According to the video's description Dr. Alexander Sich is a nuclear engineer who worked around Chernobyl for around 18 months. I'm not sure what background his audience has. He's forced to a schedule, it appears, to keep his talk limited to 30 minutes, so he rushes.
He does a good job putting radiological risks in perspective and criticizing fear mongers. A good review (for me anyway) of Chernobyl which happened so long ago.
He has some minor mis-speaks, like saying the LD 50/30 for radiation is around 600-650 rad. The "LD" stands for Lethal Dose (will kill) about 50% of the population exposed to the radiation after 30 days (assumes no medical treatment). Though one can quibble about the value, 400-450 rad is closer. He says we contain "potassium-32", but he obviously meant potassium-40.
It's good to hear him discuss the safety culture while criticizing the Russians, but I wonder if there wasn't a surplus of "accidents are impossible" mindset in Japan. He doesn't go there, but I essentially did here.
Here's a bit of an irony...Russians find Cs-137 from Fukushima.