NHK Nuclear Watch, Apr. 30, 2014:
- At :30 in — Kenichiro Okamoto, NHK reporter: The data recorded here [5.6 miles from Fukushima Daiichi] after the nuclear accident contained some surprising information.
- At 1:00 in — Okamoto: It shows a clear spike in radiation levels at 2:40p, what’s surprising about this surge is it happened almost 1 hr before the 1st hydrogen explosion.
- At 1:30 in — Okamoto: Shortly after 2pm opened [inaudible] to decrease the pressure in Reactor 1. Tepco officials explained the amount of radioactive particles released into the atmosphere would be limited. [...] The steam building up inside the reactors would pass through a water tunnel [...] that would capture radioactive particles. Nuclear engineers believed this system could limit radioactive emissions to 0.1%. The data we recovered from the monitoring post clearly contradicts this explanation. We asked scientists to verify the 0.1% theory and see if the venting could have released more radiation than expected.
- At 3:15 in — Okamoto: This institute in Northern Italy specializes in testing nuclear plant equipment. It agreed to recreate the condition of the venting system at Fukushima Daiichi [... Experts] say some of the steam generated by the meltdown had interacted with the water before venting […] the temperature was raised in the upper layer of water. The influx of steam generated a large amount of bubbles that rose all the way up to the surface. This would have allowed radioactive particles to escape […] up to 50% of radioactive elements could have been released into the atmosphere. That’s 500 times higher than the previous simulation. Our investigation has shown that crucial safety features can fail to perform as expected. It also reminds us that our understanding of what happened inside Fukushima Daiichi remains very limited.
Published: April 30th, 2014 at 9:51 am ET