Roughly 300 km northwest of Finland’s capital, Helsinki, is the island of Olkiluoto, home to two nuclear power plants and the potential site for one of the world’s first permanent underground high-level nuclear waste repositories.
Onkalo (Finnish for hiding place) is hundreds of meters deep. Research is still under way, but burial of canisters of spent fuel is scheduled to begin around 2020.
A documentary that Danish filmmaker Michael Madsen made about the repository, “Into Eternity,” has gained a strong following in Japanese theaters since the atomic crisis began at the Fukushima No. 1 nuclear power plant in Fukushima Prefecture.
The repository is designed to store high-level nuclear waste for at least 100,000 years, an inconceivably long period of time, but a reminder of just how long-lived some radioactive materials are, and how the only feasible solution for mankind to dispose of the hazardous nuclear waste it produces is to literally hide it deep in the Earth.
“It’s every nation’s responsibility to construct permanent nuclear waste repositories on its own territory, and a consensus will have to be reached in Japan to do the same,” said Kenzo Miya, professor emeritus at the University of Tokyo.
As Tokyo Electric Power Co. struggles to execute a cold shutdown of the damaged reactors, one of the main issues will be whether the utility will then be able to successfully remove the thousands of highly radioactive spent-fuel rods resting in the reactors’ storage pools.
“The situation is quite different from that of Chernobyl, where a concrete confinement sarcophagus was built to seal the hundreds of tons of radioactive fuel still in the facility,” Miya, an expert on nuclear plants, said.
“In the case of Fukushima, all spent fuel will eventually be removed and transferred to be stored at the Rokkasho nuclear reprocessing plant” in Aomori Prefecture, before ideally being buried in a permanent repository, he said.
While the Rokkasho reprocessing plant is still undergoing tests and not in full operation, the site has a landfill for low-level radioactive waste and a temporary storage space for high-level nuclear waste, where spent nuclear fuel from Japanese power plants, after being reprocessed by similar facilities in France and the United Kingdom, is sent back to be stored and cooled for 30 to 50 years.
The radioactivity of spent nuclear fuel is believed to drop by 99.9 percent after about 40 years, although it still takes another 1,000 years before its radioactivity drops to that of natural uranium.
But the radioactivity of some elements, including plutonium-239 which has a half-life of 24,200 years, remains high for more than 100,000 years and requires secure and permanent disposal to avert nuclear proliferation and radiation hazards.
Thus, the need to bury them permanently.
In Japan, the Nuclear Waste Management Organization of Japan, or NUMO, is the primary organization responsible for undertaking the task of investigating and selecting a potential burial site, and for overseeing the repository’s construction, operation and eventual closure. The whole process combined is expected to take 100 years and an estimated ¥3 trillion to complete.
To fund the operation, all electric utilities using nuclear power plants are paying NUMO a “storage” fee based on how much nuclear waste each produces in a year. This year, the fees totaled nearly ¥80 billion.
Takeshi Yamada, a NUMO representative, said that while organization has been soliciting communities nationwide to host the repository, its efforts have been fruitless despite the allure of the billions of yen in subsidies that will be awarded to any community hosting a site that matches NUMO’s criteria.
Once, in 2007, the mayor of Toyocho, Kochi Prefecture, submitted an application to NUMO without the consent of the city council, only to lose his job in the next election amid heated calls to withdraw the application.
“At present there are no potential locations for the repository,” Yamada said.
Ideally, once a location has been identified, NUMO will take 20 years to research the site’s geological characteristics. If the site receives the go-sign, NUMO will then spend the next 10 years digging through the bedrock to create storage space as deep as 500 meters.
Yamada said that according to the blueprint, the underground repository will be filled with thousands of stainless steel canisters of solidified high-level radioactive waste that will set there for the next 50 years. The 40,000 canisters will represent all the spent fuel produced by Japan’s power plants from the 1960s to around 2030.
The repository will then be backfilled and, if needed, monitored by security personnel for decades, or possibly centuries, to come.
All this, however, depends on whether NUMO can find the right location and gain the consensus of the local community, which, in light of the heightened alarm toward nuclear energy in general, seems unlikely in the near future.
Ai Fujiwara of the Radioactive Waste Management Funding and Research Center, an organization that works in tandem with NUMO, said the only operating underground permanent repository for nuclear waste in the world is the Waste Isolation Pilot Plant in Carlsbad, New Mexico.
But the site, which uses massive salt beds to store nuclear waste, primarily accepts transuranic waste, or TRU, generated by U.S. Department of Defense activities, not spent fuel.
Much time and money were spent planning a permanent repository for spent nuclear fuel and other high-level nuclear waste at Yucca Mountain in Nevada, but the project was scrapped by the Obama administration amid local opposition.
“At present, there are no operating permanent repositories for spent fuel and other high-level nuclear waste in the world,” Fujiwara said.
In the director’s English-language notes for “Into Eternity,” Madsen wrote: “The Onkalo project of creating the world’s first final nuclear waste facility capable of lasting at least 100,000 years, transgresses both in construction and on a philosophical level all previous human endeavors.”
As the crisis at the Fukushima No. 1 nuclear power plant casts a spotlight on the pros and cons of nuclear energy, general interest also appears to be increasing about the unanswered questions of where and how the massive amounts of nuclear waste produced each year will finally be laid to rest.
“The recent nuclear disaster has presented the Japanese with the crucial question of what to do with nuclear energy, and I believe people will seriously begin thinking about it,” said Tokyo University’s Miya.
“It’s difficult to say at this point, but I myself believe that we will eventually be able to construct our own, final repository for our nuclear waste.”