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Division Spotlight
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.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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
April 2024
Nuclear Technology
Fusion Science and Technology
February 2024
Latest News
Can hydrogen be the transportation fuel in an otherwise nuclear economy?
Let’s face it: The global economy should be powered primarily by nuclear power. And it probably will by the end of this century, with a still-significant assist from renewables and hydro. Once nuclear systems are dominant, the costs come down to where gas is now; and when carbon emissions are reduced to a small portion of their present state, it will become obvious that most other sources are only good in niche settings. I mean, why use small modular reactors to load-follow when they can just produce that power instead of buffering it?
Thomas R. Boyle, Robert V. Tompson, Sudarshan K. Loyalka, Tushar K. Ghosh, Michael L. Reinig, Jr.
Nuclear Technology | Volume 183 | Number 2 | August 2013 | Pages 149-159
Technical Paper | Fission Reactors/Materials for Nuclear Systems | doi.org/10.13182/NT13-A18108
Articles are hosted by Taylor and Francis Online.
Very high temperature reactors (VHTRs) and high temperature gas-cooled reactors (HTGRs) can develop extreme temperatures in excess of 900°C that make them theoretically very efficient, potentially in the range of 45% to 50%. The high temperatures, however, can also lead to a corresponding increase in fission product transport out of the fuel, which is potentially a source term-related safety issue. The aim of this work was to develop a repeatable, accurate, and cost-effective process to measure the diffusion coefficients of fission products in graphitic VHTR materials, particularly those materials used in the fabrication of TRISO [tristructural isotropic] fuel pellets. Specifically, this work has focused on the diffusion of silver in graphite. We constructed graphite cells that could be filled with a silver diffusant in the form of silver flakes, silver powder, or a preloaded, silver-laden graphite powder. The cells were hermetically sealed and heated to temperatures comparable to those that will be found in VHTRs. After being kept at various amounts of time and temperature, these cells were imaged using microtomography and electron microscopy. Concentration profiles were measured by sectioning the heat-treated cells and analyzing them using neutron activation analysis. Estimated diffusion coefficients for silver in a commercial grade of graphite are reported, but the method is easily adapted to any grade of graphite material including nuclear grades and to a variety of other fission product species.