Japan is expected to take more than 30 years to fully decommission crippled nuclear reactors at the Fukushima No. 1 nuclear plant, according to a draft report compiled by the Nuclear Safety Commission of Japan obtained by the Mainichi on Oct. 26.
It is the first time for the government's body to officially state that it is expected to take "more than 30 years" to decommission the troubled No. 1 to 4 nuclear reactors. According to the draft report, the work to remove spent nuclear fuel from nuclear fuel pools would begin sometime after 2015, while the work to remove melted nuclear fuel from the reactors would start sometime after 2022. The draft report is expected to be endorsed at a study meeting on Oct. 28 of experts on medium- and long-term measures. At the Fukushima No. 1 Nuclear Power Plant, there are a total of 1,496 spent nuclear fuel rods in the No. 1 to 3 reactors, while there are 3,108 fuel rods in the spent nuclear fuel pools of the No. 1 to 4 reactors. In order to actually decommission the reactors, those fuel rods must be recovered, cooled down and stored under stable conditions for a long time. According to the draft report, the work to decommission the reactors is expected to start as early as next year after a "cold shutdown" is achieved by the end of this year.
In order to recover melted nuclear fuel from the reactors, robots and other means would be used to decontaminate the interior of the reactor buildings before repairing damaged parts of the containment vessels. Furthermore, in order to block radiation, the entire containment vessels would be filled with water so that the work to recover melted nuclear fuel could be started sometime after 2022. Meanwhile, damage to the fuel in the spent nuclear fuel pools is relatively minor, but the existing cranes cannot be used because the reactor buildings, except for the one for the No. 2 reactor, were badly destroyed by hydrogen explosions. Therefore, new cranes have to be brought in to start to recover the fuels sometime after 2015 after fitting out the temporary storage facility installed near the No. 4 reactor.
In light of the fact that it took about 20 years to recover all fuels at the Three Mile Island nuclear complex, the draft report said it was estimated to take "at least more than 30 years to complete the measures to decommission" the reactors at the Fukushima No. 1 Nuclear Power Plant. In order to decommission the reactors as early as possible, it is necessary to 1) positively accept opinions from experts abroad, 2) respond flexibly if the plans do not work properly, 3) put priority on research and development essential for the actual work to be done on the spot, and 4) cultivate engineers at home, the draft report says. At the Fukushima plant, the decommissioning work has to be carried out on the four reactors simultaneously, and therefore it is likely to be an extremely difficult mission. For this reason, the draft report says, "it is necessary for both public and private sectors to join forces as 'all Japan' to proceed" with the project. Along with the "Nuclear Safety Agency" to be set up next spring, the draft report for the first time stressed the need to form a third-party organization tasked with checking the progress in the decommissioning work.
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