Secrecy, denials, fudging, delays, and (let's be blunt) outright lying about safety violations and "incidents," by owner/operators and inspectors of nuke facilities. are unfortunately common throughout the world.

I think there are several factors involved.  One is the enormous liability that the facilities represent -- which is why no insurance underwriter wants to write a policy on one.  Another is the technocratic culture which originated and still owns the technology;  it tends to breed a condescending/paternalistic attitude to the "ignorant public" --  an attitude almost of outrage if that public is not docile and blindly trusting.  Yet another is that the extreme lethality of the technology requires a strong-security culture (and close ties to the weapons industry only reinforce this) which is also authoritarian per se and offers good "patriotic" and "safety" excuses for secrecy, coverups, etc.

Bring private profiteering into the picture and you have the trifecta for embezzlement and incompetence:  a very high-budget operation, subsidised with guarantees by the public purse, that is also very complicated and technical (easy to snow-job the public by either dumb-down oversimplification or overwhelming technobabble) and high-security -- the perfect cosy dark juicy corner in the social fabric for cost-cutting and skimming without oversight.  Very similar to military contracts and arms deals, which are an ongoing scandal in several of the industrial powers.

All organisations tend to close ranks and emit a squidlike jet of protective disinfo when they make a major error or one of their own goes bad -- note the difficulty of getting cops to testify against corrupt or brutal "brother officers," or the difficulty of getting to the bottom of most any scandal in business of political life 'cos no one wants to rat out their buddies (or lose their job for whistleblowing).  But the sense of technical superiority and elitism, the authoritarian culture and the security/secrecy environment, can only amplify this tendency and lead to an endless series of coverups, stonewalls, and -- worst of all -- failure to take timely remedial action, when the taking of such action might draw attention to serious design or operational flaws, or a barely-averted or concealed incident.

High-lethality, centralised, heavy technologies have a warping effect on the social fabric of the subculture that designs, builds and maintains them, as well as on the culture surrounding their installations.  As I have argued before, they are inherently nonconvivial.

Technology in other words is not neutral.  It has preconditions and implications.  As Jerry Mander wrote many years ago,

If you accept nuclear power plants, you also accept a techno-scientific-industrial-military elite. Without these people in charge, you could not have nuclear power. You and I getting together with a few friends could not make use of nuclear power. We could not build such a plant, nor could we make personal use of its output, nor handle or store the radioactive waste products which remain dangerous to life for thousands of years. The wastes, in turn, determine that future societies will have to maintain a technological capacity to deal with the problem, and the military capability to protect the wastes. So the existence of the technology determines many aspects of the society.

Some "gifts" come with very long and heavy strings attached.  Secrecy and lying are part of the culture of high-toxicity/high-risk technologies, from industrial "farming" (liquidationist agriculture) and industrial food to bio-weapons and GMO, to nuke power.  All these practises concentrate control (and profit) into the hands of a small elite, and inevitably foster up a command/control business culture of "shut up, we know what is good for you, move along, nothing to see here, how dare you question us."  Not to mention a culture of passive "I'm sure they know best dear" dependency among consumers.  That paternalistic culture in turn is the perfect breeding ground for delusions of grandeur, Straussian contempt for the masses, disinfo campaigns, and just plain ordinary lying and cheating.  People tend to grow into the forms provided by their institutional cultures, like jello into a mould.

The difference between theory and practise in practise ...