I saw somewhere that the Surface stylus has a 600dpi resolution. The x86 Win8 Surface should run full-featured Photoshop/CS and assuming the stylus is pressure-sensitive (and there's no reason it wouldn't be in terms of cost, technology etc.) then this will make a portable version of the Cintiq, tempting for graphics people, photoeditors etc.
The Daini reactors did take some damage to peripherals such as external electrical equipment, the turbine halls etc. due to flooding from the tsunami. A level 4 emergency was declared to the IAEA over Daini reactor no. 3 which lost its backup power systems and took longer than necessary to achieve cold shutdown. All the other reactors on the Tohoku coastline at Onagawa, Tokai and Hamaoka suffered no ill-effects from the earthquake and tsunami.
The Daini reactors may never restart; the site is significantly contaminated by fallout from Daiichi ten km up the coast and it would be difficult to safely monitor the reactors in operation to detect any faults that release more radiation into the environment. The same goes for the Daiichi 5 and 6 reactors which were already shut down for inspection and refuelling at the time of the earthquake.
The HVDC links between the two grids have a limited capacity, about 2GW as I recall. They've not needed anything bigger since both parts of the country have adequate generating capacity for each region, or at least they did until the nuclear stations in the Kansai area and points south shut down for inspection and refuelling and didn't restart. The Kanto area (Tokyo and environs) has a lot of older coal-burning and oil-burning power stations that were demothballed after they lost the Fukushima Daiichi and Daini reactors and the other stations shut down due to the quake and tsunami (Onagawa, Tokai and Hamaoka) were refused permission to restart. Kansai (Osaka, Kobe, Hiroshima etc.) has fewer fossil-burners available to bring back to use hence the predicted electricity supply shortages in the region this summer.
It had a flickery refresh rate of 43Hz, low contrast, low brightness, crap colour spectrum and lousy off-axis viewing as the cost for the number of pixels displayed on the 22" screen. The high cost and weird hardware requirements (if you ever buy a second-hand T221 make sure the cables come with it or you are SOL) killed it in the consumer market, restricting its use to scientific and engineering areas and some odd niches like day trading setups.
"Japan has vast amounts of geothermal and plenty of off-shore wind."
Yes, Japan has lots of off-shore wind, so much their word for this has been Nicolled by the English language. "Taifu" or as we in the West spell it, "Typhoon". See the reports of the typhoon that hit Japan in September 2011 for an example of how bad they can get (over 90 people dead and missing).
Imagine what will happen to a farm of wind turbines standing out in open ocean when it gets hit by even a mild typhoon. It doesn't help that the coastal shelf of Japan is very narrow or non-existent so offshore wind turbines will have to be positioned on floating rafts rather than on towers fixed to the seabed.
"The whole reason the nuclear power industry developed based on uranium instead of thorium was for military reasons."
Crap. Uranium reactors are physically simple devices, steam kettles heated by spontaneously fissioning uranium. Thorium isn't fertile enough by itself to initiate and sustain fission in a simple reactor structure. India has been building and trying to sell thorium-fuelled reactors but they include quantities of medium-enriched (ca. 20%) uranium and plutonium in the fuel mix to provide enough sustained neutron flux to fission the thorium fuel.
The LFTR designs being touted by assorted folks are monstrously more complex than the existing uranium-fuelled reactor designs already built and operating today, and would have required decades of development back in the 1950s to make them work. The simple fertile uranium fission power reactors were an easier path to take and every country which started builing research and power reactors in that time took that route.
They need the space in the reactor building pools to take the damaged rods and debris from reactors 1 through 3. In the case of reactor 4 the spent fuel pool is pretty much full of fuel rod assemblies, some of which were due to be transferred to the site's longer-term storage pond some time last year but without a working crane this didn't happen.
The next step in the TEPCO plan is to build a weather shield over reactor 4 similar to the one they put over reactor 1. They can then rebuild the crane system on reactor 4 and start emptying the spent fuel pond.
