Nuclear reactor

Such PWR components as, e.g., steam generaotrs, main coolant pumps and pressurizers, are supported so as to be protected from earthquake and MCA conditions. The rigid support acts as a pivot point around which the components are turned towards the pressure vessel as a result of the expansion of the pipelines. It consists of a pendulum support in the plane close to the pipelines and tie rods acting at various axial planes and at several points around the circumference. The tie rods are dimensioned so as to rupture under the impact of MCA forces. Parallel to the tie rods there are shock absorbers with a slight clearance relative to the components which, when the tie rods have ruptured, will accommodate the impact forces exceeding the operating forces. (DG)