At around 8:30 p.m., a fire broke out on the tip of a 70,000 m³ pile of wood measuring 15 m in height at the outdoor storage area for raw and recycled wood at a particle board plant. The outdoor timber yard contained a total of 118,000 m³ of wood when in fact it was authorized to hold only 15,000 m³. A huge plume of white smoke was escaping from the pile. Firefighters doused the pile with water and foam. They continued spraying foam overnight to reduce the amount of smoke. The operator removed the unburnt wood with a backhoe loader. Emergency services protected the production area and the site’s other storage areas.

The next day, the fire spread to the tops of the stockpile. Mechanical excavators and fire hoses were brought in to put out the burning pile. Due to lack of space on the site, the burnt wood was spread on the clay soil of an adjacent field. Smoke from the fire drifted towards the A6 motorway. The emergency response unit (CASU) was contacted to model the dispersion of the smoke plume (CO concentration). The findings were reassuring but, as a precaution, two motorway service areas were closed from the following Tuesday onwards. The speed limits on the A6 and the N77 were lowered due to the opacity of the smoke. From 29 to 31 December, while the fire was being sprayed, emergency services dug a 5-m-wide trench to divide the pile into one 30,000 m³ heap of still-burning wood and one untouched 40,000 m³ heap.

Response complicated by the too-narrow trench and height of the piles

On 3 January 2018, strong winds whipped up by storm Eleanor hampered the firefighters’ efforts. The flames spread to other chip piles, including the untouched 40,000 m³ pile, and some facilities. The trench between the piles was widened. As the site’s 2500 m³ fire-protection pond and the municipal network were both depleted whilst fighting the fire, the firefighters laid a supply line leading from the Yonne River four kilometres away. An estimated 500 l of water was pumped in per minute (30 m³/h), with peaks at 1,000 l/min (60 m³/h). The settling of the piles was complicated by their height.

Consequences

The fire was put out at around 2:00 p.m. on 8 January. The plant continued operating as usual until 3 January when the employees were told to stay at home until further notice. Production resumed five days later on the afternoon of 8 January. Five firefighters and one employee were sickened by the smoke (CO poisoning) and treated on site. The fire destroyed two of the mechanical excavators used to extinguish the burning pile. A portion of the firewater flowed into a storm pond, which quickly filled, and then continued on to the ditch running alongside the site. The runoff and external temperature of the various piles were monitored using a drone.

Causes

The site was being redeveloped to accommodate new facilities that were experiencing startup delays. The increased amount of wood placed in storage and the longer storage period combined with inadequate settling of the pile is believed to have caused the pile to ferment. Before the incident, on 21 December, the inspection authorities for classified facilities had visited the site and told the operator to rectify the situation (storage of wood piles, application for the site’s biomass boiler, and recycling stream for wooden panels). After the fire, precautionary measures were taken to regulate the site’s wood storage operations, biomass boiler, and fire-suppression equipment and systems.

Measures envisaged

The operator plans to expand its timber yard to ensure that piles are no more than 6 m high and separated by 10-m-wide paths. The fire-protection pond will also be cleaned and repaired.

Additional equipment and facilities (hoses, dry risers, pump sets, fire-protection pond) will be installed to enhance fire protection. They will be reinforced by organisational measures aimed at:

• limiting how long wood is stored in the timber yard;
• regularly monitoring and recording woodpile temperatures.

Lastly, the internal emergency plan and licence application will include feedback from this event and past accidents.