A power plant and method of operation is provided. The power plant comprises at least one main air compressor, an oxidizer unit configured to deliver a compressed oxygen-rich gas flow to at least one gas turbine assembly. Each assembly comprises a turbine combustor for mixing the compressed oxygen-rich gas flow with a recirculated gas flow and a fuel stream to burn a combustible mixture and form the recirculated gas flow. The assembly also comprises a recirculation loop for recirculating the recirculated gas flow from a turbine to a turbine compressor. The assembly further comprises a recirculated gas flow extraction path for extracting a portion of the recirculated gas flow from the assembly and delivering this to a gas separation system. The gas separation system separates the portion of the recirculated gas flow into a nitrogen portion and a carbon dioxide portion.