Analysis of temperature fields in WWER-1000 pressure vessel

A method was developed for the calculation of nonlinear nonstationary temperature fields in the two-dimensional and three-dimensional geometries using the finite elements approach. The method was applied to the analysis of temperature fields in the WWER-1000 pressure vessel. For this purpose the vessel was divided into 8 calculation nodes. The main flange joint, the cylindrical part of the pressure vessel with the bottom, and the inlet and outlet sockets 850 mm in diameter were modeled as three-dimensional, whereas the remaining 5 nodes were modeled as two-dimensional. The calculation modes were divided into two groups, viz. for normal operation conditions and for accident regimes, associated with dehermetization of the primary circuit of the plant. The temperature field calculation method is also applicable to the welding of half-finished pressure vessel parts, austenitic overlaying and to pressure vessel surface repairs. (Z.M.). 2 figs