Candu reactors wont be allowed in the US because the NRC does not like open fuel loading and does not like reactors with positive reactivity coefficients. It's kind of sad, because we could take the used fuel from a US reactor and put it in a candu and run it for another couple years.
Waste is an interesting topic that we do have ideas how to solve. The technology isnt there yet, but its also not going to be '20 years off forever' like cold fusion is. Transmuting long lasting waste products reduces a large amount of stockpile. Reprocessing allows us to generate less total waste and reuse fuel we currently have. Breeding will allow us to take parts of our fuel and use increase efficiency of a ton of uranium. Unfortunately we havent gotten there yet. Currently fuel is stored in casks for long term storage. It is a very good storage method for the intermediate period (100-300 years at least), and hopefully we will be able to reuse or burn off a lot of the waste products in that time.
Look at the Monju plant in japan, they had a minor leak that just destroyed a room. The accident was also covered up for a week.
No injuries though, but the plant was offline for years.
The article seems a little misleading.
The article makes it appear that just by using thorium, it is possible to get better fuel efficiency (burnup). The reality is that the article is talking about using liquid fluoride based reactors, a technology that we havent been able to make commercial use of yet, and it is unlikely we will see those types of reactors for many years. Comparing liquid fluoride reactors to any type of light water reactor (the kind in use in the US) is like comparing the gas mileage for a car to an airplane. They use different fuel types due to design, and you wouldnt buy a hummer just because the car salesman says it gets better gas mileage than an airplane. The article should talk about the difference between LWRs and gen4 reactors, and how by using a gen4 reactor you can make efficient use of thorium, expanding our fuel options and reducing proliferation threats.
When thorium fuel is used in an LWR, you actually get much worse fuel economy (about 5% to 10% at best compared to traditional uranium cycles), for the same cost.
Wikipedia's thorium fuel cycle has some pretty good information about thorium in LWRs.
http://www-pub.iaea.org/MTCD/publications/PDF/TE_1450_web.pdf is a great document prepared for the IAEA and has some good bullet points about thorium viability.
its an interim solution until we get other technologies there.
Those casks are very safe (check youtube for testing videos, they put one on a rocket propelled thing and smashed it into a wall to simulate a plant crash and it was intact).
no solution exists....'yet'.
Actually we know of ways to reprocess and transmute most of the 'waste' and make use of it.
We know of ways to take the most dangerous parts of waste and make them into something less dangerous.
We know how to do it, but we havent put the money into the technology yet.
Bottom line is we are going to need this technology developed in the future, and in the next 100 years it will be there.
We also have a waste mid-term storage option that is safe and can last for a few hundred years.
If we just bury the stuff now we lose a lot of the energy that is still available in the current fuel we have, its actually going to become a valuable resource in the future, and in my mind at least it makes sense to cask it for now until we reach the point where we can start using the waste instead of just trying to bury it and 'get it out of sight', which in my mind is much more dangerous.
chernobyl also had a design where when the emergency shutdown system started, it actually increased reactor power for a split second.
When Chernobyl had its accident, the plant was extremely close to a dangerous condition, then when they did allow the automatic shutdown to occur, it spiked power and caused the incident.
US plants have negative operating coefficients in almost all operating regions. Thats void, temperature, and doppler coefficient. These things do an amazing job at controlling reactor power during transients.
Not only is there preventative maintenance, which is proceduralized, there is constant performance monitoring software in most plants which is capable of seeing any change in performance, such as power vs load, vibration, temperature, and compute a performance index and report to the people in charge of that pump the moment something is out of tolerance.
its part of the reason why nuke plants are online over 90% of the time on average in the last 10 years, compared to the 90s where nuke plants were up 60% of the time at best.
good luck trying to turn down the reactor protection system in the US. not only is it strictly disallowed while operating, but its one of those things that can get you put in jail. if you are allowed to do it, you can only jumper 1 relay out at a time, and if you mess with too much at once it will automatically scram anyways.
I swear the thing is 'ticklish' and will just trip the plant if you look at it wrong.
this ^
A lot of the improvements to core operating powers is because of being able to reclaim safety margin and still prove it is safe.
