ML20199C819
| ML20199C819 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 01/08/1999 |
| From: | Jonathan Brown UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GDP-99-2001, NUDOCS 9901190139 | |
| Download: ML20199C819 (4) | |
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. A Global Energy Company January 8,1999 GDP 99-2001 United States Nuclear Regulatory Commission
. Attention: Document Control Desk Washington, D.C. 20555-0001 Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-7002 Event Report 98-19 l
Pursuant to 10 CFR 76.120(c)(2), Enclosure 1 provides a 30-day Event Report for an event involving a failure of an electrical circuit required by the Safety Analysis Report (SAR) to shutdown an operating cell in the X-326 Building at the Portsmouth Gaseous Diffusion Plant.
i Should you require additional information regarding this event, please contact Scott Scholl at (740) 897-2373.
Sincerely, M
J. Morris Brown General Manager I
Portsmouth Gaseous Diffusion Plant
Enclosures:
As Stated cc:
NRC Region 111 Office NRC Resident Inspector-PORTS oYdpa P A
c e
1 f&D P.O. Box 800, Portsmouth, OH 45661 Telephone 614-897-2255 Fax 614-897-2644 http://www.usec.com Ofilces in Livermore, CA Paducah, KY Portsmouth, OH Washington, DC
o GDP 99-2001 Page1of2 Event Report 98-19 Description of Event l
On December 13,1998, at approximately 0802 hours0.00928 days <br />0.223 hours <br />0.00133 weeks <br />3.05161e-4 months <br />, while in standby mode (Mode III), the motor stop pushbutton in the Area Control Room (ACR) was manually actuated to shutdown cell 27-1-12 j
in the X-326 Process Building. The actuation of the pushbutton failed to perform its intended function and de-energize all of the cell motors as designed. The actuation of the pushbutton only tripped the "B" breaker and did not trip the "A" breaker. The cell motors associated with the "A" breaker remained energized and operational. At approximately 0810 hours0.00938 days <br />0.225 hours <br />0.00134 weeks <br />3.08205e-4 months <br />, operating personnel, using an approved alternate and independent means of disrupting cell power, manually tripped the feeder breaker at the switchyard, which supplies power to the process substation. The manual trip of the feeder was successful in de-energizing the remaining cell motors. The failed breaker was manufactured by ITE. The model number of the breaker was LG.
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According to the SAR for the Portsmouth Gaseous Diffusion Plant, the pushbuttons in the ACR and Plant Control Facility (PCF) are the means used to manually shutdown cell operation in the event of an emergency. The pushbutton, when actuated, causes the de trip circuit to open the "A" and "B" breakers to de-energize the cell motors. The de control trip circuit and the pushbuttons in the ACR and PCF are part of the Cell Remote Manual Shutdown System. This system is classified as an AQ safety system. This event is reportable in accordance with SAR, Section 6.9 Table 6.9-1, J (1).
Cause of Event The direct cause of the failure of the local trip circuit to function on demand was lack oflubrication on the breaker linkage. The linkage is the mechanism used to initiate the breaker trip sequence. The lubrication applied to the linkage is necessary for the mechanism to operate properly.
i The root cause of the failure of the local trip circuit to function on demand was an inadequate breaker preventive maintenance (PM) procedure. The vendor manual did not describe the type oflubrication to use or the lubrication interval. Consequently, the procedure used to effect PM on ITE breakers did not require maintenance personnel to inspect or lubricate the operating mechanism linkage.
On December 16, 1998, an Engineering Evaluation was approved that recommended required corrective actions to initiate immediate and long term assurance that the process breakers having lubrication problems will be addressed and corrected. Lubrication requirements fbr other breakers (Westinghouse Dil/DIIP) used in uprated equipment were found to be satisfactory thus no corrective actions were required for these breakers.
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GDP 99-2001 Page 2 of 2 Event Report 98-19 Preventive Maintenance activities have been suspended on the ITE breakers until the existing procedures have been revised to incorporated proper lubrication requirements.
Corrective Actions 1.
By January 15,1999, the substation PM procedure will be revised to specify the type lubrication to be used for ITE KC/LG breakers and the interval that the operating mechanism linkage will be lubricated.
Extent of Exposure of Individuals to Radiation or Radioactive Materials There were no exposures to individuals from this incident to radiation or radioactive materials.
Lessons Learned from the Event There were no new lessons teamed from this event.
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f t-GDP 99-2001 Page1 of1 Event Report 98-19 l
l List of Commitments l
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By January 15,1999, the substation PM procedure will be revised to specify the type I
l lubrication to be used for ITE KC/LG breakers and the interval that the operating mechanism l
linkage will be lubricated.
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