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Source: (consider it)
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Thread: Nuclear power stations
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Lilac
Shipmate
# 17979
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Posted
Now I know we have some atomic physicists here, how do they rate the chances of the planned nuclear power stations? Once upon a time, this country had a lead in nuclear power, but obviously something went wrong with the British-run projects. Are the French ones likely to work out better?
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Seeking...
Posts: 62 | From: Birmingham / Coventry Area, UK | Registered: Jan 2014
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Sober Preacher's Kid
Presbymethegationalist
# 12699
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Posted
I don't rate the chances very highly. It has to do with public opinion and opposition rather than science. The French, for many reasons, have a much different attitude to state projects and the role of state science. There it's seen as benign, enlightened leadership, in English-speaking countries the attitude is much more critical and suspicious.
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NDP Federal Convention Ottawa 2018: A random assortment of Prots and Trots.
Posts: 7646 | From: Peterborough, Upper Canada | Registered: Jun 2007
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Nuclear Physicist reporting for duty.
In broadest terms there are two reactor technologies - gas cooled or water cooled.
The British reactor technology (Magnox then AGR) was developed around graphite moderated, gas-cooled reactor designs. They have several advantages. First, they have very good load factors (the percentage of time they're operating at, or very near, full power). The gas coolant doesn't moderate the reactor, so changes in coolant flow (eg: pump failure, pressure loss) doesn't alter the reactor characteristics making control simpler - though, in a well designed water cooled reactor loss of coolant pressure reduces reactor power, a nice safety feature (pity they were operating the Chernobyl reactor in a state where the reverse was true at the end of April 1986). In shut down, the reactor core can be cooled passively, so you don't need to maintain the coolant flow with pumps. However, gas cooled reactors are more expensive, and can't be produced to generate as much power per reactor.
Water cooled reactors are cheaper to build, produce more power per unit, and so commercially out-compete the gas cooled versions. If you design and operate the reactor properly coolant flow disruptions cause the power to drop even without intervention. On the other hand, once you shut the reactor it is necessary to maintain primary coolant flow for weeks, needing pumps (which means the reactor a) consumes power in shut down and b) adding a safety issue as those pumps are critical). Loss of coolant pressure is the most significant cause of historic accidents at nuclear plants, including Three Mile Island (pressure lost due to a valve sticking open) and Fukushima (pressure lost due to the destruction of back-up generators and external power by tsumani).
The new build programme in England and Wales will be entirely water cooled reactor technology. The French led consortium that are on the verge of starting to build at Hinkley Point, and very likely to be building at Sizewell shortly thereafter, will be building French designed Pressurised Water Reactors (PWR).
There are two other consortia still in the game, though they're not as far along the road of getting approval for their reactor designs and planning permission to build. Toshiba hold a controlling stake in NuGen, planning to build Westinghouse (owned by Toshiba) PWRs at a site next to Sellafield. Hitachi hold a controlling stake in Horizon, planning to build Advanced Boiling Water Reactors at Oldbury and Wylfa.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Mr Clingford
Shipmate
# 7961
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Posted
Thorium commercially before 2050?
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Ne'er cast a clout till May be out.
If only.
Posts: 1660 | From: A Fleeting moment | Registered: Jul 2004
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Commercially? No, not by then. An advanced prototype generating power for the grid, possibly. Though, with issues of weapons grade material proliferation even worse than uranium fuelled reactors it may never happen until we reach a point where there aren't states or organisations seeking nuclear weapons technology.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Darllenwr
Shipmate
# 14520
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Posted
Alan, as you're the expert around here, can you correct my, apparently false, impression? I had the idea that the main reason for having settled for Uranium fission in the first place was the readiness with which it produced weapons-grade material, and that Thorium fission was dismissed because it didn't? Certainly the article in The Engineer last month implied that the attraction of Thorium reactors was that they didn't produce material that could be used in weapons.
Word change.
[ 05. February 2014, 19:36: Message edited by: Darllenwr ]
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If I've told you once, I've told you a million times: I do not exaggerate!
Posts: 1101 | From: The catbox | Registered: Jan 2009
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Mr Clingford
Shipmate
# 7961
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Posted
That's a shame, Alan. I was hoping 35 years could be enough, in fission not even fusion!
And, Darllenwr, that was my impression too, that Thorium was easily used for weapons.
You're the man in the field, Alan - clear this up would you!?
[ 05. February 2014, 20:51: Message edited by: Mr Clingford ]
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Ne'er cast a clout till May be out.
If only.
Posts: 1660 | From: A Fleeting moment | Registered: Jul 2004
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
The attractions of thorium reactors are primarily relative abundance of 232Th and the lack of non-fissionable heavy isotopes in the fuel meaning you get very little transuranic radionuclide production and no very long term storage problem. There are other attractions such as some reactor designs that are relatively cold compared to uranium or MOX fuel reactors.
