We have developed an automatic layout design system for piping and equipment using AI for the purpose of rationalizing nuclear plant costs, shortening the schedule, improving safety reliability, and maintaining design technology. This system automatically designs piping in the shortest distance, considering layout of the reactor building and equipment. In addition, a method was developed to design piping routes within a limited region. This allows piping to be automatically designed while strictly adhering to radiation control classification and safety classification according to the piping attributes. In addition, attributes can be assigned to structures, and differences in obstacles such as equipment, building frames, and access paths can be recognized. In addition, automatic design can be performed considering prohibited areas for piping installation, and designs can be performed that avoid equipment inspection spaces, passages, electrical equipment rooms, and areas near safety equipment. In addition, it can design considering walls, floors, ceilings, and columns, and functions for vertical wall penetration and wall approach have been developed. This system can automatically design several thousand piping in one day after setting the conditions, allowing efficient consideration of cost and process reduction. In addition, various functions can be used to comply with design rules and improve plant safety.