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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.
B. Boer, A. M. Ougouag, J. L. Kloosterman, G. K. Miller
Nuclear Technology | Volume 162 | Number 3 | June 2008 | Pages 276-292
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT08-A3956
Articles are hosted by Taylor and Francis Online.
The PArticle STress Analysis (PASTA) code was written to evaluate stresses in coated particle fuel embedded in graphite of high-temperature reactors (HTRs). Existing models for predicting stresses in coated particle fuels were extended with a treatment of stresses induced by dimensional change of the matrix graphite and stresses caused by neighboring particles.PASTA was applied to two practical cases in order to evaluate the significance of this model extension. Thermal hydraulics, neutronics, and fuel depletion calculation tools were used to calculate the fuel conditions in these cases. Stresses in the first fuel loading of the High-Temperature Engineering Test Reactor (HTTR) and in the fuel of a 400-MW(thermal) pebble bed reactor were analyzed.It is found that the presence of the matrix material plays a significant role in the determination of the stresses that apply to a single isolated TRISO particle as well as in the transmittal of the stresses between particles in actual pebble designs.
