Patent Number: 048204773
Section: description

DETAILED DESCRIPTION OF THE INVENTION The FIGURE shows a schematic view of a typical power plant using an atomic reactor as the heat source. The atomic reactor 2 uses enriched uranium as a fuel to heat a coolant medium to produce a high temperature stream 4 which is directed to a heat exchanger 6. After passing through the heat exchanger 6, a lower temperature stream 8 is directed back to the reactor 2 to complete a circuit. A pump 10 serves to drive the coolant medium in the circuit. The heat exchanger 6 transfers heat from a primary cooling medium to a secondary stream which is used to drive electric generators. A high temperature secondary stream 12 exits the heat exchanger 6 and is directed to a power plant 14. This power plant typically contains a plurality of turbines which are driven by a high temperature steam and which are in turn connected to generators for generating electricity. A low temperature secondary stream 16 is directed from the power plant back to the heat exchanger 6. A second pump 18 is used to drive the fluid in the secondary stream. The primary and secondary streams are used to prevent radioactive medium from being introduced into the power plant. When the primary stream is made safe in accordance with the invention, the plant may be designed so that the primary stream drives the turbines. In accordance with the invention, a bleed stream 20 is taken from the primary coolant stream and is fed into a distillation column 22. This bleed stream is preferably one percent of the primary stream, but need not be so limited, depending upon the particular circumstances. The size of the bleed stream should be adequate to reduce the amount of deuterium in the primary stream to below the concentration of deuterium found in nature. The normal concentration of deuterium is 1/6,400, and it is preferred to reduce the concentration of deuterium in the primary stream to at least between 1/6400-1/10,000. It may be practical in some instances to reduce the deuterium concentration even further. The bleed stream 20 is directed through a pressure relief valve 24 and into the reboiler 26 of the distillation column. Since the heavy water in the bleed stream has a higher boiling point than that of the light water in the bleed stream, the distillation column will separate the deuterium-containing water from the light water. Vaporized light water is taken out of the top of the distillation column at 28, and the light-water vapor is then directed to a condenser 30. Part of the condensed light water 32 is directed back into the low-temperature primary stream 8, and part becomes reflux water for the distillation column and is carried through line 38. Heavy water and intermediate weight water, containing deuterium, are taken from the distillation column at 34 and disposed of or sold for known uses. The condenser is a heat exchanger with cooling supplied by cool water 36 from the lower-temperature secondary stream 16. The cooling water 36 is returned to the stream 16 after passing through the condenser 30. This arrangement provides for a very efficient use of energy in the plant since the heat removed from the light-water steam 38 is added back to the circulating stream 16. It will be appreciated by those of skill in the art that a very safe nuclear reactor has been provided wherein the formation of dangerous tritium will be prevented. While a preferred embodiment has been described, variations within the scope of the invention will be apparent to those of skill in the art.