Mitsubishi Materials president apologizes for fatal factory blast
TSU (Kyodo) -- Mitsubishi Materials Corp. President Hiroshi Yao apologized on Saturday for the explosion at the company's semiconductor silicon plant this week that killed five maintenance workers.
In his first news conference since the accident Thursday in the central Japan city of Yokkaichi, Mie Prefecture, Yao said although the cause of the explosion is still not known, the company will have to review maintenance work safety procedures at the factory.
"The fact that the accident occurred even if (the plant workers) followed the regulations means that there was a flaw" in the regulations themselves, Yao said.
The blast occurred when the cover of a heat exchanger at the plant was removed for cleaning.
The plant did not have detailed guidelines as to when the heat exchanger could be opened for cleaning, according to Mitsubishi Materials officials. Workers checked if the heat exchanger was cool enough to open by touching the surface of the equipment, they said.
Yao said a "more scientific method" may have been needed to determine if the heat exchanger was safe for maintenance work.
The company has not decided when to restart suspended operations at the factory, he added. Mitsubishi Materials is one of the three major domestic suppliers of semiconductor silicon.
January 12, 2014(Mainichi Japan)