A colleague of mine recently had to get a Diesel Particulate Filter sensor replaced. He asked about the regeneration process it goes through (essentially it dumps some fuel to get the temperature of the filter up to several hundred degrees and that burns all the particles off). Takes about 20 minutes and the engine must be kept above 2000 RPM apparently, if it drops for more than a couple of seconds it aborts the cycle and dumps the fuel into the oil, hence a reduced oil change interval for the engine (Vauxhall Zafira 1.9 CDTI). It's an auto so keeping the engine above 2k RPM is actually quite hard - even at motorway speeds. You'd think it would force the auto box to stay a gear or two lower or something - and at least have a light on the dash to let you know it was performing the regeneration cycle.
You clearly haven't worked with any embedded systems. The PC architecture is well defined and, for the most part, backwards compatible. There's a reason you can still put a windows 95 CD in a machine and it will be able to find the display controller, enumerate the PCI busses etc. It's because much of that stuff is not going to change. Might be because the BIOS or the chipsets provide a static abstraction layer over the underlying system, but it doesn't matter - from a software view everything works the same.
When you get an embedded system what you have is a cpu core (ARM, PPC, whatever) and a whole bunch of other silicon IP on the same chip that provides additional functions. So if you want to get to the PCI bus, you need to know how that's been interfaced. Presumably there's some IP core on the chip somewhere that provides the PCI connectivity, but how do you access it? Is it at a certain memory address, do you need to write some magic control register to enable it, do you even know how it works?
If you want an example - have a look at your linux source. In my arch/x86/config I have two defconfig files, one for x86 and one for x86_64. That's it for every single PC platform out there, laptop, desktop, server, whatever. Now have a look at arch/arm/configs or arch/powerpc/configs. See the difference? Many of those will come associated with platform specific code to support that architecture. That's how Linux does it - you provide the interface between the standard system code and the underlying hardware and everything falls into place, no doubt the Windows port is similar. ARM is a CPU core, not an architecture.
You mean the politicking stops and someone either shuts them down or replaces them? At the moment no-one wants to deal with losing the fairly significant contribution that nukes make to our energy supplies, presumably the lights going out is a vote-loser, but no-one wants to build newer safer ones, presumably because it's a vote loser. The most stupid thing about the situation is that the middle ground is the most dangerous - blocking progress and the development and construction of better safer plants and meaning the older plants get lifetime extensions.
I read a comment somewhere (the register I think) that went along the lines of: There would be outrage if a sporting event was covered by someone who had absolutely no understanding of the game, but when it comes to science and technology, being completely ignorant of the subject is close to a pre-requisite for any journalist.
There's a lecture on youtube from a physicist that does the analysis on the amount of waste produced. If you reprocess it, use the breeder reactors etc. you will leave behind, as a (presumed) westerner, some high level waste approximately the size of a drink can. The amount of coal ash etc. you leave behind is in the order of thousands of tonnes. They burn hundreds of tonnes over 40 years. Coal plants burn 500 hundred tonnes an hour for 1GWe (rough figures based on wikipedia). That's 175 Million tonnes of coal over 40 years that has to come out of the ground - Fukushima Daichi represents the order a billion tonnes of coal mined for 6 reactors (assuming everything runs constantly etc. etc.). The US produced 71 Million tonnes of fly ash in 2005. 29Million tonnes was reused, leaving just 40 _million_ tonnes a year to deal with.
I think the proportions you were led to believe regarding nuclear are still pretty good, given that that's hundreds of tonnes before reprocessing. One quick googling suggests that around 32.5% of the weight of coal consume remains as ash, so that 175 million tonnes becomes 60 Million tonnes of ash. Is producing 1/100,000th of the waste the sort of figure you were hoping for?
(disclaimer: numbers may be a bit shaky, but not intentionally misleading. I just googled some stuff quickly...)
Worldwide the demand for power is only going to get much, much greater. There's a couple of billion people in India and China who are looking at the West and thinking 'we'd quite like that actually'. You want to go over there and tell them they can't have even a fraction of the energy consuming luxury you enjoy?
