Fukushima May Top Three Mile Island, French Watchdog Says

Japan’s Fukushima Dai Ichi nuclear plant has likely released more radioactivity than Three Mile Island and the crisis could last for weeks, according to France’s nuclear watchdog.

The event may rate 5 or 6 on the seven-step scale of nuclear incidents, Andre-Claude Lacoste, chairman of the Autorite de Surete Nucleaire, said at a briefing in Paris today. “There is no doubt there was the beginning of a meltdown of the core of reactors 1 and 3 and likely 2 as well.”

Tokyo Electric Power Co. engineers are trying to stabilize the three reactors, which were damaged by the biggest earthquake in Japan’s history on March 11. The plant was struck by a second explosion earlier today and water levels dropped at the No. 2 reactor, exposing fuel rods on two occasions. The utility said it can’t rule out the possibility that the fuel rods are melting, heightening the chance of a meltdown.

“We believe that the measures the Japanese authorities have taken to protect the population are sufficient,” Agnes Buzyn, head of France’s Institut de Radioprotection et de Surete Nucleaire, another nuclear regulatory body, said today at the same press conference.

Significant radioactivity was released and certainly more than at Three Mile Island,” she said, declining to provide figures. The Three Mile Island nuclear accident, in 1979, was the worst in U.S. history.

The French officials said they are basing their assessment on information provided by Japanese nuclear authorities.

Beginning of a Crisis

The cooling system failed at the Dai-Ichi No. 2 reactor while a hydrogen explosion occurred at the No. 3 reactor today, following a similar blast on March 12 at the No. 1 reactor that destroyed the walls of its building. The utility has been flooding the reactors with water and boric acid to reduce the risk of a large release of radioactivity.

“We are without a doubt at the beginning of the crisis,” Lacoste said, adding that while he could not estimate how long it will take to gain control over the nuclear reactors in Japan, it may take “weeks.”

“This isn’t a nuclear catastrophe; it’s a very serious accident,” he said. France’s existing 58 reactors operated by Electricite de France SA aren’t the same type of reactor as the ones in Japan so the ASN isn’t providing technical advice to Japanese authorities.

The Fukushima accident could resemble Three Mile Island where there was a partial meltdown of a reactor core with “moderate” radioactivity released into the atmosphere if Japanese authorities are able to cool the cores, Lacoste said.

The use of sea water, which is being used to cool the reactors, is “typically an emergency measure” and is “horrible,” Lacoste said, adding that this has never been the subject of experimentation because nuclear reactors normally require water that is as clean as possible so as not to clog up pipes and cooling circuits.

“It’s a situation that is requiring emergency measures to cool the reactors,” he said. “If there is a complete meltdown of a core we will have a much more serious accident on our hands.”