These guys should be put into a Gulag

[Kärnfysikern]

http://www.spacewar.com/2006/060711203151.gd7vblq0.html

Russia should not play nice with those environmentalist scum. Atleast they got a beating. But I like how the french treated greenpeace.

Seems like the stupidity of environmentalists is as deep as the stupidity of terrorists. Both living in some dream world where they acctualy think they are doing something good.

[Logan13]

http://www.spacewar.com/2006/060711203151.gd7vblq0.html

Russia should not play nice with those environmentalist scum. Atleast they got a beating. But I like how the french treated greenpeace.

Seems like the stupidity of environmentalists is as deep as the stupidity of terrorists. Both living in some dream world where they acctualy think they are doing something good.

Very true and well stated.

[USfighterFC]

They should be put into the gulag because they dont want nuclear waste stored in their country?

[zodiac666]

http://www.spacewar.com/2006/060711203151.gd7vblq0.html

Russia should not play nice with those environmentalist scum. Atleast they got a beating. But I like how the french treated greenpeace.

Seems like the stupidity of environmentalists is as deep as the stupidity of terrorists. Both living in some dream world where they acctualy think they are doing something good.

i dont know the specifics of that case so its hard to comment on it.

why are you so against environmentalists? an environmentalist is just someone who is trying to protect the environment, kind of a broad statement putting down all environmentalists?

[Logan13]

I do not want to speak for johan, but I know that he was not condemming these people for just being enviromentalists. He was simply pointing out how they live in the theoretical world and attempt to apply their thinking to the real world. Many are just as illogical as any other radical group...yes these people are quite radical in their thinking. If they had their way, we would all be riding horses to work everyday, anything less would be harmful to mother earth. Hell, then we would have the animal rights people bitching even more.....

[Kärnfysikern]

They should be put into the gulag because they dont want nuclear waste stored in their country?

Well not just that, but the general fanaticism such movements have. If it wherent for greenpeace and other ignorant people we would have alot less CO2 emission in the world.

What they also fail to realise is all the nuclear waste in the world would just fill up one football stadium and its very easy to keep that small ammount safe. I wouldnt mind having a nuclear waste facility in my neighboorhood.

i dont know the specifics of that case so its hard to comment on it.

why are you so against environmentalists? an environmentalist is just someone who is trying to protect the environment, kind of a broad statement putting down all environmentalists?

This dude, a co founder of greenpeace that has withdrawn from it in disgusts puts it best(his whole page is excelent and very refreshing).

http://www.greenspirit.com/

“The movement has been hijacked by people who prefer rhetoric to fact and refuse to evolve beyond confrontation,” says Dr. Moore. “As the first wave of activists in the early 1970s, we struggled to make people realize the harm that was being done to this planet—and yes, we relied on confrontational tactics. But, after more than 15 years of yelling as loud as we could, an interesting thing happened. People started to listen. Governments started to listen. Environmental protection became a fundamental part of our laws and regulations. Public participation and inclusiveness became the norm.

“And yet, I see environmental groups today becoming increasingly extreme, promoting arguments that have less to do with the environment than their own political agendas. This is not the way to achieve environmental progress.”

Basicly even if they realy want better environment they just get so pulled into the bullshit that they stop beeing sensible and start beeing against everything that can help. Like nuclear power. Im never going to stop whining about nuclear power I just can not belive how any intelligent and educated person can be against nuclear power if they have done any reading whatsoever on the issue. The treehuggers will use any absurd argument possible to bring down nuclear power and the sad part is that the avarage uneducated joe gets scared to and that leaves us with one hell of a mess.
The avarage joe because of those ****s belive a chernobyl is possible in a western nuclear plant. Thats how well they have spread there manure.

greenpeace and other similar eco fanatics just brainwash good people into beliving bullshit and that hurts the environment, the economy, workers. Hell sweden are already a energy importing country because the ****ing greens managed to convince swedes to downsize our nuclear power. Makes alot of environmental sense to disabled our clean energy production and import dirty energy from russia....

I do not want to speak for johan, but I know that he was not condemming these people for just being enviromentalists. He was simply pointing out how they live in the theoretical world and attempt to apply their thinking to the real world. Many are just as illogical as any other radical group...yes these people are quite radical in their thinking. If they had their way, we would all be riding horses to work everyday, anything less would be harmful to mother earth. Hell, then we would have the animal rights people bitching even more.....

In this case you stole the words right out of my mouth!! Could not have said it better myself. All the environmentalist movements have ever done is to HURT the environment since they are so anti technology and anti everything with scary words in it like nuclear.

other things they opose that can help this world alot:
particle physics researc(it involves nuclear cores after all, nuclear boggymen )
Geneticly enhanced crops
clean coal power
fusion research(thats right those ****ers are even so stupid that they opose the best and cleanest energy soruce we can imagine).
Forestry(they try to somehow claim this is bad )


There are good environmentalists out there like Patrick Moore. But offcourse to the nuts they are just eco-judas. When I say environmentalist I refer to the nuts and the fanatics. I am very very caring for the environment but I would never call myself a environmentalist after those assholes have made it into a dirty word.

Now Il stop ranting

[GREENMACHINE]

I am against the use of nuclear fuel as a power source particularly by irresponsible goverments like Russia's. Look at the chernovle [sic ] the reason for that diasaster was poor workmanship and materials in it's design. The head engineer of the project resigned his post in protest at the goverments insistence on using cheaper russain made structure which he considered substandard.

