Micans releases new report about bentonite clay

2015-10-23

A new report that deals with the importance of high density of the protective bentonite clay in Sweden's future final repository of spent nuclear fuel has recently been published.

Bentonite clay will be placed around the canisters of copper containing the spent radioactive fuel. The clay works here as a buffer against inward and outward transportation of hazardous substances and protect the canister against rock movements. What density the clay should have has long been discussed and this is particularly important from a microbial standpoint. A low density gives bacteria found inside the clay opportunity to become active when the clay comes in contact with water from surrounding groundwater fractures. Since no oxygen will be present deep in the bedrock where the canisters are planned to be buried these microbes breathe with sulphate instead of oxygen. This sort of metabolism produces corrosive sulfide, which can cause problems such as pitting corrosion of the canisters. In this new report Micans has investigated microbial activity in two different clay densities for a particular type of bentonite clay.