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
Aug 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
September 2026
Nuclear Technology
Fusion Science and Technology
August 2026
Latest News
NRC issues draft EA/FONSI for Duane Arnold restart
Efforts by NextEra Energy to restart the Duane Arnold nuclear power plant as early as 2029 continue to move forward with the Nuclear Regulatory Commission's preliminary environmental assessment and determination that the restart would have no significant environmental impacts.
On Thursday, the NRC posted a draft environmental assessment and a finding of no significant impact for the Palo, Iowa, facility; the Federal Register notice was published on Monday. The Department of Energy’s Office of Energy Dominance Financing is a cooperating agency on the draft EA, as the DOE is considering providing financial assistance to the restart project.
T. K. Mau, T. B. Kaiser, A. A. Grossman, A. R. Raffray, X. R. Wang, J. F. Lyon, R. Maingi, L. P. Ku, M. C. Zarnstorff, ARIES-CS Team
Fusion Science and Technology | Volume 54 | Number 3 | October 2008 | Pages 771-786
Technical Paper | Aries-Cs Special Issue | doi.org/10.13182/FST08-27
Articles are hosted by Taylor and Francis Online.
The critical issue of divertor configuration for heat and particle flux control in a conceptual ARIES compact stellarator (CS) reactor is addressed. The goal is to determine a divertor location and geometry with a peak heat load of not more than 10 MW/m2 for a CS equilibrium based on the configuration to be used in the NCSX experiment, optimized for high beta (6.4%) and designed for low alpha-particle power loss fraction (5%). The surface heat flux on the target has three components: thermal particles, lost energetic alphas, and radiation from the core and the scrape-off layer. The first two components are dominant and their magnitudes can be comparable. To maintain a tritium-breeding ratio of 1.1, the total target area should not exceed 15% of the boundary plasma surface area. The divertor concept consists of two pairs of target plates per field period, one pair each at the top and bottom of the plasma. The heat flux profile is assessed by assuming that the parallel transport can be represented by field line mapping and that cross-field transport can be modeled with a prescribed field line diffusion scheme. In this manner, the poloidal and toroidal extents of the plates and their shape and distance to the plasma are designed to intercept all the heat flux and to minimize the peak thermal heat load. An approximate scheme, based on particle drift orbits in the core and field line tracing in the edge, is derived to estimate the alpha-particle heat load distribution over the plates and the first wall. The best plate configuration to date yields total peak heat loads (thermal + alpha) ranging from 5 to 18 MW/m2. Further optimization of the target plates is required to reach the design goal, which will be addressed in a future study.