There was a report recently that Japan's Nuclear Regulation Authority had approved the decommissioning of five reactors at four nuclear power plants.
The decommission of the five reactors, which, are located at the Tsuruga and Mihama plants in Fukui Prefecture, the Shimane plant in Shimane Prefecture and the Genkai plant in Saga Prefecture, are the first such approvals by the NRA since the government introduced regulations in 2011 banning the continuance of any reactors that had been in operation for 40 years or more.
The utilities companies operating the reactors estimate it will take about 30 years to complete the decommissioning of each reactor, though the disposal sites for radioactive waste are still undecided.
According to the Nuclear Energy Institute's website decommissioning a nuclear reactor involves: decontaminating the facility to reduce residual radioactivity; dismantling the structures; removing contaminated materials to appropriate disposal facilities; storing used nuclear fuel until it can be removed from the site for disposal or consolidated storage; and releasing the property for other uses.
"The decommissioning process involves removing the used nuclear fuel from the reactor, placing it into the used fuel pool, and eventually into dry storage containers (which can be stored on-site or transported off-site); dismantling systems or components containing radioactive products (e.g., the reactor vessel); and cleaning up or dismantling contaminated materials from the facility. Contaminated materials can be disposed of in two ways: decontaminated on-site or removed and shipped to a waste-processing, storage or disposal facility," it states.