It's difficult to swing the output of most older nuclear reactors, that is to run them at a reduced output from their rated 100% figure. Fission products like Xe-135, a neutron absorber which is usually at an equilibrium level at full power settings build up in the fuel rods at lower power settings "poisoning" the fission process and can prevent the reactor from operating at full power again until they die away. More modern reactor designs like the AP1400 can be swung to as low as 70% output without this poisoning effect causing problems but it does have to be carefully managed by the reactor operators.
Given the very low cost of nuclear fuel per MWhr generated there's no real point in swinging a reactor even if there aren't any customers for the "excess" electricity being generated. Reactors are shut down on a scheduled basis for inspection and refuelling, not when the fuel is exhausted or even severely depleted so running them at 100% or nearly 100% during their uptime doesn't actually cost any more than swinging them to cope with decreased demand during the night or at weekends.
The Japanese have several mothballed coal and oil-burning power stations which were decommissioned decades ago as they were too expensive to run and/or highly polluting. These have been rushed back into service, burning bunker oil and even raw crude oil. Some of these plants have been converted to burn natural gas which they are importing in enormous quantities.
Onagawa power station to the north of the Fukushima Daiichi plant was closer to the earthquake focus and also got hit by the tsunami. The reactors in Onagawa were higher up and better protected than the Fukushima Daiichi reactors and there was no drama. They shut down perfectly well and the backup generators took over the cooling load. The Onagawa reactors were pretty much the same design and configuration as the Daiichi units although built later.
The Japanese government science and education agency, MEXT has been publishing regular reports on seawater sampling and radioactive contamination around the Fukushima Daiichi plant, from just offshore at the inlet and discharge channels of the reactor complex to areas several hundred kilometres from the shore. You can find the reports going back to May last year here, as well as many other sample measurements such as land soil, sea sediments, air particulates etc:
http://radioactivity.mext.go.jp/en/
Spot price for uranium is currently 51 bucks a pound. I'd like to get a small piece of pure or even depleted uranium as a pocket curiosity -- it's 50% denser than lead so it feels peculiar if you pick it up or hold it. Osmium would be even more interesting but it's VERY expensive.
The Chinese don't have large sources of uranium ore they can mine easily in their own national territory so they're considering leaching the fly ash lagoons from their coal-fired power stations to extract uranium for their growing fleet of nuclear power reactors. That fly ash is something like 100 to 200 ppm uranium content but it's not treated like radioactive waste from a nuclear power plant because, well, it's coal waste which isn't nuclear, you see...
Cesium doesn't linger in the human body. It has a biological "half-life", that is half the cesium taken in will be excreted between 50 to 120 days depending on what sort of tissue is collects in (bone, muscle, fat etc.). Strontium can collect in the bones but again it gets excreted over a period of time. Very little strontium was released from the Fukushima reactors as it is not particularly mobile unlike cesium compounds which make up nearly all of the radioactive contamination remaining in the environment since the short-lived iodine-131 (also mobile) died away.
Seawater is naturally radioactive due to potassium-40 (10 Bequerels/litre) and rubidium-87 (about 1 Bq/litre). Potassium is biologically conserved in the body and maintained at roughly stable levels absent disease. Measurements of seawater samples taken about 200km off Fukushima Daiichi a couple of months ago resulted in a combined value of cesium-134 and cesium-137 of around 0.1 Bq/litre, or 1% of the radioactivity from naturally-occurring potassium. It's possible some of the cesium-137 detected in these tests is not from the Fukushima reactors but residue from the 150 megatonnes or so of atmospheric thermonuclear weapons tests fired off by the US in the Pacific in the 1950s and 1960s.
Sound like a smaller version of SMART-1 launched in 2004 which used an ion thruster consuming 80kg of xenon propellant to move a 300kg satellite from orbit around Earth to a Lunar orbit about 15 months later. The neat thing you're suggesting is doing it with a microsatellite although whether it could carry out any sort of useful function once it was in Lunar orbit is debatable; just having enough radio transmission capability to return scientific data to Earth on such a small satellite would be a major stumbling block.
The US has a bunch of operational stove-sized nuclear reactors -- they're used to power submarines. I don't think your points 1 and 2 apply to them and in the case of your third point, who do you think makes them in the first place?
