ML20199C809
| ML20199C809 | |
| 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-99-2002, NUDOCS 9901190135 | |
| Download: ML20199C809 (4) | |
Text
g-d USEC A Global Energy Company
. January 8,1999 GDP 99-2002 United States Nuclear Regulatory Commissian Attention: Document Control Desk Washington, D.C. 20555-0001
- Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-7002 Event Report 98-18 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-330 Building at the Portsmouth Gaseous Diffusion Plant.
Should you require additional information regarding this event, please coraact Scott Scholl nt (740) 897-2373.
Sincerely, MW l
J. Morris Brown General Manager l_
Portsmouth Gaseous Diffusion Plant L
Enclosures:
As Stated cc:
NRC Region III Office NRC Resident Inspector - PORTS g1190135990gog'hl r
C ADOCK 0700 002 Q7)
P.O. Box 800, Portsmouth, OH 45661 Telephone 614-897-2255 Fu 614-897-2644 http://www.usec.com Offices in Livermore, CA Paducah, KY Porumouth, OH Washington, DC
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GDP 99-2002 Page1 of2 1
Event Report 98-18 1
Description of Event On December 10,1998, at approximately 2005 horrs, whi'e in operating mode (Mode 11), the motor stop pushbutton in the Area Control Room (ACRJ wat : mually actuated to shutdown cell 29-2-5 in the X-330 Process Building. The actuation of the pr.shbutton failed to perform its intended function and de-energize all of the cell motors as designed. The actuation of the pushbutton only tripped the "A" breaker and did not trip the "B" breaker. The cell motors associated with the "B '
breaker remained energized and operational. At approximately 2016 hours0.0233 days <br />0.56 hours <br />0.00333 weeks <br />7.67088e-4 months <br />, oper.,. ting personne!,
using an approved alternate and independem incans of disrupting cell power, manually tripped the feeder breaker at the switchyard, whi'.i supplies primary power to ihe process substation. The manual trip of the feeder breaker wr.s successful in de-energizing the remaining cell motors. The failed breaker was a Magne-blast type breaker, manufactured by General Electric (GE). The model number of the breaker was AM-4.16-250.
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, whe 1 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 cruse of the failure of the local trip circuit to function on demand was improper Idrication of the "B" breaker latch roller. The latch roller is the mechanism used to initiate the b eaker Mp sequence. The lubrication applied to the latch roller is necessary for the mechanism to operat pioperly.
The t oot cause of the failure of the local trip circuit to function on demand was an inadequate breaker preventive maintenance (PM) procedure. The procedure used to ef feet PM on the GE breakers was ambiguous and it did not stipulate the type oflubricant or detail the lubrication of the latch roller.
I 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 for other breakers (Westinghouse DlUDHP) used in uprated equipment were found to be satisfactory, thus no corrective actions were required for these breakers.
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GDP 99-2002 t
Page 2 0f 2 Event Report %18 Preventive Mai.cnance activities hu a been stip".ded on the GE Magne-blast breakers until the existing procedures have been revised to incorporate proper lubrication requirements.
Corrective Actions 1.
By January 15,1999, the substation PM procedure will be revised to spedfy the type of i
lubrication to be used for GE breakers and the interval that the i..ch roller is to ee lubricated.
J Extent of Exposure ofIndiv'Juals o Radiation or Radioactive Materials There were no exposures to individuals from this incident to radiation or radioactive materials.
Lessons Learned from the Event There weu.n new lessons learned from this event.
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GDP 99-2002 Page1of1 Event Report 98-18 List of Commitments
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By January 15,1999, the substation PM procedure will be revised to specify the type of lubrication to be used for GE breakers and the interval that the latch roller is to be lubricated.
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