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
2026 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
Latest Magazine Issues
Jun 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
July 2026
Nuclear Technology
June 2026
Fusion Science and Technology
May 2026
Latest News
Antares achieves zero-power criticality at INL
Leveraging more than $140 million in private capital fundraising, over 322,000 square feet of operational manufacturing space, and multifaceted partnerships with the Departments of Energy and Defense, reactor start-up Antares has become the first company involved in the Reactor Pilot Program to achieve zero-power fueled criticality—a full month ahead of the July 4 deadline set by President Trump’s Executive Order 14301.
This milestone, announced yesterday, was achieved with the company’s Mark-0: a sodium heat-pipe-cooled, TRISO-fueled microreactor. The Mark-0 is a forerunner to the company’s flagship design, which it calls the R1. For Antares, this development represents a key validation of its reactor physics, control systems, and supply chain.
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.