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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!
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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
G. W. Weber, R. L. Beatty, V. J. Tennery
Nuclear Technology | Volume 35 | Number 2 | September 1977 | Pages 217-226
Fabrication | Coated Particle Fuel / Fuel | doi.org/10.13182/NT77-A31881
Articles are hosted by Taylor and Francis Online.
The current recycle fissile fuel for steam cycle high-temperature gas-cooled reactors in the U.S. is derived from weak acid ion-exchange resin microspheres loaded with uranyl ions. This material offers great versatility in the control of chemical and physical properties through careful process control. Processing the upgraded loaded resin begins with thermal decomposition or carbonization, which yields finely dispersed UO2 in a porous carbon matrix. This step requires a controlled heating rate from 350 to 450O°C (623 to 723 K), and is complete by ∼900°C (1173 K). If carbide or mixed-oxide/carbide fuel is desired, carbothermic reduction, or conversion, is done at 1500 to 1750°C (1773 to 2023 K). This step reduces the UO2 to UC2 to optimize irradiation performance. Physical properties after carbonization correlate with the observed thermogravimetric behavior. The mercury density, volume decrease, weight loss, bulk density, carbon content, and particle size depend strongly on the particular heating rate employed through the 350 to 450°C (623 to 723 K) region. The conversion process generally follows the anticipated thermodynamic behavior for removal of carbon monoxide based on its partial pressure. The particular phases present after conversion can be manipulated by controlling the conversion temperature or by additions of hydrogen or carbon monoxide to the fluidizing gas.
