Saudi Arabia, which plans to build 16 nuclear reactors by 2030, will begin the tendering process to construct the first station by the end of next year, according to the King Abdullah Center of Atomic and Renewable Energy. The site of the reactor will be announced by March, Saleh Al Shubaili, a spokesman, said in response to e-mailed questions on Monday. “The bidding will be of a gradual pace rather than one award,” Al Shubaili said, referring to the construction of all the proposed reactors. Saudi Arabia and the UAE are investing in nuclear power to help meet rising domestic demand for electricity.