**Acknowledgements**

Special mention is offered to the International Atomic Energy Agency – IAEA for its permanent support to CNAAL, represented in technical assistance, expert missions, equipments and spare parts, trainings and scientific visits in order to strengthen our scientific capacities. Thanks are due to Mr. Peter Bode (TU-Delft) for his invaluable assistance. Acknowledgement is made to Mr. Oscar Paredes Zapata, General Director of Colombian Geological Survey, for his assistance. The authors also thank to Mr. Fernando Mosos, Technical Director of Nuclear Affairs Division for his support.
