Looking at the pair of yellow tubing running back to the operator station, I am thinking he is using a PARC System (Portable Apparatus for Radiation Control) http://www.cetmedway.co.uk/parc.php edit: looks like the hand device by his feet open the shutter to the rad source and the Geiger counter assures him when the source is closed. jmo
My posts are my opinions. Always dd to your own comfort level.