create an earthfill dam. Where appropriate, the technique should be examined as a possible competitor to conventional methods of dam construction using earth fills. VII. SALINE WATER CONVERSION The technical problems associated with the desalinization of sea water with the aid of nuclear explosives appear to be quite difficult. Nevertheless, the potential value of such a technique is great enough to justify a brief description of the basic idea. When sea water is distilled at very high pressures and temperatures, salt-free water can be produced with a minimum of expended energy. These two conditions, high pressure and temperature, along with an inexpensive source of energy, are created when a nuclear explosive is fired and the underground cavity persists after the explosion. The high temperature would be maintained by the insulating properties of the earth and the high pressure by the effects of gravity. Conceptually, sea water would be led several thousand feet down a pipe into a cavity which has been heated by the detonation of a nuclear explosive. Salt would be deposited and salt-free water returned to the surface through heat exchangers. While this application is a potentially important possibility, its value cannot be assessed until further information on the phenomenology is obtained. It is hoped that the Gnome experiment, a nuclear explosion which will be detonated in the Salado salt formation near Carlsbad, New Mexico, will shed some light on this problem. 19 VIII. SOVIET EXPERIENCE WITH LARGE EXPLOSIONS Scientists in the Soviet Union have been looking into large explosions for construction purposes for a number of years (see Appendix IV). In December, 1957, they detonated a highly instrumented charge of 1,000 tons of chemical explosives near Tashkent. The experiment was for scientific purposes, in order to acquire data for application to "the construction of canals, ditches, trenches, and reservoirs." The crater formed in the explosion is now in use as a deep reservoir holding about 150 million gallons of water. A few months later the Russians exploded the third in a series of large chemical charges to construct a diversion canal. A high explosive charge of 3,100 tons was detonated at one time to change the route of the Kolonga River (near Sverdlovsk) in order to make accessible a large deposit of iron ore. Their future plans include a 30,000-ton project (presumably using high explosives) to widen the Angara River bed in Siberia. In addition, a number of dam and river projects (see Appendix V) have been proposed during the current seven-year plan (1959-1965). It is evident, then, that the Soviets have made significant progress toward the understanding of large subsurface explosions (and hence of underground nuclear explosions) and their application to peaceful projects. It is equally evident that their future programs are even more ambitious than those they have already executed. The detailed results of their experiments have not yet been made available to us, and, in view of the present international situation, they are not likely to become available in the near future. The Russians have, therefore, a definite lead in this aspect of the scientific application of nuclear explosives for peaceful purposes. IX. PRESENT KNOWLEDGE OF EXPLOSION PHENOMENOLOGY We believe that we understand, to some extent, the interactions of a nuclear explosive with Oak Springs tuff, in which a number of nuclear detonations have already taken place, but we do not know to what extent the phenomenology will be different in other geologic environments. We certainly need data in different media. Specifically, experiments would be extremely desirable in: 1. A drier, more competent rock (e.g., granite); 2. A wet, weakly-cemented material (e.g., alluvium); 3. A common aquifer material (e.g., sandstone); 4. An easily decomposable substance (e.g., limestone); and 5. A plastic medium (e.g., salt). In all of these media, one can expect the ranges of the various effects of the explosion to be different from those we have seen in tuff; one can also anticipate that the geologic structure will exercise some influence on the observed phenomena. Some familiar processes may be absent (e.g., there may be no chimney) or some unexpected, new phenomena may be discovered. For this reason, it is vital that we gather fundamental data on the detailed interactions of nuclear explosives with other media whenever new nuclear tests (or large chemical explosions, for that matter) may be held, and for whatever objective they may be conducted. A program for this purpose involves both instrumental investigations during the explosion phase and postshot digging and drilling to examine the ultimate condition of the medium. Once we have appropriate data in another kind of rock, we will be able better to evaluate our calculational methods and to check the validity of our theoretical picture of the interactions of nuclear devices with various media. |