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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.
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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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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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Latest News
Max Planck’s ELISE reaches record values for ITER plasma heating
The Max Planck Institute for Plasma Physics (IPP) announced that it recently has achieved a new record for ion current density for neutral particle heating at its ELISE (Extraction from a Large Ion Source Experiment) experimental testing facility in Garching, Germany. ELISE is being used to test neutral beam injection (NBI) systems that will be used to heat the plasma of the ITER fusion experiment in France.
Jeffrey E. Seifried, Ehud Greenspan
Nuclear Science and Engineering | Volume 181 | Number 1 | September 2015 | Pages 82-95
Technical Paper | doi.org/10.13182/NSE14-104
Articles are hosted by Taylor and Francis Online.
An expression is derived for attributing the reactivity response due to perturbations to spectral, spatial, and isotopic effects. It is shown to be consistent at a global level with similar expressions derived in previous work but can provide more detailed information on the physics phenomena contributing to the reactivity response of the perturbation. Using this expression, the reactivity effect of local coolant density perturbations [local void coefficient of reactivity (VCR)] is studied for two reduced-moderation boiling water reactor (RBWR) core designs—the thorium-fueled RBWR (RBWR-Th) and the uranium-fueled RBWR (RBWR-AC)—as well as for a standard advanced boiling water reactor (ABWR). The RBWR core designs feature large axial variation in their neutron spectra.
The axial distribution of local VCR along the RBWR-Th seed and along the ABWR core were found to have the same general shape: negative throughout but most negative near the bottom and asymptotically approaching zero toward the top. However, the RBWR-Th VCR is roughly four times more negative. The RBWR-AC local VCR axial distribution varies greatly: it is very close to zero in the seed regions and has a significant positive component in the central blanket.
Three effects were identified as contributing to the VCR due to a local water density change in the lower part of the RBWR-Th seed: local spectrum hardening that tends to increase the local reproduction factor (ηr) of each of the fuel isotopes; a redistribution of the local neutron absorption between the fuel isotopes resulting in a shift of absorptions from higher to lower isotopic reproduction factors and, hence, to a reactivity loss; and an axial flux tilt across the core from axial zones of higher ηr to axial zones of lower ηr, which makes another negative contribution to the reactivity worth of the perturbation.