Remotely Controlled Machine for Biological Shield Concrete Dismantlement

The Japan Atomic Energy Research Institute (JAERI) has been developing necessary dismantling techniques to decommission the Japan Power Demonstration Reactor (JPDR) in the JPDR Decommissioning Program since 1981. A cylindrical geometric machine equipped with diamond sawing and coring units has been developed for activated biological shield dismantlement. This machine is suspended from a crane and moves within the inner cylindrical shaped wall fixes its position with built-in outriggers. Cutting process control and point-to-point control are used for automatic cutting. The paper summarizes current status of the biological shield, diamond sawing and coring technique and dismantling sequence, design of the machine, and a dismantling system.