FACTBOX-Hurdles to Germany's nuclear extension plans

Aug 13 (Reuters) - The German government faces a struggle to find a solution to roll back the planned closures of its 17 nuclear power plants.

Chancellor Angela Merkel's centre-right administration wants to extend the lifespans of the power stations after a previous centre-left government decided they should be phased out by 2021, after an average 32 years of life each.

With memories of the 1986 Chernobyl nuclear disaster still lingering in Germany, it is not just an ideological argument about the use of atomic energy. The dispute also centres on how to carry out the lifespan extensions.

The following details the sticking points:

HOW LONG SHOULD THE PLANTS RUN?

Merkel's coalition wants to push back the deadline agreed by ex-Chancellor Gerhard Schroeder's Social Democrats-Greens government, and views nuclear energy as a "bridging" source of energy until renewable sources become more viable.

However, there is little agreement even within the three ruling parties on how long that extension should be.

Southern states, largely dependent on nuclear power, are pushing for an extension of at least 15 years. Others worry that lengthy extensions will hurt investment in renewable energy sources and thereby delay their profitable use.

NO BUNDESRAT REQUIRED?

It is also unclear whether the Bundesrat, Germany's upper house of parliament, will need to approve any new law.

The interior and justice ministries have said the Bundesrat would probably have to be involved if the life span of nuclear plants were extended by more than 10 years.

But the ruling coalition of Merkel's Christian Democrats (CDU), Bavaria's Christian Social Union and the Free Democrats -- however, have lost the majority in the upper house. And some CDU-led states such as Lower Saxony reject lengthy extensions.

WHAT WOULD HAPPEN TO THE EXTRA EARNINGS?

It is not yet clear how much money the four utilities, E.ON (EONGn.DE), RWE (RWEG.DE), Energie Baden-Wuerttemberg (EBKG.DE) and Vattenfall [VATN.UL], would make if their nuclear plants were allowed to run for longer.

What is clear is that the government wants to take a share of those earnings, potentially up to half.

Berlin has drafted a tax which foresees the utilities paying 220 euros per extra gramme of uranium or plutonium fuel used. The tax is due to raise about 2.3 billion euros a year. But this plan has infuriated the big four power generators.

On Friday, they proposed signing up to a contract to pay the government tax-deductible, fixed charges instead, according to a draft proposal seen by Reuters. [ID:nLDE67C0L3]

How that extra money would be used, is also unclear.

The government also aims to have its budget consolidation plans, of which the proposed nuclear tax is a part, wrapped up by early September. A definitive energy policy, however, is not due to be agreed until the end of September. (Reporting by Annika Breidthardt and Andreas Rinke)