The Kárahnjúkavirkjun hydropower plant dam is located on the high plateau below the Vatnajökull glacier in the eastern tundra of Iceland. The Hálslón reservoir feeds the 690 MW Fjotsdalur power plant. The dam and spillways are continuously maintained and repaired and VELOSIT systems have been used for this since 2019. So far, 8 tons of repair mortar (VELOSIT RM 203 and RM 202) and 10 tons of our sealing slurry VELOSIT WP 101 from MVA ehf have been installed. The conditions on the construction site only allow working with cementitious materials for a short period in summer. Even then, temperatures barely reach double-digit Celsius degrees, so a repair system in this environment has to harden quite quickly.The dam of the Kárahnjúkavirkjun hydropower plant is located on the high plateau below the glaciers of Vatnajökull in the eastern tundra of Iceland. The Hálslón reservoir feeds the 690 MW Fjotsdalur power plant. The dam and spillways are continuously maintained and repaired and VELOSIT systems have been used for this since 2019. So far, 8 tons of repair mortar (VELOSIT RM 203 and RM 202) and 10 tons of our sealing slurry VELOSIT WP 101 from MVA ehf have been installed. The conditions on the construction site only allow working with cementitious materials for a short period in summer. Even then, temperatures barely reach double-digit Celsius degrees, meaning that a repair system has to harden quite quickly in this environment.