Embodiments of the invention can provide systems, methods, and an apparatus for thermally isolating a turbine rotor wheel. According to one embodiment, a method for thermally isolating a turbine rotor wheel can be provided. The turbine rotor wheel can include a pair of blade posts, or shanks, supporting respective turbine rotor blades such that a shank cavity is formed between respective blade posts. To thermally isolate the turbine rotor wheel, at least one seal operable to partition the shank cavity into an upper region and a lower region can be provided. In addition, this seal can be inserted within the shank cavity to partition the shank cavity into an upper region and a lower region. In doing so, cooling air flow can be divided between the upper region and the lower region so that the lower region can be maintained at a lower temperature than the upper region.