Calling people who you think may not have the same information as you "simpletons" is not really a way to win hearts and minds.
Asking this as someone who might be a simpleton and always assumed it was a low carbon way of energy production:
How is it not 'low carbon'?
He is probably referring to the carbon generated by the construction of the facility, which is still orders of magnitudes less than a coal plant over its lifetime.
I mean if we're talking lifetime emissions even the IPCC places nuclear pretty fucking low and refers to it as a low-carbon energy source. So I don't think anyone should be to blame for using that term. It's the exact term used in the scientific literature...
A lot of this is also kind of silly accounting. For example, if you have to put materials on a truck to build the plant, and operate construction equipment, and these things burn diesel, you can count that as CO2 emissions. But you can also use electric trucks charged from non-fossil fuel generation and that goes away.
Are you doing that cyclical thing where you incorporate the fossil fuels burned in the mining of uranium etc?
Would you believe that those are actually hydrocarbon emissions that would be eliminated if we took electrification seriously?