The court-appointed lawyers, who serve as prosecutors, have demanded five-year prison sentences for three former executives of Tokyo Electric Power Company. They say the executives are responsible for the 2011 accident at the Fukushima Daiichi nuclear power plant.
The court-appointed lawyers delivered their closing argument at the Tokyo District Court on Wednesday.
The defendants are former chairman Tsunehisa Katsumata, former vice president Ichiro Takekuro, and former vice president Sakae Muto. They all pleaded not guilty to charges of professional negligence resulting in death and injury.
Public prosecutors decided not to indict the three, but an inquest panel, comprised of randomly chosen citizens, decided that the former executives should stand trial.
In line with that decision, the men were indicted by court-appointed lawyers in February 2016.
The court-appointed lawyers say the defendants were told two to three years before the accident that a massive tsunami could hit the nuclear plant. They also say the defendants did not try to gather information about the potential danger. The court-appointed lawyers indicate that the former executives later claimed that they had not been informed, and that the executives put all the blame on their subordinates.
The court-appointed lawyers also say the defendants should have suspended the plant's operations when they were told that a massive tsunami could hit the plant.
The court-appointed lawyers maintain that the defendants are responsible because they didn't do anything to prevent the accident from occurring.
A five-year prison term is the maximum punishment handed down for professional negligence resulting in death and injury.
A lawyer for the bereaved families of the victims will speak at the trial on Thursday. The defense lawyers will deliver their closing argument next March.