The second European Commission Cluster URLs Seminar (Club of Underground Storage, TEsting and Research facilities for radioactive waste disposal) was held at the Belgian nuclear research centre in Mol, Belgium on 27 and 28 September 2001. This event was the second in the series. A first seminar on 'in situ testing in underground research laboratories for radioactives waste' was held in Alden Biesen, Belgium, on 10 and 11 December 1997, see EUR 18323 EN.