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September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Deep geologic repository progress—2025 Update
Editor's note: This article has was originally published in November 2023. It has been updated with new information as of June 2025.
Outside my office, there is a display case filled with rock samples from all over the world. It contains a disk of translucent, orange salt from the Waste Isolation Pilot Plant near Carlsbad, N.M.; a core of white-and-bronze gneiss from the site of the future deep geologic repository in Eurajoki, Finland; several angular chunks of fine-grained, gray claystone from the underground research laboratory at Bure, France; and a piece of coarse-grained granite from the underground research tunnel in Daejeon, South Korea.
J. D. Galambos, Y-K. M. Peng, L. J. Perkins
Fusion Science and Technology | Volume 19 | Number 3 | May 1991 | Pages 1463-1468
ITER | Proceedings of the Ninth Topical Meeting on the Technology of Fusion Energy (Oak Brook, Illinois, October 7-11, 1990) | doi.org/10.13182/FST91-A29547
Articles are hosted by Taylor and Francis Online.
The nominal International Thermonuclear Experimental Reactor (ITER) configuration is a double-null (DN) divertor, which requires precise plasma vertical position control. Vertical displacements of only about 1 cm (out of a plasma height of 4.7 m) are estimated to destroy the up/down symmetric distribution of power flow to the divertor plates. As an alternate configuration to avoid this difficulty, we look at the single-null (SN) option, where all the charged power flow is deposited on the lower divertor plate. The primary consideration in this study is that of technology phase performance (maximum neutron wall load) for the ITER divertor heat load and plasma constraints. With regard to the divertor heat loads, the SN case has the advantages of (a) longer scrape-off field line connection lengths and (b) more vertical space, which allows a greater spreading of the heat load on the divertor plates. These advantages offset the SN case disadvantage of having fewer divertor plates, and therefore the potential for higher heat fluxes for a given core plasma condition. The attainable wall loads for the SN and DN divertors are found to be similar for steady-state and hybrid operation scenarios.