French President Nicolas Sarkozy says France plans to invest $1.4 billion for the development of nuclear power plants.

The announcement comes amid French concerns about the safety of nuclear energy following the disaster at Japan's power plant in Fukushima in March.

Thousands of protesters on Sunday formed a human chain around France's oldest nuclear power plant in the northeastern city of Fessenheim, calling for the facility to be shut down. French officials are considering whether to allow the plant to operate for another 10 years.

France is heavily reliant on nuclear energy, with most of its electricity coming by way of nuclear power plants.