Using less is part of the answer, but to suggest it is the complete answer and that we won't need to increase our capacity to generate/capture energy is a fantasy. The energy we produce today is already polluting more than is generally considered acceptable, and there is no realistic scenario in which we can reduce that energy usage. It can only increase - or do you propose we tell third world nations that they can't heat their homes? That they should starve because we don't have enough energy? Many would suggest the West has already gone to war over Oil for luxuries like cars - I'd wager that people will gladly fight tooth and nail for the energy to stop their children from starving and freezing. There is no way we can expect to reduce our energy usage, and that is already unsustainable. Even if everyone in the western world does go and live in a cave we are (well _they_ are) still going to have exactly the same problems.
Strip mining, oil spills, fly ash, carbon dioxide? None of it is fine. That's a stupid argument. What would the environmental damage of a coal plant producing the same amount of electricity for 40 years be? And anyway, how much I131 is there going to be in a month or two?
Many of their biggest successes as films (or at least the underlying ideas for them) are based on fairy tales and folk stories that are out of copyright. The hypocrisy of them fighting so that no work they 'create' can ever be used in the same way is astonishing.
You don't pay the RRP for a chip though, you get a NSM sales rep (or any company) and you explain that you would like to use their chip, but the competitors chip is better priced and offers similar features. The prices then become more competitive. I'm guessing that won't work for very small numbers of chips, but if you're only using a few what difference does a few dollars make?
They have no power, and therefore very limited instrumentation. They are also pumping huge quantities of water into the tanks in some of the buildings. They have also been venting steam which is highly (if briefly) radioactive. There is presumably still some risk of hydrogen explosion. There have been explosions which probably mean parts of the building (I'm thinking panelling and non-structural stuff) may not be entirely sound. And they don't have much in the way of lighting.
But you propose they send their staff to plod around under the reactor looking for leaks?
I don't think they are giving out all the information they have, but that's probably because people wouldn't understand the implications or consequences of half of it anyway. I'd much rather the experts were communicating with each other and leading their teams to resolve this than wasting their time explaining to the scientific illiterates that pass for journalists in these situations that there is a difference between milli- and micro-sieverts, or that something with a half life of 5 minutes is not really anything to get worked up about.
I'd have thought it's not just the 'starving' people who need calories. Surely people in a non-industrialised society who spend their days labouring (doing stuff like farming rice) have a significantly greater calorific need than computer using desk jockeys like us? If your agrarian society can't get enough energy to its farmers to grow food then you aren't going to get your vitamins either...
Some of those problems are related to the fact that Nuclear power is more regulated. I'd be interested to see the waste disposal obligations that the Nuclear industry faces applied to other energy sources. Not to mention the reporting levels and monitoring of environmental damage (across the supply chain, so not just at the plants, but from mining/drilling to exhaust gas and fly ash disposal). How many oil spills, coal mine disasters, strip mining operations, floods caused by burst dams have occurred in that 50 years?
The battery systems worked as designed for 8 hours. They did not flood, they just ran out when they were expected to. The generators that should have come online within that period (diesel generator sets don't just start up immediately) were flooded.
Surely amounts per watt-hour are important here. It may produce waste with the same components, but if it produces less waste, or less of the particularly nasty components then it's a big improvement surely?
I'd imagine that the batteries are quite large and heavy. Turning your nuclear reactor building into an inverted pendulum with a lead and sulphuric acid bob may turn out to be a bad idea in an Earthquake.
The roof also needs to be able to explode away (as it did in several of the Fukushima reactors) in case of hydrogen explosions.
In the eventuality of a meltdown you'd have made it much more difficult (if not impossible) to smother the core in borosilicate, which is what stopped Chernobyl from melting down any further.
Nothing was wrong with the batteries, they lasted 8 hours as designed. Should they have been designed to last longer? Looks that way now. Should the backup generators have had a tsunami wall 2-3x as high as it was? Looks that way now. Should older reactors be replaced with better designs that don't require active cooling? Yes, no hindsight required. Should someone have the balls to say either accept nuclear power and build newer safer designs or turn the things off and we can all go without some electricity? Absolutely.