We are led to believe that the nuclear industry is the mostly tightly regulated industry in the world dwarfing the regulations found in the FDA regulated harmacuetical industry. Yet there has been several incidences in Sellafield in the UK of undisclosed discharges, incorrectly documented materials transfer etc.

It all sound like an excellent resource to mankind, the use of nuclear power and it appear for the most part that we have things in control. In reality as a race we are not responsible enough for nuclear power and I think we have bitten off more than we can chew.

[Kärnfysikern]

I am against the use of nuclear fuel as a power source particularly by irresponsible goverments like Russia's. Look at the chernovle [sic ] the reason for that diasaster was poor workmanship and materials in it's design. The head engineer of the project resigned his post in protest at the goverments insistence on using cheaper russain made structure which he considered substandard.

We are led to believe that the nuclear industry is the mostly tightly regulated industry in the world dwarfing the regulations found in the FDA regulated harmacuetical industry. Yet there has been several incidences in Sellafield in the UK of undisclosed discharges, incorrectly documented materials transfer etc.

It all sound like an excellent resource to mankind, the use of nuclear power and it appear for the most part that we have things in control. In reality as a race we are not responsible enough for nuclear power and I think we have bitten off more than we can chew.

Id say the western world has handled it very well. We have not no big accident that caused any harm. Three miles island was the biggest accident and just about the worst case scenario for a western plant and none got injured.

The main flaw with chernobyl was the graphite control rods. A fatal error. The lack of a protective dome aswell. If chernobyl had a protective dome like all western plants there would have been no disaster. Everything would have been contained. The whole disaster was still highly unlikely and would not have happened if they hadnt run a dangerous test with all safety systems shut down. It was a unfortunate combination of bad construction and lack of judgment When I say something like that cant happen in a western plant I am dead serious. Our designs and safety systems doesnt make it even possible.

Nuclear power IS the most tightly regulated industry in the world. Maby other industries would not even survive with the same kind of safety demand. Sure there is some meddling going on in nuclear industry aswell that is unavoidable. But the lack of any serious accident in the western world shows how safe it is imo.

Any big chem plant accident is just as bad as a meltdown. Look at the bhopa disaster in india. But for some reason nuclear power has been vilifed. We have had one serious accident in the world in the entire lifetime of the industry. To me that speaks of how safe it is. Not to mention if the population around chernobyl would have had iodine tablets they would not have suffered hardly any consequenses of the disaster.

[GREENMACHINE]

I come from a background in QA and am a firm believer that if something can go wrong it will. No process is perfect and there is always something that can go wrong, the closer you get to being error free, the more expensive it gets to create lasting improvements. At this point economics come into play and the industry is not willing to spend more money on improvements.

Nuclear power is a pretty new industry yet. Nuclear material remain a nuclear hazards. To say that we have the relevant structure in place to prevent this, is in my opinion ill conceived.

The only comparision I think of right now is how many high end consumer goods have you bought that broke within 5 minutes of using them. The only comparision Who knows what economic circumstances a country will see in the future, When the russian's built chernobyl they didn't decide to a build a crap plant. They were just over confident that they could cut corners and acheive the same result.

I can't comment specifically on the design process ofthe plants in The US or indeed in other Western countries. From my standpoint the dome might proctect an immediate fallout but future generation as going to have a timebomb on their hands that could be passed on from generation to generation.

Id say the western world has handled it very well. We have not no big accident that caused any harm. Three miles island was the biggest accident and just about the worst case scenario for a western plant and none got injured. Who know what economic circumstances a country will see in the future. When they built chernobyl they didn't decide to build a crap plant. They were just over confident that they could cut corners.

The main flaw with chernobyl was the graphite control rods. A fatal error. The lack of a protective dome aswell. If chernobyl had a protective dome like all western plants there would have been no disaster. Everything would have been contained. The whole disaster was still highly unlikely and would not have happened if they hadnt run a dangerous test with all safety systems shut down. It was a unfortunate combination of bad construction and lack of judgment When I say something like that cant happen in a western plant I am dead serious. Our designs and safety systems doesnt make it even possible.

Nuclear power IS the most tightly regulated industry in the world. Maby other industries would not even survive with the same kind of safety demand. Sure there is some meddling going on in nuclear industry aswell that is unavoidable. But the lack of any serious accident in the western world shows how safe it is imo.

Any big chem plant accident is just as bad as a meltdown. Look at the bhopa disaster in india. But for some reason nuclear power has been vilifed. We have had one serious accident in the world in the entire lifetime of the industry. To me that speaks of how safe it is. Not to mention if the population around chernobyl would have had iodine tablets they would not have suffered hardly any consequenses of the disaster.

[Kärnfysikern]

I come from a background in QA and am a firm believer that if something can go wrong it will. No process is perfect and there is always something that can go wrong, the closer you get to being error free, the more expensive it gets to create lasting improvements. At this point economics come into play and the industry is not willing to spend more money on improvements.

Nuclear power is a pretty new industry yet. Nuclear material remain a nuclear hazards. To say that we have the relevant structure in place to prevent this, is in my opinion ill conceived.

The next generation reactors have a natural negative feedback. In the pebbled bed reactor for instance the reaction stops if the temperature goes to high. This isnt controlled by a safety system or anything like but is a physical effect of the material used. Since its a effect of the material it can no fail so a meltdown is 100% impossible in such a reactor. They are also cooled by inert gases so there can be no steem explosion like in chernobyl. Even if everything in the reactor failed, every safety system, loos of coolant ect. It would still come to a natural halt if the temperature gets to high. there can be no explosion and no meltdown so there can be no spreading of radioactive material outside of the plant.

this has been tested btw, a test where they removed the control rods completely and shut down all coolant.

