. >> reporter: the video takes us inside fukushima daichi. a build-up of hydrogen caused the explosion on march 14, 2011. the blast shook the facility. and then an update. the dramatic exchange is part of 150 hours of video from the five days starting from march 11th, that tepco officials agreed to show the media. they also released an edited, 90-minute version. they stay they blurred the faces of some workers for privacy reasons. people living in fukushima prefecture are critical. >> this is no disclosure. we can't verify what is true. >> there is no meaning in releasing this video after a year and a half. the images are also processed. what is tepco thinking? >> reporter: there will also likely be questions about what tepco officials were thinking at the height of the crisis. key scenes in the 150 hours of video show how they handled the accident. one focuses on the utility task force, late on march 12th, 2011. tepco will only allow journalists to watch the images, not make audio or video copies. nhk's reporting team heard an executive say

last year's accident at fukushima daichi gave him a new focus. many people in japan wanted to hear his message. parents in particular. they worried radiation from the damaged plant could harm their children. yoko hoshimoto is a mother of two living in tokyo. >> my children grow up with what i give them to eat. and i feel horrible about the possible effect on them. [ applause ] >> hashimoto and a group of mothers turned to hida so they could be better informed. hida explained how atomic bomb victims became sick. he also criticized politicians and experts who say the radiation released by fukushima diac poses no risk. >> internal radiation exposure is indeed dangerous. once you absorb a low dose it will cause damage. we experienced this horror many times after hiroshima and nagasaki. >> reporter: hida told mothers that many a-bomb survivors tried hard to prevent being sick by taking every measure to maintain good health. >> you should spend the rest of your life working together to shut down nuclear plants and abolish nuclear weapons. >> i will thi