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2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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Perpetual Atomics, QSA Global produce Am fuel for nuclear space power
U.K.-based Perpetual Atomics and U.S.-based QSA Global claim to have achieved a major step forward in processing americium dioxide to fuel radioisotope power systems used in space missions. Using an industrially scalable process, the companies said they have turned americium into stable, large-scale ceramic pellets that can be directly integrated into sealed sources for radioisotope power systems, including radioisotope heater units (RHUs) and radioisotope thermoelectric generators (RTGs).
S. Langenbuch, W. Maurer, W. Werner
Nuclear Science and Engineering | Volume 63 | Number 4 | August 1977 | Pages 437-456
Technical Paper | doi.org/10.13182/NSE77-A27061
Articles are hosted by Taylor and Francis Online.
A coarse-mesh method for the solution of multidimensional neutron kinetics problems is presented that is based on the approximation of the desired solution by basis functions with local nonoverlapping supports corresponding to the volume elements of the spatial mesh. Integration of the approximating functions over their supports, and exploitation of continuity conditions for neutron flux and current, yields local seven-point difference operators with solution-dependent coupling coefficients. Due to the finite-difference (FD) structure of the resulting matrix equation, any technique developed for FD methods can be used for its solution. However, a novel (“almost implicit”) alternating direction explicit-implicit technique has been developed that is especially suited for coarse-mesh applications. Numerical examples that demonstrate the high efficiency of the method are presented. By using a spatial grid corresponding to the fuel element structure, it is possible to compute power distribution and its time history very accurately (at most, with a several percent error) at an economically tolerable expense.