Tokyo Electric Power Co. has set a goal of reducing airborne radiation levels outside its crippled Fukushima No. 1 nuclear power plant to one-eighth the current levels by the end of March 2016.
Tokyo Electric Power Co. has set a goal of reducing airborne radiation levels outside its crippled Fukushima No. 1 nuclear power plant to one-eighth the current levels by the end of March 2016.
TEPCO’s target of under 1 millisievert a year, part of its plans to decommission the reactors at the Fukushima No. 1 plant, was announced at a meeting with the Nuclear Regulation Authority on Feb. 14.
Annual levels of 8 millisieverts were found in December, mainly due to the effects from radiation-contaminated water kept in storage tanks on the plant site.
Radioactive strontium in the contaminated water emitted beta rays. A chemical reaction with the tank’s steel resulted in the production of X-rays, which accounted for the higher airborne radiation levels, according to TEPCO.
TEPCO officials said they would seek to reduce radiation levels due to contaminated water to under 1 millisievert per year by the end of March 2015. They said they would also take measures to reduce the levels from other sources, such as debris or the release of radioactive materials, to under 1 millisievert per year.
After reaching a combined annual level of under 2 millisieverts by March 2015, the utility will further reduce the total to under 1 millisievert by the following March, they said.
The figures are based on estimates of radiation effects only from the Fukushima No. 1 plant.