Laser technology developed to crush fuel debris in reactors

9 September 2016

The Japan Atomic Energy Agency, Hitachi-GE Nuclear Energy Ltd. and Sugino Machine Ltd. have jointly developed new laser technology to safely and effectively crush melted fuel debris for removal from inside the reactors at Tokyo Electric Power Co.'s Fukushima Daiichi nuclear power plant.

Announcing it at the fall meeting of the Atomic Energy Society of Japan held on Sept. 8 in Kurume, Fukuoka Prefecture, a research group of the three parties said the new technology is ''highly adaptable to decommissioning work'' as water is sprayed while a laser beam moves and cuts debris to prevent contaminated dust from dispersing.

Melted fuel debris is believed to have solidified together with structures inside the reactors, but its shape and position are unknown. If it is a huge mass, it needs to be crushed into small removable pieces. The new technology allows cutting any thickness of the debris, and clears the three operation conditions inside the reactors, including water-filled and no-water spaces, set by Nuclear Damage Compensation and Decommissioning Facilitation Corp.

Laser technology enables smaller devices compared to cutting methods using knives and drills, and can be much more easily remote-controlled in narrow spaces inside the reactors. It also does not cause such trouble as nicking of edges and being jammed.

The three parties are aiming at realizing the technology's practical use by establishing methods to collect water and dust generated in the crushing process.

(Translated by Kyodo News)