There's also the Vulcain 2, a well-tested fully cryogenic motor generating 1340kN or in your quaint old-fashioned American units about 300,000lbs of thrust with a similar Isp figure to the RS-25 SSMEs.
Rocket motors are effectively custom-made for the launch vehicles they are meant to propel in terms of rated thrust, endurance etc. They're not much use if they run at a lot less than their rated thrust since in that case they're heavier than they need to be and they can't be reworked to provide more thrust in any sort of economic manner since they were built down to a weight budget and will likely break if stressed beyond their design limits.
The SLS proposal started with using the SSMEs as their motors and everything else in the design derived from that point. Usually for reasons of efficiency or practicality it goes the other way round, hence the guys at SpaceX developed their own family of rocket motors to provide a specific thrust characteristic rather than buying something "off the shelf". Things were easier for them though as there was a lot of readily available components, manufacturing gear, materials, computer modelling etc. they could use to come up with their Merlin engines instead of having to reinvent the wheel several times.
Assuming the planned number of SLS launches uses up all of the available SSMEs then it is no real hardship to restart the production lines and make more of them as needed. They are not much more complex to build than any other fully-cryogenic motor currently constructed by various manufacturers especially with fifty years of experience since the first crude LOX/LH2 engines were built and flown.
There are a couple of problems with breeder reactors which make them impractical *at the present time*.
A) Uranium is cheap, really really cheap -- the spot market price today for uranium oxide (U3O8) is $51 US per lb. The fuel cost for electricity from a uranium-fuelled light-water reactor is less than a cent per kWhr. Back in the early days of nuclear power development it was thought uranium was scarce, in part because nobody had bothered to explore for it unlike, say, gold, oil, copper etc. Until WWII it had few commercial markets. That's why breeders were thought necessary, to use up more of the limited stocks of raw uranium by converting U-238 into fissile plutonium. It turned out otherwise, especially when the number of reactors being built did not match expectations.
B) Breeder reactors are cranky prototypes which run hot and tend to break in interesting ways, leaking molten radioactive sodium over the floor or damaging fuel rods etc. There's no off-the-shelf breeder design out there, just one-offs with a less than stellar record of uptime and reliability. Most of the breeders built to deliver grid power and breed fuel for light-water reactors have been decommissioned or are on hiatus. Since their primary aim is to make fuel they are less efficient in their secondary role of generating electricity which they also need to fulfill to be considered economic to operate.
When easily-extracted sources of uranium ore dry up in the future, possibly because of a renaissance of reactor construction increasing demand then breeders might be worth building again using the lessons learned from the first generation of designs. However Japanese researchers have developd techniques that can extract uranium metal from seawater for a postulated cost (in year 2000 dollars) of about $300 per kilogramme which might move the goalposts for breeder reactors into the far future.
"a) Oil is not widely used for electricity generation, but it is used."
Japan is reportedly burning about 200,000 barrels of oil a day at the moment to generate electricity to cover the loss of their nuclear reactor fleet due to shutdowns and inspections. Some of that is bunker oil but other reports say that they're also burning unrefined crude oil in old demothballed coal-fired power stations.
The ATV carries three tonnes of fuel which it uses to boost the four hundred tonne mass of the entire station using four 250N engines in-line with the vehicle and the ISS itself. It docks at a Russian module along the axis of the station. This approach and docking manoeuvre has to be an automated process since the station's robot arms can't reach that point.
The Dragon capsule can't autodock as it doesn't have the requisite hardware and software so the plan is to dock it at a side port, the one used by the Japanese cargo ships such as the "Kounotori" 2 H-2B Transfer Vehicle (HTV2). It will be grappled by one of the robot arms and manoeuvered into position for final docking. Firing the Dragon's thrusters at this point would start the entire ISS tumbling and possibly cause it to break up.
The Dragon capsule thrusters are powerful but the capsule is very limited in total fuel capacity as the thrusters are meant for use for launch escape and possible soft-landing of a manned capsule, so the amount of boost the capsule could generate is very limited even if it could dock in a place where firing its motors would not destroy the station. Besides the cargo version of the Dragon capsule will not have these rockets fitted -- they are intended for use in manned capsules.
