Energy From Thorium Discussion Forum

It is currently Jun 20, 2018 9:33 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 55 posts ]  Go to page Previous  1, 2, 3, 4  Next
Author Message
 Post subject: Re: Economising Uranium
PostPosted: Aug 04, 2014 6:00 am 
Offline

Joined: Dec 16, 2011 7:27 am
Posts: 262
I don't see supply of uranium being a bottleneck, known reserves worldwide are over 5,000,000 tons and an increase in demand which would naturally follow an increase in activation of many new reactors would also drive an increase of exploration. By the time terrestrial supplies became depleted I'd be very surprised if seawater extraction of uranium hadn't reached a level of development that was competitive in the new market.

http://www.world-nuclear.org/info/Nucle ... f-Uranium/


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 1:02 am 
Offline

Joined: Apr 19, 2008 1:06 am
Posts: 2238
Due to international politics, supply of uranium will remain a subject of perception. China is scrambling for supply of uranium in a market of apparent plenty. Supply of uranium from Australia to India remains a matter of negotiation and conjecture. Using uranium in fast reactors in a breeder mode will make mining irrelevant for some. There is resistance to uranium mining at many places.
It is therefore necessary to have a plan of fissile economy like the Indian three-stage plan. It has to be based on uranium or thorium breeders.
Thorium breeders could be even thermal.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 8:58 am 
Offline

Joined: Dec 16, 2011 7:27 am
Posts: 262
Being able to breed fuel from U-238 and thorium would completely change the supply picture.

I don't see the current state with energy production remaining stable for much longer, there's already a lot of pressure to divest from fossil fuels due to ecological issues, the Tar Sands and associated pipelines and rail shipments being a prime example.

http://www.cbc.ca/news/politics/enbridg ... -1.1327268

http://en.wikipedia.org/wiki/Lac-M%C3%A ... derailment

Expanding uranium and thorium exploration and mining is only going to have a small fraction of the impact of current energy development here in Canada and that probably includes fracking for gas. As would the building and operation of a relatively large amount of nuclear power generation stations.

http://thetyee.ca/News/2014/08/02/Minis ... -Comments/

The only sane approach is to switch to nuclear power for large scale generation of electricity, something that will create intense pressure to develop all potential commercial sources of fertile and fissile material.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 9:33 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5060
Actually the amount of high energy return uranium in the earth crust should be around 1 trillion tonnes.

Quote:
If we assume that the energy cost of extraction scales inversely with concentration and employ the Rossing experience as a benchmark, ore concentrations as low as 0.001% (10 ppm) provide an energy gain of 16. This also (and very unrealistically) assumes no further progress in mining technology or efficiency improvements in Nuclear Power operations over the course of hundreds of years. As shown here there is an estimated 1 trillion tonnes of Uranium at concentrations of 10 ppm or higher within the Earth's crust.


http://nuclearinfo.net/Nuclearpower/The ... clearPower

Currently U demand is around 70 kton/year. If this were to increase greatly because we build many converter reactors, say to 1 million tonnes/year, the terrestrial supplies would last 1 million years.

The ocean U supply would last forever because U is brought in by rivers and, more importantly, it is redissolved (chem. equilibrium) from the ocean floor and sediment. So the seawater supply would last forever as long as the extraction rate is not more than a few million tonnes per year.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 11:30 am 
Offline

Joined: Dec 16, 2011 7:27 am
Posts: 262
Cyril R wrote:
The ocean U supply would last forever because U is brought in by rivers and, more importantly, it is redissolved (chem. equilibrium) from the ocean floor and sediment. So the seawater supply would last forever as long as the extraction rate is not more than a few million tonnes per year.


From what I recall it would take about 100,000 years to bring the oceans into a chemical equilibrium at current rates of uranium flow into the ocean from erosion and transport - if you started with uranium free seawater - which is about 32,000 tons a year. Basically in combination with thorium, in human terms the supply of fertile/fissionable material is unlimited.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 12:37 pm 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5060
Do you have a source for this doug?


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 1:35 pm 
Offline

Joined: Dec 16, 2011 7:27 am
Posts: 262
Cyril R wrote:
Do you have a source for this doug?


