Naohiro Masuda, the Chief Decommissioning Officer of Japan’s Fukushima Daiichi NPP, said on 2 March that operators have yet to locate where the melted nuclear fuel has gone, five years after the meltdown caused by the 2011 earthquake and tsunami. "There are melted fuels in units 1, 2 and 3," Masuda said. "Frankly, we do not really know what the situation is for this (melted fuel), nor where it has gone."

He told reporters ahead of the 11 March anniversary of the disaster, that the first few years of decommissioning work could be compared to working in a "field hospital". He said: "The reality at Fukushima Daiichi was that we had to work day to day dealing with unexpected difficulties showering down. Things have finally started to calm down, we are now able to look ahead in our work, and I am confident that we have made great strides especially in this past year."

On 29 February, three former Japanese utility executives were formally charged with negligence in the Fukushima nuclear disaster. Five court-appointed lawyers indicted Tsunehisa Katsumata, chairman of Tokyo Electric power Co (Tepco) at the time of the crisis, and two other Tepco executives. The three were not taken into custody."I believe truths about the accident that we are not yet told will be revealed in court, and that a fair ruling will be handed down to the defendants for their responsibility," said Ruiko Muto, head of a group of more than 5,000 people from Fukushima and other parts of Japan that filed the criminal complaint four years ago.

Meanwhile, a virtual reality representation of the nuclear reactor buildings at the NPP is set to begin operation in April, for use in devising decommissioning plans and for plant workers to practice their clean-up tasks. The system has been installed at the the Japan Atomic Energy Agency’s Naraha Remote Technology Development Centre in the Fukushima Prefecture town of Naraha. It comprises a 3.6-metre-high screen onto which the interior of a reactor building is projected. Specially made 3D glasses allow the user to see the scene — recreated based on the original design plans and data collected by robots sent inside the buildings by Tepco. Users can experience walking up and down stairs and see dimly lit pipes throughout the building. Radiation levels and time spent "inside" are indicated at the top of the screen so that users can keep track of their virtual exposure to radiation.