I think it is incontrovertible that early reactors were built with plutonium production in mind. The experience thus gained in building reactors with military potential gave uranium fuelled reactors a leg up, and hence accelerated them into commercial development ahead of thorium fuel reactors. Also, the technology developed for uranium enrichment also allow low-enrichment fuel for reactors. The decision in the 1940s to pursue 235U and 239Pu as fissile material for bombs certainly influenced the direction of subsequent civil reactor technology. A thorium reactor won't produce 239Pu for a conventional nuclear weapons programme, so in that sense doesn't produce weapons material (though, it takes a lot of work to extract 239Pu from conventional reactor fuel as well - you really need a dedicated reactor where you can use some fuel elements for very short periods to produce 239Pu without large quantities of other Pu isotopes).
I don't know the details of 233U fission. There may be an issue with the number of neutrons generated (with 2 less neutrons than 235U it might be expected that the mean number of neutrons produced per fission would be less than 235U, which is in turn less than 239Pu). I read stuff about 232U contamination affecting the development of a chain reaction, although I can't see how 232U gets into the material. So, it's quite possible that 233U won't make as "good"* a bomb as 235U or 239Pu - you may need more material, different initiator or something.
But, 233U would be relatively easily separable from spent 232Th fuel - you can rely of chemical processes as you won't have other U isotopes present, although you'll need to work in heavily shielded environments as the material will be highly radioactive. And, although there may be practical issues developing a weapon, 233U is fissionable and there will be some way to make a lump of it go bang.
* Not that I consider any bomb to be "good".
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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*Leon*
Shipmate
# 3377
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Posted
Alan, could you explain in layman's terms what needs to be done/invented that takes so many decades before we can have commercial thorium reactors?
Posts: 831 | From: london | Registered: Oct 2002
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
There are two issues. One is technical, the other is legal.
Technical first. We have already a small number of old prototype thorium reactors. Although the designs are decades old this gives us useful information on the way the physics works out inside a reactor. Many of those designs, including the liquid flouride design that was probably closest to commercialisation, are radically different from current reactor technologies. So, in addition to slightly different physics in the core (number of neutrons produced, different proportions of fission products etc) you also need to develop new technologies for everything outside the core as well.
Just because it probably came closest to commercialisation in the 1960s, let's look at the LFTR. Here you have the fuel dissolved in a fluid that is pumped around a circuit through the critical core and a heat exchanger. The 1960s work showed it was possible, but you would have a reactor pumping extremely hot, albeit low pressure, fluid around.
Ensuring that the pipes carrying that do not, under any circumstances, break will be critical. Remember this fluid carries the fuel, and all the fission products. In a conventional reactor the coolant (water or gas, usually) is isolated from the core, so although it may become slightly radioactive it is relatively benign if it escapes the pipes carrying it - so, a PWR or BWR for example would have pressure release values that let this fluid escape into the reactor building (in a controlled location) if needed. It's only if the core overheats that cracking of fuel cannisters and coolant pipes allows fission products into the coolant and hence provides a route for them to get outside the core. A LFTR would routinely carry the contents of the core outside the core, hence the need for a much higher standard of engineering for those pipes.
The LFTR design allows online refuelling by simply siphoning old liquid flouride salt out of the system, containing burnt and unburnt 232Th, bred 233U and fission products. Then you just add in additional liquid flouride salt to replace it with fresh 232Th. What do you do with that old liquid flouride salt? In a conventional reactor, old fuel rods are solid objects, you can put them in a pond and allow them to cool with relative ease. Storing highly radioactive liquid is a much more challenging problem. It would also, presumably, be advantageous to try and recycle that material - if you can extract a large proportion of the fission products you will be left with liquid flouride salt containing 232Th and fissile 233U. You don't even need to get back to pure 232Th and 233U, small quantities of residual fission products wouldn't hurt. Letting it stand a couple of years would let most of short lived radioactive fission products decay, making it easier to handle. But, you'd want to remove the stable isotopes as well. Remember, these will react with your carrier salt forming different chemicals that almost certainly won't have the physical properties you want (and, may be corrosive when at high temperature in those pipes) and will also capture neutrons forming new radioisotopes and reducing the reactor efficiency.
Those are the first two technical challenges that come to mind. You would also face the challenge of making sure the salt removed from a reactor doesn't enter any process that would extract the 233U, for non-proliferation reasons. You would also need to develop capacity for producing the flouride salt fuel (but, that would be a relatively minor obstacle to MFTR development).
