Just to meet 1/3rd of global electric supply this is what we'd have to deal with:
If world electricity demand grows 2%/year until 2050 and nuclear share of electricity supply is to rise from 1/6 to 1/3...
– nuclear capacity would have to grow from 350 GWe in 2000 to 1700 GWe in 2050;
– this means 1,700 reactors of 1,000MWe each.
If these were light-water reactors on the once-through fuel cycle...
– enrichment of their fuel will require ~250 million Separative Work Units (SWU);
– diversion of 0.1% of this enrichment to production of HEU from natural uranium would make ~20 gun-type or ~80 implosion-type bombs.
If half the reactors were recycling their plutonium...
– the associated flow of separated, directly weapon- usable plutonium would be 170,000 kg per year;
– diversion of 0.1% of this quantity would make ~30 implosion-type bombs.
Spent-fuel production in the once-through case would be...
– 34,000 tonnes/yr, a Yucca Mountain every two years.
And then you have to ask "Why?"
1,200,000 engineers: We have the technology to slash global emissions
The technology needed to cut the world’s greenhouse gas emissions by 85% by 2050 already exists, according to a joint statement by eleven of the world’s largest engineering organisations.
...The statement says that generating electricity from wind, waves and the sun, growing biofuels sustainably, zero emissions transport, low carbon buildings and energy efficiency technologies have all been demonstrated. However they are not being developed for wide-scale use fast enough and there is a desperate need for financial and legislative support from governments around the world if they are to fulfil their potential.
...“While the world’s politicians have been locked in talks with no output, engineers across the globe have been busy developing technologies that can bring down emissions and help create a more stable future for the planet.
“We are now overdue for government commitment, with ambitious, concrete emissions targets that give the right signals to industry, so they can be rolled out on a global scale.” ...
http://www.imeche.org/news/archives/11-09-23/Future_Climate_2_We_have_the_technology_to_slash_global_emissions_say_engineers.aspx