Accidents postulated to occur involving chemical interactions of lithium with water and air are analyzed for the international thermonuclear experimental reactor (ITER) blanket test module using two different computer models. Vacuum vessel failure is not predicted for lithium leaks into water, but it is predicted in minutes for water leaks into any amount of lithium if the pressure suppression system fails to work as designed. Calculations for lithium leaks into the reactor vault containing air predict failure in an adiabatic system but not if heat loss is included.