Wrong. Here is an IPCC meta-analysis reference from a consensus of scientists showing that it's very low, 12 gCO2-eq/kWh, on par with wind. Solar is 40. Natural gas is 490 [1]. See Table A.III.2 | Emissions of selected electricity supply technologies.
Think about it. There is 2,000,000x more energy in a kg of uranium than in a kg of coal or gas or oil or lithium. A single train car of uranium can power a nuclear reactor for a year, vs. a mile-long traincar per day for a equivalent power coal plant. Energy density is where nuclear shines. And shines it does! That's why it's exciting and useful for a carbon-free future. It's the only large-scale low-carbon energy source we have that runs 24/7 and can be installed in very many geographical locations. It also has a tiny overall footprint. This is why James Hansen and Jim Lovelock and Bill Gates are so excited about it.
Same data in graphical form too, if you prefer [2].
[1] https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5...