Why Climate Change Won't Matter in 20 Years

[Reefmagnet]

Originally Posted by Muckle Flugga

Well… with great respect (and I mean that) this view and that of reefmagnet and some others is seriously out of date with regard to the potential of nuclear power. Fukushima was a terrible and stupid incident, but it was so precisely because its reactors were hopelessly out of date, rod and core style set ups. Suggesting that all nuclear power is massively expensive and massively dangerous based upon the likes of Fukushima is like saying all air travel is horrifically dangerous and tenuous based on the Hindenburg disaster. Fukushima was comissioned in 1970 to a design dating from the 1950s.

Reactors can be made very small, and absolutely failsafe. Fukushima et all occurred because the control rods vs fuel rods in the core idea allows for rods to overheat, bend, jam, and come together in a runaway post critical reaction, mediated only by a failure of the cooling systems. This is a really stupid set up. Pebble bed reactors have "pebbles", not rods, and do not rely on control rods to slow the reaction down, nor cooling systems. The fuel is contained within many layers of extremely high temperature resistant ceramics, such that no matter what happens to the reactor core in terms of "accident" etc. the fuel pellets cannot get closer to one another, making the system intrinsically failsafe and totally independent of the likes of Fukushimas (and Chernobyls) dreadfully tenuous reliance on the mobility of fuel rods and the functioning of massive cooling systems. It is also (and partly for this reason) far cheaper to build and run. Such systems can be used to electrolise seawater to produce hydrogen (and oxygen), providing unlimited fuel for hydrogen fuel cell powerplants, vehicles, etc. whose only by product is water, as the reaction on the return side catalyses hydrogen and oxygen into H20, producing electrical energy as part of the process.

Such reactors can be modular, down to the size of small containers.

http://web.mit.edu/pebble-bed/papers...r%20Energy.pdf

Small Nuclear Power Reactors.

Whilst all very good in theory, history tells us that if man makes it, it can fail. There is no such thing as an absolute guarantee of safety.

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[Muckle Flugga]

Originally Posted by Reefmagnet

Whilst all very good in theory, history tells us that if man makes it, it can fail. There is no such thing as an absolute guarantee of safety.

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Well… yes. But in practice things can and do become much safer with technology and time. For example high rise structures. I am not saying it would be impossible that something could go wrong, but the two main factors militating against that likelihood in the case of small scale pebble bed reactors are:

1. The intrinsically stable nature of each pebble means that you would have to have pretty much all of them completely pulverised and then the ceramic detritus removed to cause anything approaching a post critical runaway or "meltdown".

2. The comparatively small amount of nuclear material in each unit means that even if all of it did somehow melt together it would not cause the kind of catastrophic explosive meltdown seen in old style rod and core reactors.

So yes, ok, but then an undetected meteorite may suddenly end all human life on earth. The point is these reactors are massively, intrinsically safer than the likes of Fukushima and literally cannot cause the kind of incident seen there or at Chernobyl, even in principle if we tried to make it happen.

You can make a very small but functioning reactor out of a bunch of smoke detectors, if you want, you know? (Really not recommended and I believe illegal in most jurisdictions). The point is most people have no idea that pretty much every smoke detector is fairly strongly radioactive. Don't put them under your pillow at night!

[Mike OReilly]

Originally Posted by Muckle Flugga

Well… with great respect (and I mean that) this view and that of reefmagnet and some others is seriously out of date with regard to the potential of nuclear power. Fukushima was a terrible and stupid incident, but it was so precisely because its reactors were hopelessly out of date, rod and core style set ups. Suggesting that all nuclear power is massively expensive and massively dangerous based upon the likes of Fukushima is like saying all air travel is horrifically dangerous and tenuous based on the Hindenburg disaster. Fukushima was comissioned in 1970 to a design dating from the 1950s.

Reactors can be made very small, and absolutely failsafe. ...

MF, I think you missed the main point of my post. I don't think we disagree much, except to say nothing is absolutely failsafe.

