The water leakage in a cooling circuit at the center of the Penly nuclear power plant in northern France has stopped since early Friday morning, the country's leading electricity producer Electricity of France (EDF) announced Friday.

"During the night of April 5 to 6, teams from the Penly center have succeeded in controlling the water leak of a pump joint of the primary circuit of the reactor's coolant through lowering the pressure and temperature of the circuit," the EDF said in a statement.

"Since 4 am this morning, there is no leakage at the joint of the pump," the company added, confirming that the event which had not disrupted the cooling system of the reactor had no effect on the environment.

A nuclear reactor in the Penly power plant automatically went off on Thursday after a smoke evoking the fire alarm.

Firefighters were sent to the site immediately and extinguished two fires in a room located in the reactor building of number two production unit of the Penly power plant. The power operator affirmed no injury of people.

"It has been tentatively classified as level 1 on the International Nuclear Event Scale (INES), the international classification of nuclear events which has seven levels," the EDF declared.

Electricity of Penly's Nuclear Production Center is located on the coast of the Manche. It consists of two production units with a capacity of 1300 MW each, coupled to the national grid in May 1990 and February 1992 respectively.

Production of the Penly nuclear power plant is about 18 billion kilowatt hours per year, or nearly 5 percent of national production of nuclear origin.