A steam turbine is provided that is configured for post-modification for operation in a carbon capture mode. The turbine includes a turbine rotor, a turbine casing and a plurality of turbine stages. In an initial configuration of the turbine, the turbine rotor and turbine casing are each longer, by respective lengths, than is necessary to accommodate the plurality of turbine stages. The lengths are sufficient to accommodate at least one further turbine stage at an exit of the turbine during the post-modification, such that after modification, the turbine operates with an increased expansion ratio and an increased volumetric flow rate at the exit.