The containment buildings can handle even a jumbo jet crashing into it aswell so there is nothing that can break it.

The only comparision I think of right now is how many high end consumer goods have you bought that broke within 5 minutes of using them. The only comparision Who knows what economic circumstances a country will see in the future, When the russian's built chernobyl they didn't decide to a build a crap plant. They were just over confident that they could cut corners and acheive the same result.

Well that was russia during the soviet era. Its impossible to cut corners in the western world in the same way. Its also important to realise that the chernobyl accident was caused be a deliberate test that was known to be dangerous. It wasnt a accident during regular runtime. The operators of that plant had the power to manualy shut down all safety measures. This cant be done in a modern plant.

I can't comment specifically on the design process ofthe plants in The US or indeed in other Western countries. From my standpoint the dome might proctect an immediate fallout but future generation as going to have a timebomb on their hands that could be passed on from generation to generation.

Dont buy into the hype that nuclear waste have to be stored for 100 000 years for it so be safe. After just 100 years it would be easy to clean it up with not to heavy safety measures, even after just 50. Im sure it could be cleaned up safetly at once aswell. I dont know how they handled it on three miles island but Il have to read up on that.

the waste issue isnt a issue. Environmentalits just makes it into a issue. Our current pool storage is perfectly adequate untill we master transmutation or until we decide to reprocess it and use it as fuel again.
Demanding a safe storage for 100 000 years is a perfect example of how environmentalist fanatisicm has polluted politics and made the general public afraid.

I agree that things can go wrong in the best built machine. My point is just that even if something goes wrong the consequenses are not especialy bad. Nothing even remotely similar to chernobyl.

But just out of curiosity what do you imagine as beeing the worst case nuclear accident scenario?
Many seem to be scared of a nuclear accident. But what do you acctualy belive is the worst thing that might happen?

[Kärnfysikern]

if I come off as a bit argumentative and harsh please excuse me. But nuclear power is something I feel VERY strongly about.

[Kärnfysikern]

ohh btw chernobyl had a dangerously high positive void coefficient. This was know when they built it. So they intentionaly built power plants that where know to be dangerous in a loss of coolant accident. All our designs are made such that our reactors can handle a loss of coolant.

[kdawg21]

EARTH FIRST!!!!!!!!!!!!!!

We will pave other plantes later.

[GREENMACHINE]

if I come off as a bit argumentative and harsh please excuse me. But nuclear power is something I feel VERY strongly about.

No probs I feel strongly about my stand on it. I will take a look at your arguments in detail in a minute. To begin with though you were a typical arrogant american. Then I remembered you weren't american, and you realised you have an excellent technical knowledge of nuclear power.

[GREENMACHINE]

I will try to analyise your arguments as best I can. Comments in bold.

The next generation reactors have a natural negative feedback. In the pebbled bed reactor for instance the reaction stops if the temperature goes to high. This isnt controlled by a safety system or anything like but is a physical effect of the material used.

Question time. Forgive me if I am off target. What come to find here is standard temprature and preeure(STP) for some reason. That is to say that the volume of a given material is dependant on it's temprature and the pressure at which it is stored. Best I can remember the energy reasonating from radio active materials is pulsative in nature.

Question Time. What are the key elements in generating electrical current from the energy dispalced by radio active power.

I am aware that there is some degree of background radiation pretty much every where. Also I know that some natural occuring molecular elements are radioactive. Thirdly I know that most of these element have I beleive 5/6 orbitals rings. That some elements at this end of the range can only be man made in reaction chambers.

Now for the question. The material used in these reactor is it made via the means I have descibed in my last point or extracted from nature somehow. My basis of the 100,000 year thing was not based on something I learn't in chemistry as opposed, to a Greenpeace workshop or something.

My numbers could be wrong admitadly. It is 8 years since I studied chemistry.

Since its a effect of the material it can no fail so a meltdown is 100% impossible in such a reactor.

Does the effect of the material only effect the localised envioroment contained within the reactor. Or does it effect control remote of the reactor like I vacumn systems pnuematics

They are also cooled by inert gases so there can be no steem explosion like in chernobyl.

Which gases in particular? Noble gases? Nitrogen is prolly a pretty inert gas but with the right/wrong (depends on your objectives) factors it's has jekyl and hyde characteristics.

Even if everything in the reactor failed, every safety system, loos of coolant ect. It would still come to a natural halt if the temperature gets to high. there can be no explosion and no meltdown so there can be no spreading of radioactive material outside of the plant.

Will take you word on that, I don't have an engineering background.

this has been tested btw, a test where they removed the control rods completely and shut down all coolant.

when you say tested, under what conditions? I am thinking in terms of the normal control parameter of the process. 3 sigma etc, bell shaped curve all that stuff.

The containment buildings can handle even a jumbo jet crashing into it aswell so there is nothing that can break it.

That is good to know if in terms of suicide bombers or even a regular jet diaster.

Well that was russia during the soviet era. ( I agree things have changed alot an Russia was an exceptional case. I won't go into the details here)



Its impossible to cut corners in the western world in the same way. Its also important to realise that the chernobyl accident was caused be a deliberate test that was known to be dangerous. It wasnt a accident during regular runtime. The operators of that plant had the power to manualy shut down all safety measures. This cant be done in a modern plant.

What type of safety measure are in place in a modern facilities. What are the precipiating factors in their operation.