Then you would have a legislative challenge. You would want to build a prototype initially. You'd need a country willing to have that, and go through all the planning requirements, satisfy the authorities that you can do it safely etc. Let's just say you can fast track that ... you cna have a prototype running in 10 years. You'd want a few years of data to refine your design and produce a blue-print for a commercial reactor. Next step. Form a commercial partnership of companies with the necessary engineering and construction skills, an electricity producer wanting a new plant, people who can raise capital. You won't do that overnight. Then your consortium puts in a proposal to a country to build a reactor. For the new build programme in the UK this is a multi-stage process. First there's a Generic Design Assessment (GDA), does the design meet necessary safety criteria at a generic level. GDAs for conventional reactor designs take 10+ years to get, go for an unconventional design and I can see that process taking longer. Then you need to apply for permission to actually build one of these things, find a location, satisfy the specific requirements for safety at that location (eg: if near the coast that you'll take measures to prevent coastal erosion undermining the reactor or essential support buildings), get planning permission and start building. It's probably another 10 years from getting your GDA to finishing construction, minimum. You'll then still need final permission to actually turn the thing on. In a lot of other countries you'll also need to get past an initial step - to convince government and people that they need a nuclear power reactor (of any sort) at all.
So, what is the time scale:
Technical developments to get a safe, working prototype and address other technical issues. I've no idea, 10 years minimum I'd guess at.
Build prototype and run for a few years to get data. 10 years minimum.
Get GDA to actually build a commercial reactor. 10 years minimum.
Local planning permission and construction, 10 years minimum.
You can see how, by that reasoning, I consider 35 years to get to having a commercial thorium reactor as very short.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Mr Clingford
Shipmate
# 7961
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Posted
Thanks, Alan, that was comprehensive. I might be dead before commerical thorium reactors.
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Ne'er cast a clout till May be out.
If only.
Posts: 1660 | From: A Fleeting moment | Registered: Jul 2004
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Hairy Biker
Shipmate
# 12086
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Posted
quote:
Originally posted by Sober Preacher's Kid:
I don't rate the chances very highly. It has to do with public opinion and opposition rather than science.
I recall being dragged along, as a teenager, to “Nuclear Power, No Thanks” rallies in London in the late 70s. As I recall there were 3 objections to nuclear power, none of which has been addressed by the passage of time.
1) Risk of accidents. Event Japan, probably the most advanced user of this technology, can’t keep the lid on all their reactors still after all these years.
2) What happens to all the waste. The news seems to have been quiet on this front in recent years, but I still don’t know where it all goes. Has the issue been resolved, or have we just resigned ourselves to vast radioactive landfills as the legacy of our civilization?
3) “Atoms for peace are atoms for war” as the slogan used to go. The motivation for creating the reactors in the first place was the nuclear arms race, as has already been noted here. Without that side-line, the technology has never been, and can never be, profitable. I don’t know if the low carbon economy and the price of oil has changed the economics; but the charge still remains, as we have seen in Iran.
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there [are] four important things in life: religion, love, art and science. At their best, they’re all just tools to help you find a path through the darkness. None of them really work that well, but they help.
Damien Hirst
Posts: 683 | From: This Sceptred Isle | Registered: Nov 2006
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Any means of generating significant amounts of electricity is polluting. Burning coal, oil or gas generated CO2 pollution, and usually results in produciton of other pollutants (heavy metals, carbon particulates, assorted polyaromatic hydrocarbons. Even non-negligible amounts of radioactive waste). Producing solar panels involves processes that produce chemical waste. Our energy-rich western lifestyle is generating a legacy of pollutants for our descendents, and in many cases to the detriment of others in the world today.
A properly run and managed nuclear power capacity produces a small quantity of contained waste (unlike, say burning coal where a lot of the waste goes straight up a chimney and into the environment). Yes, that nuclear waste needs careful handling and storage. But, it's not intrinsically more hazardous than the waste products of many chemical processes. There are long term storage questions about how we communicate to future generations that it is dangerous to enter a store of nuclear waste. But, how do you communicate that ground contaminated with heavy metals is equally dangerous?
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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TurquoiseTastic
Fish of a different color
# 8978
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Posted
As far as accidents go, I submit that an alternative view of Fukushima would be: a nuclear power station was hit by a tsunami, one of the most devastating natural catastrophes imaginable, and the number of people who died as a result is arguably zero.
On the other hand, over 10,000 people died as a result of "living in towns on the coast". Do we therefore conclude "having towns on the coast is obviously a dangerous idea which we must back away from"?
Posts: 1092 | From: Hants., UK | Registered: Jan 2005
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no prophet's flag is set so...
Proceed to see sea
# 15560
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Posted
ISTM that the Japanese disaster has something to do with forethought of what the safe areas are to build things. I would hope the waste facilities have better forethought than this. Earthquake zones and ocean front locations seem to me to be bad ideas.
