05000298/LER-2007-003, Regarding Incorrectly Installed Fuse Block Resulted in a Condition Prohibited by Technical Specifications
| ML071700249 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 06/13/2007 |
| From: | Michael Colomb Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NLS2007049 LER 07-003-00 | |
| Download: ML071700249 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| 2982007003R00 - NRC Website | |
text
N Nebraska Public Power District Always there when you need us NLS2007049 June 13, 2007 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001
Subject:
Licensee Event Report No. 2007-003-00 Cooper Nuclear Station, NRC Docket 50-298, DPR-46
Dear Sir or Madam:
The purpose of this correspondence is to forward Licensee Event Report 2007-003-00.
Sincerely, Michael J. Colomb General Manager of Plant Operations
/j f 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 SRAB Administrator w/enclosure NPG Distribution w/enclosure INPO Records Center w/enclosure SORC Administrator w/enclosure CNS Records w/enclosure COOPER NUCLEAR STATION P.O. Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www.nppd.com jU
Abstract
On April 23, 2007, during a step in the 4160 volt bus 1G undervoltage relay and relay timer functional test procedure, an operator placed his finger on the exterior of a fuse block casing, at which time, the fuse block dropped onto the bottom of the breaker cubicle. Because a contact had been temporarily sleeved, no trip actions occurred, annunciators alarmed as expected and the bus remained energized. The fuse block was securely replaced and the condition was corrected prior to surveillance completion.
The incorrectly installed fuse block condition had existed for 35 days, traceable to the last surveillance completion. This condition violated technical specification (TS) 3.8.1, AC Sources-Operating, Condition A, One Offsite Circuit Inoperable, for 7 days.
Consequently, this condition violated CNS TS 3.8.1, AC Sources-Operating, Condition F, Required Action and Associated Completion Time of Condition A, B, C, D, or E, to be in Mode 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and Mode 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The cause of this event is that no expectation or training existed for verifying tightness following installation. Other corrective actions are to revise procedures and train operators on proper fuse holder installation.
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 (If more space is required, use additional copies of Form 366A)
- 2. A night order was issued to the operating crews discussing the event and the requirements of verifying proper installation of fuse blocks in the 4160 volt AC breakers. As noted in the night order, "...when any fuse block is reinstalled in a 4160 volt breaker enclosure the individuals involved will ensure the fuse block is properly installed by pulling on the fuse block handle to test for resistance to removal."
- 3. A work order was generated to examine the fuse block and check for possible abnormalities with nothing of significance noted.
Long term corrective actions being tracked in the CNS corrective action program include:
- 1. Preparing and implementing a training module to operators about how to pull and replace fuse holders from the fuse base, and how to verify that the fuse holder has been properly reseated.
- 2. Modify appropriate procedures to contain a note incorporating the precaution for verifying proper installation of the fuse block as stated in the night order implemented as an immediate action.
PREVIOUS EVENTS There have been no reportable events identified in the past ten years related to fuse block failures.
ATTACHMENT 3 LIST OF REGULATORY COMMITMENTSQ ATTACHMENT 3 LIST OF REGULATORY COMMITMENTSO Correspondence Number: NLS2007049 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 4-4
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