Companies and organizations in various fields, from the paint industry to space exploration, are testing technologies for the enormous task of decontaminating areas around the Fukushima No. 1 nuclear power plant.
Companies and organizations in various fields, from the paint industry to space exploration, are testing technologies for the enormous task of decontaminating areas around the Fukushima No. 1 nuclear power plant.
For example, Shiga Toso, a home-renovation company in Fukushima Prefecture’s Iwaki city, earlier this year used grinding machines to remove radioactive materials from the walls and roof of a two-story house in a residential area of Fukushima city.
The removed substances were absorbed in pipes connected to dirt collectors. The workers then repainted the walls and the roof.
Shiga Toso is testing a number of brushes for the grinders to determine which one is the best for removing radioactive substances. So far, the plastic brushes appear the most effective.
“Scraping off the roof, collecting powder and dust, and applying paint are the jobs of painting companies,” said Masafumi Shiga, 38, president of Shiga Toso. “If we apply high-pressure cleansing or grinders and do nothing after that, the blemishes will remain. As a result, dust or radioactive materials can easily reattach (to the surfaces).”
Shiga said decontamination is a business field close to paint application, and his company applied for the government’s program to find technologies effective for such work.
The Cabinet Office commissioned the government-affiliated Japan Atomic Energy Agency to acquire technologies from companies and organizations for the decontamination effort. The agency received 305 proposals, and selected 25, including Shiga Toso’s.
Another company whose technology was chosen is Koriyama Chip Industry Co., based in Koriyama, Fukushima Prefecture.
The company cleans and burns tree bark left over from sawmills and wood-chip production. The bark is generally used for compost to improve the soil of farmlands or forests.
However, bark has become contaminated with radioactive cesium from the Fukushima No. 1 nuclear power plant, scaring away buyers.
Koriyama Chip processes about 700 tons of bark every month. For now, the company is compressing the bark and storing it within the company’s compounds.
“We are facing big trouble (due to the growing amount of bark). It is an issue of critical importance to find a method to dispose of the bark,” said Masatoshi Ouchi, 64, president of the company.
Koriyama Chip is testing a method of cutting bark into small similar pieces and burning them in a furnace, which reduces the bark to about one-20th the original size.
The ashes that remain after the burning are placed in a sealed depository, and radioactive cesium released in the smoke is collected with a special filter.
Masamichi Yamashita, 63, a professor at the government-affiliated Japan Aerospace Exploration Agency (JAXA), is trying to see if his studies on living on other planets could be useful in Fukushima Prefecture.
Yamashita proposed a test using bacteria that ferment in high temperatures. These bacteria are expected to decompose grass and withered leaves that pile up as a result of the decontamination work.
Yamashita has studied systems involving the complete recycling of products for human life in an exploration base on Mars.
Mainly, the studies involved disposing of kitchen refuse and feces, which can be decomposed by bacteria that ferment in high temperatures.
The bacteria can work quickly in temperatures close to 100 degrees, which results in sterilization, and are expected to reduce the amount of kitchen refuse and feces to 1 percent of the original amount, Yamashita said.
After the accident at Fukushima No. 1 nuclear power plant, the professor said he saw agricultural products piled up in corners of farmlands.
“If the studies I have conducted for the future of 100 years later can be utilized now, it would be a great pleasure for me,” Yamashita said.
(This article was written by Shunsuke Kimura and Takashi Sugimoto.)