A snake-shaped robot and four drones are set to be dispatched in February to survey the damage at Fukushima Daiichi’s Unit 1 reactor, almost 13 years after its core melted down and triggered a hydrogen blast in one of the worst nuclear disasters in history.

Although robots have surveyed the submerged interior of the Unit 1 reactor’s containment vessel, this would be the first time a drone would enter the vessel to provide a fuller picture of the damage above water, according to Tepco.

Tepco hopes the images from the drone will help assess how the melted fuel debris could be removed.

The snake-shaped robot that will explore the nuclear containment vessel and help survey the damage at Fukushima Daiichi. (PHOTO: Reuters)

“We will make sure to conduct this investigation with a safety-first mindset, checking the procedures and instructions one by one and ensuring safety at all times,” a Tepco spokesperson said.

The nuclear reactor in Unit 1 was the first to start melting down after a massive tsunami struck the east coast of Japan in March 2011.

It is believed to be the most severely damaged out of the four reactors that were operating that day, and Tepco is still in the process of trying to understand the extent of the damage and how to remove the molten fuel - a process that experts say will take decades.

(Reporting by Sakura Murakami and Tom Bateman; Editing by Kim Coghill)

First of four giant cooling towers collapsed at RWE-owned Biblis nuclear plant in Germany 15,000 t of rubble to be recycled after dismantling of 80 m (262 ft) tower