Secondary thermal barrier for the main circulation pump of nuclear power plant primary circuit and modification and repair method of the pump by making use of that barrier

摘要

The secondary thermal barrier for the primary circulation pump of the nuclear circuit of the nuclear power plant is arranged between the cooled upper side of the distribution wheel and the shell and comprises at least a lower annular base (1) to which an internal height compensation wall (3) is connected to its inner and outer circumference. and an outer height compensating wall (2), wherein the bottom base (1) is formed to be positioned on the primary heat barrier (5) and the inner height compensating wall (3) and the outer height compensating wall (2) are formed for sealing with the shell. In carrying out a method of treating the primary circulation pump of the primary circuit of the nuclear power plant to prevent cracks in the distribution wheel flange and / or in the shell flange in the main plane of the pump to which the distributor wheel flange abuts, first of all the form changes are made to the pressure flange of the main main division plane. and then dividing the space between the primary heat barrier and the pressure flange of the main dividing plane into at least three thermally separated spaces by installing a secondary heat barrier. When performing the repair method, the material containing the indications is first removed before the shape adjustments are made.