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.
Cen Wei, Bao-Wen Yang, Bin Han, Aiguo Liu
Nuclear Technology | Volume 205 | Number 1 | January-February 2019 | Pages 328-337
Technical Paper | doi.org/10.1080/00295450.2018.1510266
Articles are hosted by Taylor and Francis Online.
Mixing vanes attached to a space grid play an important role in heat transfer enhancement, thus increasing critical heat flux. Subchannel analysis and computational fluid dynamics (CFD) are usually applied to simulate the coolant flow behavior in a fuel assembly. In subchannel analysis, the mixing effect, mainly turbulent mixing, produced by mixing vane grids (MVGs) is represented by a coefficient β without considering flow direction and mixing vane arrangement. However, in CFD computation, the mixing effect can be simulated more closely. The objective of this paper is to evaluate the mixing coefficient β used in subchannel analysis by a CFD code. Then, the effects of the three MVGs are compared qualitatively and quantitatively.
Through the analysis, an effective mixing coefficient adopted in the subchannal codes should be related to the vane arrangement. Improvements for β are needed to better reflect the true mixing function from the spacer grid relevant to its mixing vane arrangement. Besides the lateral velocity distribution, secondary flow intensity, temperature distribution, and thermal nonuniformity are different for different vane arrangement patterns.