Dont buy into the hype that nuclear waste have to be stored for 100 000 years for it so be safe. After just 100 years it would be easy to clean it up with not to heavy safety measures, even after just 50. Im sure it could be cleaned up safetly at once aswell. I dont know how they handled it on three miles island but Il have to read up on that.

Okay 100,000 might aonly apply to the likes of a nuclear fallout. I guess containment is key and allowing the material to dissapate in a controlled manner. Again this is your forte not mine.

the waste issue isnt a issue. Environmentalits just makes it into a issue. Our current pool storage is perfectly adequate untill we master transmutation or until we decide to reprocess it and use it as fuel again.

By Transmutation are you talking about carcinogenic/mutagenic effects on biological forms?

Demanding a safe storage for 100 000 years is a perfect example of how environmentalist fanatisicm has polluted politics and made the general public afraid.

I agree that things can go wrong in the best built machine. My point is just that even if something goes wrong the consequenses are not especialy bad. Nothing even remotely similar to chernobyl.

But just out of curiosity what do you imagine as beeing the worst case nuclear accident scenario?

Chernobyl the 2nd

Many seem to be scared of a nuclear accident. But what do you acctualy belive is the worst thing that might happen?

one last thing that would concern me is say a terrosist attack on a nuclear power plant

[Kärnfysikern]

No probs I feel strongly about my stand on it. I will take a look at your arguments in detail in a minute. To begin with though you were a typical arrogant american. Then I remembered you weren't american, and you realised you have an excellent technical knowledge of nuclear power.

You give me a bit to much credit though. Unfortunaly I dont yet have that much knoweledge on nuclear technology. But I am hoping Im gonna catch a reactor physics class this upcoming semester.

[Kärnfysikern]

btw Im just heading for bed so Im gonna get through that tomorrow. Im gonna have to do some searching for some of the questions for sure.

[GREENMACHINE]

You give me a bit to much credit though. Unfortunaly I dont yet have that much knoweledge on nuclear technology. But I am hoping Im gonna catch a reactor physics class this upcoming semester.

More so than me anyway. Nice to see someone base their beliefs on real world data even if you don't agree with them. It makes for more interesting debate.

[Kärnfysikern]

Question time. Forgive me if I am off target. What come to find here is standard temprature and preeure(STP) for some reason. That is to say that the volume of a given material is dependant on it's temprature and the pressure at which it is stored. Best I can remember the energy reasonating from radio active materials is pulsative in nature.

Im not sure I understand the question here

Question Time. What are the key elements in generating electrical current from the energy dispalced by radio active power.

The reactor heats up some kind of medium, can be anything from something like liquid sodium to water. The medium transferes its heat to water that vaporises and drives steem turbines. I think there has been some work done on using the temperature difference to drive a stirling engine instead since a stirling enginge theoreticaly has a higher efficiency than steem.
Here is a overview of a pressurized water reactor(as of now the most comon type of reactor)
http://upload.wikimedia.org/wikipedi...terReactor.gif


As you se from the above picture everything radioactive is enclosed in the first loop. In a boiling water reactor the water that flows through the reactor itself is the water that also drives the turbine so ints a merger of loop one and two in the above animation.

A schematic over a pebbled bed would look similar to the above picture I think. But the first loop would be inert gasses instead of water.

Im not sure if that is good enough answere?

I am aware that there is some degree of background radiation pretty much every where. Also I know that some natural occuring molecular elements are radioactive. Thirdly I know that most of these element have I beleive 5/6 orbitals rings. That some elements at this end of the range can only be man made in reaction chambers.

With orbital rings do you mean electron shells?? Alot of exotic elements with short half lifes are created in reactors that doesnt exist naturaly on earth because they have to short halv lifes.

Now for the question. The material used in these reactor is it made via the means I have descibed in my last point or extracted from nature somehow. My basis of the 100,000 year thing was not based on something I learn't in chemistry as opposed, to a Greenpeace workshop or something.

My numbers could be wrong admitadly. It is 8 years since I studied chemistry.

The fuel in a reactor is most comonly uranium. Natural uranium is mostly U-238 and its no good as fuel in regular reactors. It contains small amounts of U-235 however. The u-235 is enrichened so the uranium contains about 5% u-235 and then its ready for reactor. When the reactor is running sone of the U-238 cores capture some neutrons and will through (I belive) beta decay turn into plutonium-239. The plutonium-239 is itself as good a fuel as u-235 and the u-235 and p-239 togheter drives the reactor.

The waste created by a reactor consist of isotopes with roughly half the number of nucleons as u-235. Below is a chart showing the % yeild of different isotopes after u-235 fissions.

The yeld from the p-239 should be somewhat similar. Radioactive Xenon and Strontium seems to be comon waste products. I know plenty of cesium is produced aswell. They usaly have fairly short half lifes and therefor are highly radioactive. Thats why the pool storage is for. Its for "hot" waste. The burnt fuel is stored in the pools for 20 years or so to allow the short halflife isotopes to burn out.
Its important to note thought that this waste isnt depleted of fuel. Its only waste because many of these isotopes produced by fission have such big neutron capture cross section that they will steal all the neutrons that drives the reaction and stop the reaction. This fuel can be reprocessed by removing these isotopes and be run in a reactor again.

Here is a complete list of all isotopes and halflifes
http://133.53.31.105/CN04/index.html

the 100.000 year figure it something thrown out by environmental groups that is unresonable. Even after only 10 years the level of radioactivity is just 1/1000 of what it was when it was pulled out of the reactor. The radioactivity drops exponentialy so after that it slows down alot, but still the 100 000 years are just absurd. I dont know how they got that figure in the first place but I guess its the time it takes for the spent fuel to radiate as little as the background radiation or something like that.

