ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
May 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
July 2025
Nuclear Technology
June 2025
Fusion Science and Technology
Latest News
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
Lynn E. Weaver, Robert E. Vanasse
Nuclear Science and Engineering | Volume 29 | Number 2 | August 1967 | Pages 264-271
Technical Paper | doi.org/10.13182/NSE67-A18536
Articles are hosted by Taylor and Francis Online.
This paper presents an approach to reactor control that is a result of modern control theory, and is based on the control philosophy of feeding back all the state variables through constant gain elements. The values of these elements or feedback coefficients depend upon the desired system dynamics which is specified in terms of the system transfer function. Through state variable feedback design, the desired system dynamics can be realized exactly. Simulation studies have shown that, for the models considered, the sensitivity of parameter variations with respect to system dynamics was relatively low. Since this method depends on feeding back all the system variables, it is particularly amenable to the control of multiregion reactors. With the recent emphasis on spatial kinetics, this method of reactor control is the logical next step. Consideration is given to the case when all the state or system variables are not available for measurement.
