Abstract: The reactor pressure vessel comprises a pipe socket (2) connected to a feed-water supply line (3), in which is disposed a coaxial protective sleeve (5) (thermal sleeve) which expands with changes in temperature. With its outer end the protective sleeve (5) slidably abuts the pipe socket (2) and with its inner end it is connected to a feed-water distributing ring situated in the vessel. A pipe section (10), in which bellows (15) are disposed, is inserted between the outer end of the pipe socket (2) and the feed-water supply line (3). With one end the bellows (15) are tightly connected to the outer end of the protective sleeve (5) and with their other end they are tightly connected to the pipe section (10).