Patent Number: 
Section: claims

1. A building used for a nuclear power plant, wherein a wall portion which forms at least a part of said building is formed from a megawall structure of steel plate reinforced concrete construction that is composed by pouring concrete into megablocks composed of outer shell steel plates having a height equivalent to the plurality of floors of said building, and wherein an equipment module which is composed of steel frames formed by support columns that have a height equivalent to the plurality of said floors and function as columns inside said building and floor frames that are supported by said support columns and function as floors in said building, and various types of equipment to be installed in said building that are previously provided in said steel frames along with their ancillary piping, is provided in the building. 2. A building according to  claim 1 , wherein said equipment module being self-standing in said building, and the horizontal force that acts on said equipment module is supported by a structural member of said building which surrounding said equipment module. claim 1 3. A building according to  claim 2 , wherein said structural member surrounding the equipment modules is composed of said megawall structure of steel plate reinforced concrete construction that is composed by pouring and filling concrete into said megablocks composed of said outer shell steel plates. claim 2 4. A building according to  claim 1 , wherein said wall portion is a wall member which forms an outer peripheral wall of said building. claim 1 5. A building used for a nuclear power plant, wherein a wall portion which forms at least a part of said building is formed from a megawall structure of steel plate reinforced concrete construction that is composed by pouring concrete into megablocks composed of outer shell steel plates having a height equivalent to the plurality of floors of said building, and wherein said building is a reactor building comprising a containment vessel and a ring-shaped pool that employs a top slab of said containment vessel for its bottom, and said pool is integrally provided with said containment vessel by extending a peripheral wall of said containment vessel upward to form a pool outer peripheral wall that has a cylindrical shape when viewed from overhead and by providing a pool inner peripheral wall on said top slab so as to be concentric with said pool outer peripheral wall. 6. A building according to  claim 5 , wherein said containment vessel and pool are composed of said megawall structure of steel plate reinforced concrete construction that is composed by pouring and filling concrete into said megablocks composed of said outer shell steel plates. claim 5 7. A building according to  claim 5 , wherein said containment vessel and pool outer peripheral wall are separated from a peripheral structural member and made to stand alone. claim 5 8. A building according to  claim 6 , wherein said containment vessel and pool outer peripheral wall are separated from a peripheral structural member and made to stand alone. claim 6 9. A building according to  claim 5 , wherein said wall portion is a wall member which forms an outer peripheral wall of said building. claim 5 10. A building according to  claim 7 , wherein said structural member surrounding the equipment modules is composed of said megawall structure of steel plate reinforced concrete construction that is composed by pouring and filling concrete into said megablocks composed of said outer shell steel plates. claim 7 11. A building according to  claim 8 , wherein said structural member surrounding the equipment modules is composed of said megawall structure of steel plate reinforced concrete construction that is composed by pouring and filling concrete into said megablocks composed of said outer shell steel plates. claim 8