By Rodrigo Gaier

RIO DE JANEIRO, May 10 (Reuters) - Brazil's environment minister attacked proposals for new nuclear power plants on Thursday, a week after the president said he would push for more reactors if enough hydroelectric plants cannot be built.

Brazil now has two nuclear reactors near the coastal resort of Angra, which account for about 3 percent of all power. The long-delayed completion of a third pressurized water reactor at the site is expected to be approved by a government council.

Brazil relies on hydroelectric dams for more than 80 percent of its energy needs.

But to address the prospect of looming power shortages in Latin America's largest economy, President Luiz Inacio Lula da Silva's government is weighing a plan to build at least four new reactors with a total capacity of 4,000 megawatts by 2030.

Environment Minister Marina Silva defended the hydroelectric option as "clean and without risk" but said that environmental concerns should always be taken into account when authorizing new dam projects.

"The ministry is against nuclear energy. We have a clean energy matrix, an advantage that no other country has," said Silva, a former activist in the Amazon rain forest. "Nuclear energy has a serious problem that is waste disposal."

She advocates the use of hydroelectric, wind and biomass energy sources.

The dependence on water means droughts can cause power shortages -- as in 2001 when the world's fifth-largest country was forced to impose crippling energy rationing.

The National Energy Policy Council will meet next month to discuss completion of the Angra 3 nuclear plant. Many officials expect the council's approval despite Silva's objections.

France's state-controlled nuclear group Areva <CEPFi.PA> has said it is optimistic to restart work on the reactor.

Silva was weakened recently when Lula split up the environmental agency Ibama to speed the approval of energy projects.

Analysts warn that power shortages could arise as soon as 2010.

Silva acknowledged tensions within the government over environmental licensing of two big hydroelectric projects on the Madeira River in the Amazon, seen by many as crucial to guaranteeing normal power supplies after 2012.

But she said she did not feel under pressure to give the green light to the projects and gave no estimates for when permits may be issued. Activists say the dams would hurt aquatic life.

"I understand that environmental preservation has to be part of the development equation," Silva said.

AlertNet news is provided by