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Out of this nettle, danger, we pluck this flower, safety.
\_(ツ)_/
Posts: 11498 | From: Treaty 6 territory in the nonexistant Province of Buffalo, Canada ↄ⃝' | Registered: Mar 2010
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Zach82
Shipmate
# 3208
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Posted
Not really. The benefit of a seaside location is lots and lots of water to dilute radioactive runoff in.
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Don't give up yet, no, don't ever quit/ There's always a chance of a critical hit. Ghost Mice
Posts: 9148 | From: Boston, MA | Registered: Aug 2002
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Nuclear power plants don't, under normal circumstances, have radioactive run-off to dilute. So, that's not why they're usually built on the coast.
The main reason they're built on coasts (or near major rivers) is availability of cooling water. The power station has two enclosed coolant systems. The primary coolant (usually water or carbon dioxide) flows through the reactor core removing heat from fission, and through heat exchangers outside the core. The secondary coolant (water) takes energy from the heat exchanger and boils, the superheated steam then drives the turbines to generate electricity. Both these systems use purified water, because salt and other contaminants would cause corrosion.
So, you may ask, where does sea water come in? After the steam has driven the turbines it needs to be returned to the heat exchanger to extract more energy from the primary coolant and hence the core. It needs to be condensed back to water, and to cool the condensers power stations use readily available from sources - large river or sea.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Lilac
Shipmate
# 17979
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Posted
Surely people got suspicious because gas-cooled reactor projects like "Dungeness-B" went wrong long before generating any power. What guarantee is there it won't happen again?
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Seeking...
Posts: 62 | From: Birmingham / Coventry Area, UK | Registered: Jan 2014
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
quote:
Originally posted by TurquoiseTastic:
As far as accidents go, I submit that an alternative view of Fukushima would be: a nuclear power station was hit by a tsunami, one of the most devastating natural catastrophes imaginable, and the number of people who died as a result is arguably zero.
On the other hand, over 10,000 people died as a result of "living in towns on the coast". Do we therefore conclude "having towns on the coast is obviously a dangerous idea which we must back away from"?
The Fukushima Daiichi Nuclear Power Station wasn't hit by any old tsunami. This was a tsunami generated by the largest earthquake ever recorded in Japan, the fifth largest ever recorded. The tsunami wave in places reached 40m high and reached 10km inland. Over 15,000 died. The waves exceeded the height of tsunami defences along large sections of the coast, the wave being 2-3 higher than any previous known tsunami in the region (and, that includes wave height deduced from pre-historic tsunami debris).
The destruction from earthquake and tsunami was widespread and affected people far more severely than the accident at Fukushima Daiichi. Which isn't to say that the nuclear accident didn't have serious consequences. I wouldn't want my children playing here every day (though once in a while isn't going to hurt).
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
quote:
Originally posted by Lilac:
Surely people got suspicious because gas-cooled reactor projects like "Dungeness-B" went wrong long before generating any power. What guarantee is there it won't happen again?
People got optimistic. It takes more than 5 years to build something as complex as a nuclear reactor. Especially as Dungeness B was the first of the AGR reactors to be built. Scaling up from the Windscale prototype was found to be much more difficult than envisioned. Several parts needed to be redesigned after construction was started. So, despite Dungeness being the first to start construction Hinkley Point and Hunterston were finished first - because the lessons of building Dungeness B had been learnt before they started. It still took 8-9 years to build an AGR even after the initial problems were sorted. The reactors there have been running since 1983, which admittedly was 13 years behind the original schedule.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Gee D
Shipmate
# 13815
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Posted
quote:
Originally posted by TurquoiseTastic:
As far as accidents go, I submit that an alternative view of Fukushima would be: a nuclear power station was hit by a tsunami, one of the most devastating natural catastrophes imaginable, and the number of people who died as a result is arguably zero.
On the other hand, over 10,000 people died as a result of "living in towns on the coast". Do we therefore conclude "having towns on the coast is obviously a dangerous idea which we must back away from"?
Exactly, and another comparison would be the numbers killed in coal mining accidents and those in nuclear accidents since 1955 or so. I imagine a difficulty in that is in determining the numbers killed in the Chernobyl incident.
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Not every Anglican in Sydney is Sydney Anglican
Posts: 7028 | From: Warrawee NSW Australia | Registered: Jun 2008
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
quote:
Originally posted by Gee D:
I imagine a difficulty in that is in determining the numbers killed in the Chernobyl incident.
There were 31 people involved in the immediate emergency response who died relatively quickly from causes directly related to radiation exposure. That's the easy number to determine.
