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Perry, Frank Vinton

Publications and source records attributed to Perry, Frank Vinton.

Regional Geologic Evaluations for Disposal of HLW and SNF: Alluvial Basins of the Basin and Range Province

The DOE Spent Fuel and Waste Technology (SFWT) R&D Campaign supports research on crystalline rock, shale (argillite) and salt as potential host rocks for disposal of HLW and SNF in a mined geologic repository. Modeling involving these host rocks for the generic GDSA reference cases has assumed saturated conditions at repository depths. In order to test two-phase flow capabilities of the GDSA flow and transport models, the SFWT Campaign is developing an unsaturated zone reference case. Alluvial basin-fill deposits within the Basin and Range province have unsaturated zones that can be as thick as 600 meters, although the thickness is typically much less. Basin-fill alluvium has been considered as a potential medium for HLW disposal in the US since the 1950s (NAS,1957; Smyth et al., 1979; Winograd, 1981). Attributes considered favorable for HLW disposal in alluvium in the Basin and Range province include an arid environment, low water flux , high sorption capacity (from clay s and zeolites), and ease of construction and stability of repository openings (Hardin et al., 2012). Hardin et al. (2012) also address the thermal issues inherent in the design of a HLW repository in alluvium with low thermal conductivity, which are not discussed in this report.

58 GEOSCIENCES↗

Regional Geologic Evaluations for Disposal of HLW and SNF: The Pierre Shale of the Northern Great Plains

The DOE Spent Fuel and Waste Technology (SWFT) R&D Campaign is supporting research on crystalline rock, shale (argillite) and salt as potential host rocks for disposal of HLW and SNF in a mined geologic repository. The distribution of these three potential repository host rocks is limited to specific regions of the US and to different geologic and hydrologic environments (Perry et al., 2014), many of which may be technically suitable as a site for mined geologic disposal. This report documents a regional geologic evaluation of the Pierre Shale, as an example of evaluating a potentially suitable shale for siting a geologic HLW repository. This report follows a similar report competed in 2016 on a regional evaluation of crystalline rock that focused on the Superior Province of the north-central US (Perry et al., 2016).

58 GEOSCIENCES↗

Generic Crystalline Disposal Reference Case

A generic reference case for disposal of spent nuclear fuel and high-level radioactive waste in crystalline rock is outlined. The generic cases are intended to support development of disposal system modeling capability by establishing relevant baseline conditions and parameters. Establishment of a generic reference case requires that the emplacement concept, waste inventory, waste form, waste package, backfill/buffer properties, EBS failure scenarios, host rock properties, and biosphere be specified. The focus in this report is on those elements that are unique to crystalline disposal, especially the geosphere representation. Three emplacement concepts are suggested for further analyses: a waste packages containing 4 PWR assemblies emplaced in boreholes in the floors of tunnels (KBS-3 concept), a 12-assembly waste package emplaced in tunnels, and a 32-assembly dual purpose canister emplaced in tunnels. In addition, three failure scenarios were suggested for future use: a nominal scenario involving corrosion of the waste package in the tunnel emplacement concepts, a manufacturing defect scenario applicable to the KBS-3 concept, and a disruptive glaciation scenario applicable to both emplacement concepts. The computational approaches required to analyze EBS failure and transport processes in a crystalline rock repository are similar to those of argillite/shale, with the most significant difference being that the EBS in a crystalline rock repository will likely experience highly heterogeneous flow rates, which should be represented in the model. The computational approaches required to analyze radionuclide transport in the natural system are very different because of the highly channelized nature of fracture flow. Computational workflows tailored to crystalline rock based on discrete transport pathways extracted from discrete fracture network models are recommended.

Environmental Protection↗