I used to work for a company that provided engineering services for various nuclear power produces. Somewhere along the way the licensing documents were described to me. The license for a nuke plant is contained in many binders (most nuke plants are older than most people), and contains every single item that was used to construct the plant, the plant blueprints, highly detailed instructions for replacing any item that may need replacing, and the expected lifetime and maintenance checks and services to ensure that there isn't the equivalent of a dirty bomb dropped in PA, TX, IL, or wherever.
There's other stuff, like the explanation for the process to replace some valve that hasn't been manufactured in 50 years with some other valve that both meets or exceeds the original specifications, and is available...which is a continual process because most plants are older than most people.
I'm all for the move fast and break stuff approach when it's not going to be a mass casualty event that just keeps on giving.
Nuke plants are the most highly regulated thing in the US. Given the consequences of a catastrophic failure, they should be.