Posted on 04/13/2011 9:19:56 PM PDT by TigerLikesRooster
Temperatures rise at No.4 spent fuel storage pool
The Tokyo Electric Power Company, or TEPCO, says the water temperature in the spent fuel storage pool at the No. 4 reactor in the crippled Fukushima nuclear plant has risen to about 90 degrees Celsius. It fears the spent fuel rods may be damaged.
TEPCO took the temperature on Tuesday using an extending arm on a special vehicle. It found the temperature was much higher than the normal level of under 40 degrees.
To cool the fuel, TEPCO sprayed 195 tons of water for 6 hours on Wednesday morning.
The company thinks the pool's water level was about 5 meters lower than normal, but 2 meters above the fuel rods.
/snip
TEPCO says high levels of radiation at 84 millisieverts per hour were detected above the water surface, where radiation is rarely detected.
(Excerpt) Read more at 3.nhk.or.jp ...
Tepco Confirms Damage To No. 4 Unit's Spent Fuel
TOKYO (Kyodo)—Some of the spent nuclear fuel rods stored in the No. 4 reactor building of the crisis-hit Fukushima Daiichi power plant were confirmed to be damaged, but most of them are believed to be in sound condition, plant operator Tokyo Electric Power Co. said Wednesday.
this is what happens when you have corrupt socialist gummits covering up their mistakes. Open free market capitalism wouldn’t have these informational coverups.
Pray for America
I wonder if there is a criticality problem here. If the rods were dislodged and packed together, they could be in a slow-N delayed critical config.
I wonder if they’ve checked for neutrons.
IIRC, the storage pool in unit 4 is not all “spent” fuel. The reactor had been shut down for maintenance and its ENTIRE core PLUS all its spent fuel was in the pool at the time of the disaster.
That’s why it was so ominous and perplexing that there was a hydrogen explosion in that building. It means that its collection of spent and comparatively FRESH fuel rods was exposed to air for a lengthy time and heated to the point that the zirconium in the rod cladding began splitting water.
Think of a reactor core, completely exposed, no containment whatsoever. That’s what lurks in unit 4.
That would be the reactor itself? I’m wondering about the spent fuel rods. They still have reactivity, the reason we take them out when we do is so that we don’t make/burn too much Pu, not because the reactivity is too low.
In the wrong configuration, I suspect you can still reach criticality with the used fuel rods.
I believe even in the used fuel pools, because they lost water and therefore lost cooling, the rods could break like in the first video. What is especially bad about that is that the reactors and the rods are designed to have a certain precise shape and mass in a running reactor, and therefore the reactions are known and predictable. When the rods break, the fuel pellets are out of control, can pile up together in a mass big enough that they can spontaneously and uncontrollably restart fission. Also, from other sources and from a short comment in the second video, the recriticality is possibly caused by dumping water on the melted fuel pellets, because water slows the neutrons down and assists in the chain reaction.
http://www.youtube.com/user/dutchsinse#p/u/39/waHdMeZU34U
In the above video Gunderson says what caused the problem in Unit 4 was a crack in the fuel pool as a result of the quake which in turn led to the situation you describe.
After listening to that video, and I’ve been following him since he started producing them after the quake, I can’t imagine the situation being much worse.
An executive of Areva, a French nuclear company, said in a non-pubic meeting they convened about Fukishima, “Clearly we are witnessing one of the greatest disasters of modern time.”
I’ve seen a number of posters here at FR telling people who are worried that Fukishima is just what this executive says it is to calm down and stop fear-mongering. Anyone who isn’t fearful of this situation is not privy to the reality of it.
I don’t pretend to know enough about nuclear reactors to comment beyond saying that we have grown so pessimistic of media hype on stories - especially stories that promote the “green” agenda - that it is difficult to not be a skeptic.
This situation certainly seems to be very serious but the news coverage has been all over the map too.
I hope and pray they can control this thing.
The readings make clear why they couldn’t just send people in there to get the readings. Now that they have the ability to get the information, we can see the problem better.
This lends credence to the hypothesis that the water level dropped enough for the rods to be exposed, causing them to partially melt, give off hydrogen, which then exploded.
Fortunately, the radiation they are measuring now does not indicate catastrophic failure, and their samples of water indicate that most of the fuel is intact.
They are having to add a lot of water regularly. I would be interesting to see a dispassionate analysis to determine if that can be explained by evaporation (the water is near boiling), or if this proves there is a leak.
The rods can’t really “dislodge” from what I can tell, they are stored in their assemblies, not as individual rods.
I temper my view of Gunderson by the knowledge that he works for a company which exists by money raised by the types of claims he is making. They assist in fighting nuclear reactors.
He is interesting enough that I do watch some of his videos, but I rarely agree with his interpretations of what I am seeing in the videos.
Wait a minute, I was told this is no worse than a coal mine. It all sounds serious now. Should I now be concerned that I live next door to a nuclear power plant?
Thanks for that. One does have to consider the agenda and I did not know it.
I’m actually very relieved to know that the situation could be less threatening than he portrays it.
I feel the same way. News coverage is either end of the world, or nothing to see here, with almost nothing in between.
Before the earthquake, I was very pro nuke, especially getting new designs going. But what I am seeing in Japan is astounding, and is causing me to do some rethinking. Not in physics, reactor designs, or engineering, but of organizations, management, and bureaucracy.
What I see in Japan is an astounding, colossal degree of mismanagement and incompetence from the TEPCO management, of the crisis, and in every day events leading up to the crisis. Nuclear power and the storage of nuclear waste take a high degree of competence and vigilance, over days, years, and decades. TEPCO is obviously not up to it, and it makes me pause in my support of nuclear energy until the organizational structure which runs and regulates these reactors is reexamined.
I was one of the people posting on here that was told not to fear-monger.
I've called this one worse than Chernobyl a couple of weeks into this thing. Hey, I'm no expert buy it was obvious there was very serious when when they started dealing with the situation as if it were a forest fire, using water drops from helicopters, not to mention roofs blowing off the buildings.
When does this story turn local for the U.S.? When will increased levels of radiation no longer be reported as "no risk to humans"?
This four nuke plant melt is a very, very serious matter.
In other words, you don't trust Obama to make sure these Nuke plants are safe, that government regulators are competant and that no company would dare try to influence anyone regarding an issue that would shut down a plant and cost the company million upon millions of dollars?
My quips aside, you stated it very well.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.