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Division Spotlight
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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Nuclear Science and Engineering
March 2025
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Latest News
Penn State and Westinghouse make eVinci microreactor plan official
Penn State and Westinghouse Electric Company are working together to site a new research reactor on Penn State’s University Park, Pa., campus: Westinghouse’s eVinci, a HALEU TRISO-fueled sodium heat-pipe reactor. Penn State has announced that it submitted a letter of intent to host and operate an eVinci reactor to the Nuclear Regulatory Commission on February 28 and plans to engage with the NRC on specific siting decisions. Penn State already boasts the Breazeale reactor, which began operating in 1955 as the first licensed research reactor at a university in the United States. At 70, the Breazeale reactor is still in operation.
George E. Haynam, Marshall F. Crouch
Nuclear Science and Engineering | Volume 2 | Number 5 | September 1957 | Pages 626-630
Technical Paper | doi.org/10.13182/NSE57-A25429
Articles are hosted by Taylor and Francis Online.
The time required to slow neutrons down to various energies in a hydrogenous moderator is calculated by the Monte Carlo method. Exponential distributions are used for logarithmic energy loss and for distribution of free paths, and empirical cross section data are used to calculate the mean transit time between collisions at each energy. Kesults are presented in tabular form, and it is further shown that the distribution of slowing-down times at epithermal energies is well represented by a Pearson type III curve. Results of the calculation are compared with experimental results in an accompanying paper.
