output lowering to approximately 30% and returning to 100% upon alarm reset. The power indicating light on the inverter was observed to go off on the last alarm, returning when the alarm was reset.
HPCI was declared inoperable at 0430 resulting in entry into Technical Specification Limiting Condition for Operation (LCO) 3.5.1 Condition C, HPCI System inoperable and 3.5.1 Condition D, HPCI System inoperable AND Condition A entered. Condition A was previously entered for Core Spray System Loop A being inoperable for planned maintenance. This was determined to be reportable under 10CFR50.72 and Event Notification 43151 was made. HPCI was declared operable at 1602 on February 7, 2007. The failed HPCI inverter was sent to a test laboratory for inspection and determination of the failure mechanism. A review of the results is in progress.
NRC FORM 366 (6-2004)
(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 Form 366A)
PREVIOUS EVENTS There have been no reportable events identified in the past five years related to inverter failures due to corrosion or inadequately soldered connections.