At 6:30 a.m., while making his rounds, the shift supervisor of a biomass boiler plant found wood burning in the chip catcher (a tray used to collect chips that have fallen from a vertical conveyor). He notified his superiors and the on-call technician, turned off the equipment and doused the chip catcher using a fire hose reel. His coworkers opened the hatches at the top of the conveyor and fought the fire with extinguishers. Once the fire was controlled, the operator called the fire and emergency response service to bring in a thermographic camera to make sure that the fire was indeed out. The firefighters left at around 10:00 a.m. No serious property damage was reported. The plant was kept shut down to determine what caused the fire. The inspection authorities for classified facilities arrived the following day.

According to the plant operator, the fire was caused by a damaged guide-roller bearing at the bottom of the conveyor. Small pieces of biomass had built up in the cages of the bearing and caused them to heat up. At the time of the accident, the fire detection and suppression systems were not fully operational. The fire detection system wasn’t fully installed, one of the fire hydrants was not connected to the water supply, and the response equipment was either damaged or in the wrong location. An inspection found conditions that violated the operating permit issued by the prefecture (uninsulated firewalls, vertical conveyor not fitted with sprinklers).

According to the operator, the fire detection system in the vertical conveyor did not work because the amount of burning chips was too small. More frequent cleaning and dust removal operations have been put in place.