About half of the ATV's payload mass delivered to the ISS is fuel for the station-keeping thrusters that are used along with the ATV's own motors to allow the ISS to maintain its orbit. The Dragon capsule only carries dry or bottled cargo that must be transfered to the station by hand and the Dragon's service module can't be used to carry out stationkeeping burns.
The UK's older reactors like the Magnox units are being decommissioned on a long-term basis, about 80 years from shutdown to final clearing of the reactor site. The delay is to allow the radioactivity in the core components such as the reactor vessel and primary steam piping to decay to virtually nothing which makes future dismantling easier.
After shutdown the spent fuel is removed and a start is made demolishing non-radioactive parts of the reactor complex such as the turbine halls, control rooms etc. What is left is no real danger to anyone; the reactor containment is sealed off and left to sit with a simple wire fence around it for the next fifty or sixty years before final demolishing of the rest of the reactor is carried out.
I imagine the US reactors are up for similar custodial treatment and the newspaper reports are sensationalistic garbage as they usually are. Some decommissioning is carried out more rapidly here and there in the world but usually because the site is going to be quickly reused to build a new reactor complex on it -- for example the Japanese are in the final stages of decommissioning and dismantling a small Magnox reactor at Tokai about ten years after it shut down but it is on the site of one of their nuclear research and development centres.
I climbed towers a couple of times in my youth to carry out repeater work, rigging antennas and stringing cable. Highest was, as I recall about 400 feet up a 1000 foot mast. I didn't have any fear of falling since the pro rigger I was working showed me how to do it safely with a three-points attachment to my harness etc. As he explained if I fell I might hurt someone on the ground when I landed but I'd be already dead from hitting all the bits of the tower I would bounce off on the way down.
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Who are these "friends" you speak of so glibly? Should I get some too? Does the "life" store I was directed to sell them? Do they come in six-packs?
I saw somewhere that the Surface stylus has a 600dpi resolution. The x86 Win8 Surface should run full-featured Photoshop/CS and assuming the stylus is pressure-sensitive (and there's no reason it wouldn't be in terms of cost, technology etc.) then this will make a portable version of the Cintiq, tempting for graphics people, photoeditors etc.
The Daini reactors did take some damage to peripherals such as external electrical equipment, the turbine halls etc. due to flooding from the tsunami. A level 4 emergency was declared to the IAEA over Daini reactor no. 3 which lost its backup power systems and took longer than necessary to achieve cold shutdown. All the other reactors on the Tohoku coastline at Onagawa, Tokai and Hamaoka suffered no ill-effects from the earthquake and tsunami.
The Daini reactors may never restart; the site is significantly contaminated by fallout from Daiichi ten km up the coast and it would be difficult to safely monitor the reactors in operation to detect any faults that release more radiation into the environment. The same goes for the Daiichi 5 and 6 reactors which were already shut down for inspection and refuelling at the time of the earthquake.
The HVDC links between the two grids have a limited capacity, about 2GW as I recall. They've not needed anything bigger since both parts of the country have adequate generating capacity for each region, or at least they did until the nuclear stations in the Kansai area and points south shut down for inspection and refuelling and didn't restart. The Kanto area (Tokyo and environs) has a lot of older coal-burning and oil-burning power stations that were demothballed after they lost the Fukushima Daiichi and Daini reactors and the other stations shut down due to the quake and tsunami (Onagawa, Tokai and Hamaoka) were refused permission to restart. Kansai (Osaka, Kobe, Hiroshima etc.) has fewer fossil-burners available to bring back to use hence the predicted electricity supply shortages in the region this summer.
It had a flickery refresh rate of 43Hz, low contrast, low brightness, crap colour spectrum and lousy off-axis viewing as the cost for the number of pixels displayed on the 22" screen. The high cost and weird hardware requirements (if you ever buy a second-hand T221 make sure the cables come with it or you are SOL) killed it in the consumer market, restricting its use to scientific and engineering areas and some odd niches like day trading setups.
