ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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!
Latest Magazine Issues
Oct 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
November 2025
Nuclear Technology
October 2025
Fusion Science and Technology
Latest News
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.
Joel H. Ferziger, Alan H. Robinson
Nuclear Science and Engineering | Volume 21 | Number 3 | March 1965 | Pages 382-389
Technical Paper | doi.org/10.13182/NSE65-A20041
Articles are hosted by Taylor and Francis Online.
The disadvantage factor of a two-region slab lattice has been calculated using Case's formalism in one-velocity transport theory. Although the problem has not been solved exactly, the Fredholm equations for the expansion coefficients which are derived converge extremely rapidly under iteration. For the numerical calculations, an IBM-7090 code based on the results has been written; the disadvantage factor can be calculated with this code in two seconds. The problem treated in this paper is highly idealized, but Case's formalism admits extensions and may lead to efficient means of calculating disadvantage factors for more realistic models; some of the extensions will be given in a later paper.
