Los Alamos Neutron Science Center (LANSCE). Photo Courtesy LANL
BY MAIRE O’NEILL
Work involving a small electricity capacitor bank which caught fire Oct. 4 at the Los Alamos Neutron Accelerator Facility in Area 53 at Los Alamos National Laboratory remains suspended pending the completion of an investigation into the fire’s cause, a Department of Energy National Nuclear Security Administration spokesperson said Friday.
The Los Alamos Fire Department responded to the incident at the Los Alamos Neutron Science Center (LANSCE) along with LANL personnel.
“Given the fully-charged nature of the capacitors in the room, the decision was made not to fight the fire directly and monitor the event. Once the fire extinguished, LANL personnel secured the room in a safe configuration and LAFD was able to extinguish all hot spots,” the NNSA spokesperson said.
The report on the incident says LAFD received a fire alarm from the affected room and responded. After the decision was made not to fight the fire until after the capacitors could be safely discharged, the fire was allowed to extinguish itself which took about six hours. LAFD and radio frequency personnel entered the room to discharge the capacitor bank and eliminate any remaining hot spots. LAFD extinguished all hot spots and RFE personnel secured the room in a safe configuration. The report states that the fire was contained within the capacitor room.
A capacitor bank is a group of connected capacitors each containing hazardous electrical energy. A capacitor is similar to a battery in that the energy it contains must be discharged prior to handling the capacitor. For a capacitor bank, the report says discharging is accomplished by connecting the positive and negative terminals of each capacitor in the bank with a shorting device. LANSCE Operations personnel de-energized the capacitor bank remotely by lowering a metal bar across the capacitor terminals and tripped the breakers for any other electrical components in the room.
LAFD personnel evaluated the fire through a window and determined that the room was not safe to enter because the capacitors remained potentially charged and presented a significant electrical hazard. LAFD posted a fire watch to monitor the fire.
Following an Oct. 5 fact finding, it was noted that the LANL Chief Electrical Safety Officer determined that all proper procedures were followed and no personnel had been exposed to or potentially exposed to an electrical hazard.