Deep Geologic Repositories
Deep Geologic Repositories reviews the success stories of underground waste isolation. It focuses on repositories that did, do, and will permanently and safely isolate dangerous materials from the near-surface biosphere. Complementary topics address the isolation capability of average crustal rock, investigations at one representative underground research laboratory, and the geologic preservation of fission products from Precambrian nuclear reactors. An international cast of contributors presents proven practical solutions to a formerly confounding issue in environmental and engineering geology: What do we do with wastes that retain their dangerous characteristics in human terms forever? The principal answer: Recycling into the lithosphere by “reverse” mining.
Geological disposal of radioactive waste—Experience from operating facilities in Sweden
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Published:January 01, 2008
Abstract
Geological disposal has been the basis for the Swedish program for disposal of radioactive waste since its beginning in the mid-1970s. Two underground facilities have been in operation since the late 1980s.
The construction of the final repository for short-lived, low- and intermediate-level waste, SFR (Swedish final repository for radioactive operational waste), started in 1983, and it was put into operation in 1988. The facility is located 50 m below the sea, close to the Forsmark nuclear power plant, where the sea has a depth of ∼5 m. Low-level waste is placed in four rock vaults, each of which has a length of 160 m. Intermediate-level waste is stored in a concrete silo that has a height of 50 m and an inner diameter of 26 m. The disposal vaults are connected to the surface by two parallel access tunnels. The total disposal capacity is 63,000 m3, of which about one-half is currently in use. An expansion of the SFR is planned to accommodate radioactive waste from the decommissioning of the nation's power plants.
Construction of the interim storage facility for spent nuclear fuel, Clab, started in 1980, and the facility was put into operation in 1985. The facility is located at the Oskarshamn nuclear power plant. The fuel assemblies are stored in water pools located in two 120-m-long rock chambers. The roof of the rock chambers is ∼30 m below the ground surface. Construction of a second storage vault has recently been completed.
The Äspö Hard Rock Laboratory is an underground facility for developing and testing characterization methods and the different components of a system for deep geological disposal under realistic repository conditions. The facility reaches a depth of 460 m below the surface. After 5 yr of construction, it was put into operation in 1995.
The licensing, construction, and operation of these facilities have provided valuable experience that is being used for the site characterization and design work currently in progress for the deep geological repository for spent nuclear fuel. The spent nuclear fuel will be disposed of in a repository located at depths between 400 and 700 m. The disposal concept is based on isolation of the spent fuel in copper canisters surrounded by a buffer of highly compacted bentonite placed in a borehole in granitic rock. Site investigations are currently in progress at two potential sites. This project is a major geoscientific undertaking that is planned to be completed in 2009 with the selection of one of the sites for the deep repository.