Present situation and outlook in improvement and standardization of LWR power plants

Jointly by academic societies, power firms and nuclear plant manufacturers, the improvement and standardization of light water reactor power plants have been forwarded in stages, considering the advances in LWR technology. Four types were chosen, i.e. BWR and PWR, each of 800 MW and 1100 MW levels. In the first stage from fiscal 1975 to 1977, by increasing the size of containment vessels, the reduction of personnel radiation exposure and the increase in work efficiency were achieved. In the second stage from fiscal 1978 to 1980, by improving the components and systems, the reduction of personnel radiation exposure and the rise in the rate of operation were achieved, and the standardization was further extended to aseismic design and plant peripheries. The third stage with the technology of Japan proper and in international cooperation started in fiscal 1981 as the five-year project. (J.P.N.)