[en] In the decommissioning planning stage, it is important to select the optimized decommissioning process considering the cost and safety. Especially the selection of the optimized decommissioning process is necessary because it affects to improve worker's safety and decommissioning work efficiency. The decommissioning process evaluation technology can provide the optimized decommissioning process as constructing various decommissioning scenarios and it can help to prevent the potential accidents as delivering the exact work procedures to workers and to help workers to perform decommissioning work skillfully. It's necessary to measure the radioactive contamination in the highly contaminated facilities such as hot-cells or glove-boxes to be decommissioned for decommissioning planning. These facilities are very high radiation level, so it is difficult to approach. In this case the detector system is preferable to separate the sensor and electronics, which have to locate in the facility outside to avoid the electric noise and worker's radiation exposure. In this project, we developed the remote detection system for radiation measurement and signal transmission in the high radiation area. In order to minimize worker's exposure when decommissioning highly activated nuclear facilities, it is necessary to develop the remote handling tool to perform the dismantling work remotely. Especially, since cutting, measuring, and decontamination works should be performed remotely in the highly activated area, the remote handling tool for conducting these works should be developed. Therefore, the multi-purpose dismantling machine that can measuring dose, facility cutting, and remote handling for maintenance and decommissioning of highly activated facility should be needed