If University of Tokyo professor Toshitsugu Fujii is to be believed, it would appear that there is potential for another disaster in the Japanese nuclear power industry.

The prominent volcanologist has spoken out against regulators who have assured the population that the two reactors at the Sendai plant are safe.

Doubts On Japanese Nuclear Reactor Safety

Disaster in the Japanese nuclear reactor: Differing predictions

Regulators have stated that a major eruption in the region will not happen within the usable lifespan of the reactors. They also evaluated the reactors according to the tougher safety requirements implemented after the 2011 Fukushima disaster, and passed them..

Fujii, who is the head of a government-commissioned panel on volcanic eruption prediction, has refuted these claims. He stated that should a cauldron eruption occur at one of the various volcanoes in the region, not only could it hit the reactors, but it could cause a nationwide disaster.

“It is simply impossible to predict an eruption over the next 30 to 40 years,” Fujii said. “The level of predictability is extremely limited.”

He claimed the upper limit of accurate predictions is a matter of hours or days.

Volcanoes the cause for concern about Japanese nuclear reactor

A recent surprise eruption of nearby Mount Ontake has stoked concerns about the region’s volcanoes.

Fujii has used a previous study to predict that a pyroclastic flow from the active Sakurajima volcano could easily hit the Sendai nuclear plant, located just 40 kilometers away. The eruption would cause heavy ash fall, cutting off access to the plant and affecting much of the country, including the capital Tokyo.

The two Sendai reactors are the first to pass the new stringent safety requirements, which necessitate resistance to volcanic eruption. There is significant political pressure to restart the reactors, with Prime Minister Shinzo Abe maintaining that nuclear power is key to the economic recovery of the country.

The safety of the reactors had already been approved before the formation of the volcano panel. Fujii claims that he speaks for the assembled experts in opposing regulators’ views.

“If they still need to be restarted despite uncertainties and risks that remain, it’s for political reasons, not because they’re safe, and you should be honest about that,” he stated.