It's clear fission reactors can be made extremely safe, and as technology improves, so can cost. I still think it foolish to locate them in active earthquake zones, but I'm happy to hear newer designs are even safer and cheaper. All the more reason to support their expanded use.


Why go fast, when you can go slow

[Muckle Flugga]

Originally Posted by Mike OReilly

MF, I think you missed the main point of my post. I don't think we disagree much, except to say nothing is absolutely failsafe.

It's clear fission reactors can be made extremely safe, and as technology improves, so can cost. I still think it foolish to locate them in active earthquake zones, but I'm happy to hear newer designs are even safer and cheaper. All the more reason to support their expanded use.


Why go fast, when you can go slow

Yes I probably did, sorry. And no I don't think we do disagree on much mate, in any forum I have read your well considered posts at any rate

I also agree that most of the problems with nuclear power are related to superstition (fundamental misunderstanding of the nature of radioactive material and radiation in general, with a tendency to view it as somehow "unnatural" and human made, rather than ubiquitous, as it in fact is: perhaps the nuclear industry should fund mass distribution of geiger counters for fun in the home and school? ) and politics interdependently.

[newhaul]

I have a minor issue with the categorical grouping of Fukushima and Chernobyl they are very different reactors. Chernobyl was a lwcr breader reactor who's primary purpose was to produce weapons grade plutonium and Fukushima was just an old design of civilian power production unit that needed many safety upgrades.

[Muckle Flugga]

Originally Posted by newhaul

I have a minor issue with the categorical grouping of Fukushima and Chernobyl they are very different reactors. Chernobyl was a lwcr breader reactor who's primary purpose was to produce weapons grade plutonium and Fukushima was just an old design of civilian power production unit that needed many safety upgrades.

Sure thing. I agree. I bracketed them together mainly on the basis that they were dependent upon mechanical shielding (moving control rods) and cooling mechanisms which were intrinsically failure prone, and involved large scale reactor cores capable of catastrophic meltdown and explosion.

[socaldmax]

Originally Posted by Muckle Flugga

Well… yes. But in practice things can and do become much safer with technology and time. For example high rise structures. I am not saying it would be impossible that something could go wrong, but the two main factors militating against that likelihood in the case of small scale pebble bed reactors are:

1. The intrinsically stable nature of each pebble means that you would have to have pretty much all of them completely pulverised and then the ceramic detritus removed to cause anything approaching a post critical runaway or "meltdown".

2. The comparatively small amount of nuclear material in each unit means that even if all of it did somehow melt together it would not cause the kind of catastrophic explosive meltdown seen in old style rod and core reactors.

So yes, ok, but then an undetected meteorite may suddenly end all human life on earth. The point is these reactors are massively, intrinsically safer than the likes of Fukushima and literally cannot cause the kind of incident seen there or at Chernobyl, even in principle if we tried to make it happen.

You can make a very small but functioning reactor out of a bunch of smoke detectors, if you want, you know? (Really not recommended and I believe illegal in most jurisdictions). The point is most people have no idea that pretty much every smoke detector is fairly strongly radioactive. Don't put them under your pillow at night!

Just imagine how much it would cost just for batteries for all of those smoke detectors. Hardly seems worth it.

[socaldmax]

Originally Posted by Mike OReilly

MF, I think you missed the main point of my post. I don't think we disagree much, except to say nothing is absolutely failsafe.

It's clear fission reactors can be made extremely safe, and as technology improves, so can cost. I still think it foolish to locate them in active earthquake zones, but I'm happy to hear newer designs are even safer and cheaper. All the more reason to support their expanded use.


Why go fast, when you can go slow

Mike, you have a great point. For some odd reason, they seem to make it a habit of building reactors on top of fault zones. They recently decommissioned San Onofre, which was also near a fault line.

[Muckle Flugga]

Originally Posted by socaldmax

Just imagine how much it would cost just for batteries for all of those smoke detectors. Hardly seems worth it.

