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.
N. Tsoulfanidis, B. W. Wehring, M. E. Wyman
Nuclear Science and Engineering | Volume 43 | Number 1 | January 1971 | Pages 42-53
Technical Paper | doi.org/10.13182/NSE71-A21244
Articles are hosted by Taylor and Francis Online.
Previously, absolute measurements were reported for the time-dependent beta energy spectra from fission fragments for electron energies >0.75 MeV. The fragments were produced in the thermal-neutron fission of 235U. To obtain results for electron energies below 0.75 MeV and to provide overlap with the previous results, absolute measurements were made of the time-dependent energy spectra using an experimental system specifically designed for the electron energy range of 0.1 to 1.0 MeV. In this system, a vacuum chamber housed a thin plastic scintillator for the detection of the low-energy electrons, a source foil which was fissioned in a thermal-neutron beam, and a surface-barrier detector for the monitoring of the fission rate. The source foil consisted of 10.4 mg/cm2 of 235U covered and sealed to form a localized source of fission fragments. A deposit of 138 µg/cm2 of 235U on the outside of this foil facing the surface-barrier detector provided the fission fragments for the monitor. Electron energy spectra were measured for the cases of (i) spectrum build-up after initiation of a constant fission rate in a clean foil, (ii) spectrum decay after termination of 8 h of a constant fission rate, and (iii) spectrum decay following a sudden burst of fission produced by a reactor power pulse. The resulting spectra were corrected for the effects of energy resolution and source thickness by unfolding them with the use of a measured system response function. The time-dependent energy measurements for the low-energy betas were combined with the previous measurements for the high-energy betas and the results are presented in tables and graphs. Also given are the total number of betas per fission and the total beta energy per fission for various times during the build-up or the decay of the spectra. Comparisons are made with previous experimental and theoretical work.
