Nuclear Paper

[woodduck]

I found this paper on the internet and was wandering if anyone could answer some of the points raied. In the paper it is said that the amount of solar energy to hit the earth is 5000 more times than what we use.  If this is the case does this mean as a minimum we would have to use 1/5000 of the earths surface to collect it assuming 100% efficency?(a very large area)
I understand that the uranium mined at Roxby Downs is mined at the same time as copper and gold so the mining cost would have to be shared over all the materials extracted, is this correct? (uranium is a byproduct)
The part about rare elements being used in the manufacture of the reactor and than not being able to be reused as they are contaminated. (msr may help this as they don't have to be as "thick" to contain the pressure in the reactor?)
Some of the people that reply to this may say that wind energy uses a lot of rare earths/ materials as well, as I understand this is not the case with all turbine designs as some use induction generators with squirrel cage type rotors or wound rotors. I have a good understanding of the limitations of wind as far as capacity factor and days of little wind when demand is high.
I am also curious what a 40MW  and 100MW electrical output reactor would cost
Thanks

www.eleceng.adelaide.edu.au/personal/dabbott/publications/PIE_abbott2011.pdf

[David B. Benson]

woodduck --- In general, it looks to me that Derek Abbot first decided that nuclear is bad and then went hunting reasons. Also, there are errors. While current fast reactors might only be 60 times more efficient in the use of actinides, in principle such could (maybe) obtain up to 142.8 times greater usage than a Gen 3+ nuclear power plant. Sodium fires are an issue only to the lay public, not specialists, and not all fast reactor designs use sodium. See
www.world-nuclear.org/info/Current-and-Future-Generation/Fast-Neutron-Reactors/
The rarer materials could, in principle, be separated out of even a radioactive core. Economics is the only issue. Such are probably not required in the latest fast reactor designs.

Cooling is an issue, but there are other alternatives which Mr. Abbot did not mention. Incidentally, solar thermal has precisely the same cooling issues as those units also use a Rankine cycle electric generator.

Solar thermal is currently much more expensive than a Gen 3+ nuclear power plant. The latter cost between US$4800--6800 per kWe depending upon the country in which it is located.

[Roger Clifton]

Instead of presenting an opinion of his own, Wood Duck wants us to read his friend's opinion piece that argues that nuclear power can not be globally expanded. Don't bother. The first sentence starts by asserting that there is "... robust debate over climate science…" So the author wants us to believe that the reality of climate change is arguable. The same sentence then goes on to assert as an unarguable fact that a certain mineral resource is running out.

There are some people in this world who want us to believe that a more important global challenge than greenhouse protection is that mineral resources are running out. Only with the rising sense of imminent disaster conflated as a shortfall can they then persuade the world that we must convert to what they tout as "renewables". But the shortfalls are imagined, whereas the damage to the greenhouse is a very real threat.

Surely it is much more urgent that we all get on the same side of climate science and convert to non-carbon sources of power. Fans of wind-and-gas and solar-and-gas are already in a position to shout out loudly, proudly and inaccurately, "wind-and-gas will eliminate all emissions of greenhouse gases!" And so on. Then we could discuss how to improve on their proposition.

I challenge you, Wood Duck, would you rather speak of "reductions" to greenhouse gas emissions, or are you game to say out loud what has the capacity to eliminate them?

[woodduck]

Mate, steadyon! I am pretty well on your side, especially with the molten salt type reactors. I just found this paper (which I don't know the author) and was wandering about some of the points he raised. I'm just an uneducated fitter and was just trying to broaden my understanding of the pro's and cons of the various options. I hope not all the people who answer people's questions are not as aggressive because it will not do the nuclear cause any good! As far as Renewables go I said that I realise there limitations (I work on a windfarm so I see it a lot.) This is probably why I am following this site.

[Roger Clifton]

Wood Duck, I for one would be interested to read your knowledge and opinions on windfarm turbines. You have already pointed out that the current generation does not yet use rare earth magnets, they are still using field coils. I suspect that if anyone knows how much solid magnets would improve the lifetimes and efficiency of those generators, you would. Let's hear from you!

(Let's forget about that anti-nuclear paper. When I saw the word "personal" in the link, while I don't see it in the first fifty hits on Google, it seemed that an axe-grinder had pressed a card in your hand, patted you on the shoulder and urged you to charge against the bayonets while he took cover. We are known to give short thrift to authors who quibble about the certainty of climate change. I'm sorry if it felt personal. )

[woodduck]

Roger- A couple of things, I never said that the current wind turbines don't use rare earth magnets, I said "as I understand this is not the case with all turbine designs as some use induction generators with squirrel cage type rotors or wound rotors." Just to make it clear there are alternatives to rare earth magnets as there are alternative to the first generation of nuclear power reactors. I mentioned this because it is a common misconception that I have read on various sites that wind turbines use a lot of rare earth magnets and I felt I was in a position to clear that up. I dare say they are more efficient otherwise they would not be used as they are more expensive, Lifetime compared to a squirrel cage generator I'm not so sure about. Remember also I have said I am just a fitter who is trying to know more about all the alternatives. I have said that I agree with most people on this site saying that nuclear is probably the answer rather than the renewable s which I have also previously said I can see as I have watched turbines doing nothing while the state is in high demand for power., Obliviously the power is coming from fossil fuels.
I don't know where exactly found this paper as I found it quite a while ago and saved the link with the intention of posting it here to clear up a few of the points raised when I had time. Chances are I followed a link on a web site somewhere(possibly this site) I thought my questions where quite straight forward and I expected they would be answered fairly simply and quickly with what I thought was a high standard of people contributing here.
Has anyone else got any input as I don't think some of my points have been answered especially about the weather rare metals used in the reactor can be recovered.
David , thanks for your reply

[David B. Benson]

woodduck --- The rarer materials can be mostly recovered. Just a question of cost.

[Roger Clifton]

Wood Duck. AFAIK, there isn't a category of elements called "rare". There are elements which are rarely traded, either because they are rarely used (such as thorium) or rarely extracted (such as hafnium), but any element can be extracted from the crust, given enough energy and ingenuity. Or as DBB has put it, cost.

Hafnium is very similar in chemistry and ionic size to zirconium, so 'most anybody who would use hafnium is able to use zirconium in its place. For the same reason, hafnium is found in solid solution with zirconium compounds everywhere. And they're cheap enough. "Silver sand" is a ordinary moulding sand of natural zirconium silicate, with the hafnium still included. The same sand is used as a cheap low-quartz blasting powder, and as middle aggregate in heavy and refractory concrete.

Unlike zirconium, hafnium is a neutron absorber, so the manufacture of zirconium cladding for long-burning nuclear fuels requires the hafnium to be removed - expensively. For the same reason, the freshly separated hafnium is used within the nuclear industry as a "neutron poison" to damp down the early burning of higher enrichment fuel.

As a consequence, the nuclear industry is a net producer of hafnium at the same time as being almost its sole consumer. The international trade is non-existent, with parcels traded privately instead. I guess you could call that "rare". But it would perpetuate ignorance to say that the future is being deprived of the stuff.


(Many of us are non-engineers. You may be interested to follow DMcLane's posts, for example.)