The nuclear power plant I worked at for 25+ years has had a history of highs and lows. The Browns Ferry fire was the worst nuclear incident in the U.S. until Three Mile Island. All three units were shut down the by the NRC in 1985 for design problems and management failures. We eventually recovered two units and became a top plant in the world ranking during the 1990s and early 2000s. Then the remaining unit was brought back on-line after a complete overhaul and pervasive problems started showing up.
We were getting complacent and had our minds more focused on keeping the megawatts online than in fixing things. Maintenance was deferred through legal means but we were just putting off problems. Quick fixes became the norm. It finally caught up to the plant right after I retired when the NRC put Unit 1 in what we call 'column four space'. Column one is regular NRC oversight, the plant is doing fine. It goes down from there to Column five, which is shutdown by order of the NRC. Column four means intense regulatory scrutiny and a huge recovery plan. I worked as part of the recovery team last year. Quite a massive undertaking where the plant had hundreds of us 'experts' under contracts worth millions of dollars, doing investigations and inspections, audits, observations, reviews of old records, corrective action reports ,etc. What we recommended was essentially taken as 'you will do this'. Now the plant says they are ready to exit Column four and the NRC will be officially reviewing everything we did and what the plant has done to 'change the culture'. This will take another several months.
I am beginning to think Carnival might be in their own 'column four space'.