05000298/LER-2003-001, From Cooper Regarding Inadequate Communication Results in Both Diesel Generators Inoperable Simultaneously
| ML031260621 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 04/28/2003 |
| From: | Hutton J Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NLS2003045 LER 03-001-00 | |
| Download: ML031260621 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| 2982003001R00 - NRC Website | |
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Nebraska Public Power District Always there when you need us NLS2003045 April 28, 2003 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001
Subject:
Licensee Event Report No. 2003-001 Cooper Nuclear Station, NRC Docket 50-298, DPR-46 The subject Licensee Event Report is forwarded as an enclosure to this letter.
Sincerely, utton Plant Manager
/rer Enclosure cc: Regional Administrator USNRC - Region IV Senior Project Manager USNRC -NRR Project Directorate IV-1 Senior Resident Inspector USNRC NPG Distribution INPO Records Center Records COOPER NUCLEAR STATION P 0 Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www nppd com
Abstract
On February 28, 2003, at 0857 Central Standard Time (CST), with Cooper Nuclear Station (CNS) in cold shutdown, diesel generator (DG) 1 and DG2 were inoperable at the same time. The DGs are the standby source of emergency Alternating Current (AC) power. DGI was inoperable at the time due to failure of the fuel oil transfer system to deliver required flow during a routine inservice test. DG2 was declared inoperable as a result of discovering that a time delay relay in the diesel room ventilation system had been in service in excess of its qualified life as stated by the manufacturer. Declaring the relay inoperable resulted in the diesel room ventilation system being inoperable. The diesel room ventilation is a required support system for the diesel generator.
Immediate corrective action was to replace the relay with one that was within its service life. DG2 was returned to operable status on February 28, 2003, at 1937 CST.
The relay qualified life issue has been entered into the CNS Corrective Action Program.
The root cause of this event is inadequate communication between the Operations and Engineering departments in that the possibility that analyses could be performed that would extend the qualified life of the relay was not communicated. Corrective actions to preclude recurrence are to establish, implement, and reinforce standards for formal communication between Operations and Engineering when preparing Operability Determinations.
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)
The cause of DGI being inoperable has been addressed by revising the frequency of inspection and cleaning of the strainers in the fuel oil transfer system such that blockage of the strainers due to debris will be detected before the strainers are blocked to a significant degree. Action to remove sediment from the fuel oil storage tanks is being tracked in the CNS CAP.
The cause of DG2 relay being declared inoperable will be addressed by establishing a service life for safety-related Agastat relays and revising the PMs for maintaining these relays within that service life.
This action is being tracked in the CNS CAP.
PREVIOUS SIMILAR EVENTS
LER 93-035-02, "Both Diesel Generators declared inoperable due to incorrect relay setpoints resulting from inadequate procedure and implementation of vendor recommended checks", is related from a perspective of both DGs being inoperable at the same time. This event involved failure of a relay to operate at the correct voltage setpoint during performance of the monthly DG surveillance. This same failure was common to both diesel generators. The cause was attributed to inadequate management attention to programmatic processes and controls in not providing sufficient direction for proper maintenance.
LER 2000-012-00, 'Human Error Results in automatic Engineered Safety Features Actuation", is related from the perspective of being a result of management failure to reinforce standards and expectations.
This event involved load shedding of the Division I 416OVolt Critical Bus 1F. This load shedding caused various plant pumps and fans to trip, and resulted in CNS being in single-loop operation at 65% power.
Load shedding of a 4160-volt critical bus was caused by a human error while performing undervoltage logic surveillance procedure relay calibration. The human error was attributed to inadequate supervision caused by management failure to reinforce standard and expectations.
CNS has previously encountered problems involving various aspects of ODs, such as failure to recognize when an OD was needed and inadequate OD. This has resulted in a recognition by CNS that there are programmatic problems in the area of OD. As a result this program is being addressed in The Strategic Improvement Plan (TIP) developed by CNS.
l ATTACHMENT 3 LIST OF REGULATORY COMMITMENTS Correspondence Number: NLS2003045 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 NL&S Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.
COMMITTED DATE
COMMITMENT
OR OUTAGE Establish, implement, and reinforce standards for formal communication between the Operations and Engineering departments when determining operability and developing June 30, 2003 associated Operability Determination documentation.
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