The utility had first estimated their cost at 51.7 billion euros, though it acknowledged that figure could rise in later estimates.
The French government last year bought the stake in EDF it did not already own and delisted its shares from the stock market as it launched a major new investment programme to add more nuclear power plants in a country that mainly depends on nuclear energy.
A spokesperson for EDF did not comment on the reported sum. "We are currently in a phase of cost and schedule optimisation," EDF said in a emailed statement.
