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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
W. G. Winn, P. B. Parks, N. P. Baumann, C. E. Jewell
Nuclear Science and Engineering | Volume 65 | Number 2 | February 1978 | Pages 254-272
Technical Paper | doi.org/10.13182/NSE78-A27155
Articles are hosted by Taylor and Francis Online.
Unsymmetric perturbations were introduced into the core of a large, critical, heavy-water-moderated, multiregional reactor. The resulting three-dimensional changes in flux level and shape with time were measured. Perturbations included: 1. Free-fall insertion of rods near the reactor center. Each rod contained 235U slugs in the bottom half and lithium slugs in the top half 2. Free-fall insertion of rods into an off-center radial position. Each rod contained 235U slugs in the bottom half and aluminum in the top half. 3. Withdrawal of cadmium control rods from the central 20% of the reactor core. Flux tilts calculated with the TRIMHX code were within 5% of measured flux tilts. TRIMHX provides a three-dimensional (hex-z geometry) solution of the few-group neutron diffusion and delayed precursor equations without feedback. Inputs to the calculations are available in sufficient detail to allow other methods of solution to be tested.
