Climate Change Report

#651
#651
AM64 said:
From an old PWR guy, I don't give a lot of credit to GE for much of anything. BWRs are more prone to radiation releases than PWRs, and GE constantly argued against applying lessons learned from prior PWR events as non-applicable to BWRs. The hydrogen buildup that destroyed the spent fuel buildings at Fukushima was preventable by spark ignitors put in PWR containment buildings since TMI. Of course the power source for them would still have been a problem. Light weight buildings housing pool storage and an overhead crane parked above the pool is an accident just waiting to happen ... particularly in a quake prone area.
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I’m a laymen here on nuke specifics. I’ll take yours and @Wafflestomper professional opinion on it. Most of the reading I’ve done was generally favorable to the failsafes but again I’m reading from a layman’s perspective.

Honestly it sounds like you guys are being hard on the results and see obvious room for improvement. I think that’s typical for the way our brains work. In my field when we finish a flight test evolution I’m always left seeing where we can improve and see the warts. The lay people are upbeat and high fiving. The knowledgeable engineers look already have their hand notes on what they need to look at modifying.

Not completely equivalent I know. But sounds like that to me at a higher level.
 
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#652
#652
LouderVol said:
Thanks for the answers.

Is there a reason we can't "fission" (not sure on tenses for that as a verb, "fise"? I know "split" is generic) the not-uranium? I was thinking the fission that goes on was splitting off enough to make a Hydrogen, which seems like it would leave a good but of material to still be split. But it sounds like you are saying we are taking Uranium 232 and making it 231. or whatever those numbers are. if I understand the isotope speak.
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Yes, there is a reason. It has been a while since I studied fundamentals but there are certain isotopes which can absorb a thermal (slow) neutron and overcome the nuclear force which binds the atom together. This is applicable to certain types of reactors. Here is a link with some light reading if you're interested:
Nuclear binding energy
 
#653
#653
LouderVol said:
so seems like there are some people who know their nuke stuff in here.

I have a couple questions regarding the waste:
1. Why can't we use the same material for pretty much forever? It is still radioactive, so can it just no longer perform fission at some point? Its my understanding that all of the uranium/whatever isn't all used up in the fission process.
2. Could the waste be re-enriched? after it has gone through the fission process? Again it is my understanding that we have to treat radioactive materials to get them to the point where we can use them.
3. I know fusion is still a pipe dream of sorts but can the material that has been fissioned be fused back? It is difficult for me to imagine that a still radioactive material can't be useful. I can get it being less efficient, but its hard to accept that its useless afterwards.
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1 Fuel in power plants is not highly enriched to begin with, so it has a limited cycle of productivity, but it still decays once removed from the reactor and has to be safely stored and cooled. Commercial fuel is in the neighborhood of 3-5% fissile to non fissile uranium whereas naval fuel has been pretty much bomb grade stuff - like in the 90% enrichment range. Not being an ex navy nuke, I have no firsthand knowledge about their fuel, but I can see advantages like not lugging around the extra weight of essentially inert U-238 and faster response.
2 Spent fuel can be reprocessed except Jimmy Carter prohibited reprocessing of any US sourced fuel.
3 Who knows about fusion. I walked around a couple of facilities that were going to get us somewhere ... as I recall that was in the 70s.
 
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#654
#654
LouderVol said:
Thanks for the answers.

Is there a reason we can't "fission" (not sure on tenses for that as a verb, "fise"? I know "split" is generic) the not-uranium? I was thinking the fission that goes on was splitting off enough to make a Hydrogen, which seems like it would leave a good but of material to still be split. But it sounds like you are saying we are taking Uranium 232 and making it 231. or whatever those numbers are. if I understand the isotope speak.
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Generally fuel is enriched (diffusion and centrifuges) to enhance the ratio of existing U-235 in relation to the most common isotope, U-238. It's essentially a mechanical/chemical selection process that has nothing to do with converting one isotope to the other. You can irradiate other elements to produce fissile material - like thorium to U-233 (which like U-235 is fissile) in a breeder or converter reactor. I'm retired and have been for a while, and I honestly don't keep up much, but I haven't heard much about either type since the Clinch River Breeder Reactor was cancelled years ago.
 
