Within a nuclear fuel production plant, a fire broke out in a container holding 90 bags of radioactive waste located in the waste packaging workshop. The plant’s emergency plan was activated, the staff was confined. The plant firefighters extinguished the fire 45 minutes after detection using a water lance. 34 employees confined near the fire, suspected to have inhaled smoke, underwent radiotoxicology analysis, which showed no contamination. The operator issued a press release.

With no external heat source involved, the most likely origin of the event is an exothermic chemical reaction between incompatible products. The operator occasionally uses cellulose-free wipes impregnated with 58 % nitric acid. Nitric acid is an oxidizer which, when mixed with combustible material, may trigger fires. However, the nature of products involved is not identified with certainty.

The classified facilities inspectorate asked the operator to set up an enhanced surveillance of technological waste, to assess the risk of spontaneous combustion of waste during transport and storage and take actions accordingly, to study and implement actions to prevent the mixing of oxidizers and combustibles in solid waste, to clarify the nature of permitted and prohibited materials in waste and the associated controls. The operator must also assess the potential consequences of the rupture because of the heat of pipes of anhydrous hydrofluoric acid located 2-3 m above the container, check their integrity after the fire and remove the storage of combustible materials under the pipes of hazardous substances. Control of the fire by the plant firefighters and efficient crisis management are emphasized by the inspectors.