Mineralogy of selected geological deposits from the United Kingdom and the Republic of Ireland as possible capping materials for low-level radioactive waste disposal facilities

Solid low-level radioactive waste (LLW) is currently being disposed at a number of facilities in the United Kingdom (UK). The safety of these facilities relies to some extent on the use of engineered barriers, such as a cap, to isolate the waste and protect the environment. Generally, the material used as the barrier layer within such a cap should be of low permeability and it should retain this property over long timescales (beyond a few decades normally required for facilities containing non-radioactive wastes). The objective of this research is to determine the mineralogy of selected geological deposits from the UK and Ireland as part of a larger project to examine their suitability as a capping material, particularly on LLW sites. Mineral transformations, as a result of future climate change, may impact on the long-term performance of the cap and even the disposal facility. X-ray diffraction (XRD) was carried-out on the sand, silt and clay fractions of the London Clay, Belfast Upper Boulder Clay, Irish Glacial Till, Belfast Sleech, and Ampthill Clay geological deposits. Minerals were present that could pose both positive and negative effects on the long-term performance of the cap. Smectite, which has a high shrink swell potential, may produce cracks in London Clay, Belfast Upper Boulder Clay and Ampthill Clay capping material during dry, hotter periods as a possible consequence of future climate change; thus, resulting in higher permeability. Ampthill Clay and Belfast Sleech had elevated amounts of organic matter (OM) at 5.93% and 5.88%, respectively, which may also contribute to cracking. Over time, this OM may decompose and result in increased permeability. Gypsum (CaSO4) in the silt and sand fractions of Ampthill Clay may reduce the impact of erosion during wetter periods if it is incorporated into the upper portion of the cap. There are potential negative effects from the acidity created by the weathering of pyrite (FeS2) present in the silt and sand fractions of Belfast Sleech and Ampthill Clay that could impede the growth of grasses used to stabilize the surface of the capping material if this material is used as part of the vegetative soil layer. Additionally, acidic waters generated from pyrite weathering could negatively impact the lower lying capping layers and the disposal facility in general. However, the calcium carbonate (CaCO3) present in the silt and sand fractions of these deposits, and dolomite (CaMg(CO3)2) in Belfast Sleech, may counter act the acidity.

Proposed site-selection criteria for a low-level radioactive waste disposal facility /

"August 16, 1995."

Site-selection criteria for a low-level radioactive waste disposal facility /

"December 19, 1996."

Summary of responses to issues raised by public comment in reference to Site selection criteria for a low-level radioactive waste disposal facility /

"December 19, 1996."

Statewide screening activities for Illinois' low-level radioactive waste (LLRW) disposal facility : final report to the Illinois Low-Level Radioactive Waste Task Group and the director, Illinois Department of Nuclear Safety /

"This report was prepared under a contract with the Illinois Dept. of Nuclear Safety (IDNS) in support of the Illinois Low-Level Radioactive Waste Task Group. Numerous staff members of the Illinois State Geological Survey (ISGS) and the Illinois State Water Survey (ISWS) contributed to this report, which was compiled under the general administrative direction of Bill Shilts and Derek Winstanley, Chiefs of the ISGS and ISWS, respectively."--P. iv.

Hydrogeology of a low-level radioactive-waste disposal site near Sheffield, Illinois /

Mode of access: Internet.

Martinsville : report of the Illinois Low-Level Radioactive Waste Disposal Siting Commission on its inquiry into the Martinsville alternative site /

Includes bibliographical references.

Quaternary geology of the Martinsville alternative site, Clark County, Illinois : a proposed low level radioactive waste disposal site /

Includes bibliographical references (p. 81-83).

The determination of three selected sites for the construction and operation of a low level radioactive waste storage and burial facility

Radioactive wastes are by-products of the use of radiation technologies. As with many technologies, the wastes are required to be disposed of in a safe manner so as to minimise risk to human health. This study examines the requirements for a hypothetical repository and develops techniques for decision making to permit the establishment of a shallow ground burial facility to receive an inventory of low-level radioactive wastes. Australia’s overall inventory is used as an example. Essential and desirable siting criteria are developed and applied to Australia's Northern Territory resulting in the selection of three candidate sites for laboratory investigations into soil behaviour. The essential quantifiable factors which govern radionuclide migration and ultimately influence radiation doses following facility closure are reviewed. Simplified batch and column procedures were developed to enable laboratory determination of distribution and retardation coefficient values for use in one-dimensional advection-dispersion transport equations. Batch and column experiments were conducted with Australian soils sampled from the three identified candidate sites using a radionuclide representative of the current national low-level radioactive waste inventory. The experimental results are discussed and site soil performance compared. The experimental results are subsequently used to compare the relative radiation health risks between each of the three sites investigated. A recommendation is made as to the preferred site to construct an engineered near-surface burial facility to receive the Australian low-level radioactive waste inventory.

Development of a method for plasma - induced combustion of intermediate to low-level radioactive waste

This work demonstrates that the plasma - induced combustion of intermediate to low-level radioactive waste is a suitable method for volume reduction and stabilization. Weaknesses of existing facilities can be overcome with novel developments. Plasma treatment of LILW has a high economical advantage by volume reduction for storage in final repositories.

Permeability of covers over low-level radioactive-waste burial trenches, West Valley, Cattaraugus County, New York /

Bibliography: p. 34-35.

Annual report on the survey of low-level radioactive waste generators in Illinois for ...

Latest issue consulted: 1985.

Interim management plan for low-level radioactive waste in Illinois, 1986-1992 : draft /

"May, 1985."

Low-level radioactive waste : near-term management options for Illinois : a report to Governor James R. Thompson and the 83rd General Assembly /

Cover title.