Possibilities and distinctive details of the application of shape-memory alloys in nuclear technology

Abstract

To increase the reliability and safety of nuclear power plants, increase the compactness of parts, and decrease the irradiation of personnel, it is important to employ nonstandard technical devices, including shape-memory devices. At the present time, there is a definite scientific-technical potential for using shape-memory devices in nuclear power plants: utilization strategy, experimenal—commercial technology for fabricating different intermediate products, collection of alloys with different actuating temperatures, fundamental and construction solutions, theoretical foundations, experimental research base, experimental characteristics, verification of and experience in operation (in part, under reactor conditions), program of improvement in the direction of increasing resistance to irradiation, high speed of operation, and corrosion resistance. Of the diverse shape-memory devices the following will apparently be primarily used: stationary thermomechanical connections, gaskets, plugs, fasteners, and so on, self-operating bipositional counteraccident devices which act on the main process of the system and on the flow rate of the medium, electrically controlled driving mechanisms for closing fixtures, and small instruments. To accelerate the adoption of such devices in nuclear technology a catalog of shape-memory devices which are currently available must be compiled, a dictionary on application of shape-memory alloys must be developed, the stages of research and development must be separate, the technical conditions must be formulated, shape-memory alloys and devices must be certified, engineering methods of construction and calculation of devices must be developed, including methods for rapid heating and cooling and calculation of the speed of operation.