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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).
John Paul Kuspa, Nick Tsoulfanidis
Nuclear Science and Engineering | Volume 52 | Number 1 | September 1973 | Pages 117-123
Technical Paper | doi.org/10.13182/NSE73-A23294
Articles are hosted by Taylor and Francis Online.
Buildup factors for gamma rays traversing slab shields have been obtained using the Monte Carlo method. Secondary particles produced inside the shield were taken into account, with special attention given to the contribution of bremsstrahlung which is produced by electrons and positrons. The results indicate that annihilation gamma rays from pair production do increase the buildup factor a little, but that the bremsstrahlung contribution is much more pronounced. The contribution of bremsstrahlung to the dose buildup factor reaches 33% of its total value for 8-MeV gamma rays traversing 5 mean-free-paths of lead. For single-material shields, the results agree well with the experiment. For double-material shields, comparison with experiment is not possible due to the lack of such data.