[Kärnfysikern]

Does the effect of the material only effect the localised envioroment contained within the reactor. Or does it effect control remote of the reactor like I vacumn systems pnuematics

I am not sure I fully understand this question? Could you try to rewrie it?

Which gases in particular? Noble gases? Nitrogen is prolly a pretty inert gas but with the right/wrong (depends on your objectives) factors it's has jekyl and hyde characteristics.

Helium, nitrogen or carbon dioxide is what is used in the pebbel beds. When it comes to the chemistry of those gases I have to confess my complete ignorance.

Will take you word on that, I don't have an engineering background.

I think I will explain this a bit further anyway since its a very nice effect.
In a pebble bed reactor uranium is contained within pebbles of pyrolytic graphite. The pyrolytic graphite is the neutron moderator(i.e it slows down the neutrons so that they can be captured by the u-235 and create fission, without moderation the chanse of neutron capture becomes dramaticly small).
In essence each of these sphere is a mini nuclear reactor. If you pile enough of them togheter the reaction starts.
Normaly neutrons released by u-235 fission is to high to react with u-235 and to low to react with u-238. If the fuel heats up though the energy range of the fission neutrons will be "smeared" out to allow the neutrons to react with u-238. Since a neutron captured by u-238 doesnt produce any fission it means less neutrons are aviable to induce fission in the u-235. This means that if the heat goes up the number of neutron drops and lowers the reaction rate which in turns lowers the temperature.
So like I said this works completley independant of any safety system. A very elegant solution.

when you say tested, under what conditions? I am thinking in terms of the normal control parameter of the process. 3 sigma etc, bell shaped curve all that stuff.

They basicly just pulled out the control rods(the control rods work by capturing neutrons and lowering the number of neutrons that can react with u-235) and shut down all coolant to the reactor. They basicly ran a worst case scenario as a experiment. All that happened was that the reactor slowed down to its idle state.

That is good to know if in terms of suicide bombers or even a regular jet diaster.

Yes, those containment buildings are incredibly sturdy.

. ( I agree things have changed alot an Russia was an exceptional case. I won't go into the details here)

Chernobyl is a quite interesting case. I havent read any in depth about the chernobyl accident but I have seen a few documentaries and the stupidity of the guy running that dangerous test was just baffling. What is ironic is that he is just about the only one that survived the accident aswell. If there is a god he sure has a sense of dark humor.
The remaining reactors of chernobyl type have been improved alot so another chernobyl is unlikely even in those. But I would feel more comftertable if they shut all of them down completely. We have a couple of those old rusty bastards close to our northern border.

What type of safety measure are in place in a modern facilities. What are the precipiating factors in their operation.

The biggest safety measure is that no human can shut down any safety system. Before three miles island and chernobyl the attitude was that humans know best and should have full controll. But after those accidents its no longer possible for any human to shut down any safety system under any circumstance.

The second biggest safety measure is the controll rods. There are systems in place that can fully insert the control rods in a matter of seconds. The control rods can shut down the reaction almost completely in no time.

what happened at chernobyl was that the controll rods where such that for a split moment they increased the reaction rate before they shut it down since they had graphite tips and graphite moderates the neutrons. So when they engaged the emergency lowering of the control rods they made the whole thing go out of controll. No western plant has anything like that in the controll rods.

What safety measures they have in a total loss of coolant accident I dont know to be honest. The control rods would maby be enough but there would be alot of heat and the possibility of a steam explosion in the preasurised and boiling water reactors.

The most important safety measure is the containment building. Nothing can get out of it. You could stand right outside the containment building during a complete meltdown and you would suffer less radiation than if you are inside a apartment(because of the radon in concrete) or if you take a plane ride(thinner atmosphere high up in the air allows more cosmic and solar radiation).

Okay 100,000 might aonly apply to the likes of a nuclear fallout. I guess containment is key and allowing the material to dissapate in a controlled manner. Again this is your forte not mine.

The fact that the radiation drops with a factor of thousand in just 10 years would mean cleanup could be done fairly quickly. I have to take some time someday and read up on the cleanup of three miles island to know how they did it and how long they waited.

By Transmutation are you talking about carcinogenic/mutagenic effects on biological forms?

No transmutation is when you put the waste products into special reactors that transmutes those isotopes into less radiactive ones. It isnt a complete process and as of now its just in research stage. But In a not so distante future Im sure we will have plenty of those to take care of waste.

Chernobyl the 2nd

one last thing that would concern me is say a terrosist attack on a nuclear power plant

The containment building is what would stop both a chernobyl the second and a terrorist attack.

A meltdown like in chernobyl cant happen in the next generation reactors and are horribly unlikely in the present reactors and like I said earlier even if a complete meltdown where to happen the containment building would contain all waste.

lets say a worst case scenario is that terrorist manages to get into a plant. When they are in there there is realy nothing they can do. They can not do any security override or anything of that sort because none of the safety systems can be overridden.
I dont know what kind of damage they could to physicaly to the reactor itself. But even for that to have any effect they have to make sure the containment building is breached and that requires some very heavy firepower. I wouldnt say its impossible. But Im gonna say its very very very unlikely they could pull something like that off. It would be ALOT harder to do than it was to pull of 9/11.

[Kärnfysikern]

It feel like some of my answeres where a bit to general. Feel free to ask me to go more indepth and I will do so if I am able(otherwise I will dig up the information).

