Pod-mounted steam generator for gas-cooled nuclear reactor - has layout which minimises thermal expansion effects and facilitates tube-testing

摘要

A shrouded set of vertical concentric tube-pairs is suspended from a support-plate, and horizontal gas entrance and exit points are at the liner top and bottom respectively. A coaxial connection is made through the prod lid. for live steam (inner) and feedwater (outer). At the boiler these ducts terminate in headers above the support-plate. The higher (water) header's bottom surface is perforated and has the inner tubes of the concentric pairs welded to it at the perforations, and is positioned immediately over the steam header which bears directly on the support-plate, and has welded to it similarly outer tubes of the concentric pairs. The concentric tube-pairs are readily supplied as pre-fabricated modules at relatively low cost, while the the proposed method for suspending these allows thermal expansion to take place freely. The design also allows pod walls to be insulated in order to avoid thermal stresses.