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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.
A. P. Mills, Jr.
Nuclear Science and Engineering | Volume 110 | Number 2 | February 1992 | Pages 165-167
Technical Papers | doi.org/10.13182/NSE92-A23885
Articles are hosted by Taylor and Francis Online.
It is argued that 79Kr is uniquely suited for an intense positron source. It can be produced by neutron activation of a rare, but available, stable isotope 78Kr; it has a convenient 35-h half-life; as a nonreactive gas, it can be transported and recycled in a closed system using automated valves without exposure of personnel; and it can be vapor deposited easily on a large area cold surface using a solid neon moderator to make a slow positron source with intensity (∼1011 s−1) limited only by the availability of neutrons and cryogenic refrigeration.
