The migration of Cs-137 through three different formulations of compressively stressed grout

The effect of uniaxial, unconfined compressive stress on 137Cs penetration into grouts containing either flyash, silica fume or no admixture was investigated. Cylinders from three formulations of grout were compressively stressed to either 0, 40, 70, or 90 percent of their construction strength, then placed into an apparatus which produced a hydrostatic pressure head gradient along the cylinder axis of 103 ± 21 kPa using the 137Cs salt solution. Cylinders were sliced into thin disks and the relative 137Cs quantity in each disk was measured. The use of admixtures resulted in decreased penetration of the 137Cs into the grout. Penetration was observed to go through a maximum near the mid-range stress values. (author)