Engineers have reached the critical stage of starting to remove the graphite core in the UKAEA's Windscale Advanced Gas-cooled Reactor. The removal of the core involves the dismantling of eight layers of interlocking graphite blocks held together by steel restraint bands and interlaced by thermocouple wires and flux scanning tubes. Because of the high radiation within the core area the work will be carried out remotely. The restraint bands will be cut into pieces using a reciprocating saw deployed by a specially adapted manipulator, being used to its full extent for the first time during the programme on WAGR.
The manipulator, deploying a combined shear and gripper tool, will also be used to remove the thermocouple wires and flux scanning tubes. The waste material from this phase of the campaign is all classified as intermediate level and will be encapsulated in concrete waste boxes and taken to the specially constructed ILW store on site. The graphite core moderated the nuclear reaction during WAGR's working lifetime from 1963-1981. There are 3,344 rectangular bricks making up the graphite core weighing a total of 210tonnes.