Conditions? The coolant is removed from the rods... the rods are melting. What other conditions do you think you need?
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Japan and the Nuclear situation
- Thread starter Vihzel
- Start date
Conditions? The coolant is removed from the rods... the rods are melting. What other conditions do you think you need?
Thank you for the correction.
Homan13PSU
Android Enthusiast
Many other factors go into the equation here;
- Most importantly, the design between the Soviet era Chernobyl RBMK-1000 reactor, and Western designs are a large reason Fukushima will most likely avoid a Chernobyl, explosive type melt-down. Western reactor vessels are dome shaped, a design which in the case of a meltdown can effectively contain the pressure created in that situation. In Chernobyl's reactor the vessel itself had a flat concrete roof sitting several feet above the reactor core itself. When the fuel melted down, and flashed the water into steam, there was nowhere for that pressure to expand into blowing the top of the reactor upwards and out of the containment building. Physically only under the most intense conditions could this happen in the West. I believe the highest pressures they have been reporting in the reactor buildings and vessels so far are around 3 atmosphere's. High, but not explosive high for these designs.
- When Chernobyl happened, they were running a test on the reactor, ironically the test involved the coolant pumps and keeping the water flowing in between the time a reactor would SCRAM, and the diesel generators could spool up and begin water flow again. Mistake number one was engineers took the safety systems offline to run their tests. Mistake number 2 was power demands in the town Chernobyl served, Pripyat had a demand for power that day and the test got pushed into the night. Finally, and most fatally in the situation was that the night crew were NOT informed of the testing in the reactor taking place and the fact the safety systems were disabled at that time. As the reactor got away from them, and they reacted they did not know that nothing was happening as they tried to activate systems. Chernobyl was quite possibly the nuclear industries equal to the Perfect Storm.
^Agreed, and add the insane idea of having control rods that had to be driven up, as opposed to dropping down. As I recall, no other reactor in operation at the time (or since) featured that design flaw.
As I recall Chernobyl didn't feature an outer containment - it was a confinement design, meaning instead of a sealed container building, its design attempted to confine leaked radionuclides to a building with a large working volume where the atmosphere would be sufficiently contained to allow the air to be scrubbed by filters before passing to the outside.
Could be wrong on that last point, please correct me if I am, but I don't think so. (EDIT - Duh - I see you already identified that point.)
In any case - here's a write up from a business journal - it may help access the information -
http://www.ibtimes.com/articles/122...lear-disaster-may-be-worse-than-chernobyl.htm
The outer containment is the last defense - that's the area for concern for leaked poisons, imo.
As I recall Chernobyl didn't feature an outer containment - it was a confinement design, meaning instead of a sealed container building, its design attempted to confine leaked radionuclides to a building with a large working volume where the atmosphere would be sufficiently contained to allow the air to be scrubbed by filters before passing to the outside.
Could be wrong on that last point, please correct me if I am, but I don't think so. (EDIT - Duh - I see you already identified that point.)
In any case - here's a write up from a business journal - it may help access the information -
http://www.ibtimes.com/articles/122...lear-disaster-may-be-worse-than-chernobyl.htm
The outer containment is the last defense - that's the area for concern for leaked poisons, imo.
I never said it was likely. I said it was possible.
Yeah... I don't know how they are going to fix this, but I hope that they find a way soon.
This is discouraging - I've not had time to cross-reference to more reliable sources yet, so...
Official: Japan's nuclear situation nearing severity of Chernobyl - CNN.com
Homan13PSU
Android Enthusiast
"Whatever the level, many experts warn that it's too early, and there's too little information, to determine what it means for the people who live in the region near the Daiichi plant."
Key statement from the article. Me thinks CNN is playing a little loose with their article title; and I am in no way trying to detract from what is going on over there.
INES Scale
Accident with
Wider Consequences
Level 5
• Limited release of radioactive material likely to require implementation of some planned countermeasures.
• Several deaths from radiation.
• Severe damage to reactor core.
http://www.iaea.org/Publications/Factsheets/English/ines.pdf
Accident with
Wider Consequences
Level 5
• Limited release of radioactive material likely to require implementation of some planned countermeasures.
