EDF will not shut down any of its 58 nuclear reactors, the head of the French state-controlled utility told Le Monde, as he faces a bill for an extra 10 billion euros ($13 billion) to improve their safety.

French nuclear power watchdog ASN said on Tuesday that the world’s biggest producer of nuclear power must install flood-proof diesel generators and bunkered remote back-up control rooms at its 19 plants across the country or face having to shut down some of its reactors.

As a result, EDF estimates the cost of extending the lifespan of its nuclear plants from 40 to 60 years will now reach the top end of a 40-50 billion euro range over the next 30 years.

“Coming into an inheritance like that of EDF, we owe it to ourselves to improve it and make it profitable,” Chairman and Chief Executive Henri Proglio was quoted as saying by the newspaper when asked if it would be better to close old reactors and build gas plants or increase renewable energy sources instead.

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