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High-temperature plumbing and advanced reactors
The use of nuclear fission power and its role in impacting climate change is hotly debated. Fission advocates argue that short-term solutions would involve the rapid deployment of Gen III+ nuclear reactors, like Vogtle-3 and -4, while long-term climate change impact would rely on the creation and implementation of Gen IV reactors, “inherently safe” reactors that use passive laws of physics and chemistry rather than active controls such as valves and pumps to operate safely. While Gen IV reactors vary in many ways, one thing unites nearly all of them: the use of exotic, high-temperature coolants. These fluids, like molten salts and liquid metals, can enable reactor engineers to design much safer nuclear reactors—ultimately because the boiling point of each fluid is extremely high. Fluids that remain liquid over large temperature ranges can provide good heat transfer through many demanding conditions, all with minimal pressurization. Although the most apparent use for these fluids is advanced fission power, they have the potential to be applied to other power generation sources such as fusion, thermal storage, solar, or high-temperature process heat.1–3
Kiminori Shiba
Nuclear Science and Engineering | Volume 65 | Number 3 | March 1978 | Pages 492-507
Technical Paper | doi.org/10.13182/NSE78-A27180
Articles are hosted by Taylor and Francis Online.
Material bucklings have been determined as functions of 235U enrichment in UO2 (0.7, 1.2, and 1.5 wt% 235U), PuO2 enrichment in PuO2-UO2 (0.54 and 0.87 wt% PuO2), fissile content of plutonium (91 and 75% Pu-fissile), lattice pitch (Vmod/Vfuel: 7.4 and 9.9), and coolant void fraction. The reference loading of 1.2 wt% 235U-enriched UO2 clusters was progressively replaced by the test clusters. Buckling differences resulting from the substitutions were analyzed by the new second-order (iterative) perturbation method, on the assumption that neutron diffusion is isotropic and that no difference in diffusion coefficients exists between the two lattices. This analysis takes into account the effect of distortion in radial neutron flux distribution in the substituted core without any iterative correction procedure that is usually adopted in the first-order perturbation method. Also, it is not necessary in the case of the present analysis to introduce any usual intermediate region for taking into account the effect of spectrum mismatch between the two lattices. The material buckling differences between the test and reference lattices, which are in the range of −10.2 to 9.1 m−2, were determined within 3% of uncertainty.
