NEUTRON FLUX MEASUREMENTS FOR MATERIALS IRRADIATION EXPERIMENTS AT ARGONNE NATIONAL LABORATORY, BROOKHAVEN NATIONAL LABORATORY, OAK RIDGE NATIONAL LABORATORY, AND NATIONAL REACTOR TEST STATION

摘要

In the U.S. Naval Research Laboratory studies of the effects of nuclear radiation upon the properties of steel, a continuous effort has been made to measure accurately the neutron-flux density and energy spectrum in four research reactors. Such measurement, made with various dosimeter materials, have determined which reactor facility provides the desired nuclear environment, and have served as nec¬essary parameters in assessing mechanical property changes in irradiated steels.nFlux surveys for all reactor experiments were limited to threshold detectors with nuclear and physical charac¬teristics suitable for extended reactor exposure under varying environmental conditions. These monitors, cobalt, cadmium-shielded cobalt, nickel, and sulfur, were utilized in flux measurements for the Argonne National Laboratory CP-5 Reactor, the Brookhaven National Laboratory Graphite Reactor, the National Reactor Test Station Materials Test¬ing Reactor, and the Oak Ridge National Laboratory Low Intensity Test Reactor. The neutron-flux data for high-flux positions in these four research reactors show a high-degree of correlation with changes in materials properties after irradiation.