Published: August 28th, 2012 at 9:55 am ET
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(Subscription Only) Title: No major corrosion found in unused fuel from Fukushima No. 4 unit
Source: Kyodo News
Date: Aug. 28
Tokyo Electric Power Co. said Tuesday that it did not find any significant corrosion or damage during a detailed examination of an unused nuclear fuel assembly removed from the badly damaged No. 4 reactor unit at its Fukushima Daiichi power plant.Because the assembly was stored in the unit’s spent fuel pool when an explosion occurred at the building in the early days of the nuclear crisis last year, a dozen pieces of rubble were found in the bundle of fuel rods, according to the utility.
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Perhaps a report on the second removed assembly will follow.
Published: August 28th, 2012 at 9:55 am ET
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Unused fuel rods can easily be handled as they do not radiate. As soon they are used the radiation is tremendous from a single mini-piece.
But it is a good sign that they do at least that. The used fuel will be very difficult to handle in open air – these fuel rods will probably stay in the water many more years.
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Mystery of The destruction of Building4:
What causes Building4 to blow up?
Was it Reactor4?
No, Reactor 4 had no nuke fuel when Building4 blew up.
Was it SFP4?
No, SFP4 burned and sputtered, but did not blow up.
Was it hydrogen from Reactor3?
No, because hydrogen is lighter than air, and would rise to the top of Building3. To get to Building4 from Building3, hydrogen would have to sink into the basement, then flow through connecting tunnels into Building4, a doubtful possibility. And, because Building3 had been destroyed before Building4 blew up.
Was it something else?
Probably.
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This is a mystery Phillip. But there are clues. There was no fuel in the reactor (full off load),and they off loaded to replace feedwater piping in the drywell that is too hot to work on with the reactor filled with fuel.
There are no connected pipes or tunnels between any reactors I have ever seen, so it had nothing to do with Unit 3.
There were 2 fires a couple days apart on the refueling floor. What is flammable on a refueling floor. Not much-metal, concrete and very few other things.
But when they work on the feedwater piping they may do work inside the reactor vessel on a temporary platform. It is possible they had a fire with the plastic coated lead blankets on the platform. I actually saw that once at Fukushima unit #1. But for that to reignite would be almost impossible. And that would not create hydrogen.
All I have left then is that fuel partially uncovered and caught fire and released hydrogen that exploded.
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Report of fire in spent fuel pool 4 15/11
http://blog-imgs-53.fc2.com/r/y/u/ryuma681/IAEA.jpg
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"TEPCO said hydrogen from venting Unit 3 flowed into certain levels of Unit 4 through its Standby Gas Treatment System (SGTS). The Unit 3 data and timeline is shown below. The data shows that an explosion occurred in Unit 3 reactor building on March 14 at 10:46, that the hydrogen explosion in Unit 4 occurred at on March 15 at11:00, which is almost a day later. Once the explosion occurred in the Unit 3 reactor building, all hydrogen in that building would be released to the atmosphere therefore the impetus to force hydrogen into the Unit 4 reactor building would be gone."
http://josephmiller.typepad.com/battle-to-stabilize-the-f/2011/05/may-24-2011-update-new-information-unit-4-hydrogen-explosion-venting.html
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Any checking and reporting must be done by a second (unbiased) party.
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Reactor 4 melted down. The rpv lost coolant. 2H+3H=5He . Under extreme pressure, the nuclei will get close enough to one another to overcome the repulsive forces. Some of the 2H and 3H will fuse and the resulting mass is less than it was apart. E=MC^2. So, if you have a nuclear reaction that is exothermic, the energy created from loss of mass must manifest itself.
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Reactor 4 what is different from other meltdowns something, mox fuel? Maybe it was in pool and shock waves or earthquake caused prompt criticality, how stable is mox fuel?
We may get the answer one day, but their is no way to stop these radioactive dragons from spewing thier cancer into our atmosphere, any time in the near future, could be thousands of years.
What a tangled world we inhabit, how did we let it get to this point, are we all insaine, you would be lucky to find 2 percent of the population that is tuned into Fukushima.
I don't know how but we need to get through to these people, we need headlines, anybody got ideas, we can talk about this till the cows come home but we need action.
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I'm with the theory that the fuel rods were uncovered as the water leaked from the pool, which ignited some of them, caused a fire AND an explosion. It took several days to even get the water to stop boiling off once they got hoses to SFP 4. Then, they had to fix the leak, repipe around damaged cooling pipes, etc. Wasn't it close to a month before they managed to get the level 9 feet above the rods and hold there? It should be at least 30 feet.
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I'm a little confused by this. How can debris get INSIDE a fuel rod assembly, without damaging the assembly or the rods inside. Aren't the assemblies like metal boxes with the rods enclosed inside? I just don't see how you get debris into a closed container without there being some sort of damage to the container.
Could someone who knows something about the assemblies clear this up for me?
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Imagine the fuel assembly as a bundle of tubes.
If you throw dirt onto a such bundle, some of it will fall into tubes.
See the illustrations:
http://me1065.wikidot.com/fuel-assemblies-in-nuclear-reactors
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I think no one and two had similar accident developments. Both had hydrogen filled upper part of the buildings that came from the spent fuel pools. When the zirconium shielding gets hot and in contact with water it generate enormous amounts of hydrogen gas. It reacts like sodium with water. Then these two reactors also had their cores melted down, and melted through.
The third reactor explosion was much worse – It was felt 25 miles away. Like an earthquake. If the the pressure containment vessel was there it should be visible now. It's top had a sharp yellow colour. The building was totally destroyed. One third of that building is gone. It must have been the reactor pressure vessel itself that exploded. The mox fuel is more reactive.
The fourth building was not loaded, so it was not the reactor vessel that blow. It was damaged from the third's explosion – got a tilt in direction away from the third. The roof got a bend inwards of about five to ten feet. But it was probably also internal fire and explosion – probably the fuel pool had got dry, or something else that could cause gases. There was a big hole on the south side. And under that hole was an other about 30 times 30 feet hole in the concrete wall. It must have had an explosion. There was fire to – and it is possible some tank or vessel got so hot and exploded.
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