There have been between 6000 and 10000 thyroid cancers in the Ukraine in excess of the expected rate, a number likely to rise as more thyroid cancers develop. However, thyroid cancer is easily treated with a >95% success rate. So, there may be 50 or so deaths from thyroid cancers. As of 2011, UNSCEAR reported 15 thyroid cancer deaths. A reasonable estimate of around 30-50 deaths expected from thyroid cancers can be made (many of whom will die in the next decade or so).
There is no evidence of an increase in incidence of other cancers, nor of birth abnormalities.
Where things get difficult is with mental health effects. If people who are displaced suffer mental health issues (not unlikely) and subsequently commit suicide, are those deaths attributable to the accident? Likewise there were stories of UK hill farmers committing suicide after sheep movement restrictions shut down their farms. I don't know of any data on such deaths at all.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Gee D
Shipmate
# 13815
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Posted
Thank you Alan - it would have been better had my question been "How many people have died or will die as a result of the Chernobyl incident" but you answer covers the point well. I'm not aware of any deaths in uranium mining, but over the period there must have been thousand of deaths in coal mining alone (Chinese figures always look rubbery), to which must be added indirect deaths from pollution. That makes the usual cry about the extreme danger from nuclear power rather baseless.
And there is no record I know of that there have yet ben any deaths directly or indirectly from the disposal of waste. Even that problem disappears if thorium is the fuel.
I grew up in the 50s, when nuclear power was seen as the way to go. AFAICS, there is little, save the cost, and an agreed method of disposing of waste to ensure that it is not available for weapons, to stop that happening. Even here, with virtually no spare water other than from the sea, a programme is feasible. And think of the reduction in greenhouse gases which would follow.
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Not every Anglican in Sydney is Sydney Anglican
Posts: 7028 | From: Warrawee NSW Australia | Registered: Jun 2008
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Hairy Biker
Shipmate
# 12086
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Posted
re: Uranium mining. Friends of the Earth have some detail on the risks to the miners (mainly from lung cancer). Also point out that nuclear is quite energy intensive, creating 3-4 times the CO2 of generating the same electricity by wind turbine. Emissions are caused by the mining, processing and transport of Uranium.
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there [are] four important things in life: religion, love, art and science. At their best, they’re all just tools to help you find a path through the darkness. None of them really work that well, but they help.
Damien Hirst
Posts: 683 | From: This Sceptred Isle | Registered: Nov 2006
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Hairy Biker
Shipmate
# 12086
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Posted
Oh, and here's a fun quote from them on the waste issue:
quote:
If spent fuel rods were buried around the time of the Norman Conquest 1000 years ago, they would still be highly dangerous today.
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there [are] four important things in life: religion, love, art and science. At their best, they’re all just tools to help you find a path through the darkness. None of them really work that well, but they help.
Damien Hirst
Posts: 683 | From: This Sceptred Isle | Registered: Nov 2006
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Marvin the Martian
Interplanetary
# 4360
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Posted
quote:
Originally posted by Hairy Biker:
Oh, and here's a fun quote from them on the waste issue:
quote:
If spent fuel rods were buried around the time of the Norman Conquest 1000 years ago, they would still be highly dangerous today.
Sure. And if we'd been burning coal and gas at current rates since the Norman Conquest the world would be virtually uninhabitable by now.
No realistic method of producing the amount of power we use these days (let alone projected increases in demand) is without risk or environmental consequences. Nuclear has fewer than most, though.
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Hail Gallaxhar
Posts: 30100 | From: Adrift on a sea of surreality | Registered: Apr 2003
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Mining is, undoubtedly, the part of the uranium cycle with the greatest risk to workers. The major part of that risk is common to all forms of mining - an enclosed environment, air full of dust and gases not normally present in surface air (at least, not in the concentrations observed underground), will cause a variety of respiratory disease. Then add in the risks of cave in, other accidents in locations where getting medical treatment quickly is difficult, flooding and the like. Exposure to radiation is a minor contribution to risk - the average uranium concentrations in the rock are still quite low, the high grade ore will be in narrow veins within rocks of normal-ish uranium concentrations. There will be radon gas present, but in a reasonably well ventilated mine that can be easily controlled. Radon also accumulates in other mines, and so is another hazard common to all mines.
Also common to other mining operations, uranium mines create spoil tips with material slightly enriched in the metal sought, and often other metals co-deposited, and leach waters that are likewise contaminated. Without careful controls of these wastes there is risk to the public, especially those living downstream of these mines. But, whether uranium mining is worse than other mining activities, particularly mining for toxic metals such as lead, is a difficult question to answer.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Hairy Biker
Shipmate
# 12086
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Posted
quote:
Originally posted by Marvin the Martian:
quote:
Originally posted by Hairy Biker:
Oh, and here's a fun quote from them on the waste issue:
quote:
If spent fuel rods were buried around the time of the Norman Conquest 1000 years ago, they would still be highly dangerous today.
