The decommissioning program of the Japan Power Demonstration Reactor (JPDR) is under way. For the purpose of dismantling the biological shield of the JPDR, a diamond sawing and coring technique and an abrasive-water jet cutting technique have been developed. In the technical development, the influence of various factors on the cutting performance and the characteristics of secondary products were investigated. As a result, remote cutting systems that incorporated these techniques were fabricated for the dismantlement of the highly activated region of the biological shield.