Jul. 01, 2014

Nippon Steel & Sumitomo Metal Corporation

Power Failure at Nagoya Works (Second Report)


On Sunday, June 22, 2014, a power failure occurred at Nagoya Works of Nippon Steel & Sumitomo Metal Corporation ("NSSMC"). In order to deal with the power failure, coke oven gas was burnt off and released, resulting in massive smoke generation.  Following the smoke generation and release caused by power failure in January 2014, we deeply regret any inconvenience that may have been experienced by neighborhood residents and other related parties.

Since the incident occurred, we have made the utmost efforts to investigate the cause and have found how it occurred to a certain extent. First, electricity supply from Chubu Electric Power was shut down within the premises of Nagoya Works. Then, electricity supply within Nagoya Works was provided by only four in-house power generators. At that time, however, some functions of a stabilization controller for the power system failed to be activated properly, causing a protective device for the power generators to detect a significant fluctuation in frequency of the power system, which then led to an automatic stoppage of one of the generators. Subsequently, the balance between power generation and power consumption within Nagoya Works was disrupted and the remaining three power generators stopped operating, leading to power failures in almost all areas within the Works.

NSSMC will continue to work hard to ascertain the cause of this incident in more detail. At the same time, in order to prevent any recurrence of this situation, we will review the procedures which resulted in shutting down the power receiving lines from Chubu Electric Power and enhance management of the control of fluctuation in frequency. In addition, we will quickly make comprehensive efforts by ensuring implementation of the measures we have already begun to take, promoting the adoption of these measures across the whole Works, and continuing information sharing and coordination with the government and other parties.

By around 11:00 p.m. on Sunday, June 22, individual units of equipment and facilities had been inspected and then resumed operation one at a time. By Friday, June 27, almost all manufacturing processes had been resumed.

We will strive earnestly to ensure that product supply to our customers will not be affected.

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