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2025 ANS Annual Conference
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Chicago, IL|Chicago Marriott Downtown
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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
Benjamin M. Chase, Anthony W. LaPorta, James R. Parry
Nuclear Technology | Volume 205 | Number 10 | October 2019 | Pages 1312-1324
Technical Paper | doi.org/10.1080/00295450.2019.1585162
Articles are hosted by Taylor and Francis Online.
A core characterization process was completed as part of the Transient Reactor Test Facility (TREAT) restart project. The core characterization process is normally performed following a reconfiguration of the TREAT core. This characterization process includes performance of three temperature-limited transients. Prior to performing the transients, analysis is performed using KENO-VI to determine the high-temperature locations and the initiating reactivities for each transient. The point-kinetics code Simulating TREAT Reactor Kinetics (STREK) is used to estimate the peak power, peak temperature, and total energy deposition in the core. STREK also provides plots of pertinent parameters as functions of time to observe time-dependent behavior of the transient. After the transients are complete, the resulting data from these transients are used to develop operating limits for continued operation with the core configuration being characterized. The three transients for the characterization are performed in a progression of increasing initiating reactivity. The first transient has an initiating reactivity of 1.8%Δk/k. The second transient has an initiating reactivity of 3.0%Δk/k. The third transient has an initiating reactivity of 3.85%Δk/k. After the first two transients are performed, a two-point extrapolation of the data is used to determine a temporary estimate of the core operating limits. Once the third transient is complete, the resulting data are fit to an equation, and a three-point extrapolation of the operating limits for the core configuration is generated. This completes the characterization process and provides conservative limits for transient operation of TREAT.