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.
Wenping Wang, Andrei Khodak, Irving Zatz, Alex Nagy, Peter Titus
Fusion Science and Technology | Volume 75 | Number 8 | November 2019 | Pages 828-834
Technical Paper | doi.org/10.1080/15361055.2019.1609822
Articles are hosted by Taylor and Francis Online.
The absolute collimator currently in service at the DIII-D NB injection system has experienced localized melting and damage. As part of the DIII-D 210-deg beamline co-counter conversion, a new absolute collimator was needed, and the opportunity to resolve melting was found on the off-axis beamline configuration. The pulsed high heat flux and uneven distribution of the heat loads required the aperture surface to be axially extended to spread out and reduce the surface heat flux. Geometric sculpting of the absolute collimator aperture based on the baseline dimension was performed using ANSYS CFX software. The reshaped absolute collimator aperture surface reduces the impinged heat flux to below ~4 MW/m2. Two interchangeable inserts are designed to occupy the high heat flux region for mitigating the thermal-induced stresses. The design achieves the objective of 6-s pulse lengths with 10-min repetition rates using the original peripheral conduit cooling system in the new collimator with minor changes.