Published by: NRC
Published date: Nov 29, 2011
Description: An NRC reactor expert explains nuclear power and the March events at the Fukushima site in Japan [Emphasis Added]
Frederick (Rick) Hasselberg is a reactor engineer and incident response coordinator in NRC’s Office of Nuclear Security and Incident Response (NSIR). (SOURCE)
At 6:30 in
- At Units 1, 2 and 3, a huge amount of hydrogen was generated as the fuel rods were violently consumed by the self-sustaining zirconium-water reaction.
- Core temperatures continued to rise.
- You could hardly call them fuel rods anymore, but some of the materials that used to be inside the fuel rods were reaching 3000, 4000, 5000 degrees.
- At those temperatures, five more bad things happened:
- Localized melting of the fuel – the hottest locations in the core start to melt.
- Relocation of the fuel materials – What started out as melting at a few locations became a sizzling mass of molten material.
- As that occurs, many of the fission products that had been trapped inside the uranium fuel pellets were now released.
- The radiological impact of the core melt is huge.
- Materials that had been in solid form, sealed inside of fuel rods, were now in either liquid or gaseous form, and they are on the move.
- As the temperature went up, more and more radioactive material became available for release.
- The temperature of that sizzling mass of highly radioactive core material was higher than the melting point of the steel reactor vessel.
- So, if they came in contact, the steel reactor vessel would likely fail.
- This is the classic core melt scenario.
- NRC says Reactor No. 2 "burned continuously for several days" after meltdown -- Hydrogen "ignited" (VIDEO)
- US Gov't Video: Fukushima meltdowns a "life changing event" -- "Such a tragic cost"
Published: December 21st, 2011 at 9:42 am ET
- New images show all melted fuel is “gone” from Fukushima reactor — Experts: Molten core may have reached outer environment, can’t tell if fuel is still contained — Official: “We presume fuel still in containment vessel… but we need to check one day” (PHOTOS & VIDEO) March 20, 2015
- Water level now below BOTTOM of fuel rods in No. 1 — Suggests nuclear fuel is in a molten mass at bottom of reactor (VIDEO) May 12, 2011
- “Huge Problems”: All parts of fuel rods appear to have melted at all 3 reactors admits TEPCO May 17, 2011
- Ex-Fukushima Daiichi engineer as ‘cold shutdown’ declared: Fuel rods still active and alive — Most worried about recriticality — Tepco must measure neutrons near core (VIDEO) April 12, 2012
- IAEA ***NOT for distribution***: Molten core is suspected to have penetrated Fukushima containment vessel — Prime Minister on 3/11: We couldn’t be in Tokyo if melted fuel went through containment vessel (VIDEO) December 18, 2013