In 1954 173 boxes with 20 mm ammunition m/39 were dumped in the lake Ala Lompolo outside of Kiruna. The reason was that the ammunition were considered to be unstable and that this was a simple and "safe" way to eliminate the problem. Later, a larger and more serious environmental problem has become more urgent. In LKAB's analysis large amounts of mercury compounds have been used and washed out in Ala Lompolo. Sweden has at national level decided that Ala Lompolo must be decontaminated and before this can start, the dumped ammunition must be taken away. This work will start in the summer 2013 and be completed in 2014. FOI will assist with risk assessments and suggest solutions that minimize the risk of injury to operating personnel and civilians in the area. Knowledge of the sensitivity of the ammunition and the risk for mass detonation is currently inadequate. Since the sensitivity of the ammunition has not been examined, FOI has to base the risk assessment on "worst case", i.e. that the ammunition is very sensitive to impact and electrostatic discharge based on previous studies [3][4]. Knowledge of the risk of mass detonation is currently non-existent and, therefore, this risk cannot be excluded until experimental tests have been made.