Sorry, I don't, I've seen it in a number of articles and books on the subject. I'll look around and see if I can find the specific article on the chemical equilibrium of uranium in seawater.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 1:44 pm 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5060
well the 100k year makes no sense to me. Ocean circulation is a 1000-2000 year time constant affair. Mixing is pretty good when you take a small multiple of that. The ocean floor is enormous, the amount of sediment and rock surface area touching the ocean/sea water is orders of magnitude larger still. All that sediment and rock has many times higher U concentration than sea water. My guess is, if you extract all the 4 billion tonnes U in the sea all at once (magically, for sake of argument), it will be back to >2 billion tonnes in less than 10 ocean circulation cycles. Just wildly guestimating here but its pretty likely that the equilibrium will be restored at rates well in excess of 1 million tonnes/year.

One advantage with global warming, perhaps: ocean acidification means more uranium dissolving in :twisted: :twisted:


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 4:21 pm 
Offline

Joined: Dec 16, 2011 7:27 am
Posts: 262
Cyril R wrote:
well the 100k year makes no sense to me. Ocean circulation is a 1000-2000 year time constant affair. Mixing is pretty good when you take a small multiple of that. The ocean floor is enormous, the amount of sediment and rock surface area touching the ocean/sea water is orders of magnitude larger still. All that sediment and rock has many times higher U concentration than sea water. My guess is, if you extract all the 4 billion tonnes U in the sea all at once (magically, for sake of argument), it will be back to >2 billion tonnes in less than 10 ocean circulation cycles. Just wildly guestimating here but its pretty likely that the equilibrium will be restored at rates well in excess of 1 million tonnes/year.

One advantage with global warming, perhaps: ocean acidification means more uranium dissolving in :twisted: :twisted:


True, without uranium saturation of seawater, a lot of the uranium already deposited on the seafloor would be dissolved again. I think the paper assumed starting from zero, I just read it once, it may have been a calculation of how fast the early seas became populated with uranium. It first took about 100,000 years to reach equilibrium and there is a constant inflow of new uranium from terrestrial erosion and water flow back into the ocean as part of the hydrological cycle, about 32,000 tons a year. So at the same time we were pulling uranium from the ocean, natural cycles would be replenishing it.

As we begin to move onto the thorium fuel cycle and build fast reactors, the demand for uranium would also reach some sort of equilibrium meaning we could be taking not much more than the ocean uranium replenishment rate making it essentially a limitless energy resource.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 5:25 pm 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5060
Quote:
As we begin to move onto the thorium fuel cycle and build fast reactors, the demand for uranium would also reach some sort of equilibrium meaning we could be taking not much more than the ocean uranium replenishment rate making it essentially a limitless energy resource.


Very true. Projecting more than a million ton U/year or so is just silly. If such a large increase of uranium usage is achieved, it means the world is pro nuclear and we will quickly transition to Gen IV reactors, DMSRs, breeders and what have you. Whereas if the world stays paranoid about nuclear, so that we won't have Gen IV, DMSRs, and breeders, then we won't get a large increase in LWRs in the first place.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 05, 2014 6:48 pm 
Offline

Joined: Dec 16, 2011 7:27 am
Posts: 262
Cyril R wrote:
Very true. Projecting more than a million ton U/year or so is just silly. If such a large increase of uranium usage is achieved, it means the world is pro nuclear and we will quickly transition to Gen IV reactors, DMSRs, breeders and what have you. Whereas if the world stays paranoid about nuclear, so that we won't have Gen IV, DMSRs, and breeders, then we won't get a large increase in LWRs in the first place.


Depending on what happens with advanced design reactors in Europe, China, India and a few other places, the long delayed nuclear power revolution may finally kick off soon. I do think that the era of LWRs is largely over, which very likely means a much more efficient use of uranium and thorium resources.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 06, 2014 1:04 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5060
DougC wrote:
Cyril R wrote:
Very true. Projecting more than a million ton U/year or so is just silly. If such a large increase of uranium usage is achieved, it means the world is pro nuclear and we will quickly transition to Gen IV reactors, DMSRs, breeders and what have you. Whereas if the world stays paranoid about nuclear, so that we won't have Gen IV, DMSRs, and breeders, then we won't get a large increase in LWRs in the first place.


