At a Glance
- Treated water at a Japan nuclear plant must be cleaned further before it can be released into the ocean, the facility’s operator said Friday.
- Much of the water still contains several radioactive elements and therefore cannot be released.
- The Fukushima plant was badly damaged by a March 2011 earthquake and tsunami.
The treated water at a Japanese nuclear plant badly damaged by a March 2011 earthquake and tsunami will need to be cleaned even more before it can be released into the ocean.
Previously, Fukushima’s Tokyo Electric Power Co. and the Japanese government said all radioactive elements had been removed from the water except tritium, which is safe in small amounts, according to experts.
They referred to it as “tritium water,” but that’s not what it was.
TEPCO said Friday that studies found the water still contains other elements, including radioactive iodine, cesium and strontium. It said more than 80 percent of the 900,000 tons of water stored in large, densely packed tanks contains radioactivity exceeding limits for release into the environment.
TEPCO general manager Junichi Matsumoto said radioactive elements remained, especially earlier in the crisis when plant workers had to deal with large amounts of contaminated water leaking from the wrecked reactors and could not afford time to stop the treatment machines to change filters frequently.
“We had to prioritize processing large amounts of water as quickly as possible to reduce the overall risk,” Matsumoto said.
About 161,000 tons of the treated water has 10 to 100 times the limit for release into the environment, and another 65,200 tons has up to nearly 20,000 times the limit, TEPCO said.
Matsumoto said the plant will treat the water further to ensure contamination levels are reduced to allowable limits.
He was responding to growing public criticism and distrust about the status of the water.
More than 7 and a half years since a massive March 2011 earthquake and tsunami destroyed three reactors at the plant, Japan has yet to reach a consensus on what to do with the radioactive water. Fishermen and residents oppose its release into the ocean. Nuclear experts have recommended the controlled release of the water into the Pacific as the only realistic option.
The release option faced harsh criticism at town meetings in Fukushima and Tokyo in late August, when TEPCO and government officials provided little explanation of the water contamination, which had been reported in local media days earlier.
TEPCO only says it has the capacity to store up to 1.37 million tons of water through 2020 and that it cannot stay at the plant forever.
Some experts say the water can be stored for decades, but others say the tanks take up too much space at the plant and could interfere with ongoing decommissioning work, which could take decades.