Three former Tokyo Electric Power Company executives have denied responsibility for the 2011 meltdowns at the Fukushima nuclear power plant.
Ex-Tepco chairman Tsunehisa Katsumata and vice presidents Sakae Muto and Ichiro Takekuro entered not guilty pleas to negligence charges at Tokyo District Court on Friday.
Each apologised for the disaster and the trouble it caused, but said said they did not think they bore criminal responsibility because they could not have foreseen it.
That issue is expected to be the crux of their trial, the first to consider whether employees of the utility can be held criminally responsible. the trial is likely to last more than a year.
Tepco itself has not been charged.
The plant was hit by a powerful earthquake and tsunami in March 2011, with three reactors suffering meltdowns.
The radiation spread to surrounding communities, with tens of thousands of residents were forced to evacuate and some areas still uninhabitable six years later.
The ex-Tepco executives are accused of not taking sufficient preventive measures despite being aware of the risk of a major tsunami at the Fukushima plant at least two years before it happened.
They are charged with professional negligence resulting in death and injury, including the deaths of more than 40 pensioners during and after lengthy evacuations from a hospital, and injuries to 13 people including Tepco employees during emergency work.
Prosecutors considered the case twice and dropped it both times, but a citizens’ judicial panel overrode the decision and indicted the former executives.
They are being tried by a team of lawyers appointed by the court.
Government and parliamentary investigative reports have said Tepco’s lack of safety culture and weak risk management, including an underestimate of tsunami risks, led to the disaster.
They also said Tepco ignored tsunami measures amid collusion with then-regulators and lax oversight.
Tepco has said it could have taken safety measures more proactively, but that a tsunami of the magnitude that crippled the plant could not be anticipated.
The criminal trial for the executives was prompted by an appeal by more than 5,700 people from Fukushima and other parts of Japan, urging prosecutors to investigate and send the bosses to court to determine who is responsible for the disaster.