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.
M. S. Vorenkamp, A. Nagy, A. Bortolon, R. Lunsford, R. Maingi, D. K. Mansfield, A. L. Roquemore
Fusion Science and Technology | Volume 72 | Number 3 | October 2017 | Pages 488-495
Technical Note | doi.org/10.1080/15361055.2017.1335144
Articles are hosted by Taylor and Francis Online.
An impurity granule injector on the DIII-D tokamak (IGI) injects granules into the plasma to trigger Edge Localized Modes (ELMs). Impurities, such as lithium, carbon, and boron, are used. The IGI drops granules (0.3–1.0 mm diameter) from a four chamber segmented storage hopper into a down-tube. The downtube guides the granules into a spinning impeller, rotating at a maximum frequency of 170 hz. The granules’ collisions with the impeller propel the granules (maximum velocity 120 m/s) through a drift tube, through an open torus interface valve shield, and into the plasma. This device underwent substantial upgrades to improve its functionality, to minimize the device footprint, and to automate post injection analysis. Upgrades include: (1) a drop-tube positioner to account for impeller/granule collision trajectories; (2) a granule drop monitor using an LED and a photodetector in the drop-tube; (3) a photodiode based granule ablation monitor; (4) DC isolation from the DIII-D vacuum vessel; and (5) an electric motor impeller drive with an integrated rotational speed sensor. These modifications improved the operability and efficiency of the IGI, leading to the successful triggering of ELMs using gasless impurity injection. These recent upgrades are discussed in detail.