Gas cooled nuclear reactor system with improved flowpath and shield arrangement

Claim 1

IN A GAS-COOLED NUCLEAR REACTOR ASSEMBLY: A PRESTRESSED CONCRETE PRESSURE VESSEL HAVING A VERTICAL AXIS, DEFINING A PRESSURE TIGHT CHAMBER AND OF SUCH THICKNESS AS TO PROVIDE BIOLOGICAL PROTECTION, AN ANNULAR FLANGE INTEGRAL WITH SAID VESSEL AND PROJECTING INWARDLY FROM SAID VESSEL INTO SAID CHAMBER, A REACTOR CORE UNIT LOCATED IN SAID CHAMBER ABOVE SAID FLANGE AND PROVIDED WITH VERTICAL CHANNELS RECEIVING NUCLEAR FUEL ELEMENTS, HEAT EXCHANGERS LOCATED IN SAID CHAMBER BELOW SAID FLANGE, WALL MEANS DEFINING A FIRST ANNULAR GAS COOLANT PASSAGE BETWEEN SAID PRESSURE VESSEL WALL AND SAID CORE UNIT AND BETWEEN SAID PRESSURE VESSEL AND SAID HEAT EXCHANGERS, BIOLOGICAL SHIELD MEANS LOCATED BETWEEN SAID CORE UNIT AND SAID HEAT EXCHANGERS, DEFINING A SECOND ANNULAR GAS COOLANT PASSAGE WITH SAID WALL MEANS AND SUPPORTING SAID CORE UNIT, MECHANICAL SUPPORT MEANS FOR TRANSMITTING THE WEIGHT OF SAID CORE UNIT AND SAID SHIELD MEANS TO SAID FLANGE, MEANS FOR CIRCULATING GAS COOLANT IN CLOSED CIRCUIT DOWNWARD ALONG SAID CHANNELS, PAST SAID SHIELD MEANS THROUGH SAID SECOND PASSAGE, DOWNWARD THROUGH SAID HEAT EXCHANGERS, AND UPWARD IN RETURN TO SAID CHANNELS THROUGH SAID FIRST PASSAGE, AND RADIATION ATTENUATING MEANS LOCATED IN SAID SECOND PASSAGE ADJACENT SAID SHIELD MEANS AND COMPRISING A PLURALITY OF PARALLEL SPACED ANNULAR PLATES OF RADIATION ABSORBENT MATERIAL OF SUCH LENGTH IN THE DIRECTION OF FLOW AND IN SUCH POSITION AS TO PREVENT DIRECT STREAMING OF RADIATION FROM SAID CORE UNIT TO SAID EXCHANGERS THROUGH SAID SECOND PASSAGE.