A problem of space

April 21, 2014

Storage space for nuclear waste an issue for Japan's smaller plants

http://mainichi.jp/english/english/newsselect/news/20140421p2a00m0na004000c.html 

FUKUSHIMA -- Disaster-related equipment and facilities at the Fukushima No. 1 Nuclear Power Plant already take up more space than the entire grounds of most regular nuclear plants in Japan, it has been learned.

The finding has sparked concern that other nuclear power plants may not have enough space to cope with a similar nuclear disaster.

The grounds of the Fukushima plant, where two additional reactors were originally due to be built, span 3.5 million square meters. Before the disaster, over 90 percent of this property was unused.

Roughly 2.55 million square meters is now devoted to the disaster response, outsizing the grounds of 13 of the 16 regular nuclear power plants in Japan. Meanwhile, contaminated water continues to pile up at the plant at the rate of 400 tons per day.

Nuclear plants are required to store radioactive waste on their own premises in the event of a nuclear accident if they receive a special designation under the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors, as the Fukushima plant did.

The Mainichi asked the 10 major power companies that operate Japan's 16 regular nuclear plants how much space each plant could devote to an accident response. Only Shikoku Electric Power Co. replied, saying its Ikata Nuclear Power Plant had 440,000 square meters available. When the Mainichi looked up the areas of the other plants, it found that 13 of them were smaller than the space being used at the Fukushima No. 1 plant.

About 1,000 tanks have been set up to hold contaminated water at the Fukushima plant.

Decontamination equipment like the Advanced Liquid Processing System (ALPS) has also been prepared. Additional water storage tanks and facilities to store high-density waste removed by the ALPS are expected to be necessary in the future. Tokyo Electric Power Co. (TEPCO), the plant's owner, has said it plans to devote about another 700,000 square meters of unused land to the response.

When the Mainichi asked other plant operators how they would respond to a disaster, Japan Atomic Power Co. -- owner of two nuclear plants including Tokai No. 2 Nuclear Power Plant, the smallest of Japan's regular nuclear plants -- and Kansai Electric Power Co., which operates three nuclear plants including the Mihama Nuclear Power Plant, refused to comment on what they said was a hypothetical scenario.

Many other companies stressed that they had taken such measures as preparing against tsunamis and securing backup power sources. A representative for Chubu Electric Power Co. said, "We are determined to avoid an accident like the one at the Fukushima No. 1 Nuclear Power Plant."

A representative for Shikoku Electric Power Co. stressed that the plant could handle an accident, saying, "Even if we had an issue with contaminated water, there would be little flow of underground water (into the nuclear reactor buildings)."

Shigeaki Tsunoyama, former dean of the University of Aizu and overseer of decommissioning work on the Fukushima No. 1 Nuclear Power Plant, said, "The Fukushima disaster taught us that power companies should prepare for the leak of radioactive material. Part of that involves preparing for contaminated water. Power companies should publicly announce how much area they can devote to a disaster response and discuss how much they would be able to do within the boundaries of their plants."

Around 15 minutes by car from the "important seismic isolated building" at the Fukushima No. 1 Nuclear Power Plant are the cylindrical, two-meter tall "High Integrity Containers" (HICs) that hold radioactive material removed from contaminated water. The plant has over 120 HICs, stored within concrete facilities stretching around 200 meters long. Within each HIC are 260,000 becquerels of cesium-134, 360,000 becquerels of cesium-137 and 70 trillion becquerels of strontium. Each year the plant is expected to set up 600 to 700 more HICs.

At the ALPS building around 10 minutes away by car from where the HICs are located, a worker who was involved with the quake-resistance evaluation of the Kashiwazaki -Kariwa Nuclear Power Plant before the March 11, 2011 disasters commented, "This is the first time in the world that attempts have been made to process this much contaminated water."

Another 15-minute drive from the ALPS building is a temporary storage site for debris from the hydrogen explosions at the Fukushima plant, which is covered with dirt. North of the plant's No. 5 and 6 reactor buildings is an expanse of logged and prepared land that is to be the site of new, welded storage containers for contaminated water. These tanks are expected to grow in number by one per every two to three day, and they each will measure 8.1 meters in diameter and 15.6 meters in height.

A TEPCO employee added, "The radiation suits are thrown out after use, so the more workers that come on-site, the more radioactive waste (contaminated radiation suits) there will be. If we don't think of a fundamental countermeasure, we will eventually run out of space on the plant grounds."

April 21, 2014(Mainichi Japan)