Published online by Cambridge University Press: 10 February 2011
We have designed an apparatus which simulates the conditions of a deep geological repository in order to study the behaviour of spent fuel under leaching. A spent fuel and a Simfuel have thus been leached by synthesized clayey or granitic groundwater in sandy clay (90 % sand) or granite, in reducing conditions, at 90°C and 40 bars.
The apparent leach rate for spent fuel in clayey water is 3.33 µg.m−2.dr−1 in the presence of clay and 3.37 µg.m-−2.d−1 in the presence of granite. The apparent leach rate in granitic water is slower, being 0.37 µg.m−2d−1 in the presence of clay and 0.74 µg.m−2d−1 in the presence of granite.
For Simfuel, the apparent leach rate in clayey water is 7.4 µg.m−2.d−1 in the presence of clay and 1. 1 µg.m−2.d−1 in the presence of granite, which is the same order of magnitude as that for spent fuel. In granitic water, the apparent leach rate is 20 to 40 times greater than that for spent fuel. It is 14.8 µg.m−2.d−1 in the presence of clay and 18.5 µg.m−2.d−1 in the presence of granite.