Random yet somewhat related side note....nuclear online capacities is on average in the 90% range through 2000 to 2009, where as in the 90s was about 60% for the whole industry. This improvement comes from better performance, maintenance, and understanding of the plant.
I want to defend the operators, but only because my plant has a very strict operating code. I'm sure there are other plants out there that will push for more efficiency, and the business side of all plants pushes towards efficiency.
In the plant I'm at, it is made very clear the control room operations supervisor has the final say when it comes to putting the plant into a potentially unsafe condition, even if the plant manager says he has to do it he is legally bound (due to his operating license) to maintain a safe condition and stick to procedures at all times.
It's not perfect, but its a pretty good system.
Actually the nuclear side of the plant does change a little. There are 2 types of power uprates, one is where you find a design safety margin that you now can reclaim because you have much more accurate equipment, and the other is a change to the plant's operating domain (power/flux shaping) which will allow for more efficient burnup rates in the fuel and in some cases also increase core power. These processes go through ridiculous licensning requirements and usually take 4-6 years to happen,....after you upgrade any equipment.
tldr
Cores do run a little different, but its mainly an efficiency thing.
The other issue is accidently causing a positive reflectivity that would reduce the required critical mass.
In laymens terms if you reflect neutrons back in the right way, all the sudden the thing can go critical with a smaller amount. There are many research accidents of this nature and people are instantly given a death sentence when exposed to this kind of radiation. It is very dangerous to handle and clean up
Scary to think i'm going to be working in that area in about 2 weeks.
Either way, the hanford site supposedly has some radiation leaks going on (into the river no less).
"Had" might be the word to use, but these are just things ive been hearing.
the hanford site is where the majority of the US's weapons grade nuclear material was created, they had over 5 nuclear reactors processing fuel on site. It has been shut down for a while now, but it is considered the worst US waste site. A lot is being put in to ensure a proper cleanup, but it takes a lot of time to clean up the waste on this level without exposing it to the outside.
I agree, using the word nuclear in this article was not necessary.
The only 'story' about the nuclear plant is the safety system activated, disconnected them from the grid, and scrammed the reactor (shut it down), which just results in less electricity to go around when the grid reconnected. Nuclear reactors take a while to start up, and some models get poisoned quickly if they are shut down and can't be restarted for several days.
"No - ignition means achieving fusion. What you call ignition is called a self sustaining burn - something else ITER is intended to investigate."
We have fusion. and break even fusion for the ~1 second that it lasts. The problem is the reaction is not continuous. when you have a self sustaining continuous reaction, thats "Ignition". The reason we dont use fusion for commercial uses is because being able to ignite for ~1 second intervals will never be able to produce enough energy to power anything.
IAPE (I'm a plasma engineer....had to use it after all the IAL posts from other stories^^)
Alpha radiation is a high energy helium atom. Its ionized. Beta radiation has some penitration power...but its an electrion...
these two things can cause ionization or other reactions that are not necessesarily friendly. sure almost every time alpha particles will bounce until the lose their energy and eventually return to a normal state. of course most of the time your beta particle will lose its energy and be absorbed by an atom, but you run risks of having other decay factors in the surrounding material in order to release this energy and return to a stable state (such as release of neutrons, neutrinos, other particles, gamma waves, etc).
exposure doesnt necessesarily make something radioactive.....but that doesnt mean it cant. also exposure over a long time will most likely make something, if not radioactive, then toxic at least.
If only it was this easy to crack the PSP's security.
I dont know why microsoft even tries. If anything, by not allowing us apps like antispyware, its just going to make more of a headache for the non-savvy windows users, and force more people to switch over to a more secure system (i.e. mac and linux). with the Macs switching to intel, i think the OS business will start to get interesting soon.
well thats what they do with Spam, but for some reason people get exponentially more times what they should be getting.
Do not call is explicit to "DO NOT FREKAIN CALL ME OR ELSE"
Somehow i was getting calls on my cell phone for a period of time, it all stopped though.
seriously, if telemarketers want to call people, then telemarketers should give out "Telemarket phones" that they can call people on.
Im pretty sure no one would take them.
Slashdot Mirror
Candu reactors wont be allowed in the US because the NRC does not like open fuel loading and does not like reactors with positive reactivity coefficients. It's kind of sad, because we could take the used fuel from a US reactor and put it in a candu and run it for another couple years.
