Title: Fukushima panel told some details will take five years to learn
Source: Platts News
Date: 7 Sep 2012
Key details of how the accident at Japan’s Fukushima I nuclear plant played out have yet to be determined and may not be known for five years or more, when important parts of the plant are safer to enter, officials with the Japanese and US nuclear industries told a US National Academies review committee Thursday.
A committee of the National Academies is conducting the study, which is mandated by Congress, on behalf of the US Nuclear Regulatory Commission. The committee held its second data-gathering session Thursday in Washington.
Yasunori Yamanaka, manager of Tepco’s nuclear safety engineering group, said following the meeting that one of the key pieces of information that will be learned in the coming years is the location and condition of the core of nuclear fuel in the three reactors that experienced meltdowns. Tepco believes the uranium fuel of unit 1 at Fukushima I almost entirely melted its way through the bottom of the thick steel reactor vessel and poured to the floor of the containment structure, eating through a portion of the concrete floor of that area.
The company plans to use cameras and other surveillance equipment to determine how much of the core of units 2 and 3 remain in the reactor, Yamanaka said. The company believes almost half of the fuel in those units, which maintained core cooling longer, melted, he said. It may take more than five years before Tepco can determine whether the fuel in those units remains in the bottom of the reactor vessel or also fell to the containment floor, Yamanaka said.
Regarding Yamanaka’s statements:
- Tepco has admitted that their simulation shows the fuel at Reactor 1 not only burned through the pressure vessel, but came within 27 centimeters of leaving the containment vessel. Others have said they believe the fuel is outside containment. (Source: NHK)
- Tepco has admitted that reactors 1,2, and 3 experienced full meltdowns — not “almost half” at Reactors 2 and 3. (Source: CNN)
Published: September 7th, 2012 at 12:31 pm ET
- Washington Post: “No one knows what to do with Fukushima” — Scientific American: Plant is in “crisis mode”… fuel has melted through containers — Official: Corium may never be extracted — Gov’t suggests dumping it under Pacific Ocean February 22, 2016
- Reuters: Fukushima fuel melted through containment vessels and is “spewing radiation” — Nuke Expert: Fuel has “scattered all over the place” — Gov’t: Fuel may have burned out into environment — Tepco Official: Fuel could have flowed out “like lava in a volcano” (VIDEOS) March 15, 2016
- Caldicott: 50 years or more of highly contaminated water flowing into Pacific from Fukushima — Tepco VP not optimistic: “I have concerns” for long-term plan — Location of melted fuel a mystery (VIDEO) November 7, 2013
- Japan Times: “Deadly” radiation levels detected outside Fukushima containment vessel — “Details behind situation are unknown” — Officials unable to grasp location of melted nuclear fuel — “Impossible” to plan for decommissioning October 30, 2015
- Japan TV ‘News Flash’: Officials fear melted reactor fuel is now exposed at Fukushima — Tepco: We don’t know at this point if fuel is uncovered — Large drop in water level — Experts ‘struggling’ to find condition of nuclear cores, nothing is known for all 3 reactors (VIDEO) June 10, 2014