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 and fixes its position with built-in outriggers. Cutting process control and point to-point control are used for automatic cutting. The paper summmarizes current status of the biological shield, diamond sawing and coring technique and dismantling sequence , design of the machine , and a dismantling system.