The point was purely academic, though for the record batteries are only for the operation of the alarm and detector function. You don't need batteries to keep the radioactivity going! That is merely a physical state of a by product of the nuclear industry, americium:

Smoke Detectors and Americium

[newhaul]

There seems to be a trend in building them that way but there Also seems to be a trend in human history that they seem to build major population centers near fault zones as well . Want to read something Scarry about nuke power check out the wppss plants that thankfully never came online.

[Reefmagnet]

Just did a quick read up on pebble reactors. Whilst it does appear they are safer, although not absolutely safe, the volume of waste produced is considerably more than conventional reactors. Since this is the numero uno issue with nuclear generation, and the same greenie tree hungers wanting us to stop using oil, gas and coal are most certainly not going to allow us to drop this waste to the bottom of the Marianas Trench, even if sooner or later it will be subducted, I can't see this technology becoming widespread in use.

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[socaldmax]

Originally Posted by Muckle Flugga

The point was purely academic, though for the record batteries are only for the operation of the alarm and detector function. You don't need batteries to keep the radioactivity going! That is merely a physical state of a by product of the nuclear industry, americium:

Smoke Detectors and Americium

I was joking.

[StuM]

Originally Posted by socaldmax

Mike, you have a great point. For some odd reason, they seem to make it a habit of building reactors on top of fault zones. They recently decommissioned San Onofre, which was also near a fault line.

That's because man has historically built habitation around fault zones - for many good reasons, I might add.

[Muckle Flugga]

Originally Posted by Reefmagnet

Just did a quick read up on pebble reactors. Whilst it does appear they are safer, although not absolutely safe, the volume of waste produced is considerably more than conventional reactors. Since this is the numero uno issue with nuclear generation, and the same greenie tree hungers wanting us to stop using oil, gas and coal are most certainly not going to allow us to drop this waste to the bottom of the Marianas Trench, even if sooner or later it will be subducted, I can't see this technology becoming widespread in use.

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Yes this is true. However Mike's earlier post regarding waste disposal is apt. There are plenty of massively geostable regions, such as the Canadian Shield and other areas towards the centres of cratons where burial would present no issues whatsoever, other than to the superstitiously committed naturopaths. There are indeed plenty of those, however, to be sure.

I don't think that PBRs are the be all and end all, but they do represent an entirely realistic and far safer and more "useable" form of nuclear energy, to be added to the growing array of other forms of energy generation. Perhaps Transmitterdan will pull the ultimate genie out of his sailing hat and provide us with sustainable, containable fusion… though that would be quite some genie indeed.

However I remain concerned and rather irritated by what I perceive as a massive overfocus on climate change as a "problem", distracting us from the far more pressing problems of direct mechanical damage to the biosphere, which lately has been accellerating at an alarming rate. Energy diversification is a boon, and a good by product of the current panic, but I really can't see how the consequences of increased CO2 are worse than the consequences of annihilation of the majority of the wild biomass in the oceans, or the destruction of rainforests for palm oil and other agriculture.

[SailOar]

Muckle Flugga,
These are all important question, each worthy of extended discussions. I'll take a crack at 4a in this post, and 4b in my next post.

As an aside, the website SkepticalScience.com has a huge list of Q&A pages which address many AGW topics.

Originally Posted by Muckle Flugga

… meanwhile I would really honestly love for the various gurus here to address the following questions, raised earlier in the thread but neglected for more fashionable lines of battle in this area:

1. How is the enormous expenditure of political, social, intellectual and other capital in this area, while vast swathes of the earth are simply burned and eaten, but the latter problems not addressed, not "fiddling while Rome is burning"?

2. Given that Climate Change is happening, as all agree, and given it is in fact inevitable, what is being done simply to accomodate the change, rather than attempt to prevent it, Canute style?

3. What benefits vs. debits may we reasonably expect from this change?

4. Given the fact that the overwhelming majority of the history of life on earth, even since the Cambrian, has featured atmospheric carbon dioxide far beyond present levels, why is this fact almost never regarded in any discussion?

The short answer is that at those times when CO2 levels were enormously higher, solar output was lower, which tended to balance out temperatures.

