Fractionation

Claim 1

IN THE OPERATION OF A SHIELDED NUCLEAR REACTOR OF THE HYDROCARBON COOLANT TYPE CONTAINING A CORE OF A CRITICAL AMOUNT OF FISSIONABLE NUCLEAR MATERIAL IN A CORE ZONE, THE IMPROVED METHNOD OF OPERATION TO MAINTAIN THE CORE ZONE AT A DESIRED TEMPERATURE AND TO UTILIZE THE THERMAL ENERGY GENERATED IN THE CORE ZONE WHICH COMPRISES THE STEPS OF CIRCULATING A FIRST FLUENT HYDROCARGON COOLANT THROUGH SAID CORE ZONE, SIMULTANEOUSLY CIRCULATING A SECOND FLUENT HYDROCARBON COOLANT THROUGH A MODERATING ZONE ANNULAR TO THE CORE ZONE IN INDIRECT COUNTERCURRENT HEAT EXCHANGE CONTACT WITH THE FIRST FLUENT HYDROCARBON COOLANT IN SAID CORE ZONE AND FLOWING SAID FLUENT HYDROCARBON COOLANTS THROUGH AN UNSHIELDED HEAT UTILIZATION ZONE EXTERIOR OF SAID SHIELDED NUCLEAR REACTOR AND EXTRACTING HEAT FROM SAID FLUENT HYDROCARBON COOLANTS IN SAID HEAT UTILIZATION ZONE, SAID FIRST FLUENT HYDROCARBON COOLANT BEING A LOW SULFUR CONTENT EXTRACT OF CATALYTIC CYCLE STOCK, SAID SECOND FLUENT HYDROCARBON COOLANT BEING A MIXTURE OF VIRGIN GAS OIL WITH CARALYTIC CYCLE STOCK, SAID FLUENT HYDROCARBON COOLANT BEING FLOWED THROUGH SAID NUCLEAR REACTOR AT A FLOW RATE SUFFICIENT TO MAINTAIN SAID CORE ZONE AT A DESIRED TEMPERATURE AND TO PREVENT THERMAL CONVERSION OF MORE THAN ABOUT 5. PERCENT OF SAID FLUENT HYDROCARBON COOLANT, SAID FLUENT HYDROCARBON COOLANTS BOILILNG WITHIN THE RANGE OF ABOUT 220* TO 650*C. AND COMPRISING A MIXTURE OF HYDROCARBONS, SAID FLUENT HYDROCARBON COOLANTS CONTAINING NOT MORE THAN ABOUT 5 VOLUME PERCENT OF EXTRANEOUS MATERIALS HAVING NEUTRON CROSSSECTIONS OF MORE THAN ABOUT 10 BARNS, SID FLUENT HYDROCARBON COOLANTS BEING EXPOSED TO A TOTAL RADIATION DOSAGE WITHIN THE RANGE OF ABOUT 10**7 TO ABOUT 10**10 RADS.