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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
Yasuki Kowata, Nobuo Fukumura
Nuclear Science and Engineering | Volume 99 | Number 4 | August 1988 | Pages 299-312
Technical Paper | doi.org/10.13182/NSE88-A23560
Articles are hosted by Taylor and Francis Online.
Using the substitution method combined with the pulsed neutron technique, coolant void reactivities of PuO2-UO2 fuel lattices in pressure-tube-type heavy water reactors have been determined as functions of PuO2 enrichment in PuO2-UO2 (0.54 and 0.87 wt%), fissile content of plutonium (91 and 75% fissile plutonium), lattice pitch (Vm/Vf: 7.4 and 9.9), and coolant void fraction (0, 30, 70, 87, and 100%). The reference loading of 1.2 wt% enriched UO2 clusters was progressively replaced by PuO2-UO2 test clusters. The void reactivities were obtained from Simmons and King’s formula in which correction was made for a change of the prompt generation time. As decay constants can be maintained invariable due to substitution, buckling differences were analyzed by the first-order perturbation method, on the assumption that lattices are homogeneous and no difference in diffusion coefficients exists between the two lattices. Void reactivities of test lattices were determined with an accuracy of ∼10% when the minimum number of test fuel clusters was ∼5% of the total. The void reactivity shifted farther to the negative side as the proportion of fissile plutonium was increasingly in the PuO2-UO2 fuel of the same enrichment of plutonium.