[GREENMACHINE]

Im not sure I understand the question here

Okay that was a bad example, I though the material as immobile.




The reactor heats up some kind of medium, can be anything from something like liquid sodium to water. The medium transferes its heat to water that vaporises and drives steem turbines. I think there has been some work done on using the temperature difference to drive a stirling engine instead since a stirling enginge theoreticaly has a higher efficiency than steem.
Here is a overview of a pressurized water reactor(as of now the most comon type of reactor) So does the the process cycle within the reactor create the power for the vacumn.

No idea what that is. Is it some kind of hybrid engine.

http://upload.wikimedia.org/wikipedi...terReactor.gif


As you se from the above picture everything radioactive is enclosed in the first loop. In a boiling water reactor the water that flows through the reactor itself is the water that also drives the turbine so ints a merger of loop one and two in the above animation.

Okay that answered my last question I think.


A schematic over a pebbled bed would look similar to the above picture I think. But the first loop would be inert gasses instead of water.

Pebbled bed is a different type of reactor I assume.

Im not sure if that is good enough answere?


With orbital rings do you mean electron shells?? Exactly


Alot of exotic elements with short half lifes are created in reactors that doesnt exist naturaly on earth because they have to short halv lifes.

Yep I know that. Was sure if the purpose of the reactor was to create these exotics, something along the lines of their instability creating a more exothermic reaction.



The fuel in a reactor is most comonly uranium. Natural uranium is mostly U-238 and its no good as fuel in regular reactors. It contains small amounts of U-235 however. (Those is the two normal isotopes right)

The u-235 is enrichened so the uranium contains about 5% u-235 (Do you mean u-238 here)


and then its ready for reactor. When the reactor is running sone of the U-238 cores capture some neutrons and will through (I belive) beta decay turn into plutonium-239. The plutonium-239 is itself as good a fuel as u-235 and the u-235 and p-239 togheter drives the reactor.

I am trying to remember the exact correlation between nuetrons and electron and proton. There should be an equal number of proton and electron in a molecule right. Does this donated nuetron change the said molecules affinity to reach stability by convering to a p-239 stable molecule.

The waste created by a reactor consist of isotopes with roughly half the number of nucleons as u-235. Below is a chart showing the % yeild of different isotopes after u-235 fissions.


Nucleons huh. The nucleas is the core containing nuetrons and protons isn't it. Not sure what a nueclon is.


Does A represent the mean/mode and median can't remember how that works with a bimodal distribution.


The yeild from the p-239 should be somewhat similar. Radioactive Xenon and Strontium seems to be comon waste products. I know plenty of cesium is produced aswell.

Only thing that has me thinking is your use of the term half-life. I am more used to seeing it in a medicinal context. In the sense that somethings half life is based on biologicaly values etc. Would the half life, if this is the correct term in this context not be influenced by the overall stereochemistry within the reactor. If this is the case outside the confines of the reactor is it fair to assume that they would have a shorter half life and therefore are more radioactive oustside the control of the reactor.

They usaly have fairly short half lifes and therefor are highly radioactive. Thats why the pool storage is for. Its for "hot" waste. The burnt fuel is stored in the pools for 20 years or so to allow the short halflife isotopes to burn out. I see

Its important to note thought that this waste isnt depleted of fuel. Its only waste because many of these isotopes produced by fission have such big neutron capture cross section that they will steal all the neutrons that drives the reaction and stop the reaction. This fuel can be reprocessed by removing these isotopes and be run in a reactor again.

Here is a complete list of all isotopes and halflifes
http://133.53.31.105/CN04/index.html

the 100.000 year figure it something thrown out by environmental groups that is unresonable. Even after only 10 years the level of radioactivity is just 1/1000 of what it was when it was pulled out of the reactor. The radioactivity drops exponentialy so after that it slows down alot, but still the 100 000 years are just absurd. I dont know how they got that figure in the first place but I guess its the time it takes for the spent fuel to radiate as little as the background radiation or something like that.

Sound about right. A littl eoff topic but I wonder if there is any truth to the theory that certain esters of polythene have zero biodegradability.

[GREENMACHINE]

Does the effect of the material only effect the localised envioroment contained within the reactor. Or does it effect control remote of the reactor like I vacumn systems pnuematics

I am not sure I fully understand this question? Could you try to rewrie it?

I can't remember what I was asking exactly. i think it was something along the lines of, thether system outside of the reactor core were powered by the reactor or a different source of power.

Helium, nitrogen or carbon dioxide is what is used in the pebbel beds. When it comes to the chemistry of those gases I have to confess my complete ignorance.

Helium and nitrogen I believe are both noble gases. I would hazard a guess that the carbon dioxide acts as something of fire blanket. It is heavier than air and should accumulate at the base of the reactor, where the rods are. The same gas is used in fire extuingishers. Not sure if the same principals apply in this case. that is my guess though



I think I will explain this a bit further anyway since its a very nice effect.
In a pebble bed reactor uranium is contained within pebbles of pyrolytic graphite. The pyrolytic graphite is the neutron moderator(i.e it slows down the neutrons so that they can be captured by the u-235 and create fission, without moderation the chanse of neutron capture becomes dramaticly small).

How does this work. Does uranium occur in crystalized structers with it self ,similar to carbon in diamonds. Can't exactly visualise how a single molecule could be contained within each pebbel.

