Slovakia\'s nuclear watchdog said Tuesday a new reactor unit at one of the country\'s nuclear power plants won\'t come on line before 2025 after construction was put off by five years or more. \"The new power source will be online in 2025 at the earliest,\" Marta Ziakova, head of the Nuclear Regulatory Authority in Slovakia, told journalists at the Jaslovske Bohunice nuclear power plant in western Slovakia. Slovakia\'s previous government expected Czech energy giant CEZ to start building the new unit in 2014, but increased emphasis on nuclear security in the EU and longer feasibility and environmental studies will slow the project. Slovakia, where nuclear energy covers 55 percent of demand for power, closed two out of four Soviet-type nuclear units at Jaslovske Bohunice under commitments to Brussels which paved the way for its EU entry in 2004. The dominant Slovak power producer Slovenske Elektrarne (SE), controlled by Italian power giant Enel, expects to launch two new units at the country\'s other nuclear power plant in Mochovce, western Slovakia, in 2012 and 2013.