An incident occurred within a uranium ore treatment facility during experimentation conducted on a new fabrication process. Under stormy weather conditions, a malfunction of the lime feed pump, located in the unit assigned to neutralise effluents generated by a uranium oxide dissolution installation, was at the origin of a nitrogen dioxide discharge. 30 fire-fighters were called to the scene. The treatment line was quickly restored and the acid tank drained. The discharge was not radioactive, and the incident had no consequences for the local population.