Studies in the physics of fast neutron reactors

Abstract

ics at the Institate of Physics of the Atomic Energy Utilization Central Board are presented. Description is given of studies of fission neutron propagation through thick spheres of U/sup 238/. The experiments helped to determine a number of U/sup 238/ properties defining the role of U/sup 238/ fission in fast neutron reactors. Experimental results achieved on a series of critical assemblies are given for reactor power not in excess of 30 w. The reactor core consisted of plutonium rods. The critical facility design made it possible to study the reactor cores with relativety high plutonium content. The reactor cortrol was accomplished by moving the inner parts of screens. Three reactor design versions are described in detail. In one of them the screen is made of solid uranium slugs. In the second reactor design version it consists of a close uranium water lattice separated from the core by a layer of solid uranium. In the third design version a nonfissionable screen made of copper is used. Neutron detectors of different sensitivity to neutron energy allow determination of the neutron energy spectrum in differert parts of the reactor. Direct measurements of the neutron spectrum were made. The reactivity perturbations caused by foreignmore » particles in the reactor vessel were measured, and measurements of space dependence of the neutron value for different neutron energies were made. Experimental results are compared with the data calculated by the multigroup kinetic theory. Basic results of nuclear research of the 100-kw experimental fast neutron reactor wim mercury cooling are described. Space distribution of different processes, neutron energy spectrum, efficiency of regulating instruments, temperature effects, and other paranaeters of the reactor have been measured. Comparison is made of the experimental results with the results of theoretical calculations. (auth)« less