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Division Spotlight
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.
Meeting Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
NRC cuts fees by 50 percent for advanced reactor applicants
The Nuclear Regulatory Commission has announced it has amended regulations for the licensing, inspection, special projects, and annual fees it will charge applicants and licensees for fiscal year 2025.
Jay Basken, Jeffery D. Lewins
Nuclear Science and Engineering | Volume 122 | Number 3 | March 1996 | Pages 407-416
Technical Paper | doi.org/10.13182/NSE96-A24175
Articles are hosted by Taylor and Francis Online.
Accurate solutions of the reactor kinetics equations in a lumped model with time-varying reactivity have been obtained using a spreadsheet on a personal computer (PC)/workstation from a straightforward power series recurrence relation. These have been shown to converge readily over time steps of ∼ s in models of a thermal reactor. Solutions over such macrosteps can readily be extended to durations of interest (∼100 s). Examples are given for both a ramp reactivity input and an oscillating reactivity. This latter shows in a direct fashion the first-order phase distortion and the second-order effect on power level that are generally associated with perturbation solutions that have to be taken to second order. The method applies also to fast reactors. It is concluded that accurate calculations of thermal and fast reactor transients, obtained analytically with considerable difficulty, are readily available to the student on a PC.