TOKYO -- Work to remove melted nuclear fuel from the Fukushima Daiichi nuclear power plant will proceed as scheduled, starting in 2021, the government said Thursday.

According to a revised blueprint on plant decommissioning, the fuel debris inside the three reactors, which suffered a meltdown in 2011 after being disabled by a tsunami, will be removed by inserting robot arms into the side of the containment structure of each reactor. 

To shield the robots from the intense radiation, the structure will be kept flooded and the debris will be kept submerged in water, which helps block radiation.

The release of the blueprint came after Tokyo Electric Power (Tepco), the operator of the plant, succeeded in July in capturing images of melted fuel inside one of the three crippled reactors.

An underwater robot was used to survey inside the containment structure of the No. 3 reactor, according to Tepco.

Similar surveys were attempted on the No. 1 and No. 2 reactors from January to March, without success, due to obstacles that hindered the robots and high levels of radiation.

The Nuclear Damage Compensation and Decommissioning Facilitation Corporation, the government body overseeing the decommissioning process, as well as Tepco, say that removing the debris is not feasible without detailed information on its whereabouts.

An earlier blueprint, put together by the government and Tepco, also called for debris removal to begin in 2021. But delays in surveying the reactors had led some to question the plan's feasibility.

The blueprint provides an input for the government to produce a more concrete road map, due out next month, which will spell out specific steps toward fuel removal -- the biggest challenge to the ultimate goal of decommissioning the Fukushima Daiichi plant.

(Nikkei)