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Struggling With Japan’s Nuclear Waste, Six Years After Disaster

Thousands of plastic garbage bags sit in neat rows in the fields and abandoned towns surrounding the Fukushima plant. They contain soil that was scraped from land that was exposed to radiation in the days after the accident.

Japan’s Ministry of the Environment estimates that it has bagged 3.5 billion gallons of soil, and plans to collect much more. It will eventually incinerate some of the soil, but that will only reduce the volume of the radioactive waste, not eliminate it.

The ministry has already begun building a massive, interim storage facility in Fukushima prefecture and negotiating with 2,360 landowners for the thousands of acres needed to complete it. And that is not even a long-term solution: The government says that after 30 years it will need another site — or sites — to store radioactive waste.

1,573 Nuclear Fuel Rods

Photo

A pool at the facility for storing spent fuel rods. Credit Ko Sasaki for The New York Times

The ultimate goal of the cleanup is to cool and, if possible, remove the uranium and plutonium fuel that was inside the three reactors at the time of the disaster.

Hundreds of spent fuel rods are in cooling pools inside the reactors, and the company hopes to have cleared away enough rubble to begin removing them next year. The much bigger challenge will be removing the fuel that was in use in the reactor core at the time of the meltdown.

The condition and location of this molten fuel debris are still largely unknown. In one reactor where a robot was sent in January, much of the melted fuel is believed to have burned through the bottom of the inner reactor vessel and burrowed into the thick concrete foundation of the containment structure.

The plan is to completely seal the containment vessels, fill them with water and use robots to find and remove the molten fuel debris. But the rubble, the lethal levels of radiation and the risk of letting radiation escape make this an exceedingly difficult task.

In January, the robot sent into one of the reactors discovered radiation levels high enough to kill a person in less than a minute. Another had to be abandoned last month after debris blocked its path and radiation disabled it.

Tokyo Electric hopes to begin removing fuel debris from the reactor cores in 2021. The entire effort could take decades. Some say the radioactive material may prove impossible to remove safely and have suggested leaving it and entombing Fukushima under a concrete and steel sarcophagus like the one used at Chernobyl.

But the Japanese government and Tokyo Electric say they are committed to removing all the waste and cleaning the site, estimated at a cost of $ 188.6 billion.

“We want to return it to a safe state,” said Yuichi Okamura, general manager of the company’s nuclear power and plant siting division. “We promised the local people that we would recover the site and make it a safe ground again.”

Source: NYT > World

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