The problem at Fukushima Daiichi was not refurbishment problems: it was the fact that the emergency batteries and generators were in the basement and accessible from the sea-facing side of the structure.

Fukushima Daini did not have those problems, and thus not much drama happened at it:

* https://www.researchgate.net/figure/Comparison-of-flood-dama...

* https://hbr.org/2014/07/how-the-other-fukushima-plant-surviv...

The two plants are 12 km apart and got hit with the same tsunami.

Well, if they knew the location was a risk, instead of extending its life, they could have shut it down. But they chose to extend it.

Fukushima's main issue is related to attempts to 'save face'. International aid for cooling water and power (for cooling/etc) was offered, and rejected, despite the basement diesel generators being flooded by the tsunami that resulted from the earthquake. Realistically the plant was built somewhere they shouldn't have placed it, and the safety systems should have been retrofitted with additional raised systems once the risk was properly understood.

... hit by a tidal wave.

Well, if they knew the location was a risk, instead of extending its life, they could have shut it down. But they chose to extend it.