#655
#655
NorthDallas40 said:
I’m a laymen here on nuke specifics. I’ll take yours and @Wafflestomper professional opinion on it. Most of the reading I’ve done was generally favorable to the failsafes but again I’m reading from a layman’s perspective.

Honestly it sounds like you guys are being hard on the results and see obvious room for improvement. I think that’s typical for the way our brains work. In my field when we finish a flight test evolution I’m always left seeing where we can improve and see the warts. The lay people are upbeat and high fiving. The knowledgeable engineers look already have their hand notes on what they need to look at modifying.

Not completely equivalent I know. But sounds like that to me at a higher level.
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Pretty much. I think one of the most important characteristics in a good engineer is to always look to see what can be improved and what the potential faults are. Probably makes us dull people because we are looking more at that generally than celebrating what did work right.
 
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#656
#656
AM64 said:
Pretty much. I think one of the most important characteristics in a good engineer is to always look to see what can be improved and what the potential faults are. Probably makes us dull people because we are looking more at that generally than celebrating what did work right.
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Agree completely. I routinely try to remind our younger engineers that yes it’s our job to find the warts and determine how solution X won’t work. But when messaging to mgrs and lay people about solution X try to be a little less “rainman”.

“That’s bad... very bad.”

It’s a balancing act.
 
#657
#657
NorthDallas40 said:
Agree completely. I routinely try to remind our younger engineers that yes it’s our job to find the warts and determine how solution X won’t work. But when messaging to mgrs and lay people about solution X try to be a little less “rainman”.

“That’s bad... very bad.”

It’s a balancing act.
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Trying to keep the marketing types restrained and reasonably honest was even worse than dealing with most management types. I honestly loved the job I did, but so much of the non technical part felt like a salmon swimming upstream that I don't miss it.
 
#658
#658
AM64 said:
Trying to keep the marketing types restrained and reasonably honest was even worse than dealing with most management types. I honestly loved the job I did, but so much of the non technical part felt like a salmon swimming upstream that I don't miss it.
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Lol. Indeed.

WHAT THE HELL DID YOU PROMISE THEM?!
 
#659
#659
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#663
#663
Wafflestomper said:
There's nothing to refute as I've said numerous times now. I brought up the volcano because it was a) a huge explosion; and b) put a ****load of ice and rock high into the atmosphere--you know, sort of like you'd expect an exploding asteroid or comet to do. You can keep playing stupid, but it isn't making this asteroid theory any more plausible.
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Global-warming May Have Been Jump-started By The Tunguska Meteorite Churning Up Atmosphere
I don't know how much you know about Science Daily, but it is well respected. There are several facts in the article.

Fact: Just a rise of 1% of water vapour could raise the global average temperature of Earth's surface more then 4 degrees Celsius.
-I'll wait for your refutation
Fact: Water vapor has an affect on climate which far outweighs the effects of carbon dioxide and other gases released by human activities.
-I'll wait for your to refutation
Fact: The Tunguska event is the largest impact event on Earth in recorded history. Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.[4] For emphasis: (Largest EVER in recor!)
-I'll wait for your refutation.

Claim: As such, Shaidurov has concluded that only an enormous natural phenomenon, such as an asteroid or comet impact or airburst, could seriously disturb atmospheric water levels, destroying persistent so-called 'silver', or noctilucent, clouds composed of ice crystals in the high altitude mesosphere (50 to 85km). The Tunguska Event was just such an event, and coincides with the period of time during which global temperatures appear to have been rising the most steadily - the twentieth century.

Guess what? This claim could be wrong. But it doesn't really matter from my perspective. Volcanoes and events like this most certainly affect the amount of greenhouse gasses in our atmosphere. Whether the Tunguska event triggerd GW, I don't know. It's an interesting hypothesis.
 
