PARIS, Oct 18 (Reuters) - French nuclear power production fell to its lowest level since August 1998 in September to 26.6 terrawatt hour (TWH), French grid operator RTE said in its monthly report on Tuesday.
RTE said French nuclear output has been on a steady decline since May.
It did not give reasons for the decline but France, which depends on nuclear power for about 75 percent of its electricity needs, could face a tight supply in the coming months after nuclear regulator ASN asked utility EDF to carry out tests on 12 reactors.
RTE said solar power production rose 15 percent in September, while wind power output fell 41 percent compared with the same month a year ago. (Reporting by Bate Felix; Editing by Mathieu Rosemain)