That's not true at all.
And it makes no sense.
Wind and utility PV are now much cheaper than fossil, so why replace expensive nukes with expensive fossil ?
Makes no economic sense at all, it's more of a legend.
An exemple is germany:
The decomissioning of nukes is ongoing, and they are replaced by renewables.
Of course that hindered their reduction in coal, but that's their next big target after all nukes are gone.
And what your saying is not correct either. Germany is decommissioning nuclear power plants, installing more solar and wind and is burning more coal. They Still rely on nuclear power, but that they are getting from France.
“Germany’s carbon emissions are not declining much, despite renewables increasing to almost 30% of the country’s power mix this year (see figure below), and over 50% of its installed capacity. Unfortunately, coal has also increased to about 30% and, along with power purchases from France and other countries in Europe, is used to load-follow, or buffer, the intermittency of the renewables.”
“Coal is the largest domestically-produced source of power in Germany, despite a tremendous surge in renewables over the last ten years. As a result, the country’s CO2 emissions have not declined much. AGEB”
“France has the lowest carbon emissions per person because it’s power is majority nuclear. The United States has the most emissions per person since we are still two-thirds fossil fuel. Germany is in-between with 50% fossil fuel.”
Solar is provides 3% of Germany’s power ams wind 12%.
Germany IS funding Next Gen nuclear power as is the EU, China, Russia, India, Japan and other countries. Just do the math to see how much or how little electricity we can get from solar and wind, And with storage of that electricity more costly than producing it, its not a complete solution.
Hydro is not the solution either as that’s only 3% in Germany. And we don”t hear of new hydro projects being proposed. As the world’s needs for electricity continues to increase next gen nuclear is really the only solution with the technology we have at this time.