#665
#665
Roustabout said:
Global-warming May Have Been Jump-started By The Tunguska Meteorite Churning Up Atmosphere
I don't know how much you know about Science Daily, but it is well respected. There are several facts in the article.

Fact: Just a rise of 1% of water vapour could raise the global average temperature of Earth's surface more then 4 degrees Celsius.
-I'll wait for your refutation
Fact: Water vapor has an affect on climate which far outweighs the effects of carbon dioxide and other gases released by human activities.
-I'll wait for your to refutation
Fact: The Tunguska event is the largest impact event on Earth in recorded history. Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.[4] For emphasis: (Largest EVER in recor!)
-I'll wait for your refutation.

Claim: As such, Shaidurov has concluded that only an enormous natural phenomenon, such as an asteroid or comet impact or airburst, could seriously disturb atmospheric water levels, destroying persistent so-called 'silver', or noctilucent, clouds composed of ice crystals in the high altitude mesosphere (50 to 85km). The Tunguska Event was just such an event, and coincides with the period of time during which global temperatures appear to have been rising the most steadily - the twentieth century.

Guess what? This claim could be wrong. But it doesn't really matter from my perspective. Volcanoes and events like this most certainly affect the amount of greenhouse gasses in our atmosphere. Whether the Tunguska event triggerd GW, I don't know. It's an interesting hypothesis.
Click to expand...

Those kinds of theories don't get scientists paid.
 
#666
#666
Let's assume that these assertions are all true for the time being.

Roustabout said:
Fact: Just a rise of 1% of water vapour could raise the global average temperature of Earth's surface more then 4 degrees Celsius.
-I'll wait for your refutation

Fact: Water vapor has an affect on climate which far outweighs the effects of carbon dioxide and other gases released by human activities.
-I'll wait for your to refutation

Fact: The Tunguska event is the largest impact event on Earth in recorded history. Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.[4] For emphasis: (Largest EVER in recor!)
-I'll wait for your refutation.
Click to expand...

Do you have any idea just how much water is in the atmosphere? According to Dr. Google it's approximately 3.75E+16 gallons. What's the volume of a 600 foot spherical asteroid? Approximately 8.5E+8 gallons. So, assuming the thing is made entirely of ice, and that it all ends up in the atmosphere, this addition is several orders of magnitude less than 1% of the water in the atmosphere. If my math is correct, 1% of the water in the atmosphere is roughly equal to 400,000 600' ice meteors. I'll call this one refuted.

Roustabout said:
Claim: As such, Shaidurov has concluded that only an enormous natural phenomenon, such as an asteroid or comet impact or airburst, could seriously disturb atmospheric water levels, destroying persistent so-called 'silver', or noctilucent, clouds composed of ice crystals in the high altitude mesosphere (50 to 85km). The Tunguska Event was just such an event, and coincides with the period of time during which global temperatures appear to have been rising the most steadily - the twentieth century.
Click to expand...

Maybe I missed it, but does he have evidence that there is extra water vapor, compared to prior to the Tunguska event, in the mesosphere?

Also, the asteroid is said to have exploded about 3 to 6 miles above the surface. This is well below the mesosphere, and it seems that the energy would have been mostly directed downward.
 
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#667
#667
Wafflestomper said:
Let's assume that these assertions are all true for the time being.



Do you have any idea just how much water is in the atmosphere? According to Dr. Google it's approximately 3.75E+16 gallons. What's the volume of a 600 foot spherical asteroid? Approximately 8.5E+8 gallons. So, assuming the thing is made entirely of ice, and that it all ends up in the atmosphere, this addition is several orders of magnitude less than 1% of the water in the atmosphere. If my math is correct, 1% of the water in the atmosphere is roughly equal to 400,000 600' ice meteors. I'll call this one refuted.



