Protective shell for nuclear reactor and method for assembling the shell

The method of assembling a hollow, substantially spherical shell for a nuclear reactor or the like comprising the steps of

• assembling a plurality of vertical cylindrical rings upon a base platform, said upper annular edges of said rings being in alignment with the spherical surface of said shell;
• joining spherical shell plate segments to the upper annular ring edges to form a lower spherical portion of the shell;
• joining additional spherical plate segments to form the lower hemispheric portion of said shell;
• assembling a vertical hoop on said lower hemispheric portion, said hoop having an outer radius commensurate with the inner radius of said spherical shell;
• temporarily securing spherical segments on and over said hoop to form a first vertical arch extending along the desired shape of the spherical shell from one side of the lower hemispheric portion to an opposite side;
• joining the segments of said first arch together and to said lower hemispheric portion;
• disengaging the hoop from said arch and then moving the hoop to an adjacent support position and joining a second vertical arch of spherical steel segments to each other, to said first vertical arch and to said lower hemispheric portion;
• and then repeating said arch forming steps until the upper hemispherical portion of the spherical shell has been formed on and joined to the lower hemispheric portion.

The method of assembling a hollow, substantially spherical shell for a nuclear reactor or the like comprising the steps of

• assembling a plurality of vertical cyclindrical steel rings upon a base platform;
• coupling a plurality of tie rods in a generally horizontal orientation between each of said rings to position the rings so that said upper annular edges of said rings are in alignment with the spherical surface of said shell;
• joining spherical shell plate segments to the upper annular ring edges to form a lower spherical portion of the shell;
• joining additional steel spherical plate segments to form the lower hemispheric portion of said shell;
• encircling the said lower hemispheric portion at about the equator of said spherical shell with a multiple of cable wraps;
• tensioning the cable to provide an inwardly directed force to reduce equatorial bulging of said shell;
• assembling a vertical hoop on said lower hemispheric portion, said hoop having an outer radius commensurate with the inner radius of said spherical shell;
• temporarily securing steel spherical segments on and over said hoop to form a first vertical arch extending along the desired shape of the spherical shell from one side of the lower hemispheric portion to an opposite side;
• joining the segments of said first arch together and to said lower hemispheric portion;
• disengaging the hoop from said arch and then moving the hoop to an adjacent support position and joining a second vertical arch of spherical steel segments to each other, to said first vertical arch and to said lower hemispheric portion;
• and then repeating said arch forming steps until the upper hemispherical portion of the spherical shell has been formed on and joined to the lower hemispheric portion.