"Japan has vast amounts of geothermal and plenty of off-shore wind."
Yes, Japan has lots of off-shore wind, so much their word for this has been Nicolled by the English language. "Taifu" or as we in the West spell it, "Typhoon". See the reports of the typhoon that hit Japan in September 2011 for an example of how bad they can get (over 90 people dead and missing).
Imagine what will happen to a farm of wind turbines standing out in open ocean when it gets hit by even a mild typhoon. It doesn't help that the coastal shelf of Japan is very narrow or non-existent so offshore wind turbines will have to be positioned on floating rafts rather than on towers fixed to the seabed.
"The whole reason the nuclear power industry developed based on uranium instead of thorium was for military reasons."
Crap. Uranium reactors are physically simple devices, steam kettles heated by spontaneously fissioning uranium. Thorium isn't fertile enough by itself to initiate and sustain fission in a simple reactor structure. India has been building and trying to sell thorium-fuelled reactors but they include quantities of medium-enriched (ca. 20%) uranium and plutonium in the fuel mix to provide enough sustained neutron flux to fission the thorium fuel.
The LFTR designs being touted by assorted folks are monstrously more complex than the existing uranium-fuelled reactor designs already built and operating today, and would have required decades of development back in the 1950s to make them work. The simple fertile uranium fission power reactors were an easier path to take and every country which started builing research and power reactors in that time took that route.
They need the space in the reactor building pools to take the damaged rods and debris from reactors 1 through 3. In the case of reactor 4 the spent fuel pool is pretty much full of fuel rod assemblies, some of which were due to be transferred to the site's longer-term storage pond some time last year but without a working crane this didn't happen.
The next step in the TEPCO plan is to build a weather shield over reactor 4 similar to the one they put over reactor 1. They can then rebuild the crane system on reactor 4 and start emptying the spent fuel pond.
It's difficult to swing the output of most older nuclear reactors, that is to run them at a reduced output from their rated 100% figure. Fission products like Xe-135, a neutron absorber which is usually at an equilibrium level at full power settings build up in the fuel rods at lower power settings "poisoning" the fission process and can prevent the reactor from operating at full power again until they die away. More modern reactor designs like the AP1400 can be swung to as low as 70% output without this poisoning effect causing problems but it does have to be carefully managed by the reactor operators.
Given the very low cost of nuclear fuel per MWhr generated there's no real point in swinging a reactor even if there aren't any customers for the "excess" electricity being generated. Reactors are shut down on a scheduled basis for inspection and refuelling, not when the fuel is exhausted or even severely depleted so running them at 100% or nearly 100% during their uptime doesn't actually cost any more than swinging them to cope with decreased demand during the night or at weekends.
The Japanese have several mothballed coal and oil-burning power stations which were decommissioned decades ago as they were too expensive to run and/or highly polluting. These have been rushed back into service, burning bunker oil and even raw crude oil. Some of these plants have been converted to burn natural gas which they are importing in enormous quantities.
Here's a picture I took at the exit of Ueno station in central Tokyo in early June last year.
http://s231.photobucket.com/albums/ee12/nojay_photo/2011%20June%20Japan%20trip/?action=view¤t=Uenotempandtime.jpg
An advertising sign display was reporting the temperature was 31 deg C at 07:33 AM. It gets much hotter in August and September though.
Onagawa power station to the north of the Fukushima Daiichi plant was closer to the earthquake focus and also got hit by the tsunami. The reactors in Onagawa were higher up and better protected than the Fukushima Daiichi reactors and there was no drama. They shut down perfectly well and the backup generators took over the cooling load. The Onagawa reactors were pretty much the same design and configuration as the Daiichi units although built later.
The Japanese government science and education agency, MEXT has been publishing regular reports on seawater sampling and radioactive contamination around the Fukushima Daiichi plant, from just offshore at the inlet and discharge channels of the reactor complex to areas several hundred kilometres from the shore. You can find the reports going back to May last year here, as well as many other sample measurements such as land soil, sea sediments, air particulates etc: http://radioactivity.mext.go.jp/en/
Spot price for uranium is currently 51 bucks a pound. I'd like to get a small piece of pure or even depleted uranium as a pocket curiosity -- it's 50% denser than lead so it feels peculiar if you pick it up or hold it. Osmium would be even more interesting but it's VERY expensive.
