Patent Number: 044903286
Section: description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The bottom shield, generally designated 10 and arranged underneath the reactor core, not shown, consists essentially of an upper thin plate 12 and a lower thick plate 14 placed concentrically around a socket 16. The lower plate 14 is held at a distance from the bottom liner 20 of the prestressed concrete pressure vessel 22 by means of the lower bearing supports 18 distributed over the entire surface. The upper plate 12 is held at a distance from the lower plate by means of uniformly distributed bearing supports 24. The lower plate 14 is surrounded by a supporting ring 26 and is equipped with passage orifices 28, distributed over the entire surface for the cooling gas. The upper plate 12 is provided on its bottom side with a plurality of cooling ribs 30 in a distribution over its entire surface. Its surface has either a waffled surface 32 or a flat layer consisting of sheet metal sections 34. Expansion gaps 36 are provided between the sheet metal sections. The latter are secured by means of studs 38. The upper and lower plates 12 and 14 are composed of circular segments 40, 41, joined with each other along the concentric and overlapping partition seams 42 by means of pins 46, 47. The support ring 26 surrounding the lower plate 14 is also composed of segments 48 connected with each other at the partition seams 51 by means of pins 50. The specification and drawings set forth preferred embodiments of the invention. It should be noted, however, that the invention is not limited to those specific embodiments and methods specifically disclosed, but extends instead to all embodiments, substitute and equivalent constructions falling within the scope of the invention as defined by the claims.