Which nuclear accident ware worse Chernobyl or Fukushima

[OdinYggd]

Um, no. There was not a lag of "hours" between control input and reactor response - such a reactor would be impossible to operate. (And hideously unsafe even by Soviet standards.)

The lag is only a few percent of the total reactivity, but it was enough that Chernobyl buried itself in neutron absorbers while running at too low a power. Because the core was poisoned they had to pull the rods up unacceptably far to get enough reactivity to restart, and once it restarted not only was there the problem with the rod tips but the neutron absorbers also were quickly consumed by further irradiation- making the reactor rapidly become more reactive than it had been.

Your neutron flux changes almost instantly with your rod movement, but other factors such as power history, thermal mass, and rod reactivity all conspire to make several different bands of control lag varying from the half-lives of neutron absorbing isotopes that were produced by the reaction to the time it takes the core to heat up or cool down.

That kind of surprises me though that the nuclear submarines actually can throttle their reactors quickly. They'd have the same physics constraints as a power reactor, just smaller scale because they use a higher density core with highly enriched fuel. I would think that there would still be a noticeable delay between control movement and output change, since it takes a brief period of time for the steam output to rise or the turbine to accelerate.

Edited May 14, 2013 by OdinYggd

[Caldari Navy]

Livestock in Wales were still considered too radioactive for human food a few years back because it's cheaper to have radioactive lamb than to clean up all that grassland.

The radiation also turned the sheep's wool yellow... just saying

[Tura]

Fukushima was no accident the plant was about to be going from the powernet a few years after the tsunami happened. Tebco just used this event to avoid the unbuilding costs of the plant.

[ZetaX]

The radiation also turned the sheep's wool yellow... just saying

Sources please.

[KasperVld]

Please consider that conspiracy theories are forbidden content on this forum, as per forum rule 2.2f

Forum Rules.

[Jim DiGriz]

Hilarious bit of info I discovered recently through this forum or by accident was the Thorium salt nuclear reactor... They don't blow up, they are small, they were proposed around the same time as atomic energy was being developed and they're reliable. The reason everyone went for gas cooled uranium reactors was to make plutonium for .... agricultural purposes or something.

Engineering with molten salt is a bit harder than engineering with water or steam. The cost of molten salt reactors is extremely high.

[Jim DiGriz]

There are many ironies about the anti-nuclear movement. It's a continual source of amusement to me that the green movement tends to be, by and large, such an anti-nuclear force. Yeah, ignoring the single source of virtually carbon-free base load generation technique that we have is simply a great idea... It amuses me further that any kind of subsidy for wind or wave power is supporting the development of low carbon technologies while subsidies for nuclear power are apparently "market manipulation." The level of hypocrisy is astounding.

Nuclear has a negative learning curve. It keeps getting more expensive, not less, the curve is running the wrong direction. Subsidizing it is delaying the inevitable. Solar keeps getting better and cheaper (without subsidies it is much cheaper than Nuclear at this point), so subsidizing it helps accelerate the learning curve.

Energy Policy article on the French experience with the negative learning curve in Nuclear Power (which was unencumbered with issues over regulatory burden and anti-nuke hippies trying to kill it):

http://www.sciencedirect.com/science/article/pii/S0301421510003526

Nuclear energy died in the late-70s/early-80s because it was too expensive. Blaming it on the leftists (or the leftists taking credit for it), was politically useful for both sides though.

[Fractal_UK]

Nuclear has a negative learning curve. It keeps getting more expensive, not less, the curve is running the wrong direction. Subsidizing it is delaying the inevitable. Solar keeps getting better and cheaper (without subsidies it is much cheaper than Nuclear at this point), so subsidizing it helps accelerate the learning curve.

Energy Policy article on the French experience with the negative learning curve in Nuclear Power (which was unencumbered with issues over regulatory burden and anti-nuke hippies trying to kill it):

http://www.sciencedirect.com/science/article/pii/S0301421510003526

Nuclear energy died in the late-70s/early-80s because it was too expensive. Blaming it on the leftists (or the leftists taking credit for it), was politically useful for both sides though.

Nonsense, no technology has a negative learning curve. The idea that something gets more expensive by doing it more, as a general rule, is totally ridiculous and illogical. It is possible in specific circumstances, e.g. diminshing returns from the last group of power plants in a predominantly nuclear grid that have to be restricted to load following duties. Nuclear is not an ideal power source for these load following duties, it's great for baseload. These are specific circumstances, creating a particular condition, in a particular country and it is dishonest to suggest that such a thing applies universally.

Additionally, nuclear power has suffered from a lack of investment during the 80 and 90s which has meant that a lot of the positive curving curve that could have been maintained wasn't and construction costs have leapt right back as a result of lost expertise and experience at dealing with these power plants have been lost.

As for nuclear power being expensive, that's nonsense. Almost every study done on the relative costs of power from different sources suggests that nuclear power is currently quite modestly priced but often more expensive than most fossil fuels, yet they also, in general, show it could be cheapest option or second only to gas in this respect and is utterly superior to all renewable generation methods (except maybe onshore wind, which provides incredibly unreliable power and every KW needs, at worst, 0.9KW of backup).

