Nuclear reactor shielding wall structure

A shielding wall of a nuclear reactor is formed entirely into a cylindrical shape by using an inner wall members made of steel plates and outer wall members made of the same steel plates, and disposed around a reactor pressure vessel placed at the center so as to surround the outer circumference thereof. A containing space is formed by the outer circumference of the inner wall members and the inner circumference of the outer wall members, and shielding members are filled into the containing space. As the shielding members, composite lead spheres comprising a surface layer made of lead at a predetermined thickness, and boron or boron compound contained therein is used. The shape may not always be spherical but may be indefinite. As the shielding members, iron spheres entirely comprising iron and lead sphere entirely comprising lead may be used in combination at a predetermined ratio. With such a constitution, reactor shielding walls can be constructed easily in a short period of time. (I.S.)