Cement technology for plugging boreholes in radioactive-waste-repository sites. Progress report, October 1, 1978-September 30, 1979

Abstract

Laboratory evaluations were made of several borehole plug formulations proposed for the Bell Canyon field test. Measurements included compressive strength, permeability, density, and thermal conductivity. A few preliminary tests with saltcrete formulations showed no significant difference in physical properties of the solid as a function of fly ash or cement composition. The saltcrete proposed for the field test gave acceptable pushout strength and permeability values using miniature borehole plugs in anhydrite. Similar labora tory tests made with a freshwater formulation indicated high permeability. Electron micrographs showed dissolution cavJties or cracks at the plug-wall interface. These studies showed that the reactions occurring between the borehole plug and the adjacent rock wall are an important factor in obtain ing a good seal and that laboratory tests are useful to indi cate the possibility of success or failure of field tests. Abstracts of separate reports on permeability exp^iiments and systematic studies of pozzolanic cement and s~ tcretes are included.

Laboratory Studies of Fluid Flow Through Borehole Seals

“…In a related study Rhoderick and Buck (1981) Moore et al (1979) and by McDaniel (1980). Shrinkage of neat cement pastes and saltcretes varied approximately linearly with time, but cement/fly-ash solids exhibited a high lSaltcrete is a standard mortar with 10 to 30 wt % salt added.…”