My head hurts hehe

In essence each of these sphere is a mini nuclear reactor. If you pile enough of them togheter the reaction starts.
Normaly neutrons released by u-235 fission is to high to react with u-235 and to low to react with u-238. If the fuel heats up though the energy range of the fission neutrons will be "smeared" out to allow the neutrons to react with u-238. Since a neutron captured by u-238 doesnt produce any fission it means less neutrons are aviable to induce fission in the u-235. This means that if the heat goes up the number of neutron drops and lowers the reaction rate which in turns lowers the temperature.
So like I said this works completley independant of any safety system. A very elegant solution.

I don't really understand it, but okay.

They basicly just pulled out the control rods(the control rods work by capturing neutrons and lowering the number of neutrons that can react with u-235) and shut down all coolant to the reactor. They basicly ran a worst case scenario as a experiment. All that happened was that the reactor slowed down to its idle state.

That was a serious oversight on their part indeed. Someone there must have like playing nad scientist.

Yes, those containment buildings are incredibly sturdy.

Maybe an example no need to go as far as blue prints of a design or anything. that would just confuse me more.

Chernobyl is a quite interesting case. I havent read any in depth about the chernobyl accident but I have seen a few documentaries and the stupidity of the guy running that dangerous test was just baffling. What is ironic is that he is just about the only one that survived the accident aswell. If there is a god he sure has a sense of dark humor.
The remaining reactors of chernobyl type have been improved alot so another chernobyl is unlikely even in those. But I would feel more comftertable if they shut all of them down completely. We have a couple of those old rusty bastards close to our northern border.

Okay that is a very reasonable point. Nice to see someone who can be so objective.

The biggest safety measure is that no human can shut down any safety system. Before three miles island and chernobyl the attitude was that humans know best and should have full controll. But after those accidents its no longer possible for any human to shut down any safety system under any circumstance.

(How long did it take to put these structures in place and can we be sure than counties say in the middle east are complying with these standards.

The second biggest safety measure is the controll rods. There are systems in place that can fully insert the control rods in a matter of seconds. The control rods can shut down the reaction almost completely in no time.

what happened at chernobyl was that the controll rods where such that for a split moment they increased the reaction rate before they shut it down since they had graphite tips and graphite moderates the neutrons.

Sorry if this sound dumb put why the hell did they put control rod in there with graphite tips. Didn't they know graphite moderates the nuetrons.

So when they engaged the emergency lowering of the control rods they made the whole thing go out of controll. No western plant has anything like that in the controll rods.

I hope not.

What safety measures they have in a total loss of coolant accident I dont know to be honest. The control rods would maby be enough but there would be alot of heat and the possibility of a steam explosion in the preasurised and boiling water reactors.

Lets hope that doesn't happen eh.

The most important safety measure is the containment building. Nothing can get out of it. You could stand right outside the containment building during a complete meltdown and you would suffer less radiation than if you are inside a apartment(because of the radon in concrete) or if you take a plane ride(thinner atmosphere high up in the air allows more cosmic and solar radiation).

So your saying less backgroung radiation outside the containment building, than would ordinarily be found in the envioroment.

The fact that the radiation drops with a factor of thousand in just 10 years would mean cleanup could be done fairly quickly. I have to take some time someday and read up on the cleanup of three miles island to know how they did it and how long they waited. (Would like to here about it. Keep in touch.

No transmutation is when you put the waste products into special reactors that transmutes those isotopes into less radiactive ones. It isnt a complete process and as of now its just in research stage. But In a not so distante future Im sure we will have plenty of those to take care of waste.

That is one thing that I don't like personal. We have all of this waste. We can't do anything with it yet. But we will learn to discharge it safely sometime.



The containment building is what would stop both a chernobyl the second and a terrorist attack.

A meltdown like in chernobyl cant happen in the next generation reactors and are horribly unlikely in the present reactors and like I said earlier even if a complete meltdown where to happen the containment building would contain all waste.

lets say a worst case scenario is that terrorist manages to get into a plant. When they are in there there is realy nothing they can do. They can not do any security override or anything of that sort because none of the safety systems can be overridden.
I dont know what kind of damage they could to physicaly to the reactor itself. But even for that to have any effect they have to make sure the containment building is breached and that requires some very heavy firepower. I wouldnt say its impossible. But Im gonna say its very very very unlikely they could pull something like that off. It would be ALOT harder to do than it was to pull of 9/11.

[Kärnfysikern]

So does the the process cycle within the reactor create the power for the vacumn.

Im not sure what vacum you are refering to?

No idea what that is. Is it some kind of hybrid engine.

A stirling engine is a engine that gets its energy from a temperature difference.
This wikipedia article explains it better than I can
http://en.wikipedia.org/wiki/Stirling_engine

Yep I know that. Was sure if the purpose of the reactor was to create these exotics, something along the lines of their instability creating a more exothermic reaction.

No they are pretty much unwanted. Some of the isotopes created are extracted and used in medicine and in smoke detectors and stuff like that. But for the power plant itself they are unwanted since they hinder fission. Just before fuel is taken out to be replaced a reactor hardly has to have its control rods inside the fuel because the waste in the fuel captures so many neutrons. The neutron capturing isotopes are refered to as poisons. Not because of the toxic effects on humans but because its a posion on the reaction.

(Those is the two normal isotopes right)

Yepp. Natural uranium is more than 99% u-238 and the rest beeing u-235

(Do you mean u-238 here).

Yes, the sentance should have been.
The natural uranium is enrichened so it contains 5% u-235, my bad.

