The Tokyo Electric Power Company announced Monday a revised schedule for decontaminating water at the Fukushima Daiichi nuclear power station, claiming it would have 90 percent of the water treated by the end of May.
"We are re-evaluating the risks of not just contaminated water, but all factors including solid waste, liquid and airborne risks," Chief Decommissioning Officer Naohiro Masuda said in a statement. "Even if some contaminated water remains, I feel that we can reduce a substantial amount of risk."
The company had originally projected it would treat all contaminated water on the site by the end of March, but in January it announced that it would need more time. In a statement, the company blamed “challenges of implementing new technologies” and a “safety first” approach as slowing down the water treatment process.
The new targets call for most of the remaining water to be treated by the end of May. This includes:
・Water which has had strontium and other contaminants removed through the multi-nuclide removal system.
・Contaminated water treated in the days when the multi-nuclide removal systems had encountered performance issues and which needs to be treated again to further remove contaminants.
・Strontium-removed contaminated water which requires treatment through the multi-nuclide removal system to further remove contaminants.
What will remain is water with “relatively high levels of seawater components,” the company said, pointing out that seawater was used to cool the reactors immediately following the earthquake and tsunami events that crippled the plant in March 2011. Seawater, however, requires a slower treatment process than fresh water, TEPCO said.
It will take “several more months" to treat the seawater, said TEPCO.
About 300 tons of groundwater that seeps into the reactor buildings each day and 100 tons of well water used at the plant will be treated “on a daily basis,” TEPCO said.
In addition, there is some residual water at the bottom of each storage tanks that cannot be pumped out with the current systems. This will be treated when the storage tanks are decommissioned.