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.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Sep 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
From operator to entrepreneur: David Garcia applies outage management lessons
David Garcia
If ComEd’s Zion plant in northern Illinois hadn’t closed in 1998, David Garcia might still be there, where he got his start in nuclear power as an operator at age 24.
But in his ninth year working there, Zion closed, and Garcia moved on to a series of new roles—including at Wisconsin’s Point Beach plant, the corporate offices of Minnesota’s Xcel Energy, and on the supplier side at PaR Nuclear—into an on-the-job education that he augmented with degrees in business and divinity that he sought later in life.
Garcia started his own company—Waymaker Resource Group—in 2014. Recently, Waymaker has been supporting Holtec’s restart project at the Palisades plant with staffing and analysis. Palisades sits almost exactly due east of the fully decommissioned Zion site on the other side of Lake Michigan and is poised to operate again after what amounts to an extended outage of more than three years. Holtec also plans to build more reactors at the same site.
For Garcia, the takeaway is clear: “This industry is not going away. Nuclear power and the adjacent industries that support nuclear power—and clean energy, period—are going to be needed for decades upon decades.”
In July, Garcia talked with Nuclear News staff writer Susan Gallier about his career and what he has learned about running successful outages and other projects.
José Canosa, Harvey Brooks
Nuclear Science and Engineering | Volume 26 | Number 2 | October 1966 | Pages 237-253
Technical Paper | doi.org/10.13182/NSE66-A28166
Articles are hosted by Taylor and Francis Online.
The xenon-induced oscillations in the power level (fundamental mode) and in the power distribution (first harmonic) have been studied for a slab reactor with prompt power reactivity feedback. One-group space-dependent kinetics equations and linearized theory are used throughout. The linear analysis rigorously predicts the onset of xenon oscillations; however, it does not say anything on how much the oscillation amplitude grows or decays. Explicit formulas giving the effects of the coupling of the infinite number of reactor modes with the fundamental mode and first harmonic are obtained and used for the first time to explain mode-coupling effects both qualitatively and quantitatively. Mode-coupling effects are quite small at the thermal flux levels of present power reactors [1013−1014 n/(cm2sec)]. At higher fluxes [1015 n/(cm2sec)] mode coupling is destabilizing and might be significant; here the negative feedback reactivity needed to provide stability must be increased by ≈ 10%, relative to the value obtained from a calculation where coupling is neglected. A study has been made on the influence of the equilibrium power distribution on both types of oscillations; this study gives information concerning the effects of a reflector on reactor kinetics. A new result is that, depending on flux level, a reflected reactor may be more stable than a bare reactor against fundamental mode oscillations.