Sure. And if we'd been burning coal and gas at current rates since the Norman Conquest the world would be virtually uninhabitable by now.
No realistic method of producing the amount of power we use these days (let alone projected increases in demand) is without risk or environmental consequences. Nuclear has fewer than most, though.
But we haven't been burning coal and gas for 1000 years. And in 1000 years, we probably won't be using electricity to transmit power to our devices, whatever those devices might be. Plant life will have re-absorbed all the spare carbon we put in the atmosphere over these two misguided centuries, and quarries and mines will have reverted to their natural state. Nuclear waste will continue to be a hazard and will compromise our options for the use of whatever space they take up.
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there [are] four important things in life: religion, love, art and science. At their best, they’re all just tools to help you find a path through the darkness. None of them really work that well, but they help.
Damien Hirst
Posts: 683 | From: This Sceptred Isle | Registered: Nov 2006
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Spoil tips and tailings from mines (including, but not limited to, uranium mines) will contain toxic materials for millenia, unlike radioactive materials heavy metals don't decay. Our nuclear waste will occupy a relatively small area of land. Especially if we break it apart, remove the valuable fissionable material to fuel more reactors, and only store the very small fraction of the spent fuel that has very long half lives. The nuclear waste from the UK can be stored in a space comparable to a single mine. The difficulty isn't finding the space for it, it's finding the right space - somewhere geologically stable with the right ground water (non)movement properties etc. The irony is that we'll spend a lot of time and money finding long term storage solutions for nuclear waste, but won't even think about the legacy of other industrial wastes that are equally, if not more, toxic.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Lilac
Shipmate
# 17979
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Posted
Around 10 years ago I heard of one prominent nuclear company being investigated by MI5. I think it was in "Newsnight" on BBC2. I never heard any more about this, which makes me wonder what the issue was, Communist saboteurs, terrorists or whatever, and whether anything effective got done about it.
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Seeking...
Posts: 62 | From: Birmingham / Coventry Area, UK | Registered: Jan 2014
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
It's very difficult to speculate on a partially remembered story from a decade ago.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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shadeson
Shipmate
# 17132
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Posted
Just a very simple question for Alan Cresswell . No bias either way as far as nuclear power stations are concerned, but could you explain why a new power sation cannot be built on the site of an old one. It seems that the country will become littered with places like Bradwell (Essex) or Hinkley 'A'.
Posts: 136 | From: uk | Registered: May 2012
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
All the proposed new build sites are on existing nuclear power station sites.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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shadeson
Shipmate
# 17132
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Posted
Sorry Alan , that not quite what I meant.
It looks as if the buildings and ground area are just left to rot - why can't they be used again?
Posts: 136 | From: uk | Registered: May 2012
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
Oh, right ... on exactly the same spot as existing reactors.
Put simply, at present those reactors are safer left alone. They contain significant quantities of radioactive material, even after the spent fuel removed is. There were lots of neutrons in the core that activated a lot of the structure, making it radioactive. Activation products have relatively short half lives, certainly in comparison to transuranic elements formed in the fuel, so it'll only take a few decades for most of that activity to decay away. Then it will be possible to carefully remove the buildings and dispose of the remaining waste, or concentrate the waste in one location and entomb the lot. So, the actual reactor buildings will have to remain for 20-30 years. Of course, many of the ancillary buildings will be removed before then, or reused for other purposes if appropriate.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Gee D
Shipmate
# 13815
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Posted
quote:
Originally posted by Hairy Biker:
re: Uranium mining. Friends of the Earth have some detail on the risks to the miners (mainly from lung cancer). Also point out that nuclear is quite energy intensive, creating 3-4 times the CO2 of generating the same electricity by wind turbine. Emissions are caused by the mining, processing and transport of Uranium.
And by the mining, processing and transport of material for wind turbines as well and the energy costs of construction. Then there's the large area of land needed for a wind farm sufficient to provide the power needs for even a small city.
I recall reading (in The Economist in the early 70s from memory) that there was a higher level of radiation in the streets of Edinburgh and other Scots cities than in the countryside around nuclear power stations. The cause - the use of Scots granite for constructing buildings, there being much more radioactive material in that than in materials used in other parts of the UK, and the tight control on emissions from the power stations,
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Not every Anglican in Sydney is Sydney Anglican
Posts: 7028 | From: Warrawee NSW Australia | Registered: Jun 2008
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Hairy Biker
Shipmate
# 12086
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Posted
quote:
Originally posted by Gee D:
quote:
Originally posted by Hairy Biker:
re: Uranium mining. Friends of the Earth have some detail on the risks to the miners (mainly from lung cancer). Also point out that nuclear is quite energy intensive, creating 3-4 times the CO2 of generating the same electricity by wind turbine. Emissions are caused by the mining, processing and transport of Uranium.
