Modular heat exchangers for consolidated nuclear steam generator

A group of modular heat exchangers each of the heat exchangers comprising a steam header, a feedwater header spaced from the steam header, said headers each forming respectively a steam chamber and a feedwater chamber, a feedwater tube that passes through the steam chamber to establish fluid communication with the feedwater chamber, a shroud positioned around the feedwater tube, said steam header and feedwater header having surface recesses for confining the shroud, a feedwater manifold and coiled feedwater manifold tubing in fluid communication with the feedwater manifold and the shrouded feedwater tube in at least some of the modular heat exchangers.