By Inti Landauro 

PARIS--A fire and explosion forced French state-controlled utility Electricité de France SA, or EDF, to shut down one of the reactors of its Flamanville nuclear power plant Thursday morning, the company said.

The fire and subsequent explosion happened in the "nonnuclear zone" of the plant, which is located in northern France on the English Channel shore. The fire started in a room where a huge turbine transforms steam into electricity, the company said, adding that the cause had not been determined.

The turbine is located in a long building a few dozen yards from the nuclear reactor, which is isolated by a thick cement wall.

"The blaze was immediately controlled by the crews in the power plant," EDF said.

EDF said it would carry out an internal investigation to try to determine precisely what caused the fire and explosion and would update local authorities and the country's nuclear regulator as soon as possible.

EDF said that no one had been injured in the fire and explosion and that there had been no environmental damage.

The incident comes as the safety of the 58 reactors the company operates in France is being scrutinized. The French Nuclear Safety Authority, the ASN, has ordered EDF to shut down a series of reactors to test for flaws in the steel of reactor containment areas.

The second reactor located on the site of Thursday's explosion is still operating.

EDF is building a third reactor on the site, but the project is over budget and years behind schedule.

At another EDF site, the Cattenom nuclear plant, a fire burned down administrative offices on Jan. 31.

Write to Inti Landauro at inti.landauro@wsj.com

(END) Dow Jones Newswires

February 09, 2017 10:53 ET (15:53 GMT)