A series of laboratory experiments are also being carried out by JNC (now JAEA).

Both column and batch experiments are underway to examine the alteration of the Grimsel rocks (fault gouge and Grimsel granite). The experimental set up is shown below.

Samples from the alteration experiments were then examined using a Scanning Electron Microscope (SEM). The images below clearly show the alteration of the samples subject to percolation of high pH solution.

SEM Analysis of high pH-altered rock