Waste is an interesting topic that we do have ideas how to solve. The technology isnt there yet, but its also not going to be '20 years off forever' like cold fusion is. Transmuting long lasting waste products reduces a large amount of stockpile. Reprocessing allows us to generate less total waste and reuse fuel we currently have. Breeding will allow us to take parts of our fuel and use increase efficiency of a ton of uranium. Unfortunately we havent gotten there yet. Currently fuel is stored in casks for long term storage. It is a very good storage method for the intermediate period (100-300 years at least), and hopefully we will be able to reuse or burn off a lot of the waste products in that time.
Look at the Monju plant in japan, they had a minor leak that just destroyed a room. The accident was also covered up for a week. No injuries though, but the plant was offline for years.
The article seems a little misleading. The article makes it appear that just by using thorium, it is possible to get better fuel efficiency (burnup). The reality is that the article is talking about using liquid fluoride based reactors, a technology that we havent been able to make commercial use of yet, and it is unlikely we will see those types of reactors for many years. Comparing liquid fluoride reactors to any type of light water reactor (the kind in use in the US) is like comparing the gas mileage for a car to an airplane. They use different fuel types due to design, and you wouldnt buy a hummer just because the car salesman says it gets better gas mileage than an airplane. The article should talk about the difference between LWRs and gen4 reactors, and how by using a gen4 reactor you can make efficient use of thorium, expanding our fuel options and reducing proliferation threats. When thorium fuel is used in an LWR, you actually get much worse fuel economy (about 5% to 10% at best compared to traditional uranium cycles), for the same cost. Wikipedia's thorium fuel cycle has some pretty good information about thorium in LWRs. http://www-pub.iaea.org/MTCD/publications/PDF/TE_1450_web.pdf is a great document prepared for the IAEA and has some good bullet points about thorium viability.
its an interim solution until we get other technologies there. Those casks are very safe (check youtube for testing videos, they put one on a rocket propelled thing and smashed it into a wall to simulate a plant crash and it was intact).
no solution exists ....'yet'.
Actually we know of ways to reprocess and transmute most of the 'waste' and make use of it.
We know of ways to take the most dangerous parts of waste and make them into something less dangerous.
We know how to do it, but we havent put the money into the technology yet.
Bottom line is we are going to need this technology developed in the future, and in the next 100 years it will be there.
We also have a waste mid-term storage option that is safe and can last for a few hundred years.
If we just bury the stuff now we lose a lot of the energy that is still available in the current fuel we have, its actually going to become a valuable resource in the future, and in my mind at least it makes sense to cask it for now until we reach the point where we can start using the waste instead of just trying to bury it and 'get it out of sight', which in my mind is much more dangerous.
chernobyl also had a design where when the emergency shutdown system started, it actually increased reactor power for a split second. When Chernobyl had its accident, the plant was extremely close to a dangerous condition, then when they did allow the automatic shutdown to occur, it spiked power and caused the incident. US plants have negative operating coefficients in almost all operating regions. Thats void, temperature, and doppler coefficient. These things do an amazing job at controlling reactor power during transients.
Not only is there preventative maintenance, which is proceduralized, there is constant performance monitoring software in most plants which is capable of seeing any change in performance, such as power vs load, vibration, temperature, and compute a performance index and report to the people in charge of that pump the moment something is out of tolerance. its part of the reason why nuke plants are online over 90% of the time on average in the last 10 years, compared to the 90s where nuke plants were up 60% of the time at best.
good luck trying to turn down the reactor protection system in the US. not only is it strictly disallowed while operating, but its one of those things that can get you put in jail. if you are allowed to do it, you can only jumper 1 relay out at a time, and if you mess with too much at once it will automatically scram anyways. I swear the thing is 'ticklish' and will just trip the plant if you look at it wrong.
this ^ A lot of the improvements to core operating powers is because of being able to reclaim safety margin and still prove it is safe. Random yet somewhat related side note....nuclear online capacities is on average in the 90% range through 2000 to 2009, where as in the 90s was about 60% for the whole industry. This improvement comes from better performance, maintenance, and understanding of the plant.
