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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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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How to talk about nuclear
In your career as a professional in the nuclear community, chances are you will, at some point, be asked (or volunteer) to talk to at least one layperson about the technology you know and love. You might even be asked to present to a whole group of nonnuclear folks, perhaps as a pitch to some company tangential to your company’s business. So, without further ado, let me give you some pointers on the best way to approach this important and surprisingly complicated task.
Eugene C. Gritton, A. Leonard
Nuclear Science and Engineering | Volume 37 | Number 3 | September 1969 | Pages 397-409
Technical Paper | doi.org/10.13182/NSE69-A19115
Articles are hosted by Taylor and Francis Online.
An exact solution of the energy-dependent Boltzmann transport equation in the region near a temperature discontinuity is obtained for a nonabsorbing medium which is infinite in extent and has a temperature T1 in one half space and T2 in the other. The scattering cross section is assumed to be energy independent, and the scattering transfer kernel is represented by a degenerate-kernel approximation to the heavy-gas model. The method of solution is based upon a space-dependent thermalization theory developed earlier using the formalism of Case. Numerical calculations of both the scalar neutron flux and the total neutron density are included for various temperature ratios and neutron-to-moderator mass ratios. These results are compared with diffusion theory to assess the accuracy and range of validity of diffusion theory. For small temperature discontinuities, both diffusion theory and transport theory give very nearly the same value of the total neutron density at the interface. Away from the interface, a discrepancy between these theories becomes apparent because diffusion theory incorrectly predicts the energy-mode relaxation lengths, thus giving rise to an incorrect spatial dependence. Diffusion theory predicts the diffusion lengths accurately only when the energy exchange between the diffusing neutrons and the moderator material is weak. In addition, diffusion theory is found to become progressively less accurate for the higher energy modes. Thus, as the higher energy modes become more important, such as for a larger neutron-to-moderator mass ratio or for a larger temperature discontinuity, transport theory calculations of the neutron flux must replace the diffusion theory analysis.
