CRITICAL CONFIGURATION AND PHYSICS MEASUREMENTS FOR GRAPHITE REFLECTED ASSEMBLIES OF U(93.15)O2 FUEL RODS (1.506-CM PITCH)

Margaret A. Marshall

关键词: NESDPS Office of Nuclear Energy Space and Defense Power Systems;    1.506-cm pitch UO2 Assembly;    criticality safety benchmark;    graphite reflected;    highly enriched uranium;    medium power reactor experiment;    small modular reactor;    space reactor;    uranium dioxide;   

DOI  :  10.2172/1055964
RP-ID  :  INL/EXT-12-25264
PID  :  OSTI ID: 1055964

美国|英语

来源: SciTech Connect

【 摘 要 】

A series of critical experiments were completed in 1962-1965 at Oak Ridge National Laboratory???s Critical Experiments Facility in support of the Medium-Power Reactor Experiments (MPRE) program. In the late 1950???s efforts were made to study ???power plants for the production of electrical power in space vehicles???. The MPRE program was a part of those efforts and studied the feasibility of a stainless steel system, boiling potassium 1 MW(t), or about 140 kW(e), reactor. The program was carried out in [fiscal years] 1964, 1965, and 1966. A summary of the program???s effort was compiled in 1967. The delayed critical experiments were a mockup of a small, potassium-cooled space power reactor for validation of reactor calculations and reactor physics methods. Initial experiments, performed in November and December of 1962, consisted of a core of 253 unmoderated stainless steel tubes, each containing 26 UO2 fuel pellets, surrounded by a graphite reflector. Measurements were made to determine critical reflector arrangements, fission-rate distributions, and cadmium ratio distributions. Subsequent experiments used beryllium reflectors and also measured the reactivity for various materials placed in the core. ???The [assemblies were built] on [a] vertical assembly machine so that the movable part was the core and bottom reflector.??? The first experiment in the series was evaluated in HEU-COMP-FAST-001. It had the 253 fuel tubes packed tightly into a 22.87 cm outside diameter (OD) core tank (References 1 and 2). The second experiment in the series, performed in early 1963, which is studied in this evaluation, had the 253 fuel tubes at a 1.506-cm triangular lattice in a 25.96 cm OD core tank and graphite reflectors on all sides. The experiment has been determined to represent an acceptable benchmark experiment. Information for this evaluation was compiled from published reports on all three parts of the experimental series (Reference 1-5) and the experimental logbook as well as from communication with the experimenter, John T. Mihalczo.