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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.
J. T. Fisher, J. W. Leachman
Fusion Science and Technology | Volume 68 | Number 2 | September 2015 | Pages 388-391
Technical Paper | Proceedings of TOFE-2014 | doi.org/10.13182/FST14-970
Articles are hosted by Taylor and Francis Online.
Flow and heat transfer measurements of solid hydrogenic materials inside twin screw extruders are not available. Fusion tokamaks like ITER require fuel pellet injection at 99.9% reliability which requires validated twin screw extruder throughput models for operation. The throughput of an extruder is limited by the amount of leakage flow through clearance gaps which depends on flow properties that vary strongly with temperature for hydrogenic materials. A Diagnostic Twin Screw Extruder (DTSE) has been built to measure azimuthal and axial temperature distributions as well as torque, cooling power, and screw speed for H2, D2, and Ne extrusions. In this paper the experimental procedure for the DTSE is described and azimuthal temperature measurements at three locations along the screws are discussed. The results show variations in temperature as large as 0.5 K azimuthally and >0.5 K axially. The overall temperatures stay close to the solidification temperature and therefore support high backflow and explain extrudate stall scenarios experienced in other hydrogenic twin screw extruders. This temperature data is therefore useful to size tolerance gaps in future extruder designs and enables refinement of predictive models for continuous operation.