The Chinese don't have large sources of uranium ore they can mine easily in their own national territory so they're considering leaching the fly ash lagoons from their coal-fired power stations to extract uranium for their growing fleet of nuclear power reactors. That fly ash is something like 100 to 200 ppm uranium content but it's not treated like radioactive waste from a nuclear power plant because, well, it's coal waste which isn't nuclear, you see...
Cesium doesn't linger in the human body. It has a biological "half-life", that is half the cesium taken in will be excreted between 50 to 120 days depending on what sort of tissue is collects in (bone, muscle, fat etc.). Strontium can collect in the bones but again it gets excreted over a period of time. Very little strontium was released from the Fukushima reactors as it is not particularly mobile unlike cesium compounds which make up nearly all of the radioactive contamination remaining in the environment since the short-lived iodine-131 (also mobile) died away.
Seawater is naturally radioactive due to potassium-40 (10 Bequerels/litre) and rubidium-87 (about 1 Bq/litre). Potassium is biologically conserved in the body and maintained at roughly stable levels absent disease. Measurements of seawater samples taken about 200km off Fukushima Daiichi a couple of months ago resulted in a combined value of cesium-134 and cesium-137 of around 0.1 Bq/litre, or 1% of the radioactivity from naturally-occurring potassium. It's possible some of the cesium-137 detected in these tests is not from the Fukushima reactors but residue from the 150 megatonnes or so of atmospheric thermonuclear weapons tests fired off by the US in the Pacific in the 1950s and 1960s.
Sound like a smaller version of SMART-1 launched in 2004 which used an ion thruster consuming 80kg of xenon propellant to move a 300kg satellite from orbit around Earth to a Lunar orbit about 15 months later. The neat thing you're suggesting is doing it with a microsatellite although whether it could carry out any sort of useful function once it was in Lunar orbit is debatable; just having enough radio transmission capability to return scientific data to Earth on such a small satellite would be a major stumbling block.
The US has a bunch of operational stove-sized nuclear reactors -- they're used to power submarines. I don't think your points 1 and 2 apply to them and in the case of your third point, who do you think makes them in the first place?
There's also the Vulcain 2, a well-tested fully cryogenic motor generating 1340kN or in your quaint old-fashioned American units about 300,000lbs of thrust with a similar Isp figure to the RS-25 SSMEs.
Rocket motors are effectively custom-made for the launch vehicles they are meant to propel in terms of rated thrust, endurance etc. They're not much use if they run at a lot less than their rated thrust since in that case they're heavier than they need to be and they can't be reworked to provide more thrust in any sort of economic manner since they were built down to a weight budget and will likely break if stressed beyond their design limits.
The SLS proposal started with using the SSMEs as their motors and everything else in the design derived from that point. Usually for reasons of efficiency or practicality it goes the other way round, hence the guys at SpaceX developed their own family of rocket motors to provide a specific thrust characteristic rather than buying something "off the shelf". Things were easier for them though as there was a lot of readily available components, manufacturing gear, materials, computer modelling etc. they could use to come up with their Merlin engines instead of having to reinvent the wheel several times.
Assuming the planned number of SLS launches uses up all of the available SSMEs then it is no real hardship to restart the production lines and make more of them as needed. They are not much more complex to build than any other fully-cryogenic motor currently constructed by various manufacturers especially with fifty years of experience since the first crude LOX/LH2 engines were built and flown.
There are a couple of problems with breeder reactors which make them impractical *at the present time*.
A) Uranium is cheap, really really cheap -- the spot market price today for uranium oxide (U3O8) is $51 US per lb. The fuel cost for electricity from a uranium-fuelled light-water reactor is less than a cent per kWhr. Back in the early days of nuclear power development it was thought uranium was scarce, in part because nobody had bothered to explore for it unlike, say, gold, oil, copper etc. Until WWII it had few commercial markets. That's why breeders were thought necessary, to use up more of the limited stocks of raw uranium by converting U-238 into fissile plutonium. It turned out otherwise, especially when the number of reactors being built did not match expectations.
