USE OF EFFICIENT LIQUID-METAL COOLANTS SUCH AS LITHIUM, SODIUM, OR NAK IN SPACE REACTORS PRESENTLY REQUIRES A THERMALLY-HOT LAUNCH TO KEEP THE COOLANT MOLTEN UNTIL START-UP.

USE OF EFFICIENT LIQUID-METAL COOLANTS SUCH AS LITHIUM, SODIUM, OR NAK IN SPACE REACTORS PRESENTLY REQUIRES A THERMALLY-HOT LAUNCH TO KEEP THE COOLANT MOLTEN UNTIL START-UP. THIS REQUIREMENT SEVERELY COMPLICATES POWER PLANT ASSEMBLY, TESTING, AND SHIPPING AS WELL AS VEHICLE INTEGRATION, HEATING ON THE LAUNCH PAD, THERMAL MANAGEMENT IN THE LAUNCH VEHICLE, AND LAUNCH SAFETY. THE USE OF SUCH FREEZABLE LIQUID METAL COOLANTS COMPLICATES THE PROVISIONS NEEDED FOR LONG PERIODS OF SHUTDOWN DORMANCY. A PROPRIETARY CONCEPT HAS BEEN DERIVED THAT WILL USE REACTOR HEAT TO RAPIDLY MELT THE REACTOR COOLANT AND ESTABLISH PRIMARY SYSTEM FLOW WITHOUT DAMAGING THE PRIMARY VESSEL OR PRIMARY LOOP INTEGRITY. A MATHEMATICAL MODEL WILL BE CONSTRUCTED OF A TYPICAL REACTOR FILLED WITH FROZEN COOLANT. THIS MODEL WILL BE USED TO VALIDATE THE CONCEPT AND TO ESTABLISH THE LIMITING DESIGN PARAMETERS. A PROTOTYPIC DEVICE WILL BE FABRICATED AND TESTED. THE RESULTS ARE EXPECTED TO VALIDATE THE CONCEPT AND TO ESTABLISH THE DESIGN CRITERIA FOR THE PROPRIETARY COMPONENTS AND THE PRIMARY LOOP SYSTEM. PHASE I RESULTS WILL BE USED TO DESIGN THE PHASE II DEMONSTRATION EXPERIMENTS.