Abstract: Rupture protection device for a steam generator of substantially cylindrical shape, includes a rupture protection enclosure for surrounding the steam generator, the enclosure including a base, a cover and a jacket formed of tension-resistant and compression-resistant material, and axially stressable connecting means for connecting the base, the cover and the shell to one another, the jacket being formed of substantially cylindrical sections, the cover being formed of a substantially concave divided spherical shell and an undivided bearing ring, the spherical shell having an outer rim surface, the bearing ring being formed with an inner ring surface corresponding to the outer rim surface, the spherical shell being braced as a separate structural member through the outer rim surface thereof against the inner ring surface of the bearing ring, the bearing ring forming part of a bracing assembly including the base, the cover, and the substantially cylindrical jacket through the intermediary of the axially stressab