B) Breeder reactors are cranky prototypes which run hot and tend to break in interesting ways, leaking molten radioactive sodium over the floor or damaging fuel rods etc. There's no off-the-shelf breeder design out there, just one-offs with a less than stellar record of uptime and reliability. Most of the breeders built to deliver grid power and breed fuel for light-water reactors have been decommissioned or are on hiatus. Since their primary aim is to make fuel they are less efficient in their secondary role of generating electricity which they also need to fulfill to be considered economic to operate.
When easily-extracted sources of uranium ore dry up in the future, possibly because of a renaissance of reactor construction increasing demand then breeders might be worth building again using the lessons learned from the first generation of designs. However Japanese researchers have developd techniques that can extract uranium metal from seawater for a postulated cost (in year 2000 dollars) of about $300 per kilogramme which might move the goalposts for breeder reactors into the far future.
Japan is reportedly burning about 200,000 barrels of oil a day at the moment to generate electricity to cover the loss of their nuclear reactor fleet due to shutdowns and inspections. Some of that is bunker oil but other reports say that they're also burning unrefined crude oil in old demothballed coal-fired power stations.
The ATV carries three tonnes of fuel which it uses to boost the four hundred tonne mass of the entire station using four 250N engines in-line with the vehicle and the ISS itself. It docks at a Russian module along the axis of the station. This approach and docking manoeuvre has to be an automated process since the station's robot arms can't reach that point.
The Dragon capsule can't autodock as it doesn't have the requisite hardware and software so the plan is to dock it at a side port, the one used by the Japanese cargo ships such as the "Kounotori" 2 H-2B Transfer Vehicle (HTV2). It will be grappled by one of the robot arms and manoeuvered into position for final docking. Firing the Dragon's thrusters at this point would start the entire ISS tumbling and possibly cause it to break up.
The Dragon capsule thrusters are powerful but the capsule is very limited in total fuel capacity as the thrusters are meant for use for launch escape and possible soft-landing of a manned capsule, so the amount of boost the capsule could generate is very limited even if it could dock in a place where firing its motors would not destroy the station. Besides the cargo version of the Dragon capsule will not have these rockets fitted -- they are intended for use in manned capsules.
About half of the ATV's payload mass delivered to the ISS is fuel for the station-keeping thrusters that are used along with the ATV's own motors to allow the ISS to maintain its orbit. The Dragon capsule only carries dry or bottled cargo that must be transfered to the station by hand and the Dragon's service module can't be used to carry out stationkeeping burns.
The UK's older reactors like the Magnox units are being decommissioned on a long-term basis, about 80 years from shutdown to final clearing of the reactor site. The delay is to allow the radioactivity in the core components such as the reactor vessel and primary steam piping to decay to virtually nothing which makes future dismantling easier.
After shutdown the spent fuel is removed and a start is made demolishing non-radioactive parts of the reactor complex such as the turbine halls, control rooms etc. What is left is no real danger to anyone; the reactor containment is sealed off and left to sit with a simple wire fence around it for the next fifty or sixty years before final demolishing of the rest of the reactor is carried out.
I imagine the US reactors are up for similar custodial treatment and the newspaper reports are sensationalistic garbage as they usually are. Some decommissioning is carried out more rapidly here and there in the world but usually because the site is going to be quickly reused to build a new reactor complex on it -- for example the Japanese are in the final stages of decommissioning and dismantling a small Magnox reactor at Tokai about ten years after it shut down but it is on the site of one of their nuclear research and development centres.
I climbed towers a couple of times in my youth to carry out repeater work, rigging antennas and stringing cable. Highest was, as I recall about 400 feet up a 1000 foot mast. I didn't have any fear of falling since the pro rigger I was working showed me how to do it safely with a three-points attachment to my harness etc. As he explained if I fell I might hurt someone on the ground when I landed but I'd be already dead from hitting all the bits of the tower I would bounce off on the way down.