‘Snake’ robot to test nuclear plant

A snake-like robot designed to examine the inside of one of three melted reactors at the Fukushima Dai-ichi nuclear plant is ready to begin its expedition.

Assessing the damage inside the reactors is a crucial step in decommissioning the plant, which was badly damaged by a 2011 earthquake and tsunami. Use of a remote-controlled robot is essential because no humans can go close to the reactor chambers because of their fatally high radiation levels.

Operator Tokyo Electric Power plans to repair the damaged chambers enough so they can be filled with water in preparation for the removal of melted radioactive debris, in a decade.

The 2ft-long robot, developed by electronics giant Hitachi and its nuclear affiliate Hitachi-GE Nuclear Energy, was demonstrated this week.

It has a lamp at the front and is designed to crawl like a snake through a 4in-wide pipe into the containment vessel. From there it must dangle and descend on to a steel-mesh platform just below the reactor core.

There, the robot will transform into a U-shape auto-drive crawler and capture live images and temperature and radiation levels and transmit them to a control station outside the building.

Because of the reactor damage, large volumes of cooling water continue to leak, causing contamination and hampering the plant’s clean-up process.