If you're going to use nuclear energy, it's a very, very bad idea to rely on for-profit companies who have every incentive to cut corners and cover up. Can anyone honestly say they still believe anything TEPCO says? Not a great position for Japan to be in:

Tokyo Electric Power Co. injected boric acid into a reactor at its crippled Fukushima nuclear plant to prevent an accidental chain reaction known as re-criticality after temperatures rose in the past week.

The temperature of the No. 2 reactor was 70.1 degrees Celsius (158 degrees Fahrenheit) as of 6 a.m. today, according to preliminary data, Akitsuka Kobayashi, a spokesman for the utility, said by phone. The reading fell from 72.2 degrees at 5 a.m. this morning, and is below the 93 degrees that’s used to define a cold shutdown, or safe state, of the reactor.

Since Feb. 1, temperatures at the bottom of the No. 2 reactor vessel have risen by more than 20 degrees Celsius, according to the company’s data. Tepco, as the utility is known, and the government announced that the Fukushima plant reached a cold shutdown on Dec. 16, nine months after the Tohoku earthquake and tsunami wrecked the nuclear station, and caused three reactors to meltdown and release radiation.

“It was too early to say the plant is safe in December. They declared cold shutdown even though nobody is sure about the location of melted fuel,” Tetsuo Ito, the head of the Atomic Energy Research Institute at Kinki University in western Japan. “A similar incident will probably occur again.”