A cooling path is defined through a double-flow steam turbine. The steam turbine includes a generator end and a turbine end and a double-flow tub diaphragm disposed axially between the generator end and the turbine end. A first stage of the steam turbine includes a plurality of first stage nozzles and a plurality of first stage buckets, and a steam path is defined from an inlet region, through the turbine end, to a steam outlet. The cooling path includes cooling holes in the tub diaphragm and root radial seals permitting steam flow beneath the tub diaphragm and around the first stage nozzles and back into the steam path before the first stage buckets.