The root cause of the Fukushima-Daiichi accident in Japan almost 10 years ago was structural flaws in nuclear administration that led to a breakdown in public trust and raised concerns about the nuclear industry elsewhere in the world, a report published on Wednesday by the Nuclear Energy Agency says.

The report, which examines progress, lessons and challenges from the accident, says understanding that the accident was a system failure rather than attributable to just one or more components in the system is key to ensuring that wider lessons are learnt.

Regulation in Japan was reformed to specifically address these structural flaws – particularly issues of transparency, openness, and independence – with the creation of the Nuclear Regulation Authority (NRA) in 2012.

The report says the regulatory transformation has been challenging but has met with success in the implementation of plant improvements against natural phenomena such as tsunamis and in safety improvements aimed at station blackout threats to core cooling and backup electrical power. These were all specific lessons learnt from the Fukushima-Daiichi experience.