Mineral Resources and Energy Minister Gwede Mantashe has justified the issuance of a controversial request for information (RFI) relating to a possible 2 500 MW new nuclear build programme on the basis of the long lead-time involved for the building of such power stations. In a Tweet following the publication of the June 14 notice, Mantashe said the RFI signalled the start of preparatory work for a future nuclear energy build programme.