A report by leading scientists advising the UK's government suggests that the country turn to fast reactors, small modular reactors and other advanced technologies if it wants to meet an ambitious framework for phasing out fossil power.

The report addresses the most nuclear-focused of four scenarios laid out by the government in 2011 to reduce carbon emissions by 80 percent by 2050. The Guardian acquired a draft of the Civil Nuclear Industrial Strategy written by John Beddington, David MacKay and John Perkins in advance of its publication. The newspaper reported Tuesday that their research concludes the UK could generate as much as two-thirds of its power from reactors in that time.

Nuclear accounted for 18 percent of power generation in the UK in 2011. The report concluded that increasing nuclear's share to the envisioned levels would require the development of nuclear technologies beyond those currently in use. That could include thorium fuel, emerging fusion technology and reactors that can burn the country's stockpile of plutonium. The latter is currently being explored by the Nuclear Decommissioning Authority as it studies GE-Hitachi's Prism SMR.

The research and development and construction investments to achieve the nuclear-intensive scenario would be extensive. The Guardian calculated that the number of UK power reactors would have to triple by 2050, with more units required if SMRs were used.