The Oita Works of Nippon Steel & Sumitomo Metal Corporation (NSSMC) in Western Japan resumed operations on 6 August after a major fire in January in the plant’s power equipment room. Online media reports claimed that it took 35 hours to extinguish the flames.

Days after the incident, NSSMC formed the Oita Works Plate Mill Fire Accident Response Committee, which included outside experts, and set about establishing the cause of the fire.

A report later published by the committee stated that almost all control panels and cables in the electrical room ‘burned’. The control room building including its floor-supporting steel frames, were damaged. The rolling line of the plate mill became inoperable.

According to NSSMC, the fire was caused by an abnormality inside an MC panel for auxiliary rolling equipment, which entered operation in 2009. The problem led to ‘arcing,’ which caused the fire and then set adjacent flammable materials on fire. The fire spread to other panels and cables.

In addition to the installation of circuits that shut of electric current in the event of an abnormal control signal, the committee has recommended the installation of smoke and heat detectors as well as monitoring cameras to identify problems as they occur. Additional fire extinguishers, Halon injection equipment for putting out fires inside the panels, additional fire hydrants and an overall electricity shutdown device have also been agreed upon along with enlarged smoke-exhaust windows to facilitate smoke release.

In essence, measures are being put in place to detect future fires, extinguish them and prevent them from spreading.

There were no injuries reported, according to NSSMC.