Shortening and management of construction schedule for nuclear power plants

Japan in now in Phase II increasing period for building nuclear power plants. Since atomic energy is the most promising alternative energy source, its early development is a national requisite. The necessity for shortening the construction schedule also increased from the viewpoint of construction cost. Hitachi Ltd. has continued the efforts for improving construction methods and management from the early stage of atomic energy use. The shortening of construction schedule has been investigated by dividing the full process into five stages. It also requires to exactly control the delivery time of products so that the equipment to be installed can be carried in the site at the desired time over the entire construction period. Improvement of construction method which have resulted in the construction schedule shortening includes the early start of PCV assembling on the ground by vertical digging, the outdoor installation and the adoption of large capacity of tower cranes for machinery installation works, advancing the equipment and piping works by deck plate working method, the prefabrication of reactor building pool liners using large panels, the factory-assembling of reactor inner structure, the modularization of equipment and piping, and Hitachi Cabling Techniques (HICAT) for advancing cabling and the employment of multicore cables. The kernel of construction management system is the Big Project Management System (BPMS) which implements the overall work-term management synchronized with the site installation schedule, comprehensive project management with computers, and resulting data collection. (Wakatsuki, Y.)