Regardless, France as has some of the cheapest electricity in Europe as well as amongst the least carbon intensive energy grids, so suggesting the French have suffered for their pro-nuclear apprach is totally absurd.

[ZetaX]

Fractal_UK, do you have a good source for the actual costs¿ Most things I can find are not fully considering the possible costs of storage, decomission and desasters (yes, as long as the possibility exists, these costs have to count; as have the global warming costs of carbon based ones, or the costs of solar panels' creation causing chemical waste), or are just considering the part that is not shouldered by the state.

[Fractal_UK]

Fractal_UK, do you have a good source for the actual costs¿ Most things I can find are not fully considering the possible costs of storage, decomission and desasters (yes, as long as the possibility exists, these costs have to count; as have the global warming costs of carbon based ones, or the costs of solar panels' creation causing chemical waste), or are just considering the part that is not shouldered by the state.

There are different assumptions made in different countries with regard to things like decomissioning costs and disaster funding, for example in the US, there is a liability limit for nuclear power plants and the state will cover the rest beyond this limit; the Price–Anderson Nuclear Industries Indemnity Act is what it is called. The costs are estimated to be something like $600k to $2.3million per reactor per year, which obviously doesn't make a vast difference to the economics of a reactor though.

This is a fairly recent estimate of comparitive costs of electricity generation for the UK https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/223940/DECC_Electricity_Generation_Costs_for_publication_-_24_07_13.pdf. I did have a really good study done by the Department of Energy and Climate Change (DECC) that contained a breakdown of all the different costs for different components of each power plant design but I'm struggling to find it right now, I might have to look for some links where I've posted it previously. That one is better because you can see the breakdown based on construction costs, fuel costs, decomissioning costs, etc. I'll try and get back you with that one soon.

There's a decent enough page on wikipedia about the Relative cost of electricity generated by different sources which uses a wide variety of sources and tells you something about the stated assumptions used in each.

[Nibb31]

Regardless, France as has some of the cheapest electricity in Europe as well as amongst the least carbon intensive energy grids, so suggesting the French have suffered for their pro-nuclear apprach is totally absurd.

France's electricity is cheap because it only takes into account the operational cost of producing electricity. Most of the R&D that went into the construction was paid for by the French government. The cost of securing and monitoring nuclear sites is paid for by the government, and so is the cost of storing and processing used fuel. But the biggest expense that is not factored into the operational cost is the decommissioning of nuclear power plants. Most of France's nuclear power plants were built in the 80's and will be reaching their end of life during the 2020's and the total decommissioning cost for the 58 reactors has been estimated at 750 billion euros.

[Fractal_UK]

France's electricity is cheap because it only takes into account the operational cost of producing electricity. Most of the R&D that went into the construction was paid for by the French government. The cost of securing and monitoring nuclear sites is paid for by the government, and so is the cost of storing and processing used fuel. But the biggest expense that is not factored into the operational cost is the decommissioning of nuclear power plants. Most of France's nuclear power plants were built in the 80's and will be reaching their end of life during the 2020's and the total decommissioning cost for the 58 reactors has been estimated at 750 billion euros.

If I just accept that estimate without doing any investigation, we're looking at ~13 billion euros per reactor, which is probably 1.5x or 2x the cost of building the reactor. So capital costs are maybe 500million euros per year over a 40 year plant lifetime. A 1.6GW power plant produces electricity worth ~2 billion euros per year at French electricity prices so the capital costs (which are the predominant cost of a nuclear reactor) are accounted for 4x over in reactor revenue. The reactors are paying for their decomissioning and far more besides.

[Jim DiGriz]

France's electricity is cheap because it only takes into account the operational cost of producing electricity. Most of the R&D that went into the construction was paid for by the French government. The cost of securing and monitoring nuclear sites is paid for by the government, and so is the cost of storing and processing used fuel. But the biggest expense that is not factored into the operational cost is the decommissioning of nuclear power plants. Most of France's nuclear power plants were built in the 80's and will be reaching their end of life during the 2020's and the total decommissioning cost for the 58 reactors has been estimated at 750 billion euros.

Scaling up 58 reactors in France to the global economy would also spike uranium prices, which is mined and is going to suffer from a "peak uranium" issue since there's a very finite amount of easily accessible uranium.

[Jim DiGriz]

Nonsense, no technology has a negative learning curve. The idea that something gets more expensive by doing it more, as a general rule, is totally ridiculous and illogical. It is possible in specific circumstances, e.g. diminshing returns from the last group of power plants in a predominantly nuclear grid that have to be restricted to load following duties. Nuclear is not an ideal power source for these load following duties, it's great for baseload. These are specific circumstances, creating a particular condition, in a particular country and it is dishonest to suggest that such a thing applies universally.

Additionally, nuclear power has suffered from a lack of investment during the 80 and 90s which has meant that a lot of the positive curving curve that could have been maintained wasn't and construction costs have leapt right back as a result of lost expertise and experience at dealing with these power plants have been lost.

