HYGROSCOPIC MOISTURE ISOLATOR IN CONTAINMENT VESSEL FOR REACTOR

PURPOSE:To enable the prevention of a rise in moisture within a reactor containment vessel with the infiltration of a steam into a dry well section from a pool water of a pressure suppression chamber by mounting a detachable isolator between the dry well section and the pressure suppression chamber. CONSTITUTION:An isolator 1 is built up of a thin plate sheet and with slits 2 cut, it is placed on a vent tube 5. A jet deflector 6 section is cut 6' concentrically to be carried on a deflector 6. The isolator 1 is made detachable from a part 6'. A deflector 6' section is provided with a handle 3 and lifted or lowered therewith. In such an arrangement, in the normal operation of a nuclear reactor, the inflow of a steam into a dry well section 4 is prevented from a pooled water of the pressure suppression chamber 8. In case of an accident of spouting a steam as caused by a breakage of a reactor pressure vessel or others, the isolator 1 is broken due to a pressure difference between the well section 4 and the suppression chamber 8 and the steam within the well 4 is condensed by the pooled water in the suppression chamber 8 through the vent tube 5 thereby enabling the suppression of a rise in pressure within the well 4.