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[en] Peaceful applications introduce some new environmental considerations into the design of nuclear explosives. Much of the experience gained in weapon work can be applied, but the requirement of survival in a very deep hole is not found in any military system. We will briefly mention the overall environment and make a few comparisons with some general characteristics of the weapon environment. The major portion of this paper is devoted to the special problems of pressure and temperature found in the emplacement environment. Potential users should know where we stand with regard to survival in hostile environments in terms of feasibility and possible effects on field operations. In all applications there are several things competing for the available diameter. Given that explosives can be made to work over a range of diameters and that necessary environmental control is feasible, all further discussions can be related to the cost of providing a hole big enough to accomplish the task. The items competing for diameter are: 1) bare nuclear assembly 2) insulation and cooling system if needed 3) pressure canister 4) shielding material 5) emplacement clearance All of these must be considered with the cost of the hole in optimizing an overall design. Conditions in a particular location will affect the shielding requirements and the emplacement clearance. The nuclear assembly can vary in size, but the long development time requires that decisions be made quite early, perhaps in ignorance of the economic details of a particular application. The pressure canister is a relatively straightforward design problem that can be resolved by giving appropriate consideration to all of the design requirements. In particular for 20,000 psi pressure in the emplacement hole, a canister of heat-treated alloy steel having a yield strength of 200,000 psi and a wall thickness which is about .07 times the outside diameter is adequate and straight- forward to fabricate. The insulation and cooling requirements are not settled by compromise between competing elements of the design. There is a more basic question: Can adequate cooling be provided at reasonable cost? Some insulation is required, and some means of controlling thermal gradients in the assembly must be included. Even if these can be provided at small cost in diameter, how is the temperature difference between the world and the explosive to be maintained?
[en] Based on the premise that there will always be a finite chance of a Plowshare project failure, the implications of such a failure are examined. It is suggested that the optimum reliability level will not necessarily be the highest attainable, but rather that which results in minimum average project cost. The type of performance guarantee that the U. S. should provide for nuclear explosive services, the determination of nuclear yield, courses of action to take in the event of failure, and methods to offset remedial costs are discussed. (author)
[en] Two-dimensional calculations have been done to determine the feasibility of constructing deep canals with nuclear explosives subject to the limitation in the proposed PNE Treaty. The conditions under which a series of explosives set in a row can be approximated by a cylindrical line source have been determined. Using this result, the possibility of lifting 250 m of overburden with 150-kt charges spaced at 50-m intervals has been investigated. This study shows that for a variety of equations of state for the geological medium, there appears little possibility that such an excavation can be accomplished
[en] The availability of nuclear explosives for peaceful projects has given the engineer a new dimension in his thinking. He can now seek methods of adapting Plowshare to a variety of industrial applications. The full potential of the Plowshare Program can only be attained when industry begins to use nuclear explosives on a regular basis, for economically sound projects. It is the purpose of this paper to help the engineer familiarize himself with Plowshare technology to hasten the day when 'Plowsharee goes commercial'. An engineering project utilizing nuclear exposives ordinarily involves three main phases: Phase I (a) The theoretical and empirical analysis of effects. (b) Projected economic and/or scientific evaluation. (c) A safety analysis. Phase II (a) Field construction. (b) Safe detonation of the nuclear explosive. (c) Data acquisition. Phase III The evaluation and/or exploitation of the results. This paper will be restricted to Phase II, referred to collectively as the 'nuclear operation'
[en] The course of cavity and crater formation in an underground explosion is described. Formulae are given for cavity and crater radius and chimney height estimation. Applications disscussed include the stimulation of oil and natural gas reservoirs, and water resource management. Safety is discussed from the points of view of seismic effects and release of radioactivity
[en] The development of nuclear excavation technology is based on the promise that the relatively inexpensive energy available from thermonuclear explosives can be used to simultaneously break and move age quantities of rock and earth economically and safety. This paper discusses the economic and other advantages of using nuclear excavation for large engineering projects. A brief description of the phenomenology of nuclear excavation is given. Each of the several proposed general applications of nuclear excavation is discussed to include a few specific example of possible nuclear excavation projects. The discussion includes nuclear excavation for harbors, canals, terrain transits, aggregate production, mining and water resource development and conservation. (author)