This progress report documents the progress of the ECN contribution in the High Active Waste experiment, a large-scale in situ test being performed underground at the Asse salt mine in Remlingen FRG, during the period July 1st through December 31st, 1990. In ch. 2 a general overview is given of the experiment development. Problems and solutions are discussed in ch. 3. (author). 3 refs.; 10 figs.