BERLIN (Reuters) - Chancellor Angela Merkel's ruling coalition is expected on Sunday to formulate a timetable for closing Germany's nuclear power plants and a plan for replacing their output.
Merkel in March backtracked on an unpopular decision just months earlier to extend the life of aging nuclear stations in Germany, where the majority of voters opposes nuclear energy.
Merkel's Christian Democrats (CDU), her Bavarian sister Christian Social Union (CSU) party and junior coalition partner the Free Democrats (FDP) were meeting on Sunday after an ethics commission ended its deliberations this weekend.
After meeting with heads of the federal states and just before the start of the coalition meeting, Merkel said:
"I think we're on a good path but very, very many questions have to be considered," she told reporters, referring to the costs of electricity and a secure power supply.
"If you want to exit something, you also have to prove how the change will work and how we can enter into a durable and sustainable energy provision."
Bild am Sonntag newspaper reported an agreement among the coalition was not expected on Sunday and the coalition parties had already called another round of crisis talks next weekend, but it gave no sources.
The ethics commission, set up by the government after the Fukushima disaster to report on the future of Germany's nuclear power industry, will present its findings formally on Monday.
A draft of the commission's report, seen by Reuters, concluded that nuclear power can be phased out by 2021 at the latest, a call that the conservatives support.
One sticking point could be that the junior coalition partner FDP does not want a firm date but rather a flexible window for the exit, plus the option of bringing back at least one of the seven oldest nuclear reactors in case of emergency.
A massive earthquake and tsunami in March crippled the Japanese nuclear power plant, causing releases of radioactivity, sparking calls for tougher global safety measures and prompting some governments to reconsider their nuclear energy strategy.
Merkel shut the seven oldest reactors just after Fukushima while her government decided on the future of the industry. Some analysts believe they will never reopen.
The government also may decide to scrap a tax on nuclear fuel rods, which was expected to raise 2.3 billion euros ($3.29 billion) a year from this year, but so far has not been levied.
Media reports have suggested the tax may be scrapped in return for the power firms supporting an earlier exit from nuclear energy.
Merkel's about-turn on the decision to extend the life of nuclear power stations has drawn scorn from the opposition and from within her own party ranks.
The 17 nuclear power plants are run by four utilities -- RWE , E.ON, Vattenfall and EnBW.
Juergen Grossmann, chief executive of Germany's biggest power provider RWE, has lobbied for nuclear plants to stay open longer, arguing a quick exit would cost energy-intensive industry dearly and could threaten Germany's industrial base.
Last week, environment ministers from Germany's federal states called for all seven suspended reactors to be permanently shut, while the federal environment ministry argued that nuclear power could be phased out entirely by 2017.
Before Merkel shut down the oldest seven plants for three months, Germany got 23 percent of its power from nuclear plants.
Nuclear policy is more closely watched in Germany than in some of its neighbors and has boosted the Greens party, which has risen from rank outsider to take control of one of the CDU's stronghold states, Baden-Wuerttemberg.
Merkel's majority in the Bundesrat upper house vanished last year after the CDU failed to hold onto North Rhine-Westphalia, Germany's most populous state. Losing Baden-Wuerttemberg this year, a regional vote held after Fukushima and fought in part over energy issues, dealt another blow to Merkel's authority.
Additional reporting by Hans-Edzard Busemann and Andreas Rinke; editing by Michael Roddy and David Cowell