Thursday, April 12, 2007
1999 uncontrolled reaction suspected
An uncontrolled nuclear reaction may have occurred during a 1999 accident at Hokuriku Electric Power Co.’s Shika power plant, the Japan Nuclear Technology Institute said Wednesday.
Michio Ishikawa, president of the institute comprising companies related to the electricity business, dismissed concerns that the “prompt critical” reaction could have resulted in a serious accident, like the deadly Chernobyl meltdown in 1986, saying what happened at the Shika plant was “a phenomenon of a very small scale.”
According to Ishikawa, the reaction might have occurred in parts of the reactor where three control rods were accidentally dislodged. The plant is located in Shika, Ishikawa Prefecture, on the Sea of Japan coast.
The institute analyzed various conditions that could have resulted from the development. The worst possible case it came up with suggested that the temperature of the troubled spot could have gone up to about 150 degrees. He said 3,300 degrees is the point that can melt nuclear fuel and release radioactivity into cooling water, according to Ishikawa.