Maybe I missed it, but does he have evidence that there is extra water vapor, compared to prior to the Tunguska event, in the mesosphere?

Also, the asteroid is said to have exploded about 3 to 6 miles above the surface. This is well below the mesosphere, and it seems that the energy would have been mostly directed downward.
Click to expand...
Look! We’re having a discussion!
 
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#672
#672
AM64 said:
1 Fuel in power plants is not highly enriched to begin with, so it has a limited cycle of productivity, but it still decays once removed from the reactor and has to be safely stored and cooled. Commercial fuel is in the neighborhood of 3-5% fissile to non fissile uranium whereas naval fuel has been pretty much bomb grade stuff - like in the 90% enrichment range. Not being an ex navy nuke, I have no firsthand knowledge about their fuel, but I can see advantages like not lugging around the extra weight of essentially inert U-238 and faster response.
2 Spent fuel can be reprocessed except Jimmy Carter prohibited reprocessing of any US sourced fuel.
3 Who knows about fusion. I walked around a couple of facilities that were going to get us somewhere ... as I recall that was in the 70s.
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thanks again for the answers.

back to number 1, is there a reason we don't enrich it more? Just because its cheaper? Seems like having less, but more potent, would be better and safer than the opposite.

I am wondering if the still radioactive waste could be used in another system, do pretty much the same thing, but a new system?

Is the 90% stuff, once it is used up, any more dangerous/radioactive than the commercial stuff?
 
#673
#673
LouderVol said:
thanks again for the answers.

back to number 1, is there a reason we don't enrich it more? Just because its cheaper? Seems like having less, but more potent, would be better and safer than the opposite.
Click to expand...

Naval reactors generally have to be smaller to fit onto ships and have a high power density while only needing to be refueled about once every 20 years or so. With commercial plants there is more of a concern over using bomb-grade uranium as fuel. To be clear though, someone couldn't just steal naval/high enriched fuel and use it as a weapon without reprocessing it for that purpose.

LouderVol said:
I am wondering if the still radioactive waste could be used in another system, do pretty much the same thing, but a new system?
Click to expand...

No, not for the same purpose. Spent highly enriched fuel (and probably spent low enriched fuel to a lesser extent) can be reprocessed to retrieve the remainder of the U-235 (or whatever). Then it can be made into new fuel. But this is a pretty involved process.

LouderVol said:
Is the 90% stuff, once it is used up, any more dangerous/radioactive than the commercial stuff?
Click to expand...

I'd say it's mostly dependent upon how long it had decayed and its power history. U-235 isn't super radioactive. You could sleep next to a new highly enriched fuel element and be fine. Spent fuel is pretty radioactive and will kill you with no shielding though.
 
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#674
#674
Wafflestomper said:
Naval reactors generally have to be smaller to fit onto ships and have a high power density while only needing to be refueled about once every 20 years or so. With commercial plants there is more of a concern over using bomb-grade uranium as fuel. To be clear though, someone couldn't just steal naval/high enriched fuel and use it as a weapon without reprocessing it for that purpose.



No, not for the same purpose. Spent highly enriched fuel (and probably spent low enriched fuel to a lesser extent) can be reprocessed to retrieve the remainder of the U-235 (or whatever). Then it can be made into new fuel. But this is a pretty involved process.



I'd say it's mostly dependent upon how long it had decayed and its power history. U-235 isn't super radioactive. You could sleep next to a new highly enriched fuel element and be fine. Spent fuel is pretty radioactive and will kill you with no shielding though.
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Out of curiosity and no idea if you can answer in a public domain. But the sizing of a single rod. Is the mass sized so that no single rod is a threat by itself and they only go critical when combined with other rods in close proximity and no control rods inserted? I am assuming that’s why a new fuel element is relatively safe?
 
#675
#675
From a waste perspective, highly enriched is better. Less U238 absorption means less higher actinides, which are the longer lived radioactive products. Also makes it worse for plutonium production. The reason it is not done is proliferation concerns.
 
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