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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).
R. T. Santoro, R. G. Alsmiller, Jr., J. M. Barnes, G. T. Chapman
Nuclear Science and Engineering | Volume 78 | Number 3 | July 1981 | Pages 259-272
Technical Paper | doi.org/10.13182/NSE81-A20303
Articles are hosted by Taylor and Francis Online.
Integral experiments that measure the transport of ∼14-MeV deuterium-tritium (D-T) neutrons through laminated slabs of proposed fusion reactor shield materials have been carried out at the Oak Ridge National Laboratory. Measured and calculated neutron and gamma-ray energy spectra are compared as a function of the thickness and composition of Type 304 stainless steel, borated polyethylene (BP), and Hevimet (a tungsten alloy), and as a function of detector position behind these materials. The measured data were obtained by means of an NE-213 liquid scintillator using pulse-shape discrimination methods to resolve neutron and gamma-ray pulse-height data and spectral unfolding methods to convert these data to energy spectra. The calculated data were obtained using two-dimensional discrete-ordinates radiation transport methods in a complex calculational network that takes into account the energy-angle dependence of the D-T neutrons and the nonphysical anomalies of the Sn method. The transport calculations incorporate ENDF/B-IV cross-section data from the VITAMIN C data library. The measured and calculated neutron energy spectra are in good agreement behind slab configurations of Type 304 stainless steel and BP (∼10% for all neutron energies >850 keV). When 5 cm of Hevimet are added to a 45-cm-thick Type 304 stainless steel plus BP slab assembly, the agreement is less favorable. The agreement among the measured and calculated gamma-ray spectra for energies >750 keV ranges from ∼25% to a factor of ∼5 depending on the slab composition.