In July 2011 the Secretary of State for Energy and Climate Change approved the National Policy Statements for Energy Infrastructure and as a result they are now designated under the Planning Act 2008.
The Sizewell C project is being dealt with under the National Infrastructure Planning regime. Details are available on the Planning Inspectorate's website. They have produced a series of advice notes on the process for Nationally Significant Infrastructure Projects.
There is also a series of guidance notes published by the Department for Communities and Local Government to provide guidance on a range of matters relating to the application process.