福島第一 Fukushima Unit 3 Report - Steam-Explosion Model

UNIT 3 REPORT: http://iangoddard.com/fukushima01.html

A steam explosion does not necessarily exclude a nuclear criticality as considered in my first video (in fact the explosion of the Borax test reactor was both a criticality and a steam explosion http://www.youtube.com/watch?v=yUhVGH-WHKk#t=4m00s ), but at the same time a steam explosion does not require a nuclear criticality because interactions of molten fuel and water can be sufficient to generate a steam explosion.

A few cites on ex-vessel steam explosions

http://www.tandfonline.com/doi/abs/10.1080/18811248.2006.9711159#preview

http://jolisfukyu.tokai-sc.jaea.go.jp/fukyu/mirai-en/2006/5_7.html

Figure 4.3-4 in this paper:
http://pbadupws.nrc.gov/docs/ML0210/ML021080117.pdf

Category:

News & Politics

Tags:

• nuclear
• fukushima
• daiichi
• dai-ichi
• tepco
• steam explosion
• ex-vessel steam explosion
• explosion
• nuclear energy
• nuclear power
• mushroom cloud
• 福島第一
• 核
• 爆発

[Tekknorg]

TEPCO covers up all reactor fuel location by showing us weekly / daily spent fuel pool videos. They found zirconium from the cladding already in march / april 2011 outside of the plant. So, fuel was blown out.

[GoddardsJournal]

@Tekknorg, seems that the Japanese paper The Yomiuri Shimbun reported back in March that Zirconium 95 was detected in water at an outlet that empties into the sea. The expert opinion reported was that the Zr-95 detection indicated fuel rods were melting in a spent-fuel pool.

That finding of Zr in water would not be suggestive of a direct ejection of core fuel. Is there another case of finding Zr cladding?

[Tekknorg]

Some basics for all readers: UO² melts at 2800+°C . Hydrogen and oxygen no longer explode at such temperatures. Steam explosion: Impossible. Steam ionizes at such temperatures. It was a nuclear explosion of the reactor type and fuel was blown out from the containment. TEPCO's latest video shows an undamaged grid (which is below the core) in reactor 2. Some fuel melted, bust most was blown out. Bye.

[GoddardsJournal]

@Tekknorg, yes, UO2 melts at 2865°C, which is 3140 K. However, according to Song et al: "corium has a very high melting temperature of about 2900 K." [*]

To study steam-explosion risk during meltdowns, Song et al. modeled meltdowns and reported: "About 4-9 kg of corium melt jet is delivered into a sub-cooled water pool at atmospheric pressure. Spontaneous steam explosions are observed in four tests among six tests."

Google: Fuel coolant interaction experiments in TROI using a UO2/ZrO2 mixture

[GoddardsJournal]

Song et al. (not free online) is described in Min et al. (free online), which describes the Song experiment: "a liquid jet stream of molten corium at about 3000 K was discharged from the exit of the crucible into a pool of water at room temperature. [...] It can lead to either an energetic steam explosion or non-energetic reaction." [*]

Fact: corium-induced steam explosions are considered possible.

[*] Goggle: A physical and chemical analysis of fast quenched particles of UO2 and ZrO2 mixture

[cbuchner1]

Your explanation seems more probable to me than Arnie Gundersen's theory of prompt criticality insidethe spent fuel pool - in particular in light of more recent admission by Tepco and others that it was indeed a full meltdown in three reactors.

You are posting good research here and this deserves a lot of viewers.

[GoddardsJournal]

@cbuchner1, thanks! I hope to eventually post a proper video on this theoretical model. This video was just a pointer to my written report.

[iamgoddard]

cont ... so I'm addressing your two points, noting

(1) The broken U3 vent is irrelevant because we can see H vented inherently before the vent broke, and that's when some H could have been injected into U4 (if the backward venting into U4 is possible as is claimed).

(2) If such H injection occurred a day before U4 exploded, that's also irrelevant because H can explode spontaneously at any time. There's no requirement that a suitable mixture of H and O explode in any time frame.

[iamgoddard]

@HOTDotaku, also, seems you're saying once H was injected into U4, it would have flowed back out. But I doubt that. Tepco would initiate deliberate ventings. It's not like air inside a unit just casually flows out the stacks. The whisp we see ejected with the U3 explosion was ejected only due to explosive force as opposed to intentional activation of venting.

The path to refuting Tepco's U4 theory seems to be proving gas could not flow backward into U4. That's claimed to be possible.

[iamgoddard]

@HOTDotaku, I don't see two different things here, I described one continuous event. As pointed to, hydrogen ejects from the shared stack as U3 explodes. That's all that's needed to happen (presuming that there's also the possibility of venting at that same instant backwards along U4's vent into U4). That makes the vent brake that must have followed irrelevant.

That that happened the day before U4 exploded is irrelevant as hydrogen explodes randomly. Pool 4 would also add hydrogen.

[HOTDotaku]

@iamgoddard wait. back up a second, two different things here, I agree , that the vent blew of in unit 3 explosion, thats why i find it difficult to believe that the explosion at U4 was related to Hydrogen in a shared stack with U3. U3 was a day before U4 explosion , vent was off U3 for a day , stack was open at top .Hydrogen , lighter than air , would have gone up the stack , theres no way it came from U3 after U3 blew up , thats the point of U4 not sounding right on the official story.

[iamgoddard]

@Tekknorg, the scenario you propose seems to rest on accepting the premise: "They found zirconium from the cladding already in march / april 2011 outside of the plant." But how do you know that is true?

Even if it is true, it's possible that that the explosive projection that blasted out the south side of Unit 3 took out the SFP3 gate and with it some contents like fuel assemblies. But I'm skeptical and I don't know that your premise that Zr-cladding was found outside is accurate.

[Tekknorg]

but they should have been there. And we have not seen the fuel, because it is no longer there. to cover this up, they show us daily some spent fuel videos and call us panic makers. Hypothetically, how could vaporized UO² reactor fuel leave the containment: Via Steam nozzle flow restrictor? Shutdown cooling outlet? Head vent?