Steam generator coolant reservoir and method for manufacturing same

The invention relates to the electric power industry and may be used in horizontal steam generators of nuclear power plants having a water-cooled, water-modified reactor. Claimed is a primary loop coolant reservoir for a steam generator, which has a horizontal heat exchange bundle with U-shaped tubes and is in the form of a welded, thick-walled vessel having: a perforated middle cylindrical portion capable of having installed and secured therein a bundle of U-shaped heat-exchange tubes which are formed into packets and are separated, within the bundle, by vertical inter-tube corridors; a lower cylindrical portion, capable of being welded to a fitting on the steam generator housing; and an upper cylindrical portion, having a tapered transition to a flanged connection between an access port and a cover. Wherein, apertures for securing the heat-exchange tubes are provided in the middle cylindrical portion of the reservoir, in a checkerboard pattern, in such a way that the horizontal distance between the edges of