05000387/LER-2003-005, Corrected LER 03-005-00 for Susquehanna Steam Electric Station Re D Diesel Generator Fuel Rack Linkage Became Disconnected. Date of 11/10/03 Added to Block 7
| ML040230467 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 01/13/2004 |
| From: | Richard Anderson Susquehanna |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-5691, PLA-5704 LER 03-005-00 | |
| Download: ML040230467 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 3872003005R00 - NRC Website | |
text
R. L Anderson Vice President - Nuclear Operations PPL Susquehanna, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.3883 Fax 570.542-1504 rlanderson~ppiweb.com S.
I I
a mu p P I.::, §.
JAN 13 2004 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station OP1-17 Washington, DC 20555 SUSQUEHANNA STEAM ELECTRIC STATION CORRECTION TO LICENSEE EVENT REPORT 50-387/2003-005-00 TRANSMITTED VIA PLA-5691 (DATED 11/10/2003)
PLA-5704 Docket No. 50-387 This letter is being issued to provide a correction to Licensee Event Report 50-387/2003-005-00 which was transmitted via PLA-5691 (dated 11/10/2003).
The date of 11/10/03 should have been typed in Block 7 (Report Date) of this LER.
The attached LER corrects this omission. No other changes were made to the Licensee Event Report.
If you have any questions, please contact Mr. John L. Tripoli at (570) 542-3021.
Richard L. Anderson Vice President - Nuclear Operations Attachment
-r645)
Document Control Desk PLA-5704 cc:
Mr. H. J. Miller Regional Administrator U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. S. L. Hansell Sr. Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 35 Bervick, PA 18603-0035 Mr. R. Osborne Allegheny Electric Cooperative P. 0. Box 1266 Harrisburg, PA 17108-1266 Mr. R. Janati Bureau of Radiation Protection Rachel Carson State Office Building P. 0. Box 8469 Harrisburg, PA 17105-8469
Abstract
During the performance of a monthly surveillance on March 19, 2003, the D Diesel Generator (DG) load suddenly decreased from 3000 kW to 2000 kW. Investigation revealed that the fuel control linkage had separated from the governor terminal shaft lever causing the change in generator output. A %/2 inch bolt that is designed to attach the fuel control linkage to the governor terminal shaft lever was found to have backed out. The bolt was reinstalled and tightened and the D DG successfully passed the monthly surveillance. A Root Cause Analysis Team is nearing the completion of its review of this event. A review of maintenance records indicated that the only time this bolted connection is disturbed is when the EGB50 electro/mechanical governor is replaced. This governor was last replaced on the D DG on July 5, 2000. It is believed that a human performance error occurred when the 1/2 inch bolt was installed in a hand tight condition only. Since the bolt was not adequately tightened, it was subject to further loosening each time the D DG was run. During diesel generator runs, the linkage is exposed to movement as the fuel racks reposition and to the movement associated with normal diesel generator running vibration. These combined effects gradually allowed the 2 inch bolt to back out until the linkage became disconnected during the monthly surveillance run conducted on March 19, 2003. Immediate corrective actions included restoration of the D DG fuel control linkage to the governor terminal shaft lever, and verifying that this linkage was tight on all five Susquehanna Emergency Diesel Generators. Actions to prevent recurrence include human performance reviews, enhancing the work instructions that control the relevant activities to provide specific direction to apply Loctite and torque the Y/2 inch bolt, adding a confirmation requirement to this work step, and determining the torque requirements for any critical component fasteners that do not already have an established torque requirement on all five diesel generators.
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 NRC Form 366A)
Assessment of Safety Consequences
There were no actual safety consequences from this event since the diesel generators were not called upon to perform their safety function. The potential safety significance is low since the period of time with less than three diesel generators was short, and the D Diesel Generator had some capability for a run under load. Although no provisions were in place, it is also believed that recovery of the D Diesel Generator from this condition could be achieved relatively quickly. Furthermore, the Susquehanna PRA concludes that two (2) diesel generators are required for a dual unit LOOP.
CORRECTIVE ACTIONS
The following corrective actions were taken or are planned:
- The bolted connection on the fuel control linkage to the governor terminal shaft lever was verified to be tight on all five Susquehanna Emergency Diesel Generators.
- Appropriate personnel, using a case study approach, will review the human performance and other aspects of this event. Susquehanna has found the case study method to be effective for learning from human performance events.
- The work instructions controlling the relevant activities have been enhanced to provide specific direction to apply Loctite and to torque the 112 inch bolt. Recognizing that self-checking and peer checking were factors in this event, a confirmation step will be added to ensure this connection is torqued.
- A torque requirement will be determined for any critical component fastener that does not already have an established torque requirement on all five Diesel Generators. Critical components are those that directly affect the operation of the Diesel Generator.
A Root Cause Analysis Team is nearing completion of its review of this event. A supplement to this LER will be provided if the final results of this evaluation would significantly change the perception of the course, significance, or consequences of this event or if there are substantial changes in corrective actions.
ADDITIONAL INFORMATION
Failed Component Information:
Diesel Generator (OG501 D)
Manufacturer - Cooper Energy Services Model Number - KSV-1 6-T