More like anti-nuclear groups are extremely effective at FUD, and don't fear lying to people. They have literally used every dirty trick in the book to kill commercial nuclear policies. For instance, a large majority of french people believe that nuclear contributes to global warming [1].
Of course, if you freeze an industry for 20 years, there is going to be some loss of knowledge and know-how.
"Deliberate valve mispositioning cannot be confirmed or completely dismissed. In regard to the last point, the Commission chairman requested that the FBI reexamine this possibility. The FBI response indicates that they have not found sufficient grounds for further investigation. SUMMARY: The findings from this analysis are as follows: There has been no positive identification of an explanation for the valves being in the closed position."
The really sad part about the TMI accident is that the entire thing could have been avoided if TMI had modified its cooling system with the lessons learned from a literally-identical series of events that happened two years earlier at an also-identical Babcock&Wilcox BWR in Ohio. Davis-Besse was luckily operating at 9% power instead of at 100% like TMI in Pennsylvania in 1979: https://www.nrc.gov/docs/ML1920/ML19208C067.pdf#page=4
"On September 24, 1977, Davis Besse Nuclear Power Station Unit No. 1 experienced a depressurization when a pressurizer power relief valve failed in the open position. The Reactor Coolant System (RCS) pressure was reduced from 2255 psig to 875 psig in approximately twenty-one (21) minutes. At the beginning of this event, steam was being bypassed to the condenser and the reactor thermal power was at 263 MW, or 9.5%. Electricity was not being generated. The following systems malfunctioned during the transient:
a. Steam and Feedwater Rupture Control System (SFRCS).
b. Pressurizer Pilot Actuated Relief Valve.
c. No. 2 Steam Generator Auxiliary Feed Pump Turbine Governor"
"At approximately 21 minutes into the transient, the operators discovered that the pressurizer power relief valve was stuck open. Blowdown via this valve was stopped by closing the block valve, thus terminating the reactor vessel depressurization. The RCS pressure recovered to normal and cooldown of the system followed."
"The reason for the spurious 'half-trip' of the SFRCS has not yet been determined. An extensive investigation revealed several loose connections at terminal boards, but nothing conclusive. Investigation into the failure of the pressurizer pilot actuated relief valve revealed that a 'close' relay was missing from the control circuit. This missing relay would normally provide a 'seal-in' circuit which would hold the valve open until the pressure dropped to 2205 psig. Without the relay the power relief valve cycled open and closed each time the pressure of the RCS went above or below 2255 psig. The rapid cycling of the valve caused a failure of the pilot valve stem, and this failure caused the power relief valve to remain open."
Some engineers-turned-Hollywood-consultants even went public trying to warn us about these problems in the industry. At least we got an actually really good movie out of it which in a singularity of the universe's ultimate irony came out two weeks before the TMI accident and actually contains a line that says "an area the size of Pennsylvania" could be left radioactive and uninhabitable. I have it on LaserDisc and it's one of my favs :)
https://en.wikipedia.org/wiki/GE_Threehttps://www.youtube.com/watch?v=nemYBeT4aQY
Of course, if you freeze an industry for 20 years, there is going to be some loss of knowledge and know-how.
[1]: https://www.bva-group.com/sondages/francais-nucleaire-sondag...