I want to defend the operators, but only because my plant has a very strict operating code. I'm sure there are other plants out there that will push for more efficiency, and the business side of all plants pushes towards efficiency. In the plant I'm at, it is made very clear the control room operations supervisor has the final say when it comes to putting the plant into a potentially unsafe condition, even if the plant manager says he has to do it he is legally bound (due to his operating license) to maintain a safe condition and stick to procedures at all times. It's not perfect, but its a pretty good system.
Actually the nuclear side of the plant does change a little. There are 2 types of power uprates, one is where you find a design safety margin that you now can reclaim because you have much more accurate equipment, and the other is a change to the plant's operating domain (power/flux shaping) which will allow for more efficient burnup rates in the fuel and in some cases also increase core power. These processes go through ridiculous licensning requirements and usually take 4-6 years to happen,....after you upgrade any equipment. tldr Cores do run a little different, but its mainly an efficiency thing.
The other issue is accidently causing a positive reflectivity that would reduce the required critical mass. In laymens terms if you reflect neutrons back in the right way, all the sudden the thing can go critical with a smaller amount. There are many research accidents of this nature and people are instantly given a death sentence when exposed to this kind of radiation. It is very dangerous to handle and clean up
Scary to think i'm going to be working in that area in about 2 weeks. Either way, the hanford site supposedly has some radiation leaks going on (into the river no less). "Had" might be the word to use, but these are just things ive been hearing. the hanford site is where the majority of the US's weapons grade nuclear material was created, they had over 5 nuclear reactors processing fuel on site. It has been shut down for a while now, but it is considered the worst US waste site. A lot is being put in to ensure a proper cleanup, but it takes a lot of time to clean up the waste on this level without exposing it to the outside.
I agree, using the word nuclear in this article was not necessary. The only 'story' about the nuclear plant is the safety system activated, disconnected them from the grid, and scrammed the reactor (shut it down), which just results in less electricity to go around when the grid reconnected. Nuclear reactors take a while to start up, and some models get poisoned quickly if they are shut down and can't be restarted for several days.
remember, there is no child left behind
After what I put my tupperware through im not surprised that it can stop a bullet
i think ive seen this article or several articles like it, once every other week, for the past 6 months.
if this were an image board id be posting the dead horse.
mother3 is a GBA game that came out this year. its the long awaited sequal to mother2 (known as earthbound on the snes)
i think the way the article was worded, people are reading it as this game is 11 years old.
"No - ignition means achieving fusion. What you call ignition is called a self sustaining burn - something else ITER is intended to investigate."
We have fusion. and break even fusion for the ~1 second that it lasts. The problem is the reaction is not continuous. when you have a self sustaining continuous reaction, thats "Ignition".
The reason we dont use fusion for commercial uses is because being able to ignite for ~1 second intervals will never be able to produce enough energy to power anything.
IAPE (I'm a plasma engineer....had to use it after all the IAL posts from other stories^^)
Alpha radiation is a high energy helium atom. Its ionized.
Beta radiation has some penitration power...but its an electrion...
these two things can cause ionization or other reactions that are not necessesarily friendly. sure almost every time alpha particles will bounce until the lose their energy and eventually return to a normal state. of course most of the time your beta particle will lose its energy and be absorbed by an atom, but you run risks of having other decay factors in the surrounding material in order to release this energy and return to a stable state (such as release of neutrons, neutrinos, other particles, gamma waves, etc).
exposure doesnt necessesarily make something radioactive.....but that doesnt mean it cant. also exposure over a long time will most likely make something, if not radioactive, then toxic at least.
Vista is so secure i cant get it to install itself on my computer.
If only it was this easy to crack the PSP's security. I dont know why microsoft even tries. If anything, by not allowing us apps like antispyware, its just going to make more of a headache for the non-savvy windows users, and force more people to switch over to a more secure system (i.e. mac and linux). with the Macs switching to intel, i think the OS business will start to get interesting soon.
well thats what they do with Spam, but for some reason people get exponentially more times what they should be getting. Do not call is explicit to "DO NOT FREKAIN CALL ME OR ELSE"
Somehow i was getting calls on my cell phone for a period of time, it all stopped though. seriously, if telemarketers want to call people, then telemarketers should give out "Telemarket phones" that they can call people on. Im pretty sure no one would take them.