New view of the conventional construction of the vessel of a nuclear reactor with supercritical coolant pressure

The conventional construction of the vessel of a nuclear reactor with supercritical coolant pressure is studied. The main type of vessel reactor in our country is the VVER-1000 reactor, where the pressure of the coolant is 160 MPa and its temperature is about 330°C. The lower part of the vessel, which consists of the lower and cylindrical parts, where the core is located, and the upper part with the connections for inflow and outflow of coolant are hot forged, after which both parts are joined together by fusion welding. The end faces are pressed together by means of pins, which bind the parts of the vessel together. The ends being joined are centered by means of a scroll, in which the ring-shaped projection is fitted during assembly. The end surface with the centering ring-shaped projection is made to be smooth, and the surface of receiving face with the centering scroll is made with ring-shaped projections of triangular form similar to threads.