A method to determine the probability of a turbine missile striking a specified region of a nuclear power plant uses the concept of geometrical probability of a missile trajectory to intersect a target area. The geometrical probability is derived as a function of the missile exit parameters and the plant geometry. The method is general and can be applied to two- or three-dimensional problems. A computer code, TURBMSL, has been developed by the United Engineers & Constructors to obtain the numerical results. The effectiveness and the reliability of the present method has been demonstrated.