Nuclear reactor pressure vessel for nuclear reactors with plastically deformable spacers

Claim 1

Cylindrical pressure vessel structure for nuclear reactors comprising a steel pressure vessel adapted to receive therein a pressurizing medium, said steel pressure vessel, during operating condition thereof wherein said steel pressure vessel is heated and pressurized, being expansible, an outer concrete enclosure, said steel pressure vessel being mounted within said outer concrete enclosure in unheated and unpressurized condition and being radially and axially spaced from said outer concrete enclosure, and a supporting and insulating layer secured in the radially extending space between said steel pressure vessel and said outer concrete enclosure in radially spaced-apart relationship to both said steel pressure vessel and said outer concrete enclosure, a layer of concrete interposed in the radial spacing between said supporting and insulating layer and said outer concrete layer, said layer of concrete being produced in situ by solidification of a matrix thereof poured into the radial spacing between said supporting and insulating layer and said outer concrete enclosure, said supporting and insulating layer having support plates on the side thereof adjacent said steel pressure vessel, spacer members connected with said support plates and having projections extending beyond the surface of said support plates in direction toward said steel pressure vessel, said spacer members defining a given radial spacing of said support plates from said pressure vessel, said spacer members being unyieldable against radial forces produced during solidifcation of said layer of concrete interposed in the radial space between said supporting and insulating layer and said outer concrete enclosure, so as to maintain said given radial spacing of said support plates from said pressure vessel, said spacer members being yieldable, however, to radial forces applicable thereto by said expansion of said pressure vessel during said heated and pressurized condition thereof, so that said projections of said spacer members plastically deformed to permit the expanding pressure vessel to expand into the radial spacing between said pressure vessel and said supporting and insulating layer and bear against said outer concrete enclosure through the intermediary of said deformed spacer members, said supporting and insulating layer and said layer of concrete.