Thanks for link:
According the wikipedia article:
".. on a leveraged basis we expect EDF to earn a Return on Equity (ROE) well in excess of 20% and possibly as high as 35%. Having considered the known terms of the deal, we are flabbergasted that the UK Government has committed future generations of consumers to the costs that will flow from this deal"
Sounds like EDF pulled a really sweet deal that sold the British Government to pay way more than needed to profitably run the nuclear facility. Nice work if you can get it.