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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Alexey Soldatov, Todd S. Palmer
Nuclear Science and Engineering | Volume 167 | Number 1 | January 2011 | Pages 77-90
Technical Paper | doi.org/10.13182/NSE09-39
Articles are hosted by Taylor and Francis Online.
To address the energy needs of developing countries and remote communities, Oregon State University has proposed the Multi-Application Small Light Water Reactor (MASLWR) design. This design uses 8% enriched fuel to achieve five years of operation without refueling. The specific operational conditions (lower pressure and temperature of fuel and coolant), increased enrichment of fuel, and extensive use of gadolinium burnable absorbers lead to significantly different neutron physics compared to conventional pressurized water reactors. In particular, spectrum hardening due to increased thermal neutron absorption, changes in kinetic parameters due to the isotopic content of the fresh and irradiated fuel, and fuel and control rod shadowing by burnable absorbers are consequences of the design requirements. Enhanced neutron leakage from the small MASLWR core also adds complexity. Neutron reflectors and a unique fuel-loading pattern compensate the pronounced axial and radial gradients of the neutron flux and power generation.This paper discusses the neutron physics and thermal-hydraulic issues of the core design for a small reactor with increased fuel enrichment and natural circulation of the coolant. The paper describes three evolutionary steps of the MASLWR core design process and discusses core parameters, advantages, disadvantages, and design limitations as they appeared during the core design feasibility study. The paper demonstrates the feasibility of the core design for five effective years of nonrefueled operation with 8.0% enriched UO2 fuel.