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Nuclear Energy Conference & Expo (NECX)
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.
H. Alan Robitaille, John S. Hewitt
Nuclear Science and Engineering | Volume 63 | Number 4 | August 1977 | Pages 391-400
Technical Paper | doi.org/10.13182/NSE77-A27056
Articles are hosted by Taylor and Francis Online.
The spectrum of neutrons in thermal pseudo-equilibrium with a mixture of partially hydrogenated terphenyls and high-boiling polymers, an organic material known commercially as HB40, has been measured at room temperature. The spectrum was measured in each of seven mixtures of HB40 and a thermal-neutron absorber, trimethyl borate, in various concentrations. The spectra were determined by the time-of-flight method using the University of Toronto linear electron accelerator as a pulsed source of fast neutrons. These spectra were compared with those calculated using several different bound-hydrogen approximations to the actual energy transfer kernel for the mixture. Of these approximations, the best agreement between theory and experiment occurred for a scattering kernel derived using the diphenyl and the polyethylene scattering kernels, combined according to a weighting scheme reflecting the degree of hydrogenation of the organic material.