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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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!
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The newest era of workforce development at ANS
As most attendees of this year’s ANS Annual Conference left breakfast in the Grand Ballroom of the Chicago Downtown Marriott to sit in on presentations covering everything from career pathways in fusion to recently digitized archival nuclear films, 40 of them made their way to the hotel’s fifth floor to take part in the second offering of Nuclear 101, a newly designed certification course that seeks to give professionals who are in or adjacent to the industry an in-depth understanding of the essentials of nuclear energy and engineering from some of the field’s leading experts.
A. R. Massih
Nuclear Technology | Volume 205 | Number 7 | July 2019 | Pages 992-1001
Technical Note | doi.org/10.1080/00295450.2019.1568102
Articles are hosted by Taylor and Francis Online.
Oxidation of UO2 fuel under off-normal and normal reactor conditions occurs when fuel cladding fails, thereby allowing steam/water to enter the fuel rod. The steam/water will react with the fuel to produce UO2+x thus releasing hydrogen, with x standing for the amount of interstitial oxygen ions above the stoichiometric value.
In this technical note the impact of fuel oxidation on fission gas release (FGR) is modeled and discussed. The classical diffusion equation is used to describe migration and release of fission product gas (Xe) in UO2+x under time-varying postirradiation annealing conditions. We assume that the main quantity affected by fuel oxidation is the effective diffusivity of fission gas. Fuel oxidation enhances the diffusivity as a function of x in UO2+x in a parabolic fashion for 0.005 ≤ x ≤ 0.12 in the temperature range of 1000 ≤ T ≤ 1600 K. We first benchmark our model against an annealing test in which for x = 0.004 the Xe release fraction was measured as a function of time (temperature) during annealing. Furthermore, we apply the model to simulate a series of postirradiation annealing tests on UO2+x fuel, in which FGR fractions were measured for a given thermal ramp history in the range 0.00 ≤ x ≤ 0.66. The results of our computations in the range 0.004 ≤ x ≤ 0.20 show good agreement with measurements.