Because that would complicate the handling of the spent fuel. You need to do the risk assessment to work out if repeatedly moving the fuel over a large distance is more dangerous than the chance of the larger than expected earthquake occurring, followed by the larger than expected tsunami, followed by all the other things that went wrong.
There have been cases of spent fuel bundles catching fire after removal from the reactor, so I'd wager that's why the pools are close to the top of the reactors.
Whether we should need the spent fuel ponds is a different matter, and one that to me stinks of the same cheap politicking that affects the entire nuclear debate. Building a proper waste repository or breeder reactors that can significantly reduce the amount of waste means someone would have to stick their neck out and upset some voters. Building more modern plants that are safer and have passive cooling and intrinsic safety designed in would upset some voters. Shutting down the existing plants and losing 25% of base load power would upset some voters. Doing nothing and pretending like there isn't a problem has worked until something went wrong, so now someone or something needs blaming or some voters would get upset. No-one wants to stick their neck out now and say they should have had the guts to do something about the problem before we narrowly avoided disaster.
The BBC does have some slightly bipolar reporting though. In amongst the many articles with experts explaining what is happening and what the risks are in a rational and balanced way there's a couple of gems like the one about an Irish guy living 150 miles from Tokyo (in the good direction - he's 400 miles from Fukushima) who is concerned that his unborn child will be damaged by the radiation and is flying home (might even get more radiation doing that than staying put). There's also the occasional piece of 'spokesperson from Greenpeace says the world will end because of this' which always grates because it gets given the same kind of authority as quotes from experts who may actually have the first clue what they're talking about. Overall it's been pretty reasonable so long as you read most of the articles and not just the more inflammatory ones.
Slashdot Mirror
A colleague of mine recently had to get a Diesel Particulate Filter sensor replaced. He asked about the regeneration process it goes through (essentially it dumps some fuel to get the temperature of the filter up to several hundred degrees and that burns all the particles off). Takes about 20 minutes and the engine must be kept above 2000 RPM apparently, if it drops for more than a couple of seconds it aborts the cycle and dumps the fuel into the oil, hence a reduced oil change interval for the engine (Vauxhall Zafira 1.9 CDTI). It's an auto so keeping the engine above 2k RPM is actually quite hard - even at motorway speeds. You'd think it would force the auto box to stay a gear or two lower or something - and at least have a light on the dash to let you know it was performing the regeneration cycle.
You clearly haven't worked with any embedded systems. The PC architecture is well defined and, for the most part, backwards compatible. There's a reason you can still put a windows 95 CD in a machine and it will be able to find the display controller, enumerate the PCI busses etc. It's because much of that stuff is not going to change. Might be because the BIOS or the chipsets provide a static abstraction layer over the underlying system, but it doesn't matter - from a software view everything works the same.
When you get an embedded system what you have is a cpu core (ARM, PPC, whatever) and a whole bunch of other silicon IP on the same chip that provides additional functions. So if you want to get to the PCI bus, you need to know how that's been interfaced. Presumably there's some IP core on the chip somewhere that provides the PCI connectivity, but how do you access it? Is it at a certain memory address, do you need to write some magic control register to enable it, do you even know how it works?
If you want an example - have a look at your linux source. In my arch/x86/config I have two defconfig files, one for x86 and one for x86_64. That's it for every single PC platform out there, laptop, desktop, server, whatever. Now have a look at arch/arm/configs or arch/powerpc/configs. See the difference? Many of those will come associated with platform specific code to support that architecture. That's how Linux does it - you provide the interface between the standard system code and the underlying hardware and everything falls into place, no doubt the Windows port is similar. ARM is a CPU core, not an architecture.
And yet everywhere pregnant women are told to not eat too many fish due to mercury?
You mean the politicking stops and someone either shuts them down or replaces them? At the moment no-one wants to deal with losing the fairly significant contribution that nukes make to our energy supplies, presumably the lights going out is a vote-loser, but no-one wants to build newer safer ones, presumably because it's a vote loser. The most stupid thing about the situation is that the middle ground is the most dangerous - blocking progress and the development and construction of better safer plants and meaning the older plants get lifetime extensions.
