[Update: Confirmed] Unlimited* Powaaa! – Scientists achieve net positive nuclear fusion reaction

[CarlBar]

5 hours ago, Bitter said:

Not to pick nits but to nitpick a bit, what the UK considers a renewable is a bit loose. Burning wood pellets from Canada it considers renewable because the trees grow back and recover some of the carbon emissions... eventually. I don't know if they're taking into account the carbon of logging and shipping the pellets. Also it was found that the contracted company was logging old growth, not new growth forest so there's that too. I don't know what percentage those pellets account for but I personally can't call that renewable.

 

I got the figure from an online source showing renewables percentage by country and year as a map, i assume they used the same criteria for each couintry so in general i'd assume the wood pellets aren't counted.

 

3 hours ago, Dracarris said:

Due to its sheer complexity and many local, national regulations, there's quite a limit as to how far economy of scale applies to NPPs. As I said before, what is "of scale" for plants that cost double-digit billions per unit? 100, 1000?

 

Economies of scale is a complex subject and despite my background i am not by far the best person to explain all the nitty gritty details but i'll try to cover it as best i can.

 

The first thing is to not confuse the traditional concept of economy of scale with it's larger scale brother. Economy's of scale can really refer to two things.

 

The first is the simple mass production thing. Buy something or manufacture somthing in very large quantities and you tend to get a discount on materials supply for the very large order, and because you can defray tooling costs and transport costs, and a whole host of other costs across the larger number of units produced. Most of this either doesn't apply, or is very limited in application in projects on the scale of a building.

 

But there's a second form of economy of scale thats based on a seperate set of principles. And what all of those boil down to is that the more rarely somthing is done and the more specialised some of the knowledge is, the more expensive it gets to maintaining the capability to do somthing. Companies have to employ the appropriate specialists, and if there's not a lot of activity in the sector those people are going to be quite rare which means they tend for various reasons, (including but not limited to the workers bargaining power), to be expensive to employ. This leads into the additional factor that companies which only do a specialist type of work may go long periods with no work to do at all which means long periods where the company is surviving on it's last jobs money. And that also has the downside of encouraging companies to optimise their workflow for minimising costs to the company, even at the expense of speed and/or cost to the customer.

The same hyper specialisation factors mean that if a product has a discrete physical location, (like a building), workers may have to travel long distances and be given long term temporary accommodation, that tends to be expensive and result in higher wage demands from the workers. If the work requires this it's also not uncommon for a customer to have few options when it comes to finding someone to do the work, the lack of competition further drives down incentives for the companies to minimise cost and time taken for their customer because the customer can't go anywhere else.

On top of all that as i already noted, if somthing isn't done for long enough all those specialists retire or die and companies wanting to do the work have to figure out all the little details no one ever writes down about how to manage and otherwise carry out the day to day operations of  from scratch, which is allways a very painful, and thus expensive, process.

[leadeater]

Good old scary Google put this video on my YouTube recommended home page, was actually very interesting. 

 

 

Quote

Uranium abundance under water is about 80 thousand times that of Thorium in the Earth's crust which is also non-existent under water.

Paraphrasing a little but essentially there is no shortage and likely never will be of Uranium we just do not currently mine Uranium from our oceans as it is currently not economically viable. Over time that will change due to need and also technology advancements. 

 

Something I hadn't thought of that was mentioned around safety was that Thorium reactors need to operate at very high temperatures so if there is a problem and heating power is lost the fuel could cool too much and turn solid which would cause a lot of damage and safety issues.

 

Another interesting point was the fuel and reaction efficiency of light water reactors is only about 1% of the mined Uranium. Enrichment and processing is expensive but what I think is important is that there is still 99% remaining potential energy from removed fuel, which can be reprocessed. So there are two sources of fuel supply for light water reactors which essentially don't have concerns about long term supply, short term yes.

 

Now a big concern with Thorium reactors, current designs remove U233 (watch the video) as part of it's operation so anyone operating such a reactor has ready to use weapons grade Uranium.

 

So I think both light water and molten salt can co-exist and both should be getting built and usage expanded. One or the other may eventually get favored, usage increased proportionally higher or something else but I personally don't see any problems with fuel or safety for either.