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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. T. Hogan, N. A. Uckan
Fusion Science and Technology | Volume 19 | Number 3 | May 1991 | Pages 1504-1508
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-A29554
Articles are hosted by Taylor and Francis Online.
The MHD stability limits to the operational space for the International Thermonuclear Experimental Reactor (ITER) have been examined with the PEST ideal stability code. Constraints on ITER operation have been examined for the nominal operating scenarios and for possible design variants. Rather than relying on evaluation of a relatively small number of sample cases, the approach has been to construct an approximation to the overall operational space and to compare this with the observed limits in high-β tokamaks. An extensive database with ∼20,000 stability results has been compiled for use by the ITER design team. Results from these studies show that the design values of the Troyon factor (g ∼ 2.5 for ignition studies and g ∼ 3 for the technology phase), which are based on present experiments, are also expected to be attainable for ITER conditions, for which the configuration and wall-stabilization environment differ from those in present experiments. Strongly peaked pressure profiles lead to degraded high-β performance. Values of g ∼ 4 are found for higher safety factor (qψ ≥ 4) than that of the present design (qψ ∼ 3). Profiles with q(0) < 1 are shown to give g ∼ 2.5, if the current density profile provides optimum shear. The overall operational spaces are presented for g-qψ, qψ-li, q-αp, and li-qψ.