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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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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Latest News
Commercial nuclear innovation "new space" age
In early 2006, a start-up company launched a small rocket from a tiny island in the Pacific. It exploded, showering the island with debris. A year later, a second launch attempt sent a rocket to space but failed to make orbit, burning up in the atmosphere. Another year brought a third attempt—and a third failure. The following month, in September 2008, the company used the last of its funds to launch a fourth rocket. It reached orbit, making history as the first privately funded liquid-fueled rocket to do so.
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.