I am trying to remember the exact correlation between nuetrons and electron and proton. There should be an equal number of proton and electron in a molecule right. Does this donated nuetron change the said molecules affinity to reach stability by convering to a p-239 stable molecule.

Yes number of electrons=number of protons. Number of neutrons is most often roughly equal to number of protons. But the heavier the element the more neutrons it has. u-235 has 92 protons and 143 neutrons.

When a u-238 core capture a neutron it becomes u-239 for a smal moment. u-239 is unstable and through beta decay(a neutron is converted into a proton and a electron is emited) it turns into Np-239, but Np-239 is also unstable and it in turn also through beta decay becomes p-239 and like you say p-239 is fairly stable.

Nucleons huh. The nucleas is the core containing nuetrons and protons isn't it. Not sure what a nueclon is.

Yeah a nucleon is a proton or neutron. the 235 in u-235 is the number of nucleons while the atomic number 92 is the number of protons.

Does A represent the mean/mode and median can't remember how that works with a bimodal distribution.

Ohh shit bro I suck at statistics the curve is just the probability distribution though. A is the most probable isotopes created. I guess its the expected values of the distribution?

Only thing that has me thinking is your use of the term half-life. I am more used to seeing it in a medicinal context. In the sense that somethings half life is based on biologicaly values etc. Would the half life, if this is the correct term in this context not be influenced by the overall stereochemistry within the reactor. If this is the case outside the confines of the reactor is it fair to assume that they would have a shorter half life and therefore are more radioactive oustside the control of the reactor.

No half life(its the correct term btw) is not influenced by anything realy.
If you have a radiactive isotope outside of a core or inside, its half life remains exactly the same. Remember the nuclear cores have no effect on eachother and the decay is a process in the core. So the environment the core is in have no influence on the core.
If you remember the model of a atom consider how smal the core is compered to the orbits of the electrons. The cores are proportionaly speaking separated by huge distances because of the electron shells. They never get close enough to interact in anyway.

The only interaction the waste in the reactor has is when it captures neutrons. That can effect the half lifes offcourse. But this is because the isotope becomes another isotope, not that the half life itself is changed.
Im not sure how much of a impact this has on the avarage waste halflife but I dont think its very big.

The half life here is exactly the same meaning as in medicine btw. The time it takes for half of the substance to decay.

[Kärnfysikern]

I can't remember what I was asking exactly. i think it was something along the lines of, thether system outside of the reactor core were powered by the reactor or a different source of power.

I think so, I know that all plants atleast have emergency disel generators that kick in imidietly if there is any power loss.

Helium and nitrogen I believe are both noble gases. I would hazard a guess that the carbon dioxide acts as something of fire blanket. It is heavier than air and should accumulate at the base of the reactor, where the rods are. The same gas is used in fire extuingishers. Not sure if the same principals apply in this case. that is my guess though

Sounds resonable

How does this work. Does uranium occur in crystalized structers with it self ,similar to carbon in diamonds. Can't exactly visualise how a single molecule could be contained within each pebbel.

My head hurts hehe

The uranium(or thorium which can also be used) is in the form of oxides or carbides. Its not single molecules enclosed. I guess its a few grams or something like that. Im not at all sure on the size of the pebbles.

That was a serious oversight on their part indeed. Someone there must have like playing nad scientist.

lol Im sure it was just to demonstrate the safety of the pebble bed. Since nothing happening can be worse than a total loss of coolant with all controll rods withdrawn.

(How long did it take to put these structures in place and can we be sure than counties say in the middle east are complying with these standards.

The way we can be sure is because we are building those reactors. Either euro/usa companies or the russians. Nowdays the russians build very safe reactors. So since we(as in the western countries) or ruskies build them we can be sure the safety systems is implemented properly

India builds its own reactors though. But India has very bright engineers and scientists so I hope they have the same standards as europe and usa.

Sorry if this sound dumb put why the hell did they put control rod in there with graphite tips. Didn't they know graphite moderates the nuetrons.

To be honest I dont know. I know there was a reason for it that had to do with the general design. The main thing was that the control rods where never meant to be withdrawn completely. Since the tips where always suposed to be within the core there would never have been such a sudden boost to the reaction. The guy running the experiment that day disregarded ALL safety measures, even the one about not lifting the rods completely.

So your saying less backgroung radiation outside the containment building, than would ordinarily be found in the envioroment.

No but less radiation than in a avarage concrete apartment. The control room inside a nuclear power plant is probably the places in the world with the least radiation.

There was a documentary about a guy checking radiation levels in different places and the avarage apartment has far far more radiation than outside and inside a nuclear power plant.

Would like to here about it. Keep in touch.

Give me a reminder if it slips my mind

Maybe an example no need to go as far as blue prints of a design or anything. that would just confuse me more.

This wiki article talks about containment buildings.
http://en.wikipedia.org/wiki/Containment_building
I dont know any specifics so that link gives much better info than I can

This is a very cool clip on what happens if you crash a fighter jet into a containment building. Look at how the jet pulverises while the containment isnt even scratched.
http://en.wikipedia.org/wiki/Containment_building

[Kärnfysikern]

Sound about right. A littl eoff topic but I wonder if there is any truth to the theory that certain esters of polythene have zero biodegradability.

I have heard so to. But chemistry isnt my cup of tea I flat out suck a chemistry

[GREENMACHINE]

Thx for all your answers You posted the same link twice though. Would be interested to see the fighter jet pulverised by the containment building.

[Kärnfysikern]

opps

here is the correct link
http://www.break.com/index/concreteplane.html

if you got anymore questions please ask away I love talking physics