In a waste treatment and recovery centre, an explosion occurred in the incinerator furnace at around 3 p.m., expelling incandescent waste from the furnace feed hopper. A fire broke out, which spread to a pit containing 3,000 tonnes of non-hazardous waste. The staff tried to extinguish it using pressurised water hoses and 2 foam canons provided for this purpose. Faced with the persistence of the flames, the emergency services were alerted at around 3:15 p.m. and the site’s non-essential employees were evacuated. Firefighters were able to drown the waste with 200 m³ of water and foam, which extinguished the flames and left a smouldering fire. At 3:45 p.m., the fire was drowned, and half the firefighters were demobilised at 7:00 p.m. Two fire hoses remained deployed in the event the fire restarted. After 11 p.m., the waste was removed with the grapple and transferred to the oven while being sprayed down by the fire brigade. The waste was removed entirely over the course of several days.
No injuries or property damage were reported, and the environmental impact was limited to fire smoke.
The Inspection authorities for classified facilities went to the site the next day, accompanied by the fire brigade, to check on the measures undertaken to limit the environmental impacts.
The initial explosion was due to the start-up of the auxiliary burners in the presence of carbon monoxide in the furnace. The causes that led to the event can be summarised as follows:
- A blockage in the waste loading hopper led to the shutdown of the waste supply and the formation of CO in the furnace,
- After the necessary conditions were met, the restart sequence was launched. However, the pre-ventilation designed to reduce the CO level was insufficient due to the malfunction of one of the two temperature sensors to which it was slaved (temperature indicated was higher than the actual temperature),
- The auxiliary burners started in hazardous areas leading to a CO explosion that threw incandescent waste into the pit, which was the point where the fire started.
To prevent such an event from happening again, the facility operator worked on improving specific layout features, optimising servo-controls and organisational measures for waste admission.