Using more nuclear power was not only environmentally damaging but would also risk increasing nuclear proliferation, Steve Shallhorn, the head of Greenpeace Australia said on Monday.
He was responding to suggestions by John Ritch, the director general of the WNA, that using more nuclear power instead of burning fossil fuels would help reduce global warming.
"Scientists now warn, with ever increasing certainty, that greenhouse gas emissions, if continued at the present massive scale, will yield consequences that are, quite literally, apocalyptic," Ritch told the 15th Pacific Basin Nuclear Conference in Sydney, Australia on Monday.
Ritch said at least 8,880 reactors would be needed to cope with voracious power demand from fast-developing countries such as India and China by mid-century.
Greenpeace however said that Rich's proposal not only threatened the environment but also risked contributing to the spread of nuclear weapons.
"The uranium and nuclear power industries pose unacceptable risks of contributing to the proliferation of nuclear weapons," Shallhorn said.
"North Korea is the latest example that developing nuclear power for 'peaceful purposes' just cannot be guaranteed."
Greenpeace said that more than 20 of the 60 countries that have nuclear power or research centres have used those facilities for covert weapons research.
Proponents of nuclear power say it is a cleaner alternative than burning coal or natural gas because it produces fewer greenhouse gases.
Scientists predict an average increase in global temperatures of just two degrees centigrade could cause increasingly severe weather patterns, droughts, flooding, species extinction, rising sea levels, widespread disease and famine.
Environmental groups say renewable energy sources - such wind and solar power - offer a safer, more sustainable long-term solution to global warming.
"We should be backing the real, clean energy solutions that we have," said Jim Green, a Friends of the Earth anti-nuclear campaigner.
"Climate change can be tackled using renewable energy such as solar and wind and by introducing energy efficiency measures."