Abstract: A thermal insulating blanket used for insulating pipes and equipment in nuclear power plant containment buildings is resistant to tearing if impinged upon by a high force liquid stream (i.e., during a loss of coolant accident--LOCA) and if torn is cut into small pieces which will not clog the protective screen of the emergency cooling system recirculating sump. The blanket consists of a filler layer of thermal insulating fibers, such as glass fiber wool or ceramic fiber wool, a waterproof sheet, and a wire mesh casing surrounding the filler layer and sheet. The wire casing dissipates the force of high force liquid streams which may strike the blanket during a LOCA and in the event that the filler layer is torn, the filler layer is cut into small pieces as it passes through the casing. Preferably, a wire mesh spetum lies within the filler layer to assist in cutting up the torn filler layer.