Not true, unfortunately. The same political dynamics that made nuclear expensive in the U.S. eventually made it expensive in Japan, France and, mostly recently South Korea. None of those countries, which were global leaders during their respective nuclear industry booms, can build nuclear nearly as cheaply as they used to; certainly not domestically, and not even internationally as the absence of continuous construction meant loss of skilled labor and project management expertise. See, e.g., https://www.vox.com/2016/2/29/11132930/nuclear-power-costs-u... (Google other more recent articles that better detail the current state for South Korea.)
Very much no.
https://en.wikipedia.org/wiki/Olkiluoto_Nuclear_Power_Plant#...
"The main contractor, Areva, is building the unit for a fixed price of €3 billion, so in principle, any construction costs above that price fall on Areva." [...] "The total cost of the project, therefore, is estimated to be €11 billion."
Since it's hard for me to track the scandals surrounding Areva and the different ownership structures of it, involving EDF, Framatome, TVO and who-knows-what-else, take this with a grain of salt, but I think the cost overruns may ultimately have to be paid by French tax payers?
"The construction of the unit began in 2005. The start of commercial operation was planned for 2010,[19] but has been pushed back several times.[20] As of August 2020, the estimate for start of regular production is June 2022.[21]"
https://en.wikipedia.org/wiki/Flamanville_Nuclear_Power_Plan...
"EDF estimated the cost at €3.3 billion[4] and stated it would start commercial operations in 2012, after construction lasting 54 months.[5] The latest cost estimate (July 2020) is at €19.1 billion, with commissioning planned tentatively at the end of 2022.[6][2]"
And there were also problems with the EPR reactor containment vessel EDF/Areva/Framatome delivered to China.
This is all from the foremost "experts" at fission plant production in France.
To my knowledge, only China has successfully (that we know) built new reactors lately.
https://edition.cnn.com/2021/07/31/asia/taishan-nuclear-plan...
Basically, in his description this is entirely due to the environmental movement. Any time a nuclear plant gets planned the green groups move in a mountain of lawyers and lock down the process for years and years. The costs this adds to the projects are staggering and it is solely because of this that nuclear power can't be built in the US. In Europe, people have no problem building nuclear cheaply and on time.