Rokkasho: How is an atomic-powered island nation riddled with fault lines supposed to handle its nuclear waste?
Part of the answer was supposed to come from this windswept village along Japan’s northern coast. By hosting a high-tech facility that would convert spent fuel into a plutonium-uranium mix designed for the next generation of reactors, Rokkasho was supposed to provide fuel while minimizing nuclear waste storage problems.
Those ambitions are falling apart because years of attempts to build a “fast breeder” reactor, which would use the reprocessed fuel, appear to be ending in failure. 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 tonnes 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. In nearby Oma, construction is set to resume on an advanced reactor that is not a fast-breeder but can use more plutonium than conventional reactors. Its construction, begun in 2008 for planned operation in 2014, has been suspended since the March 2011 Fukushima nuclear meltdowns, and could face further delays as Japan’s new nuclear watchdog prepares new safety guidelines.
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. Countries such as the US and Britain have similar problems with nuclear waste storage, but Japan’s population density and seismic activity, combined with the 2011 Fukushima Dai-ichi nuclear disaster, make its situation more untenable in the eyes of the nation’s nuclear-energy opponents.
“Our nuclear policy was a fiction,” former national policy minister Seiji Maehara told a parliamentary panel in November. “We have been aware of the two crucial problems. One is a fuel cycle: A fast-breeder is not ready. The other is the back-end (waste disposal) issue. They had never been resolved, but we pushed for the nuclear programs anyway.” Nuclear power is likely to be part of Japan for some time to come, even though just two of its 50 functioning reactors are operating and Japan recently pledged to phase out nuclear power by the 2030s. That pledge was made by a government that was trounced in elections on 16 December, and the now-ruling Liberal Democratic Party was the force that brought atomic power to Japan to begin with. Liberal Democrats have said they will spend the next 10 years figuring out the best energy mix, effectively freezing a nuclear phase-out. Japan’s new Prime Minister, Shinzo Abe, said he may reconsider the previous government’s decision not to build more reactors.
Reprocessing creates an opportunity to reuse the spent fuel rather than storing it as waste, but the stockpiling of plutonium produced in the process raises concerns about nuclear proliferation.
Fast-breeder reactors are supposed to solve part of that problem.
They run on both uranium and plutonium, and they can produce more fuel than they consume because they convert uranium isotopes that do not fission readily into plutonium. Several countries have developed or are building them, but none has succeeded in building one for commercial use. The US, France and Germany have abandoned plans due to cost and safety concerns.
The prototype Monju fast-breeder reactor in western Japan had been in the works for nearly 50 years, but after repeated problems, authorities this summer pulled the plug, deeming the project unworkable and unsafe.
When launched, Rokkasho could reprocess 800 tonnes of spent fuel per year, producing about 5 tonnes of plutonium and 130 tonnes of MOX per year, becoming the world’s No. 2 MOX fabrication plant after France’s Areva SA, according to Rokkasho’s operator.
Rokkasho’s reprocessing plant has been plagued with mechanical problems, and its commercial launch has been delayed for years. The operator most recently delayed the official launch of its plutonium-extracting unit until next year. The extracted plutonium will sit there for at least three more years until Rokkasho’s MOX fabrication starts up.
Giving up on using plutonium for power would cause Japan to break its international pledge not to possess excess plutonium not designated for power generation. That’s why Japan’s nuclear phase-out plan drew concern from Washington; the country would end up with tonnes of plutonium left over. To reassure Japan’s allies, government officials said the plan was only a goal, not a commitment. Japan is the only nation without nuclear weapons that is allowed under international law to enrich uranium and extract plutonium without much scrutiny. Government officials say they should keep the privilege. They also want to hold on to nuclear power and reprocessing technology so they can export that expertise to emerging economies. Many officials also want to keep Rokkasho going, especially those in its prefecture (state) of Aomori. Residents don’t want to lose funding and jobs, though they fear their home state may become a waste dump.
Nearly 17,000 tonnes of spent fuel are stored at power plants nationwide, almost entirely in spent fuel pools. Their storage space is 70% filled on average. Most pools would overflow within several years if Rokkasho were to close down, forcing spent fuel to be returned, according to estimates by a government fuel-cycle panel. “Even if we operate Rokkasho, there is more spent fuel coming out than it can process. It’s just out of balance,” Nuclear Regulation Authority chairman Shunichi Tanaka said.
A more permanent solution—an underground repository that could keep nuclear waste safe for tens of thousands of years—seems unlikely, if not impossible.
The government has been drilling a test hole since 2000 in central Japan to monitor impact from underground water and conduct other studies needed to develop a potential disposal facility.
But no municipality in Japan has been willing to accept a long-term disposal site. AP