1. The 2 reactors under construction [1 > CONSTRUCTION] are expected to take 20 years and >20 years respectively [2][3].

2. Nuclear Safety Commission Chairman Haruki Madarame told a parliamentary inquiry that "Japan's atomic safety rules are inferior to global standards and left the country unprepared for the Fukushima nuclear disaster". There were flaws in, and lax enforcement of, the safety rules governing Japanese nuclear power companies. [4 (Bloomberg: "Nuclear Safety Chief Says Lax Rules Led to Fukushima Crisis")]

3. Additionally, your source is from more than 5 years ago; in those additional >5 years, neither of the 2 under-construction Japan plants (started in 2006 and 2010) have finished, and 1 is not expected until 2030 (I couldn't find an expected date for the other).

4. The phase you mentioned is a relatively small amount (~1/3) of a nuclear reactor's total startup timeline. [6]

5. Japan was the fastest country from your 2021 source (before taking into account that current JP builds are taking 20+ years).

6. The last Japan reactor to go online was in the 2000s [1 > OPERATION].

[1] https://cnpp.iaea.org/public/countries/JP/profile/preview

[2] https://en.wikipedia.org/wiki/%C5%8Cma_Nuclear_Power_Plant

[3] https://pris-stats.iaea.org/reactor/862

[4] https://www.bloomberg.com/news/articles/2012-02-16/nuclear-s...

[5] https://www.researchgate.net/figure/Typical-timeline-of-a-nu...