And by the mining, processing and transport of material for wind turbines as well and the energy costs of construction. Then there's the large area of land needed for a wind farm sufficient to provide the power needs for even a small city.
I recall reading (in The Economist in the early 70s from memory) that there was a higher level of radiation in the streets of Edinburgh and other Scots cities than in the countryside around nuclear power stations. The cause - the use of Scots granite for constructing buildings, there being much more radioactive material in that than in materials used in other parts of the UK, and the tight control on emissions from the power stations,
yeah, there was a lot of that sort of stuff around in the '70s. The thing was though, that no one doubted that they could keep the radiation in on a good day. It was exactly the sort of stuff that happened at Chernobyl we were worried about. And it turns out we were right to worry. But concerns were dismissed by saying that radiation is completely natural, especially in Scotland. We design these things not to leak, so how could they possibly leak? How indeed?
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there [are] four important things in life: religion, love, art and science. At their best, they’re all just tools to help you find a path through the darkness. None of them really work that well, but they help.
Damien Hirst
Posts: 683 | From: This Sceptred Isle | Registered: Nov 2006
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
We all live exposed to radiation every day from natural sources. Those natural sources are highly variable, and some parts of the world are considerably higher than others. In Scotland, Aberdeen (the "Granite City") would be thought of as being particularly radioactive. By coincidence a group of honours students doing their projects with us have mapped radiation levels around parts of old Aberdeen and Edinburgh, and there's considerable variability in activity even within small parts of each city. Mostly driven by the geology rather than construction materials, although some building materials (granite cobblestones being the most significant) do produce a noticeable increase in activity on a local scale.
Of course, the natural activity is variable around nuclear sites as well. The vast majority of nuclear sites have no impact on the levels of radioactivity in their local environment. Indeed, many coal fired power stations have a bigger impact on the local radiation level (though the urban myth that burning coal produces more radioactivity than nuclear power is an urban myth - the radioactivity produced by burning coal exceeds the radioactivity released into the environment from nuclear power stations, excluding accidental releases ... but that's not the same at all).
I'll be flying to Fukushima tomorrow. The radiation dose I'll receive in flight from cosmic radiation will exceed what I'll receive during a week in Fukushima. And, my dose while in Fukushima from fallout will be at least an order of magnitude less than what I'll get from natural sources - and a good deal of that artificial dose will be because work takes me to contaminated environments. That doesn't mean that it's OK that there is widespread contamination from radioactive materials from Fukushima Daiichi, it also doesn't mean that there is a very small chance that residents of Fukushima (especially those who were there during the accident and got a much larger dose, including from radioiodine that is thyroid seeking) will develop cancers they would have other wise avoided. Of course, what happened was a tragedy, and any extra exposure to radioactivity is best avoided. But, a sense of perspective is missing when you read about people in California in March 2011 worried about radiation from Fukushima, yet those same people wouldn't think twice about boarding a plane to travel to New York.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Gee D
Shipmate
# 13815
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Posted
Yes, the Fukashima response shows that modern technology and decent maintenance may be stretched by the most violent of incidents, but that security wins through. I appreciate that the consequences of failure at a conventional station would have been less severe, but would it have withstood the quake and subsequent tsunami?
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Not every Anglican in Sydney is Sydney Anglican
Posts: 7028 | From: Warrawee NSW Australia | Registered: Jun 2008
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Alan Cresswell
Mad Scientist 先生
# 31
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Posted
No building would have withstood the tsunami impact undamaged. All along that coast there are what had been substantial buildings and structures reduced to barely more than foundations. I linked to some photos earlier, that collection includes some pictures of the sea defences with massive holes knocked through. If you go to Google Earth and look up and down the coast there are vast areas which had at one stage been industrial sites wiped off the map.
The fact is that the Fukushima Daiichi power station buildings were relatively undamaged by the tsunami. What did it for the reactors was loss of power to maintain the pumps, and hence the coolant overheated. Normally in shut down pumps are maintained from the main electric supply, this was knocked out by the earthquake and tsunami bringing down power lines. In the event of no main power, water cooled reactors have diesel generators to prove emergency backup. The tsunami flooded the diesel generator rooms for reactors 1-4. The generators for reactors 5 and 6 (built on slightly higher ground) were undamaged but there was no means of connecting them to the other reactors - and, even if they could be connected they wouldn't have been powerful enough to maintain cooling for 6 reactors and associated fuel storage ponds. There were batteries designed to maintain power between loss of external power and the diesel generators kick in, but they were depleted in an hour.
