Word: reactor
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Balance or Blow. The engine is simple enough-in nuclear theory: a high-power density reactor (lots of power from a small volume) honeycombed with channels through which a large amount of hydrogen gas can be blown. The hydrogen cools the reactor, keeps it from melting or vaporizing. At the same time, the hydro gen is heated to a temperature (about 2,000°-3,000° C.) just below that of the reactor, expands enormously, and blows out of the nozzle in a high-speed jet. Hydrogen is essential because its molecules are the smallest known, and the smaller...
Kiwi-A's actual thrust is probably quite small. The difficulties are so great that no one knew whether such an engine would work at all. The reactor must run extremely hot; otherwise the hydrogen will not form an effective gas jet. Thus Kiwi-A's innards are probably made of tricky, heat-resistant metals such as tungsten, tantalum and molybdenum. Control is far more difficult than with chemical engines, because the flow of hydrogen must be balanced perfectly against the production of energy by the reactor. A slight maladjustment of the controls might melt the nuclear engine...
...they are fertilized by currents from colder areas, tropical seas are largely sterile. Since the richest harvests of the sea derive from bottom water rising to the surface, oceanographers have long had the notion of creating artificial upwelling in sterile parts of the ocean. One possibility is a nuclear reactor sitting on the bottom and slightly warming the water around it. The warmed water will rise, carrying nutrients to the surface and turning clear water, admired only by tourists, into rich, turbid pastures. Another way would be to pump deep water into some closed area, such as a Pacific atoll...
Plutonium is found in nature only in tiny traces. But when fissionable U-235 is burned in a nuclear reactor with the U-238 that forms the bulk of natural uranium, some of the neutrons that it sends out are captured by the U-238 atoms, turning them into plutonium (Pu-239). The plutonium can then be separated from uranium by a comparatively simple chemical process. If the reactor is made right, it "breeds," i.e., it makes more plutonium than it burns U-235. Used as fuel in turn, the new-made plutonium breeds even faster, making good nuclear fuel...
Says Father Laboon, who is soon to be joined by a Protestant chaplain: "The 60-day patrol of the atomic sub Seawolf," he explains, "indicated a need for religious coverage. We have crews away from port for extended periods, weeks on end of living with an atomic reactor, and soon, ballistic missiles as well. These patrols are almost the equivalent of war, in the minds of all who are involved in them, and morale must be kept high...