I read a comment somewhere (the register I think) that went along the lines of: There would be outrage if a sporting event was covered by someone who had absolutely no understanding of the game, but when it comes to science and technology, being completely ignorant of the subject is close to a pre-requisite for any journalist.
You can group them with all the people that think wind or solar is the answer to our power needs in the foreseeable future then.
The heavy metal being from the power plant or from the industrialised nation that just got partly washed away?
http://www.theregister.co.uk/2011/04/07/wind_power_actually_25_per_cent/
There's a lecture on youtube from a physicist that does the analysis on the amount of waste produced. If you reprocess it, use the breeder reactors etc. you will leave behind, as a (presumed) westerner, some high level waste approximately the size of a drink can. The amount of coal ash etc. you leave behind is in the order of thousands of tonnes. They burn hundreds of tonnes over 40 years. Coal plants burn 500 hundred tonnes an hour for 1GWe (rough figures based on wikipedia). That's 175 Million tonnes of coal over 40 years that has to come out of the ground - Fukushima Daichi represents the order a billion tonnes of coal mined for 6 reactors (assuming everything runs constantly etc. etc.). The US produced 71 Million tonnes of fly ash in 2005. 29Million tonnes was reused, leaving just 40 _million_ tonnes a year to deal with.
I think the proportions you were led to believe regarding nuclear are still pretty good, given that that's hundreds of tonnes before reprocessing. One quick googling suggests that around 32.5% of the weight of coal consume remains as ash, so that 175 million tonnes becomes 60 Million tonnes of ash. Is producing 1/100,000th of the waste the sort of figure you were hoping for?
(disclaimer: numbers may be a bit shaky, but not intentionally misleading. I just googled some stuff quickly...)
Worldwide the demand for power is only going to get much, much greater. There's a couple of billion people in India and China who are looking at the West and thinking 'we'd quite like that actually'. You want to go over there and tell them they can't have even a fraction of the energy consuming luxury you enjoy?
Using less is part of the answer, but to suggest it is the complete answer and that we won't need to increase our capacity to generate/capture energy is a fantasy. The energy we produce today is already polluting more than is generally considered acceptable, and there is no realistic scenario in which we can reduce that energy usage. It can only increase - or do you propose we tell third world nations that they can't heat their homes? That they should starve because we don't have enough energy? Many would suggest the West has already gone to war over Oil for luxuries like cars - I'd wager that people will gladly fight tooth and nail for the energy to stop their children from starving and freezing. There is no way we can expect to reduce our energy usage, and that is already unsustainable. Even if everyone in the western world does go and live in a cave we are (well _they_ are) still going to have exactly the same problems.
Strip mining, oil spills, fly ash, carbon dioxide? None of it is fine. That's a stupid argument. What would the environmental damage of a coal plant producing the same amount of electricity for 40 years be? And anyway, how much I131 is there going to be in a month or two?
Many of their biggest successes as films (or at least the underlying ideas for them) are based on fairy tales and folk stories that are out of copyright. The hypocrisy of them fighting so that no work they 'create' can ever be used in the same way is astonishing.
You don't pay the RRP for a chip though, you get a NSM sales rep (or any company) and you explain that you would like to use their chip, but the competitors chip is better priced and offers similar features. The prices then become more competitive. I'm guessing that won't work for very small numbers of chips, but if you're only using a few what difference does a few dollars make?
Or from steam venting, if the fuel rods had already begun to break down.
Or from the spent fuel pool that had MOX fuel in it, if it had begun to break down and boil.
The leak is suspected in reactor 2. The only reactor with plutonium fuel is reactor 3.
Or from the suspected damage to the suppression chamber.
Or they have a leak of coolant somewhere that has picked up radioactive material from the damaged reactor core.
Speculation is fun.
They have no power, and therefore very limited instrumentation. They are also pumping huge quantities of water into the tanks in some of the buildings. They have also been venting steam which is highly (if briefly) radioactive. There is presumably still some risk of hydrogen explosion. There have been explosions which probably mean parts of the building (I'm thinking panelling and non-structural stuff) may not be entirely sound. And they don't have much in the way of lighting.
But you propose they send their staff to plod around under the reactor looking for leaks?
