It was hoped that the so-called "dream reactor" would burn a plutonium-uranium mix that would yield more plutonium. But the dream remains elusive and the plant faced too costly upgrades in the post-Fukushima era.
Japan has decided to pull the plug on its so-called "dream reactor" that was designed to burn a plutonium-uranium mixture, while producing more plutonium in the process, which, it was hoped, could be converted into more nuclear fuel.
But the Monju nuclear plant cost 20 billion yen ($170 million, 163 million euros) per year, and over its 22-year lifetime, it operated just 250 days. And its operating costs were about to go up.
The reactor would have required costly upgrades to meet new safety standards that were implemented after the meltdown at Japan's Fukushima reactor in 2011.
That plant was flooded by a tsunami that was triggered by an earthquake. It was the world's worst nuclear disaster since the 1986 meltdown at the Chernobyl reactor in Ukraine.
Japan's upgrades would cost hundreds of billions of yen, and the government - led by the Liberal Democratic Party - believes
The plant has also been plagued by accidents, missteps and scandals involving falsification of documents.
The government "will not restart (Monju) as a nuclear reactor and will take steps to decommission it," Science Minister Hirokazu Matsuno told the governor of western Japan's Fukui prefecture where it is located.
Governor opposes decision
Fukui governor Issei Nishikawa, who was informed of the decision by Matsuno and Industry Minister Hiroshige Seko, criticized the decision as "fast and sloppy."
"I don't think there were sufficient deliberations," Nishikawa added.
Some local governors in Japan have opposed the restart of the reactors, but others support the plant's operation because of the economic benefits and jobs nuclear technology brings their regions.
The Fukui government, for example, has been cooperative, partly in return for financial support from Tokyo.
Despite the decision to scrap Monju, the government has not completely given up on fast nuclear breeder technology.
The area around the Monju facility will be turned into a research center for nuclear technology, including plans to explore a different type of fast breeder reactor, according to the Science Ministry.
The ministry said the reactor will remain "a long-term project" that will also involve international joint research.
The government decision will not affect Japan's nuclear recycling policy as Tokyo plans to continue to co-develop a fast-breeder demonstration reactor that has been proposed in France, while research will continue at another experimental fast-breeder reactor, Joyo, which was a Monju predecessor.
"The move will not have an impact on nuclear fuel balance or nuclear fuel cycle technology development or Japan's international cooperation," said Tomoko Murakami, nuclear energy manager at the Institute of Energy Economics, Japan,
bik/sms (AP, AFP, Reuters)