Regulations say you can't just ran any random device (including software) there, that's unsafe.
Unfortunately regulations weren't being made with PCs in mind where anybody can plug in an infected USB stick. Or needs to in case he's a service technician. (Yes, those ports are not available for "anybody" who is there, but somebody needs to install software on those machines).
There are things I have seen I wish I could unsee to feel safe.
Windows has no business being used in any application that is life or safety critical. Its license even says so. Doing so should be a crime. There are much better OSes out there for this kind of thing: just ask anyone who builds jet aircraft.
Don't worry, the most important parts are running on DOS or OS/2, so we're saved from doom!
I'd rather have my local solar power plant infected with viruses or hit by cyberattacks.
The problem with modern nuclear reactor designs is that they're just that, designs. Great ideas people in comment sections love to mentally masturbate about. In reality almost all nuclear reactors are decades old.
Politics alone ensure nuclear reactors with the exception of maybe fusion (which will be way too late for climate change) will never get off the ground. In the meantime renewables, solar especially, get cheaper and more efficient every day, not designs but actual installations.
Few years ago, Westinghouse tried to kick out Rosatom from VVER power plants in Eastern Europe as a supplier of the fuel. They pulled very heavy levers to do that, but in the end, they were still refused due to their pellets not being up to the task and being a security hazard.
And yet they still try that in Ukraine...