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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
L. L. Carter, N. J. McCormick
Nuclear Science and Engineering | Volume 39 | Number 3 | March 1970 | Pages 296-310
Technical Paper | doi.org/10.13182/NSE70-A19991
Articles are hosted by Taylor and Francis Online.
A scheme is devised which combines in a coupled manner the sampling from the transport equation and the adjoint transport equation to improve the sampling for a functional such as the space- and velocity-dependent neutron distribution due to a given source distribution. Specific use is made of sampling from the transport equation to construct a scheme for a near-optimal subsequent sampling from the adjoint equation, even when inelastic scattering is present. The energy-dependent reciprocity relation is utilized to relate the solution of the adjoint equation to that of the transport equation itself. This procedure may be expected to be advantageous when the phase-space volume contributing to the functional in the region of interest is smaller than that volume in the source region. Numerical results demonstrate that calculation times in two example problems can be significantly reduced with the coupled sampling approach.
