Shielding for nuclear reactors

Claim 2

A GAS-COOLED NUCLEAR REACTOR COMPRISING A PRESSURE VESSEL, SAID VESSEL HAVING A PRIMARY OPENING, A PRESSURE DOME REMOVABLY SECURED TO SAID OPENING, A GAS INLET TO SAID DOME, A REACTOR CORE WITHIN SAID VESSEL, A BIOLOGICAL SHIELD CONSTRUCTED TO PROVIDE SAFE ACCESS BY PERSONNEL TO THE TOP OF SAID SHIELD POSITIONED INTERIORLY OF SAID VESSEL AND FILLING A SPACE THEREIN BETWEEN SAID CORE AND SAID PRESSURE DOME, TUBULAR MEANS IN SAID SHIELD AND IN SAID CORE ARRANGED TO FORM ALIGNED PASSAGES FOR CONTAINING FUEL TUBES WITH FUEL ELEMENTS INSERTED IN SAID TUBULAR MEANS OF SAID CORE, A PLURALITY OF REMOVABLE PLUGS FOR INSERTION IN SAID TUBULAR OPENINGS FORMED IN SAID BIOLOGICAL SHIELD, SAID PLUGS CLOSING SAID TUBULAR MEANS THEREIN AND PREVENTING ACCESS TO THE REACTOR FUEL ELEMENTS SAID PLUGS BEING REMOVABLE SO AS TO ALLOW REMOVAL OF SAID FUEL ELEMENTS FROM SAID PASSAGES, A GAS PASSAGE THROUGH SAID SHIELD, AND SUPPORT MEANS IN SAID VESSEL OF THE SELFCENTERING TYPE HAVING INWARDLY AND DOWNWARDLY CIRCUMFERENTIALLY EXTENDING SURFACES ENGAGEABLE WITH CORRESPONDING SURFACES ON SAID SHIELD AND ON SAID CORE TO MAINTAIN PASSAGE ALIGNMENT SO THAT SAID PLUGS AND FUEL ELEMENTS MAY BE REMOVED, SAID SEALS CONFINING THE FLOW OF GAS TO SAID GAS PASSAGE.

Claim 3

IN A GAS-COOLED NUCLEAR REACTOR COMPRISING A CORE OF NUCLEAR FUEL WITHIN A PRESSURE VESSEL WHICH INCLUDES A HOUSING ENCLOSING SAID CORE OF NUCLEAR FUEL, SAID HOUSING HAVING A SIDE WITH A PRIMARY OPENING, THE IMPROVEMENT COMPRISING A BIOLOGICAL SHIELD OF MATERIAL CONSTRUCTED TO PROVIDE SAFE ACCESS BY PERSONNEL TO THE TOP OF SAID SHIELD AND DISPOSED TO FILL A SPACE IN SAID PRESSURE VESSEL IN SPACED RELATION TO SAID CORE AND BETWEEN SAID CORE AND SAID PRIMARY OPENING AND HAVING A PLURALITY OF APERTURES EXTENDING THERETHROUGH FROM THE PRIMARY OPENING SIDE OF SAID SHIELD TO THE SIDE OF SAID SHIELD ADJACENT SAID CORE, A GAS CIRCULATING SYSTEM INCLUDING A GAS OUTLET FROM SAID HOUSING ADJACENT SAID CORE AND A GAS INLET MEANS FOR INTRODUCING THE PRINCIPAL PORTION OF THE COOLANT GAS INTO SAID HOUSING BETWEEN SAID SHIELD AND SAID CORE, AND MEANS FOR CONDUCTING GAS FROM SAID GAS CIRCULATING SYSTEM AND INTRODUCING THIS PORTION OF SAID GAS INTO SAID HOUSING BETWEEN SAID PRIMARY OPENING AND SAID SHIELD AT A GREATER PRESSURE AND LOWER TEMPERATURE THAN ON THE CORE SIDE OF SAID SHIELD SO AS TO CAUSE SAID PORTION INTRODUCED BETWEEN SAID PRIMARY OPENING AND SAID SHIELD TO FLOW INWARDLY TOWARD SAID CORE THROUGH SAID APERTURES IN SAID SHIELD AND COOL SAID HOUSING ON THE OPPOSITE SIDE OF SAID SHIELD FROM SAID CORE.

Claim 4

IN A GAS-COOLED NUCLEAR REACTOR COMPRISING A CORE OF NUCLEAR FUEL WITHIN A PRESSURE VESSEL WHICH INCLUDES A HOUSING ENCLOSING SAID CORE OF NUCLEAR FUEL, SAID HOUSING HAVING A SIDE WITH A PRIMARY OPENING, THE IMPROVEMENT COMPRISING A BIOLOGICAL SHIELD OF MATERIAL CONSTRUCTED TO PROVIDE SAFE ACCESS BY PERSONNEL TO THE TOP OF SAID SHIELD AND DISPOSED TO FILL A SPACE IN SAID PRESSURE VESSEL IN SPACED RELATION TO SAID CORE AND BETWEEN SAID CORE AND SAID PRIMARY OPENING AND HAVING A PLURALITY OF APERTURES EXTENDING THERETHROUGH FROM THE PRIMARY OPENING SIDE OF SAID SHIELD TO THE SIDE OF SAID SHIELD ADJACENT SAID CORE, A GAS CIRCULATING SYSTEM INCLUDING A GAS OUTLET FROM SAID HOUSING ADJACENT SAID CORE AND A GAS INLET MEANS FOR INTRODUCING THE PRINCIPAL PORTION OF THE COOLANT GAS INTO SAID HOUSING BETWEEN SAID SHIELD AND SAID CORE, AND MEANS FOR CONDUCTING GAS FROM SAID GAS CIRCULATING SYSTEM AND INTRODUCING THIS PORTION OF SAID GAS INTO SAID HOUSING BETWEEN SAID PRIMARY OPENING AND SAID SHIELD AT A GREATER PRESSURE AND LOWER TEMPERATURE THAN ON THE CORE SIDE OF SAID SHIELD SO AS TO CAUSE SAID PORTION INTRODUCED BETWEEN SAID PRIMARY OPENING AND SAID SHIELD TO FLOW INWARDLY TOWARD SAID CORE THROUGH SAID APERTURES IN SAID SHIELD AND COOL SAID HOUSING ON THE OPPOSITE SIDE OF SAID SHIELD FROM SAID CORE.