"Dry" method for fuel removal not so easy

August 2, 2017

NRA chief: Fuel debris removal method is not easy

https://www3.nhk.or.jp/nhkworld/en/news/20170802_28/

The chief of Japan's Nuclear Regulation Authority has said it is "far from easy" to retrieve nuclear fuel debris from the damaged Fukushima Daiichi power plant using the "dry removal" method. A government body has recommended using the process.

NRA Chairman Shunichi Tanaka spoke to reporters on Wednesday about the method proposed by the Nuclear Damage Compensation and Decommissioning Facilitation Corporation earlier this week. The government body is considering how to decommission 3 reactors of the Fukushima plant. They suffered meltdowns in the 2011 nuclear accident.

Removing nuclear fuel debris, which is believed to be at the bottom of containment vessels, is considered the biggest hurdle in decommissioning the reactors.

Officials of the corporation initially considered filling the containment vessels with water to block high levels of radiation given off by the debris. But on Monday they said the "dry removal" process should be predominantly considered. It does not fill the vessels to the upper levels with water.

Tanaka noted that it is common for nuclear fuel to be stored and transported underwater to block radiation.

He said it is very difficult to handle nuclear fuel that gives off a massive amount of radiation. Tanaka said simply retrieving the debris from the vessel will not end the difficulties. He added that once nuclear fuel is exposed to air no one can stay nearby.

Tanaka stressed that finding ways to block the extremely high levels of radiation is crucial.