The Tokyo Electric Power Company (Tepco) announced a significant achievement in the decommissioning efforts at the devastated Fukushima Daiichi Nuclear Power Station in Japan on Sunday, two days after a citizen's panel announced it would override two previous decisions and pursue charges of negligence against three former Tepco executives.
Tepco said it had removed a 20-ton fuel handling machine (FHM) from the severely damaged Unit 3 reactor building, completing the safe extraction of the largest piece of rubble from the site after extensive preparations.
The machine, prior to the events of March 2011, which included a major 9.0-magnitude earthquake and a following tidal wave or tsunami event, was used to move both fresh and spent nuclear fuel within the reactor building. But along with the rest of the building, the FHM was badly damaged in the accident. The special consideration, Tepco said, was to move the machine without causing further damage to the spent fuel or the fuel assemblies within it.
Removal of the large piece of machinery clears the way for clearing away the remaining rubble and the rest of the 514 spent fuel assemblies in the building 3 pool, Tepco said.
The removal of the 14-meters long machine, accomplished with two 600-ton cranes outfitted with special clamps and hooks, was accomplished in an hour, but preparation took months. Tepco said to move the machine safely required prevention of oil leakage from the machine, creating the necessary hooks and clamps, training operators on lifting procedures, use of anti-dust agents, including water, to contain contaminated debris, adding a water injection system to the cooling pool, and setting pumps in place to retrieve escaping water should that have occurred.
Chief Decommissioning Officer Naohiro Masuda, said the operation “paves the way for continued progress and is a milestone in reducing the risk of removing spent fuel assemblies.”
Meanwhile, on Friday, an 11-member panel of citizens trumped prosecutors by voting to indict three former company officials, including former Chairman Tsunehisa Katsumata, 75, for failing to prepare the facility for a tsunami event, like the one that knocked out the plant's backup power system in 2011.
The case now goes to the Tokyo District Court, but some media reports indicate the case against Katsumata and former Tepco vice presidents Sakae Muto, 65, and Ichiro Takeguro, 69, is likely to be weak given the point that prosecutors twice decided not to pursue the case.
The panel's decision involves charges of neglect that lead to deaths, but no deaths have been linked to the radiation leaks or explosions at the plant, although deaths did occur during the evacuation of the area.
The Great East Japan Earthquake killed more than 16,000 people and caused the evacuation of 300,000 from their homes, including tens of thousand in the vicinity of the nuclear power plant.