New robot for No.1 survey

February 24, 2017

Another robot survey to be tried at reactor

https://www3.nhk.or.jp/nhkworld/en/news/20170224_09/

The operator of the crippled Fukushima Daiichi nuclear plant says it will conduct another robot survey at a different reactor after one at its No.2 reactor failed earlier this month.

For the survey in March, Tokyo Electric Power Company will use a robot that is 70 centimeters long and less than 10 centimeters wide. It will move through a narrow pipe into the containment vessel of reactor No.1.

It will travel on grating inside the vessel. At 5 locations where there are openings, it is to drop a camera and dosimeter using a thin cable to probe deep inside the vessel.

Like some other reactors at the plant, fuel inside the No.1 reactor is believed to have melted down through the reactor core. The fuel is likely to have mixed with other materials used in the plant when it spread along the bottom of the vessel.

The vessel is also filled with contaminated water more than 2 meters deep. If the camera cannot capture images inside the water, engineers plan to estimate the spread of the debris from data to be obtained by dosimeter.

Engineers are eager to find any information on fuel debris through these robotic surveys as it is crucial to advance decommissioning of the crippled plant.