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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.
Yun-Je Cho, Hyoung-Kyu Cho, Goon-Cherl Park
Nuclear Technology | Volume 162 | Number 1 | April 2008 | Pages 92-106
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT08-A3935
Articles are hosted by Taylor and Francis Online.
Seoul National University (SNU) proposed a new concept of a reactor cavity cooling system (RCCS), which is a critical safety feature in high-temperature gas-cooled reactors. To provide reasonable experimental data for the code assessment and evaluate the feasibility of the proposed system, performance and integrity were tested by separate-effects test apparatuses and a reduced-scale mockup facility named RCCS-SNU. Calculations were performed using the MARS-GCR code for the validation of its capability to simulate multidimensional behavior, natural convective heat transfer, radiative heat transfer, etc. This assessment showed that the MARS-GCR code reasonably predicts the characteristics of the radiative heat transfer in the cavity and the forced convective heat transfer through the air-cooling pipes. However, the study showed deviation in the simulation of heat transfers that occur inside the cavity and water pool, especially the thermal stratification phenomenon. As a result, it was concluded that applying the system code with coarse node, MARS-GCR had certain limitations in the simulation of local phenomena.