The Japanese government unveiled Friday a map indicating potential deep-underground disposal sites for high-level radioactive nuclear waste, identifying some 70% of the country’s land as suitable.
Based on the map, the government is expected to ask multiple municipalities to accept researchers looking into whether those areas can host sites to dispose of waste left by nuclear power generation. But the process promises to be both difficult and complicated amid public concerns over nuclear safety following the 2011 Fukushima nuclear disaster.
The nationwide map showed that up to 900 municipalities, or half of the country total, encompass coastal areas deemed “favorable.” Areas near active faults, volcanoes and potential drilling sites such as around oil fields are considered unsuitable.
For permanent disposal, high-level radioactive waste, produced as a result of the process of extracting uranium and plutonium from spent fuel, must be stored more than 300 meters underground so that it cannot impact human lives or the environment.
The government will store the waste in vitrified canisters for up to some 100,000 years until the waste’s radioactivity decreases.
As of March, some 18,000 tons of spent fuel existed in Japan with the figure set to increase as more nuclear plants resume operation. When spent fuel that has already been reprocessed is included, Japan will have to deal with about 25,000 such canisters.
The map, illustrated in four different colors based on levels of the suitability of geological conditions, was posted on the website of the Ministry of Economy, Trade and Industry.
Energy minister Hiroshige Seko said Friday that the unveiling of the colored map is an “extremely important step toward the realization of the final disposal but also the first step of a long road.”
Taking the map as an opportunity, “we hope to have communications (with municipalities) nationwide and earn the understanding of the public,” he said.
“It scientifically and objectively shows nationwide conditions, but it is not something with which we will seek municipalities’ decisions on whether to accept a disposal site,” Seko said.
Areas near active faults, volcanoes and oil fields which are potential drilling sites are deemed unsuitable because of “presumed unfavorable characteristics” and colored in orange and silver.
Areas other than those are classified as possessing “relatively high potential” and colored in light green.
Among the potential areas, zones within 20 kilometers of a coastline, around 30 percent of total land, are deemed especially favorable in terms of waste transportation and colored in green.
The map has also colored as suitable a part of Fukushima Prefecture, where reconstruction efforts are underway from the 2011 massive earthquake and tsunami that led to the Fukushima nuclear plant disaster.
But Seko said the government has no plans at this stage to burden the prefecture additionally with the issue of disposal of high-level radioactive waste.
The minister also indicated that Aomori Prefecture in northeastern Japan, home to a facility to reprocess nuclear fuel, is exempt as the prefectural government and state have agreed not to construct a nuclear waste disposal facility there.
Japan, like many other countries with nuclear plants, is struggling to find a permanent geological disposal repository, while Finland and Sweden are the only countries worldwide to have decided on final disposal sites.
A process to find local governments willing to host a final repository site started in 2002 in Japan, but little progress was made due mainly to opposition from local residents.
In 2015, the government decided to choose candidate sites suitable on scientific grounds for building a permanent storage facility, rather than waiting for municipalities to offer to host such a site.
The government aims to construct a site that can house more than 40,000 canisters, with estimated costs amounting to 3.7 trillion yen ($33 billion).