Patent Number: 053923235
Section: summary

The invention relates to a reactor pressure vessel in a nuclear power station, having at least one pipe socket connected to a feed-water supply line, in which a coaxial protective sleeve (thermal sleeve) expanding with changes in temperature is disposed, which with its outer end slidably abuts the pipe socket and with its inner end is connected to a feed-water distributing ring situated in the pressure vessel. In reactor pressure vessels of this type cold feed-water is conveyed via the feed-water supply line into the distributing ring, from which it then overflows into hot reactor water, which is situated in the remaining space of the vessel. Between the end of the protective sleeve slidably abutting the pipe socket and the pipe socket, cold feed-water can overflow into an annular gap which is situated between the protective sleeve and the pipe socket and is filled with hot reactor water. By the coming together of hot reactor water and cold feed-water in this annular gap, thermal stresses can be produced in the pipe socket, which then may result in cracks in the material of the pipe socket. With regard to the regulations on the safety of the reactor, such cracks should be avoided. The object of the invention is to improve the reactor pressure vessel of the type mentioned at the beginning so that cracking in the pipe socket is safely avoided. This object is achieved in accordance with the invention in that a pipe section is inserted between the outer end of the pipe socket and the feed-water supply line and in that in the pipe section are disposed bellows, which with one end are tightly connected to the outer end of the expanding protective sleeve and with their other end are tightly connected to the pipe section. By the arrangement of the bellows in the pipe section and the tight connection of the bellows to the pipe section and the expanding protective sleeve it is ensured that the protective sleeve can freely expand in the pipe socket under the affect of temperature changes, whereby the bellows also experience these expansion movements, but that cold feedwater is prevented from overflowing into the annular gap filled with hot reactor water. Therefore no periodic changes in the water temperature can occur in the annular gap, so that thus surface temperature changes in the pipe socket are avoided. The occurrence of cracking in the material of the pipe socket is thus prevented.