The tsunami that disrupted its power systems was well outside design parameters. The controversy around the plant's operation was around whether the parameters should have been altered given proximity to the ocean, not whether the plant (given the parameters) was well-built or well-maintained.
To this day, Fukushima's meltdown is responsible for zero deaths (in contrast to the tsunami that instigated the meltdown, which killed over 15,000).
I fail to see the relevance. Were you on-site? Do you have first-hand knowledge of a cover-up or are you extrapolating from naval nuclear regulatory standards to the standards of a different country?
All engineering is tradeoffs. At multiple layers, the risk assessment of how much flooding the plant should withstand was deemed acceptable... Until the day it wasn't.