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Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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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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NRC updating GEIS rule for new nuclear technology
The Nuclear Regulatory Agency is issuing a proposed generic environmental impact statement (GEIS) for use in reviewing applications for new nuclear reactors.
In an April 17 memo, NRC secretary Carrie Safford wrote that the commission approved NRC staff’s recommendation to publish in the Federal Register a proposed rule amending 10 CFR Part 51, “Environmental Protection Regulations for Domestic Licensing and Related Regulatory Functions.”
Ruixian Fang, Dan G. Cacuci, Madalina C. Badea
Nuclear Technology | Volume 198 | Number 2 | May 2017 | Pages 132-192
Technical Paper | doi.org/10.1080/00295450.2017.1294430
Articles are hosted by Taylor and Francis Online.
Based on the adjoint sensitivity models for the saturated case of the counter-flow cooling tower developed in the accompanying Part I, this work computed and analyzed the sensitivities, with respect to all of the 52 model parameters, of the following responses (i.e., model outputs of interest): the outlet air temperature, outlet water temperature, outlet water mass flow rate, and outlet air relative humidity. The sensitivity results indicate that, in general, all these response of interest are mostly sensitive to the boundary-related parameters (e.g., Ta,in, Tdb, Tw,in, Tdp, mw,in, and ωin) and also somewhat sensitive to those parameters (e.g., a0, a1, a1f, a0,cpa, a1,dav, kair, and fht) that directly relate to the heat and mass transfer terms in the cooling tower model. The rankings of these parameters depend on the respective model responses. With the sensitivities known, the propagation of the uncertainties in the model parameters to the uncertainties in the model outputs are readily obtained. The uncertainties associated with the model outputs were reduced by applying the “predictive modeling for coupled multiphysics systems” (PM_CMPS) methodology. For a typical case studied in this work, the uncertainties associated with the model outputs of the outlet air temperature, outlet water temperature, and outlet air relative humidity, are reduced by 22%, 38%, and 68%, respectively. Moreover, the PM_CMPS methodology also generated optimal best-estimate nominal values for the model parameters and model responses. It also improved (i.e., reduced) the uncertainties associated with model parameters through the process of model calibration, as shown in the paper. The results presented in this work demonstrate that the PM_CMPS methodology reduces the predicted standard deviations to values that are smaller than either the computed or the experimentally measured ones, even for responses (e.g., the outlet water flow rate) for which no measurements are available. These improvements stem from the global characteristics of the PM_CMPS methodology, which combines all of the available information simultaneously in phase-space, as opposed to combining it sequentially, as in current data assimilation procedures.