As for nuclear power being expensive, that's nonsense. Almost every study done on the relative costs of power from different sources suggests that nuclear power is currently quite modestly priced but often more expensive than most fossil fuels, yet they also, in general, show it could be cheapest option or second only to gas in this respect and is utterly superior to all renewable generation methods (except maybe onshore wind, which provides incredibly unreliable power and every KW needs, at worst, 0.9KW of backup).

Regardless, France as has some of the cheapest electricity in Europe as well as amongst the least carbon intensive energy grids, so suggesting the French have suffered for their pro-nuclear apprach is totally absurd.

I see negative learning curves all the time. The startup that can produce a website in weeks turns into the corporation that takes months to produce the same result.

[ZetaX]

There are different assumptions made in different countries with regard to things like decomissioning costs and disaster funding, for example in the US, there is a liability limit for nuclear power plants and the state will cover the rest beyond this limit; the Price–Anderson Nuclear Industries Indemnity Act is what it is called. The costs are estimated to be something like $600k to $2.3million per reactor per year, which obviously doesn't make a vast difference to the economics of a reactor though.

This is a fairly recent estimate of comparitive costs of electricity generation for the UK https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/223940/DECC_Electricity_Generation_Costs_for_publication_-_24_07_13.pdf. I did have a really good study done by the Department of Energy and Climate Change (DECC) that contained a breakdown of all the different costs for different components of each power plant design but I'm struggling to find it right now, I might have to look for some links where I've posted it previously. That one is better because you can see the breakdown based on construction costs, fuel costs, decomissioning costs, etc. I'll try and get back you with that one soon.

You can't use some state-given limits, as this also is a subtle subsidation. If it causes those costs, it causes them, and it's not relevant if we pay it on the electric bill or by taxes (or by loosing our property).

But the link seems not to work for me.

[Fractal_UK]

Scaling up 58 reactors in France to the global economy would also spike uranium prices, which is mined and is going to suffer from a "peak uranium" issue since there's a very finite amount of easily accessible uranium.

Straight out of the anti-nuclear book of nonsense once again. Uranium availability is not an issue. Sea water extraction of Uranium can be done at only 10x the cost of current commercial deposits and this has purely been demonstrated as an academic exercise. Note that a 10x increase in the costs of fuel accounts for a maybe 2% increase in the operating cost of the reactor's lifetime costs. There are sufficient deposits on land to maintain production at slightly increased costs for thousands of years and sea water production for hundreds of thousands. Uranium availability is not and never will be an issue.

Next please.

Apologies about the link https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/223940/DECC_Electricity_Generation_Costs_for_publication_-_24_07_13.pdf

[magnemoe]

I see negative learning curves all the time. The startup that can produce a website in weeks turns into the corporation that takes months to produce the same result.

This is because of bureaucracy in the company. All decisions has to run through multiple layers.

Add that the designers are not in an hurry as they get paid anyway in the large company.

This does not scale up.

[Seret]

You can't even compare the two. Chernobyl was much, much worse. They're was a full meltdown and containment breach, with a significant release of radiation and a large contaminated area. Fukushima was small fry. The contaminated zone is small, people are already able to return to much of it, and the health effects are so small they won't even be detectable in the statistics.

[kiwi1960]

Fukushima was no accident the plant was about to be going from the powernet a few years after the tsunami happened. Tebco just used this event to avoid the unbuilding costs of the plant.

Seriously, so they caused a Tsunami to end up paying billions more for the clean up?

You can't even compare the two. Chernobyl was much, much worse. They're was a full meltdown and containment breach, with a significant release of radiation and a large contaminated area. Fukushima was small fry. The contaminated zone is small, people are already able to return to much of it, and the health effects are so small they won't even be detectable in the statistics.

The accident in Russia has been contained. Fukishima is still leaking radioactive coolant in to the pacific. Its spread from Japan to virtually to the USA. Contaminated fish are being caught everywhere.

There is no sign that the leak will be contained any time soon. It is THE worst Nuclear accident EVER, and will continue to be for years.

Edited November 30, 2013 by kiwi1960
added to

[lajoswinkler]

The accident in Russia has been contained. Fukishima is still leaking radioactive coolant in to the pacific. Its spread from Japan to virtually to the USA. Contaminated fish are being caught everywhere.

There is no sign that the leak will be contained any time soon. It is THE worst Nuclear accident EVER, and will continue to be for years.

You should learn about dosages and dillutions.

It is not the worst accident ever. Chernobyl was.

[ZetaX]

And to claim it is spreading to the USA can only be called fearmongering. Nuclear accidents are bad, but not at a world threatening level.

[rkman]

To early to tell.

^This

fukushima was

Fukushima is not over yet.

[Psycix]

As bad as they were, they are not as bad as the public thinks they are. Radiophobia prevents mankind from tapping into one of the most powerful clean energy sources.

[rkman]

As bad as they were, they are not as bad as the public thinks they are. Radiophobia prevents mankind from tapping into one of the most powerful clean energy sources.

Or so the nuclear industry keeps telling us.

[Kryten]

It is not the worst accident ever. Chernobyl was.

And it's not even second-why does everybody always forget Kyshtym?