The lessons learnt from the disaster were that diesel generators need to be located with more thought to what might potentially damage them, preferably more dispersed around the site so that one event is less likely to take them all out. Also, that there needs to be means of connecting generators for one reactor to others on the site. These should be features of all new reactors (though, personally I'd much prefer gas cooled reactors which don't need diesel generators at all), it may not be possible to retrofit all existing reactors to make these changes.
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Don't cling to a mistake just because you spent a lot of time making it.
Posts: 32413 | From: East Kilbride (Scotland) or 福島 | Registered: May 2001
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Lilac
Shipmate
# 17979
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Posted
[post temporarily deleted by B62]
[ 08. February 2014, 22:27: Message edited by: Barnabas62 ]
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Posts: 62 | From: Birmingham / Coventry Area, UK | Registered: Jan 2014
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Barnabas62
Shipmate
# 9110
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Posted
Lilac
I've temporarily deleted the contents of your post above, pending an Admin view about any legal exposure to the Ship which it may contain.
I may be being overcautious, but we have very conservative policies over Commandment 7 matters. If Admin OK it, the contents will be reinstated. Please bear with us and please refrain from any repetition until the Admin view is known.
Barnabas62
Purgatory Host
[ 08. February 2014, 22:32: Message edited by: Barnabas62 ]
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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Lilac
Shipmate
# 17979
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Posted
Okay, I'm sure there's a reason for these rules. I looked on the Companies House website and found a number of organizations with similar names, so it might not be clear which was involved. But you can check the records of the Parliamentary Select Committees for some details. I can send you a private communication about this. I trust this is okay.
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Seeking...
Posts: 62 | From: Birmingham / Coventry Area, UK | Registered: Jan 2014
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Barnabas62
Shipmate
# 9110
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Posted
Thanks
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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Barnabas62
Shipmate
# 9110
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Posted
Lilac
While Admin are deliberating, this Hostly advice may render their consideration moot.
The Ship is a public forum for discussion. We are not in any sense, nor ever will be, an investigative news organisation, even in part. It is therefore quite inappropriate to invite investigatory support from another Shipmate in their real life role.
Please also bear in mind Commandment 8.
You should also note that we apply Commandment 7 very cautiously here, to minimise the chance of legal complaint re possible libel. We are too strapped for cash to take that risk.
I hope this helps. I appreciate you have not been on board very long. Please bear this advice in mind for the future.
Barnabas62
Purgatory Host
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Who is it that you seek? How then shall we live? How shall we sing the Lord's song in a strange land?
Posts: 21397 | From: Norfolk UK | Registered: Feb 2005
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Lilac
Shipmate
# 17979
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Posted
Anyway, I got to wondering why Alan Cresswell doesn't seem to share many people's antipathy towards nuclear power. Then the obvious occurred to me: He lives in Scotland. I heard a rumour that the Scottish Nuclear power stations were alot more successful than the English ones.
Could this be connected with cultural differences between the two countries? Scotland has different legal and educational systems. Would this make Scottish engineers more competent at complex construction projects?
Should we consider buying Scottish nuclear power stations rather than French or Japanese ones? And if Scotland decides on independence, should they guard against nuclear sabotage by setting up a Scottish intelligence service, less secretive than the English one?
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Seeking...
Posts: 62 | From: Birmingham / Coventry Area, UK | Registered: Jan 2014
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Gee D
Shipmate
# 13815
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Posted
The opposition here to nuclear power stations, and I suspect that it's the same elsewhere, is emotional rather than thought out. Nuclear weapons = bad; therefore nuclear power = bad also. And emotion, rather than thought, is how the Greens operate. But even allowing for Chernobyl, the safety record of nuclear power, including the mining of uranium, is much better than coal powered, and probably better even than that of hydro-electric stations.
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Not every Anglican in Sydney is Sydney Anglican
Posts: 7028 | From: Warrawee NSW Australia | Registered: Jun 2008
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Eutychus
From the edge
# 3081
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Posted
quote:
Originally posted by Lilac:
I heard a rumour that the Scottish Nuclear power stations were alot more successful than the English ones.
The usual standard in Purgatory is to deal in sourced assertions rather than rumours. And I'm curious to know on what basis you think nuclear power stations in Scotland were designed by Scottish designers, or built by Scottish construction firms.
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Let's remember that we are to build the Kingdom of God, not drive people away - pastor Frank Pomeroy
Posts: 17944 | From: 528491 | Registered: Jul 2002
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Lilac
Shipmate
# 17979
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Posted
I believe it's more than just a rumour, though it dates back awhile. My point is that we don't want English nuclear power stations which flop the way they did before.
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Seeking...
Posts: 62 | From: Birmingham / Coventry Area, UK | Registered: Jan 2014
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