• Several deaths from radiation.
• Severe damage to reactor core.
http://www.iaea.org/Publications/Factsheets/English/ines.pdf
ElasticNinja
Android Expert
ElasticNinja
Android Expert
2037: The US-based Institute for Science and International Security (ISIS) has said it agrees with the assessment of France's Nuclear Safety Authority (ASN) that the incident at Fukushima should be classified as level 6 on the International Nuclear Event Scale (INES), one below Chernobyl.
Following a number of explosions and a fire at the plant which released dangerous levels of radiation, ISIS said the situation had "worsened considerably" and was now closer to a level 6 event. "It may unfortunately reach a level 7," it added.
Following a number of explosions and a fire at the plant which released dangerous levels of radiation, ISIS said the situation had "worsened considerably" and was now closer to a level 6 event. "It may unfortunately reach a level 7," it added.
ElasticNinja
Android Expert
ElasticNinja
Android Expert
fire at reactor 4 [again]
Can someone please explain to me how dropping water from a helicopter was even on the table?
It seems to me that a helicopter is what happens when the plan fails. And it will not even work.
Water bombing ruled out to cool reactor | Herald Sun
It seems to me that a helicopter is what happens when the plan fails. And it will not even work.
Water bombing ruled out to cool reactor | Herald Sun
ElasticNinja
Android Expert
i presume they will have to send staff to connect water injectors.. poor guys
wiretap
Android Enthusiast
Their contingency and emergency plans suck. It seems like they have very little cooperation and planning for certain scenarios between the company, government, and emergency workers. Then again, we don't know what roads and cities around there are affected by the tsunami and earthquake, or what type response is even available.
The idea is to quench and cool as quickly as possible. Considering a helicopter has several benefits:
- they're using sea water (see illustrations in links above, the sea is right there) and helicopter water delivery systems can recharge rapidly from a large body of water
- nothing fights fires like large deluges of water
- nothing cools things like large deluges of water
- we only have sketchy media reports on existing and available infrastructure to deliver water by other means, there's considerable site damage, so it's not unreasonable for them to consider helicopters for water delivery
- distance matters when dealing with radioactive material, the further a firefighter is away from the fire, the better his survival chances and at present, the risks on site may not be fully known
Probably all common-sense stuff you already knew, but there it is just in case.
Not an expert, but if you dump a large amount of water on anything that is very hot, it kind of explodes.
But the biggest problem I see with dumping water is moving large, and radioactive containers, down flow and into concentrated groups. I would think you would not want to do that, which is why they probably gave up on it.
I hope this is a good thing.
Tokyo Electric Evacuates All Workers from Damaged Nuclear Plant
What happens now? No one is now trying to put out the fire, the plant as been completely abandoned.
But the biggest problem I see with dumping water is moving large, and radioactive containers, down flow and into concentrated groups. I would think you would not want to do that, which is why they probably gave up on it.
I hope this is a good thing.
Tokyo Electric Evacuates All Workers from Damaged Nuclear Plant
What happens now? No one is now trying to put out the fire, the plant as been completely abandoned.
Yep, there's a concern for steam explosions from the water bound into the concrete - I don't know if at this point in the transient that that would be a large concern.
Two reports I saw said that they wanted to drop the water into one of the open buildings so as to cover material (probably spent fuel rods exposed by their coolant boiling off) so that poisons would be trapped by water and reduce opportunity to get airborne (and re-cool things in the case of fuel rods). Those reports said they gave up on the helicopter idea because the opening was not in a place that made the idea feasible.
No telling if those reports are true, there's so much confusion.
Another says there's simply a no-fly zone there now.
A two-hour fire at #4 was reported out by around 5 PM PDT today (9 AM in Japan's Wednesday).
Also worded oddly (and somewhat conflicting with that) - IAEA: Japan reactor building fire seen for 30 minutes | Reuters
With everyone spinning the news right now, it's very hard to see what's really happening.
That TEPCO's workers are out doesn't mean that the site is abandoned by all responders.
http://www.youtube.com/watch?v=UoYOpjuEA8A
ElasticNinja
Android Expert
oh great RT