But Japan still intends to reprocess spent fuel at Rokkasho. It sees few other options, even though it will mean extracting plutonium that could be used to make nuclear weapons.
If the country were to close the reprocessing plant, some 3,000 tons of spent waste piling up here would have to go back to the nuclear plants that made it, and those already are running low on storage space. There is scant prospect for building a long-term nuclear waste disposal site in Japan.
So work continues at Rokkasho, where the reprocessing unit remains in testing despite being more than 30 years in the making, and the plant that would produce plutonium-uranium fuel remains under construction.
The effort continues on the assumption that the plutonium Japan has produced - 45 tonnes so far - will be used in reactors, even though that is not close to happening to a significant degree.
If Japan decided that it cannot use the plutonium, it would be breaking international pledges aimed at preventing the spread of weapons-grade nuclear material. It already has enough plutonium to make hundreds of nuclear bombs - 10 tonnes of it at home and the rest in Britain and France, where Japan's spent fuel was previously processed.