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Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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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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.
Morton R. Fleishman, Harry Soodak
Nuclear Science and Engineering | Volume 7 | Number 3 | March 1960 | Pages 217-227
Technical Paper | doi.org/10.13182/NSE60-A25705
Articles are hosted by Taylor and Francis Online.
The Spinrad three-group theory of the fast effect is formulated. Recipes are presented for determining the necessary cross sections directly from fundamental data and three-group cross sections for various materials are tabulated. A comparison is made between the three-group theory and one-group theory with respect to the calculation of R, the ratio of fast-to-thermal fissions, and it is found that the three-group theory appears to give better agreement with experiments. The three-group values of Є — 1 are about 20% higher than those calculated from the one-group formula.
