Inside a foundry handling bronze, copper and aluminium, an explosion occurred at 1:30 pm in an electric melting furnace containing 300 kg of bronze flakes and 100 kg of copper shot. Projections of molten metal seriously burned an employee, who had been working in the foundry since 2007 and was alone in the workshop as the event took place. The damage to this wall reached over 1.5-m behind the furnace, as well as a piece of sheet metal above this furnace and some electrical cables. The smoke exhaust fan was spared. No impacts were recorded off-site.

Judicial authorities locked down the specific furnace. The gendarmerie restricted access around this furnace and undertook a judicial investigation. During its 27 February site visit, the inspection authorities for classified facilities found, as corroborated by the Head of Smelting Operations, that the batches of copper flakes and shot being used at the time of the accident had already been deployed the day before. This manager also indicated that the furnace loading procedure had never been described in any document, as the orders to load furnaces were simply spoken. The general recommendations addressed to the technician on the day of the accident consisted of carefully ensuring that loads were being regularly lowered into the furnace to enable effective melting.

Furnace maintenance, especially refractory equipment, was performed in-house, with the graphite crucible made of silicon carbide remaining under the manufacturer’s responsibility. A visual verification conducted before restarting the furnace took into account the number of fusions; the crucible used in the damaged furnace had reached 40% to 50% of its normal wear.

The foundry operator, who mentioned that no comparable incident had occurred for some 10 years at the facility, forwarded the hypothesis of an explosion subsequent to air bubble formation inside the crucible.