Completion of Kashiwazaki Kariwa Nuclear Power Station Unit No. 4

No. 4 plant in Kashiwazaki Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc. is a BWR plant in which the results of the LWR improvement and standardization project by Japanese independent technology were adopted. Hitachi Ltd. has applied the experiences of construction and operation obtained so far, the improved technology based on research and development and the latest technologies to it, in addition to the technology which was verified in the preceding No. 5 plant. In the aspect of the systems and facilities, the various improvements based on the experience in past plants were reflected from the initial stage of design. Also in the design techniques, the three-dimensional CAD system using the newest computer technology was applied to the layout and piping design, and the quality and efficiency of design were improved. In the aspect of construction, a crawler crane with the largest lifting capacity in the world was used, and the large section module method, by which large prefabricated machinery, equipment and piping are directly lifted in, was applied. By these means, the safety of workings was secured, the construction period was shortened, and the plant showed good, stable results in the trial, and started the commercial operation in August, 1994. No. 4 plant is a BWR plant of 1100 MW output. The applied new technologies and the contents of the improvement of the design and facilities are shown. The outline and the features of the construction works and the trial operation are reported. (K.I.)