The Environment Agency is responsible, in England and Wales, for authorization of radioactive waste disposal under the Radioactive Substances Act 1993. British Nuclear Fuels plc (BNFL) is currently authorized by the Environment Agency to dispose of solid low level radioactive waste at its site at Drigg, near Sellafield, NW England. As part of a planned review of this authorization, the Environment Agency is currently undertaking an assessment of BNFLs Post-Closure Safety Case Development Programme for the Drigg disposal facility. This paper presents an outline of the review methodology developed and implemented by the Environment Agency specifically for the planned review of BNFL's Post-Closure Safety Case. The paper also provides an overview of the Environment Agency's progress in its on-going assessment programme.