* Draft policy considering smallest of advised range of cuts to 29 pct
* Plan had been for nuclear to make up 41 pct of power by 2030
* Govt did not specify how many reactors needed by 2035
* Civic group say draft outlines nuclear 'expansion' policy (Recasts, adds civic group quotes, detail)
By Meeyoung Cho
SEOUL, Dec 10 (Reuters) - South Korea is looking to scale back plans to rely on nuclear power, but growing energy demand and the shutdown of aging reactors mean it will still likely need to build new nuclear-fired plants in the next two decades.
Asia's fourth-largest economy has been under pressure to curb its usage of nuclear power after a scandal forced the shut down of some reactors that had received replacement parts using fake safety certificates.
The government had planned to increase reliance on nuclear power to 41 percent of power generation by 2030, but a draft policy revision is now targeting 29 percent by 2035, the least stringent reduction recommended by a public advisory group.
One anti-nuclear group criticized the proposed target, saying it still amounted to a policy of expansion because it would still require additional reactors.
The energy ministry said in a statement on Tuesday unveiling the draft of its policy revision that nuclear power still has a role to play in South Korea and that it would not be drastically slashing or expanding capacity.
"If the government is going to keep its nuclear power proportion at 29 percent by 2035 ... we would need an additional six to eight nuclear power plants," Roh Dong-seok, a research fellow at state-funded Korea Energy Economics Institute, said.
"The exact number of the units would be decided by how many of the existing nuclear reactors can still operate by then."
Tuesday's ministry statement did not specify how many nuclear reactors would be needed by 2035, and ministry officials declined to comment.
South Korea currently has 23 nuclear reactors, which produce about a third of its electricity, and it plans to add 11 more, with five already under construction.
Under the previous plan for nuclear power to make up 41 percent of power supply, South Korea would have needed to add as many as 20 additional reactors, according to industry data.
And that would not take into account the 13 units -- more than half the current total -- that will face expiry of their operating licences by 2035.
"This is obviously an expansion policy for nuclear power," said anti-nuclear civic group Energy Justice Actions.
A study group advised the government in October that Seoul should reduce its reliance on nuclear power to between 22 to 29 percent of power supply in the light of public anger over corruption in the industry and heightened worries about safety as Japan struggles to clean up after the Fukushima disaster.
The Korean government aims to finalise its energy policy revision by the end of this year, incorporating suggestions that may come out of a public hearing on Wednesday.
Five of South Korea's reactors remain offline, including three shut since late May to replace control cables originally supplied with false documentation.
A fourth is awaiting an extension of its licence after its 30-year lifespan expired in November last year; a fifth is shut by scheduled maintenance extended to mid-January to repair cracks found on the reactor head.
The total number of closures may rise to six as reactor operator Korea Hydro & Nuclear Power, owned by state-run utility Korea Electric Power Corp (KEPCO), plans to go ahead with maintenance for another reactor scheduled for Dec. 12 through Jan. 19. (Reporting by Meeyoung Cho; Additional reporting by Jane Chung; Editing by Tom Hogue and Ed Davies)