I don't think they are giving out all the information they have, but that's probably because people wouldn't understand the implications or consequences of half of it anyway. I'd much rather the experts were communicating with each other and leading their teams to resolve this than wasting their time explaining to the scientific illiterates that pass for journalists in these situations that there is a difference between milli- and micro-sieverts, or that something with a half life of 5 minutes is not really anything to get worked up about.
I'd have thought it's not just the 'starving' people who need calories. Surely people in a non-industrialised society who spend their days labouring (doing stuff like farming rice) have a significantly greater calorific need than computer using desk jockeys like us? If your agrarian society can't get enough energy to its farmers to grow food then you aren't going to get your vitamins either...
Fair enough. Bet they'd still be heavy and in the way though...
Some of those problems are related to the fact that Nuclear power is more regulated. I'd be interested to see the waste disposal obligations that the Nuclear industry faces applied to other energy sources. Not to mention the reporting levels and monitoring of environmental damage (across the supply chain, so not just at the plants, but from mining/drilling to exhaust gas and fly ash disposal). How many oil spills, coal mine disasters, strip mining operations, floods caused by burst dams have occurred in that 50 years?
The battery systems worked as designed for 8 hours. They did not flood, they just ran out when they were expected to. The generators that should have come online within that period (diesel generator sets don't just start up immediately) were flooded.
Surely amounts per watt-hour are important here. It may produce waste with the same components, but if it produces less waste, or less of the particularly nasty components then it's a big improvement surely?
I'd imagine that the batteries are quite large and heavy. Turning your nuclear reactor building into an inverted pendulum with a lead and sulphuric acid bob may turn out to be a bad idea in an Earthquake.
The roof also needs to be able to explode away (as it did in several of the Fukushima reactors) in case of hydrogen explosions.
In the eventuality of a meltdown you'd have made it much more difficult (if not impossible) to smother the core in borosilicate, which is what stopped Chernobyl from melting down any further.
Nothing was wrong with the batteries, they lasted 8 hours as designed. Should they have been designed to last longer? Looks that way now. Should the backup generators have had a tsunami wall 2-3x as high as it was? Looks that way now. Should older reactors be replaced with better designs that don't require active cooling? Yes, no hindsight required. Should someone have the balls to say either accept nuclear power and build newer safer designs or turn the things off and we can all go without some electricity? Absolutely.
Because that would complicate the handling of the spent fuel. You need to do the risk assessment to work out if repeatedly moving the fuel over a large distance is more dangerous than the chance of the larger than expected earthquake occurring, followed by the larger than expected tsunami, followed by all the other things that went wrong.
There have been cases of spent fuel bundles catching fire after removal from the reactor, so I'd wager that's why the pools are close to the top of the reactors.
Whether we should need the spent fuel ponds is a different matter, and one that to me stinks of the same cheap politicking that affects the entire nuclear debate. Building a proper waste repository or breeder reactors that can significantly reduce the amount of waste means someone would have to stick their neck out and upset some voters. Building more modern plants that are safer and have passive cooling and intrinsic safety designed in would upset some voters. Shutting down the existing plants and losing 25% of base load power would upset some voters. Doing nothing and pretending like there isn't a problem has worked until something went wrong, so now someone or something needs blaming or some voters would get upset. No-one wants to stick their neck out now and say they should have had the guts to do something about the problem before we narrowly avoided disaster.
Because you're not the guy that gets to influence politicians and be quoted in the media... that all happens to the other guy...
The BBC does have some slightly bipolar reporting though. In amongst the many articles with experts explaining what is happening and what the risks are in a rational and balanced way there's a couple of gems like the one about an Irish guy living 150 miles from Tokyo (in the good direction - he's 400 miles from Fukushima) who is concerned that his unborn child will be damaged by the radiation and is flying home (might even get more radiation doing that than staying put). There's also the occasional piece of 'spokesperson from Greenpeace says the world will end because of this' which always grates because it gets given the same kind of authority as quotes from experts who may actually have the first clue what they're talking about. Overall it's been pretty reasonable so long as you read most of the articles and not just the more inflammatory ones.
Well, in that case, sir, I hope you will not object if I also offer the doctor my most enthusiastic contrafibularities