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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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The journey of the U.S. fuel cycle
Craig Piercycpiercy@ans.org
While most big journeys begin with a clear objective, they rarely start with an exact knowledge of the route. When commissioning the Lewis and Clark expedition in 1803, President Thomas Jefferson didn’t provide specific “turn right at the big mountain” directions to the Corps of Discovery. He gave goal-oriented instructions: explore the Missouri River, find its source, search for a transcontinental water route to the Pacific, and build scientific and cultural knowledge along the way.
Jefferson left it up to Lewis and Clark to turn his broad, geopolitically motivated guidance into gritty reality.
Similarly, U.S. nuclear policy has begun a journey toward closing the U.S. nuclear fuel cycle. There is a clear signal of support for recycling from the Trump administration, along with growing bipartisan excitement in Congress. Yet the precise path remains unclear.
Churl Yoon, Joo Hwan Park
Nuclear Technology | Volume 160 | Number 3 | December 2007 | Pages 314-324
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT07-A3902
Articles are hosted by Taylor and Francis Online.
The fluid flows going through the Canada Deuterium Uranium (CANDU) moderator inlet diffuser assembly consist of a pipe flow, a curved pipe flow, and an impinging jet. For predicting the velocity profile at the diffuser outlet faces, a computational fluid dynamics (CFD) analysis has been performed to simulate the internal flow in the diffuser assembly. For the validation of a CFD code, some experimental data were chosen for each flow, and various turbulence models were examined. The shear stress transport turbulence model was proven to be the most appropriate for a prediction of the impinging jets and to give better predictions for a curved pipe flow compared to the standard k-[curly epsilon] turbulence model. As a result of the investigation, detailed velocity profiles and turbulent parameters at the real diffuser outlets were obtained, which can be applied as an inlet boundary condition for the CANDU moderator analysis.