Areva has been ordered by French, British and Finnish safety bodies to modify its next-generation nuclear power plants, causing its shares to fall.
A joint statement by the safety bodies said that control and safety systems in the European pressurised reactors should be amended to avoid both failing at the same time, Reuters reports.
Areva is building reactors in Finland and France in an effort to export nuclear power abroad.
The company believes the safety of the plants was not in question, the news service said.
Strategies to improve safety at nuclear reactors and power plants are being discussed at Arena International’s Fire Protection & Safety of Power Plants being held on 3 and 4 November in Boston, US.