The U.S. Nuclear Regulatory Commission told French nuclear power company Areva SA it will publish as early as next week the names of U.S. reactors that contain components from its Le Creusot forge that the firm is suspected of falsifying documents despite the company's claim that the information is proprietary.

The written notice, dated Dec. 30 and seen by Reuters on Thursday, underscores rising tension between the U.S. nuclear regulatory body and Areva after French authorities opened an investigation last month into decades of alleged forgery relating to the quality of parts produced at the forge and used in power plants around the world.

The NRC has investigated whether the suspected falsification of documents poses any risks for U.S. nuclear plants, but has said it has found that the plants are safe.