A dome was installed over Reactor No.1 in 2011 to stop radioactive particles from escaping into the atmosphere after the facility suffered a meltdown when a tsunami caused by a powerful earthquake crippled the Fukushima nuclear plant.
TEPCO began preparatory work to dismantle the protective cover over the Reactor 1 building in May. The preparations began with anti-dispersal agents poured through holes in the cover’s roof to prevent radioactive dust from escaping into the surrounding environment during the dismantling process.
Dismantling has been delayed several times due to technical failures.
Source: Sputnik News