The paper deals with the problems of risk assessment in Estonian oil shale mines, where room-and-pillar mining with blasting is applied. This paper examines the risks associated with the application of a new room-and-pillar mining technology using modern machines at the Estonia mine. The new mining technology is based on the transition from packet blasting to emulsion blasting, from 2.0 m boreholes to 4.0 m boreholes (ATLAS Copco machine) and on a new undercutting method (SMAG machine). With this equipment with the new technique, the advancement speed at the entrance reached 4 m. As a result of this increase in advancement speed, situations with unsupported room lengths of up to 5.5 m can be expected with a decrease in the stability of the immediate roof. Various factors relevant for Estonian oil shale mines have been identified. The study showed that the probability and consequences of the risk are acceptable. The used concept of the risk assessment method is applicable to Estonian oil shale mines. It can be used for different purposes and levels. The results of the risk assessment are of particular interest for practical purposes.
