Nuclear fusion and fission

It is common knowledge that the ultimate source of all our energy and negative entropy is the radiation of the sun.
— Albert Szent-Gyorgyi (1893 – 1986), Light and Life (1961)

We can be certain that the radiation did not change appreciably during the last 500 million years; because during all this time life existed on earth, which means that the temperature of the earth during the whole period must have been very nearly what it is today. This temperature is determined by the sun’s radiation.
— Hans Albrecht Bethe (1906 – 2005), The Sky, December 1940.

Personally, I think there is no doubt that subatomic energy is available all around us, and that one day man will release and control its almost infinite power. We cannot prevent him from doing so and can only hope that he will not use it exclusively in blowing up his next-door neighbour.
— Francis William Aston (1877 – 1945), Background to Modern Science, Cambridge, 1938, 113.

We have now reached the conclusion that it will be possible to make an effective uranium bomb which would be equivalent as regards destructive effect to 1,800 tons of TNT.
— Report of the MAUD Committee, July 15, 1941, quoted in James Phinney Baxter, Scientists Against Time, 1946, 426.

The gaunt face hardened to grimness, and with both hands the bomb-thrower lifted the big atomic bomb from the box and steadied it against the side. It was a black sphere two feet in diameter. Between its handles was a little celluloid stud, and to this he bent his head until his lips touched it. Then he had to bite in order to let the air in upon the inducive. Sure of its accessibility, he craned his neck over the side of the aeroplane and judged his pace and distance. Then very quickly he bent forward, bit the stud, and hoisted the bomb over the side.
— H. G. Wells, The World Set Free, 1913.

We are now at the same stage as fission research was in 1940 when the possibility of a chain reaction was well understood but many uncertainties remained, and a further fifteen years elapsed before large-scale nuclear power was developed.
— Sir John Cockcroft on fusion power in 1957, quoted by Egon Larsen, Atomic Energy, Pan Books, 1958, 161.

Solid wastes can be disposed of by incineration, closed storage, open burial, or drainage out to sea. Incineration is especially valuable for treating animal carcases and as a means to reduce the volume of the solid waste, but it gives rise to active gases and ash. The discharge of the gases should be clear of windows. Burial may be used on permanently enclosed sites at levels depending on the rainfall so that local groundwater is not contaminated. Even highly radio-active solid wastes can be disposed of safely in the sea provided all relevant factors are kept in mind: movement of the surface water, the breeding and migratory habits of fish, and the possible hazard to seaweed where it is harvested for food, fertilization, or industrial use.
— Egon Larsen, Atomic Energy, Pan Books, 1958, 136.

Armed with such knowledge the nuclear chemists, I am convinced, will be able to synthesise elements just as ordinary chemists synthesise compounds, and it may be taken as certain that in some reactions subatomic energy will be liberated … There are those about us who say that such research should be stopped by law, alleging that man’s destructive powers are already large enough … Personally, I think there is no doubt that subatomic energy is available all around us, and that one day man will release and control its almost infinite power. We cannot prevent him from doing so and can only hope that he will not use it exclusively in blowing up his next-door neighbour.
— Francis William Aston (1877 – 1945), Background to Modern Science, Cambridge, 1938, 113.

In order to operate the pile, all the cadmium strips except one are first taken out of the pile. The last rod is then slowly pulled out of the pile. As the critical conditions are approached, the intensity of the neutrons emitted by the pile begins to increase rapidly. It should be noticed, however, that when this last strip of cadmium is so far inside the pile that the effective reproduction factor is just below 1, it takes rather a long time for the intensity to reach the saturation value. In a similar way, if the cadmium strip is so far outside the pile that the reproduction factor is greater than 1, the intensity rises at rather a slow rate. Indeed, for our pile, when all the cadmium is completely outside of the pile, the intensity rises approximately at the rate of a factor of 2 every minute. When the cadmium strip is close to the critical position, these relaxation times become exceedingly long. It has been found for example, that for one of our controlling strips, the relaxation time is given by: 230 minutes/x, where x is the distance of the rod from the critical position, expressed in cm. This means that if the rod is only 1 cm off the critical position, the relaxation time is about 4 hours. For the automatic control rod the corresponding constant is 180 minutes. These long relaxation times which are due to the existence of a small percentage of delayed neutrons emitted in the fission process make it rather easy to keep the pile operating at a constant level of intensity even without the use of automatic regulation …

In order to keep the level constant, it is sufficient to push the rod one or two cm in or out every once in a while so as to compensate for the small variations in the reproduction factor due primarily to changes of atmospheric pressure.
— Enrico Fermi (1901 – 1954), Experimental Production of a Divergent Chain Reaction, American Journal of Physics, 20 (1952), 536-541.

Uranium power plants are already operating and producing electricity at a profit. But it is equally well known that three basic difficulties block the way to their further and wider expansion.

First, uranium disintegration wastes are highly radioactive and their safe disposal raises serious technical problems which so far have no generally acceptable solutions. The best method would be to rocket them into space, but as yet it is not considered sufficiently safe.

Second, a large atomic power plant generating millions of kilowatts is a grave danger to the surrounding environment and especially to the population. In the case of an accident or sabotage the escaping radioactivity could destroy all life over an area of many square kilometres, just as effectively as the atom bomb in Hiroshima. This danger is now considered so grave that no insurance company in the capitalist world dares to risk cover on such a scale.

Third, extensive use of atomic power plants will also result in the widespread propagation of plutonium a necessary participant in the nuclear reaction. The availability of plutonium in all countries of the world will make it difficult to control the proliferation of atomic weapons …

Clearly under the threat of the energy crisis mankind will find a way to circumvent these obstacles. The two latter difficulties, for example, could be overcome by siting atomic power stations on small uninhabited oceanic islands far from densely populated localities. These stations would be under strict control and the results of any consequence would not endanger people to a great extent. The energy generated by an electric power station could be used, for example, to decompose water, transporting the hydrogen obtained in liquid form and using it as a fuel which does not pollute the atmosphere when burning.
— Peter Kapitza (1894 – 1984), Energy the fusion solution, New Scientist, 14 October, 1976, 83.

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