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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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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Sandra Poumerouly, Gérald Rimpault
Nuclear Technology | Volume 174 | Number 1 | April 2011 | Pages 1-17
Technical Paper | Accident Analysis and Consequences | doi.org/10.13182/NT11-A11675
Articles are hosted by Taylor and Francis Online.
Core disruptive accidents in fast reactors need to be monitored carefully since they may lead to possible criticality configurations. However, the worst-case scenario may have small probability occurrences, but the proof of it requires multidisciplinary studies. Even with the upgrade in computer performance, calculations would require several months on several parallel computers. Accurate calculations with short running times are thus required. Updating the neutronics module of SIMMER set up in the 1970s was therefore carried out with the help of routines able to handle probability tables for generating broad group libraries. The use of such libraries together with new SIMMER options is now able to produce reliable results in all sorts of situations while maintaining reduced calculation times.Indeed, until now, neutronics calculations from SIMMER gave results quite far from ERANOS ones (differences in reactivity larger than 1.5 $). The discrepancies were mainly due to the libraries used. As a consequence, in 2000, an ERANOS module (BISIM) was created to generate SIMMER nuclear data libraries (for both cross sections and self-shielding factors) from the ERANOS nuclear data file, thereby reducing the major source of inconsistencies. Other improvements were added by the Japan Atomic Energy Agency, on the way of calculating the transport cross section and on the library group scheme so as to better calculate the k-effective within a reasonable time frame, but also at the Commissariat à l'Energie Atomique et aux Energies Alternatives on the -effective calculation. A new option (using the Keepin data) was implemented in 2010 in SIMMER.Once all these optimizations were carried out, a comparison between the SIMMER (III for two dimensions and IV for three dimensions) and ERANOS results was performed for a series of disruptive and representative configurations. While the computation time has not changed significantly, the differences on k-effective between ERANOS reference route results and SIMMER 16 energy-group calculations were drastically reduced by [approximately]0.8 $.