The progress of the Japan Power Demonstration Reactor (JPDR) dismantling activities: Dismantling the biological shield concrete by controlled blasting

In the Japan Power Demonstration Reactor (JPDR) decommissioning program, the controlled blasting technique has been applied to dismantling the relatively low radioactive part of the biological shield concrete. The dismantling activities started after removing highly radioactive components such as the reactor internals, the reactor pressure vessel and the protuberant part of the biological shield concrete. By September 1992, the dismantling of the inner layer, about 40 cm depth, was completed. All wastes were put into containers and these were stored in the waste storage facility in the Japan Atomic Energy Research Institute (JAERI). Various data on project management, waste arisings, radiation dose were collected from the work. Based on the data obtained, the controlled blasting technique was confirmed to be useful for dismantling the massive concrete structures in the reactor facility