[en] In advanced boiling water reactor type power generation facilities, the function of pressure restriction, the layout of equipment and piping, the economical efficiency, the construction workability and others were evaluated under the basic condition of adopting internal pumps, and as the result, for the first time in the world, the adoption of a cylindrical reactor containment vessel made of reinforced concrete into one body with a reactor building has been examined. In this reactor building containing the reactor containment vessel, the rationalization of the building structure by the one-body construction with the reactor containment vessel, the reduction of the space for installing equipment by the rationalization of the facilities placed in it, the common use and rationalization of maintenance and checkup space and so on were carried out, and the decrease of the volume in the reactor building and the shortening of its construction process were planned. The outline of the cylindrical reactor containment vessel and the decision of its form, the examination on the main specification of the containment vessel, the adoption of a horizontal vent pipe for pressure restriction, the access tunnel for the lower dry well, and the layout in the reactor building are reported. (Kako, I.)