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
Robotics & Remote Systems
The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Mar 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
March 2025
Nuclear Technology
Fusion Science and Technology
April 2025
Latest News
Nuclear News 40 Under 40 discuss the future of nuclear
Seven members of the inaugural Nuclear News 40 Under 40 came together on March 4 to discuss the current state of nuclear energy and what the future might hold for science, industry, and the public in terms of nuclear development.
To hear more insights from this talented group of young professionals, watch the “40 Under 40 Roundtable: Perspectives from Nuclear’s Rising Stars” on the ANS website.
A. M. Christie, C. G. Poncelet
Nuclear Science and Engineering | Volume 51 | Number 1 | May 1973 | Pages 10-24
Technical Paper | doi.org/10.13182/NSE73-A23253
Articles are hosted by Taylor and Francis Online.
The control of spatial xenon-induced oscillations in large power reactors is considered from the point of view of practical operator manual control. A control strategy is developed based on control theory concepts and considerations of the physics of the problem. It is shown that oscillations can be eliminated by a simple control action consisting of positioning a control rod in a specified location for a specified length of time; upon retrieval of the control rod to its equilibrium position, the flux, xenon and iodine distributions will have returned to equilibrium conditions. A control equation is derived from which the control rod insertion time and the duration of control can be calculated. For large pressurized water reactors of current and anticipated designs, control rod insertion times are in the range from one to four hours before the peak in the oscillation, while control times vary from one-half to two hours. Digital diffusion theory simulations are described which tend to verify the control concepts developed in the paper. Constraints in local power peaking are introduced by considering control at off-optimal times. The study provides guidelines for operator control which is near optimal in the sense that control actions are minimized in number and are most effective in terms of eliminating the oscillation.