Depending on what happens with advanced design reactors in Europe, China, India and a few other places, the long delayed nuclear power revolution may finally kick off soon. I do think that the era of LWRs is largely over, which very likely means a much more efficient use of uranium and thorium resources.


It may be largely over, but I hope not. LWRs are the best hope of reducing coal usage in my lifetime. In the interest of my lungs and veins, and everyone else alive right now, that means best hopes for an order of magnitude increase in LWRs. Higher temp reactors are the best hope for future generations.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 06, 2014 4:19 am 
Offline

Joined: Apr 19, 2008 1:06 am
Posts: 2238
Once through system of nuclear fuel and LWR was perhaps the suitable system for starting with the nuclear power. More of mining uranium or fossil fuels to meet increased energy requirement may not be so. Gen IV nuclear has been discussed but only Russia, China and India are continuing with fast reactors which can fit in with Gen IV. Uranium and thorium breeders which can produce enough fissile to effectively use the fertile isotopes as fuel, are the way to sustainable energy production. Used thermal reactor fuel is the fuel stock for the future.
What now needs to be done besides the breeders is advanced reprocessing to produce nuclear fuel to compete with enriched uranium and fossil fuels, which, except for the gas at some places, are getting costlier. Volatility of Chloride/fluorides needs a closer look.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 06, 2014 11:00 am 
Offline

Joined: Jul 14, 2008 3:12 pm
Posts: 5060
jagdish wrote:
Once through system of nuclear fuel and LWR was perhaps the suitable system for starting with the nuclear power. More of mining uranium or fossil fuels to meet increased energy requirement may not be so. Gen IV nuclear has been discussed but only Russia, China and India are continuing with fast reactors which can fit in with Gen IV. Uranium and thorium breeders which can produce enough fissile to effectively use the fertile isotopes as fuel, are the way to sustainable energy production. Used thermal reactor fuel is the fuel stock for the future.
What now needs to be done besides the breeders is advanced reprocessing to produce nuclear fuel to compete with enriched uranium and fossil fuels, which, except for the gas at some places, are getting costlier. Volatility of Chloride/fluorides needs a closer look.


You are operating under the assumption of choice with your recurring propaganda and preaching to the choir. Choice is a luxury we don't have. LWRs is what we have today. Unless regulatory and business environment changes rapidly, and simultaneously some Rickover the Second comes along, nuclear product development cycle is a long term strategic thing. It takes 40 years to develop a simplified LWR to the point of multi GWe level market acceptance (AP1000). If you're lucky and attritious that is, and have strong leadership (ESBWR failed here).

With good effort and benign environment we could be talking prototype new reactor in 10 years, then big commercial in another 5 years. Then another 15 years to the tens of GWe level, then another 20 to the TWe level.

It is not either or. We should be building LWRs as if we had no other option, while we develop next gen reactors as if LWRs don't exist.


Top
 Profile  
 
 Post subject: Re: Economising Uranium
PostPosted: Aug 06, 2014 11:12 am 
Offline

Joined: Dec 16, 2011 7:27 am
Posts: 262
Cyril R wrote:
It may be largely over, but I hope not. LWRs are the best hope of reducing coal usage in my lifetime. In the interest of my lungs and veins, and everyone else alive right now, that means best hopes for an order of magnitude increase in LWRs. Higher temp reactors are the best hope for future generations.


I think the first fleet of new reactors will be LWRs and hopefully heavy water reactors here, but I think a lot of the political and regulatory roadblocks that have been keeping nuclear power on the social/economic margins are soon going to come down. They have to as we have no other real alternative to an energy sector that is already killing about 7,000,000 people a year from air pollution alone.

When the imperative is to get advanced design reactors online as soon as possible I don't think we're going to be seeing the decades long foot-dragging of the past. The people responsible will pay too high a personal price, many former anti-nuclear activists are beginning to look at people like Helen Caldicott in the same light they did nuclear sector companies for years. With good reason, because whether they care to admit it or not, anti-nuclear power leaders have been lying about the risks of nuclear power for decades.


Last edited by DougC on Aug 06, 2014 4:18 pm, edited 1 time in total.

Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 55 posts ]  Go to page Previous  1, 2, 3, 4  Next

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group