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Fusion Energy
This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Report: New York state adding 1 GW of nuclear to fleet
New York Gov. Kathy Hochul has instructed the state’s public electric utility to add at least 1 gigawatt of new nuclear by building a large-scale nuclear plant or a collection of smaller modular reactors, according to the Wall Street Journal.
P. Reuss
Nuclear Science and Engineering | Volume 92 | Number 2 | February 1986 | Pages 261-266
Technical Paper | doi.org/10.13182/NSE86-A18174
Articles are hosted by Taylor and Francis Online.
Because of the large number of heavy nuclide resonances, a detailed neutron flux calculation in the epithermal range cannot be made by standard nuclear reactor codes: It would need several tens of thousands of energy points. However, by using precalculated effective reaction rates, only a few tens of groups are sufficient for accurate spectrum and reaction rate calculations, if a consistent formalism is used. Such a formalism was elaborated in the 1970s by M. Livolant, F. Jeanpierre for the “one resonant nuclide-one resonant zone” problem, and was implemented in the APOLLO code. In practical cases there are several resonant nuclides and often resonant zones of different characteristics, e.g., a lattice constituted with different kinds of pins, a lattice with irregular “water holes,” a fuel element with temperature (therefore Doppler effect) gradients, and so on. Since these problems cannot be correctly treated by APOLLO, a generalization of the formalism was derived. The basic principles were retained, and an algorithm was constructed that would not require too expensive calculations. The Livolant-Jeanpierre theory is briefly summarized, equations for the most general case are presented, some approximations for practical calculations are proposed, and numerical tests on significant examples are discussed.