Arney: "Maybe someone noted this earlier, but I just realized that the spent fuel cooling ponds in reactors 4,5,6 may not actually be holding "spent fuel" as in depeleted fuel rods. Reactors 4,5,6 were already shut down and emptied for inspections when the quake hit, not for refueling, so to me, that that raises the possibility that those fuel rods were intended to be reloaded into the core and are still hot enough to restart fission (outside the protection of a containment vessel!) in the worst case scenario. Or maybe they are being inspected at a natural refueling point, I don't know. "

Arney ... I've got a co-worker who used to be a nuclear engineer, and actually he did some of the analysis of the reactor core that came out of Three Mile Island. I had a fairly long talk with him this morning. A few things came out of that discussion:

1. The general consensus amongst nuclear engineers who reviewed the Three Mile Island incident is that you don't want fuel rods to get uncovered by water (doesn't matter what kind, reactor rods or spent fuel rods). And IF it does happen, you want to get water back on them as soon as possible. So this leads to the conclusion that the Japanese need to get a lot of seawater back onto those exposed rods as fast as possible. This is not to say that the process will be straightforward, or without a lot of risks and complications, just that it's probably the best option going forwards.

2. When fuel rods get hot (as in several hundred degrees), they can start developing exothermic chemical reactions if water or oxygen is present. These reactions are "oxidation" reactions. But they create extra heat. So it's possible that some of the events from Japan that have been called "on fire" in the news reports are really oxidation reactions taking place in the fuel rods. Both the zirconium and the uranium in the rods can oxidize and liberate heat.

cheers,
other Pete

I've just read a claim that the power company fairly recently re-stacked the storage pools so they could cram more fuel rods in there. It appears that the entire core of reactor 4 was put in the pool 3 months ago.


I don't know what that means, or if the claim is reliable or not. The claim is based on this presentation (pdf). I've skimmed through it, but haven't the background to draw any conclusions from it.


Caveat: The above conclusions are from an environmental organization that is firmly opposed to nuclear power, but generally regarded as reliable and fact based.

Hmmmmmm.
This is the first news report that I've seen where the Japanese authorities have admitted that one possible outcome is that their nuclear fuel could go critical. They have still not explained the exact mechanism that is causing concern, but it appears that we cannot rule out a nuclear reaction that increases in rate.

http://news.sky.com/skynews/Home/World-News/Video---Japan-Global-Energy-Authorities-Voice-Concerns-Over-Situation-At-Fukushima-Nuclear-Plant/Article/201103315953955?lpos=World_News_Carousel_Region_0&lid=ARTICLE_15953955_Video_-_Japan%3A_Global_Energy_Authorities_Voice_Concerns_Over_Situation_At_Fukushima_Nuclear_Plant

Meanwhile, both the US and the UK are pulling out their rescue teams from Japan. And there are unconfirmed reports that the US aircraft carrier(s) has been told to leave Japanese waters.

other Pete

Pete, do you have a citation or source for the allegation that "the US and the UK are pulling out their rescue teams from Japan"? I can't find anything saying that is true. And its known that the USS Ronald Reagan has repositioned itself a couple times to avoid the worst effects of radiation from the plants - yes, it may have left Japanese waters, which only run 12-200 miles depending on your political ruler, but the carrier is still actively engaged in rescue and assistance work in Japan regardless of the location.

Can your firm up your sources, or perhaps admit that this is just rumor, and incorrect rumor at that?

Firefighters searching for tsunami survivors to leave Japan.

http://www.stourbridgenews.co.uk/news/89...to_leave_Japan/

There are a number of British references to their team pulling out, like this BBC article.

Sky doesn't say which American team is leaving and I never saw any articles about it, but last night, CNN did a piece on Fairfax County's team that I watched and they said they'd only be there one more day. Maybe even LA County Fire Rescue is also pulling out at the same time.

As I understand it, they are leaving not because they have given up all hope or because of radiation, but it's more a bureacratic thing about Japan not requesting their help beyond this point.

Wow, I hope the scale on the lower right hand side is incorrect.

Forecast for Fukushima Reactor Plume's Path Is a Function of Wind and Weather simulation by the Comprehensive Nuclear Test Ban Treaty Organization.

http://www.nytimes.com/interactive/2011/...s&emc=thab1


Another interesting story;

http://www.bloomberg.com/news/2011-03-17...-post-says.html

I have this article (actually coming from a popular economics blog) that quotes news sources as saying that the UK and USA are pulling their search teams out of Japan. The blog article does quote further news sources, and an informal email source, so feel free to track down the public info.

Normally I would not quote an article from an economics blog on this forum. But to be honest - these guys at ZeroHedge do a great job of picking up lead stories from the media across the world. So I actually check them as a news source these days. I'm not sure how they do it - but they do pick up stories quickly. For example, I heard about the first riots in Cairo on this blog - and that was long before mainstream media had any journalists in Egypt covering the event. Go figure.

http://www.zerohedge.com/article/us-uk-pull-search-teams-out-japan-tepco-admits-situation-severe

other Pete

Search health food stores for KI nutritional supplements.
Example.

-Blast

More on using the robots in nuclear accidents: http://www.telegraph.co.uk/news/worldnew...the-robots.html