©AFP

Buddhist monks offer prayers for tsunami and earthquake victims at Soma in Fukushima, the scene of a radiation leak

A welter of conflicting legal decisions has left Japan’s nuclear reactors in a state of limbo as national energy strategy clashes with the courts.

The reactors are being turned on and off like light switches as activists file lawsuits, highlighting the tension between safety fears and energy supply, and raising questions about the role of courts in nuclear regulation.

At stake is a multibillion-dollar nuclear infrastructure that is mothballed, reducing the risk of accidents but forcing energy-poor Japan to import and burn millions of tonnes of polluting fossil fuels.

The nuclear industry received a small boost on Wednesday when Fukuoka’s high court refused to grant an injunction against the Sendai nuclear plant on the southern island of Kyushu — the only reactor in operation.

But it does not make up for last month, when a district court ordered Japan’s only other online reactor, at Takahama on the main island of Honshu, to shut down again.

The Takahama shutdown was a particular blow to the industry because a court in the district that hosts the reactor had lifted its injunction against the plant. That showed how plaintiffs can try different judges, given the wide areas potentially affected by an accident.

The stop-start court decisions are a huge frustration to government policymakers, who last year set a goal of restoring nuclear power to 20-22 per cent of Japan’s energy mix.

“I think [Takahama] was a very strange judgment,” says Masakazu Toyoda, chairman of the Institute of Energy Economics in Tokyo, pointing out that courts around the world scrutinise whether regulators and generators have properly followed their safety procedures.

“But in Japan we have the really strange situation where the court has decided the safety standard itself is not sufficient to alleviate every possible adverse impact,” Mr Toyoda says.

The court in the Takahama case said the causes of the 2011 Fukushima nuclear disaster were not fully understood. It cited various problems and questions about tsunami risk and disaster preparedness.

To Mr Toyoda, that overrides the regulators who wrote the safety standards, clearing Takahama to operate, and leaves no room for concerns such as climate change, energy security or the health risks from alternative power sources.

But to Hiroyuki Kawai, one of the leading legal campaigners against Japan’s reactors, independence from nuclear experts and national energy strategy is the whole point of the courts.

“We tried leaving everything to the experts and what we got is Fukushima,” he says, arguing that one way or another, Japan’s nuclear experts are tied to the industry.

“The courts don’t consider energy strategy, they just consider whether a reactor should start or stop,” Mr Kawai says. “Thinking too much about energy strategy and government policy is what leads courts to error.”

Kenichi Ido, a former judge who issued an injunction against a nuclear power station in 2006 — well before the Fukushima disaster — said it was not surprising Japan’s courts kept coming to different opinions given the widely different views in society.

The courts have wide discretion to rule based on civil law or the constitutional rights to life and liberty. Mr Ido said a supreme court ruling would only settle the issue if it was framed widely, rather than on the facts of a particular case.

That leaves Japan’s reactors facing a future of constant litigation — and Mr Kawai is revelling in it. “We’ll aim to get injunctions against any reactor that tries to restart,” he says.

With the Sendai plant operating, he recognises his alliance of lawyers may not stop them all. But, he promises: “There’s no chance of all Japan’s reactors starting up again.”