ETA [Current CO2 levels are ~400ppm. In the distant past CO2 levels may have been as high as 5,000 ppm]

Do high levels of CO2 in the past contradict the warming effect of CO2? | Skeptical Science

Climate Myth...CO2 was higher in the past

"The killer proof that CO2 does not drive climate is to be found during the Ordovician- Silurian and the Jurassic-Cretaceous periods when CO2 levels were greater than 4000 ppmv (parts per million by volume) and about 2000 ppmv respectively. If the IPCC theory is correct there should have been runaway greenhouse induced global warming during these periods but instead there was glaciation."
(The Lavoisier Group)

What the science says...

Over the Earth's history, there are times where atmospheric CO2 is higher than current levels. Intriguingly, the planet experienced widespread regions of glaciation during some of those periods. Does this contradict the warming effect of CO2? No, for one simple reason. CO2 is not the only driver of climate. To understand past climate, we need to include other forcings that drive climate. To do this, one study pieced together 490 proxy records to reconstruct CO2 levels over the last 540 million years (Royer 2006). This period is known as the Phanerozoic eon.


Figure 1: Atmospheric CO2 through the Phanerozoic.
Dashed line shows predictions of the GEOCARB carbon cycle model with grey shading representing uncertainty range.
Solid line shows smoothed representation of the proxy record (Royer 2006).

Atmospheric CO2 levels have reached spectacular values in the deep past, possibly topping over 5000 ppm in the late Ordovician around 440 million years ago. However, solar activity also falls as you go further back. In the early Phanerozoic, solar output was about 4% less than current levels. The combined net effect from CO2 and solar variations are shown in Figure 2. Periods of geographically widespread ice are indicated by shaded areas.


Figure 2: Combined radiative forcing from CO2 and sun through the Phanerozoic.
Values are expressed relative to pre-industrial conditions (CO2 = 280 ppm; solar luminosity = 342 W/m2).
The dark shaded bands correspond to periods with strong evidence for geographically widespread ice.

Periods of low CO2 coincide with periods of geographically widespread ice (with one notable exception, discussed below). This leads to the concept of the CO2-ice threshold - the CO2 level required to initiate a glaciation. When the sun is less active, the CO2-ice threshold is much higher. For example, while the CO2-ice threshold for present-day Earth is estimated to be 500 ppm, the equivalent threshold during the Late Ordovician (450 million years ago) is 3000 ppm.

However, until recently, CO2 levels during the late Ordovician were thought to be much greater than 3000 ppm which was problematic as the Earth experienced glacial conditions at this time. The CO2 data covering the late Ordovician is sparse with one data point in the CO2 proxy record close to this period - it has a value of 5600 ppm. Given that solar output was around 4% lower than current levels, CO2 would need to fall to 3000 ppm to permit glacial conditions. Could CO2 levels have fallen this far? Given the low temporal resolution of the CO2 record, the data was not conclusive.

Research examining strontium isotopes in the sediment record shed more light on this question (Young 2009). Rock weathering removes CO2 from the atmosphere. The process also produces a particular isotope of strontium, washed down to the oceans via rivers. The ratio of strontium isotopes in sediment layers can be used to construct a proxy record of continental weathering activity. The strontium record shows that around the middle Ordovician, weatherability increased leading to an increased consumption of CO2. However, this was balanced by increased volcanic outgassing adding CO2 to the atmosphere. Around 446 million years ago, volcanic activity dropped while rock weathering remained high. This caused CO2 levels to fall below 3000 ppm, initiating cooling. It turns out falling CO2 levels was the cause of late Ordovician glaciation.

So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now. What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008).

If climate scientists were claiming CO2 was the only driver of climate, then high CO2 during glacial periods would be problematic. But any climate scientist will tell you CO2 is not the only driver of climate. Climatologist Dana Royer says it best: "the geologic record contains a treasure trove of 'alternative Earths' that allow scientists to study how the various components of the Earth system respond to a range of climatic forcings." Past periods of higher CO2 do not contradict the notion that CO2 warms global temperatures. On the contrary, they confirm the close coupling between CO2 and climate.