Energy From Thorium Discussion Forum

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PostPosted: Mar 09, 2009 10:49 am 
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Lars wrote:
... since we only need 1 tonne to generate 1GWe-year...


I'm just wondering where this value come from? Is it a theoretical limit based on energy released per fission reaction and then conversion to electrical energy or is it based on experimental data? If it is the second, then what type of reactor is this? Do you have a source I could look at? Is this energy generation achievable with net breeder reactors in which some of the U-233 is used as start-up for future reactors? If it is theoretical then how close are we to being able to achieve this? What are the energy production amounts of current thorium breeder reactors like? Sorry for the bombardment of questions!


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PostPosted: Mar 09, 2009 11:24 am 
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thorium87 wrote:
Lars wrote:
... since we only need 1 tonne to generate 1GWe-year...


I'm just wondering where this value come from? Is it a theoretical limit based on energy released per fission reaction and then conversion to electrical energy or is it based on experimental data? If it is the second, then what type of reactor is this? Do you have a source I could look at? Is this energy generation achievable with net breeder reactors in which some of the U-233 is used as start-up for future reactors? If it is theoretical then how close are we to being able to achieve this? What are the energy production amounts of current thorium breeder reactors like? Sorry for the bombardment of questions!


One gram of thorium converted in fissile uranium 233 and completely fissionated produces about 0,9 MWday of thermal energy; more than 98% of thorium is pratically fissionated; high thermal efficiency is easily achievable with MSR technology (> 50%)
I' ve opened a thread about the topic, many deatails there
viewtopic.php?f=2&t=1147


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PostPosted: Mar 09, 2009 11:44 am 
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Quote:
I'm just wondering where this value come from? Is it a theoretical limit based on energy released per fission reaction and then conversion to electrical energy or is it based on experimental data? If it is the second, then what type of reactor is this? Do you have a source I could look at? Is this energy generation achievable with net breeder reactors in which some of the U-233 is used as start-up for future reactors? If it is theoretical then how close are we to being able to achieve this? What are the energy production amounts of current thorium breeder reactors like?


The energy released per fission is something that is well established both by theory and by experience in current reactors for u235 and for pu239. For u233 it is the same theory with less experience - we do have experience from MSRE and a few other experiments. The energy released per fission varies only slightly between the various fuels. Some of the energy is given off in the form of kinetic energy in neutrinos. This energy escapes as neutrinos almost never interact with anything - they just fly through the earth and then off into space taking their 12 Mev of energy with them. The rest of the energy gets converted to thermal energy within the reactor fairly quickly. If you are interested in learning about this the book "Introduction to Nuclear Engineering" by John Lamarsh is a good source.

Of necessity, all reactors must be very efficient at transfering the energy to the heat exchangers. Imagine for a moment that they were only 99% efficient at transfering the heat to the heat exchangers. This would mean a 2.4GWthermal/1GWe reactor would have a heat load of 24 MWthermal! It would get intolerably hot inside the containment building real fast!

For the various fuels the capturable energy per fission is somewhere between 190 and 205 MEv. It is then a simple calculation to decide how many fissions per second it takes to generate a particular power level (that is thermal power not electrical power). Once you have the fissions per second, it is easy to calculate how much fissile one consumes. This much is verifiable in any reactor and is certain. Thus there is little doubt about the amount of u233 (or any fissile) it takes to generate a particular thermal power level. (At least to the level of precision we need).

I use 1 tonne because it is an easy number to remember. Others use as low as 800 kg. I think the true number is in between. I haven't fussed with resolving the difference since it doesn't change anything for me.

Converting the thermal power to electrical power does involve efficiencies. A good upper bound on performance can be found using thermodynamics. We do not fully achieve the thermodynamic limits in real systems as there are various losses. In existing reactors the turbines get pretty close to theoretical. For new reactors with higher temperature heat sources there will need to be a change in the turbines. I fully expect that turbines designed for the new reactors will also come pretty close to the thermodynamic limit - though there will be significant R&D expense to get there.


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PostPosted: Mar 09, 2009 2:59 pm 
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Ok, so i understand how 190MeV/fission of U-233 gives 20TWh/tonne of electrical energy, minus unburned fuel and thermodynamic conversion. If I am interested in establishing a thorium energy economy which does not rely on U-235 for start-up what factor should I use for burnup, ie how much U-233 do I need to leave behind to use in a future reactor?

Also, how does this limit compare to experiments and how fair are these experiments. My lecturer (David Mackay, who's book is mentioned in this forum a couple of times) quotes a value of 3.6 TWh/tonne Th based on the Atom Versuchs HTGR. Is this fair? How does it compare to other net breeder reactors that would be most suited for a uranium-free fission economy? Essentially I am trying to work out the best energy/mass value to use to calculate the very long term sustainability of thorium.


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PostPosted: Mar 09, 2009 3:56 pm 
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1000 kg per GW*y
3 kg per GW*d
3 g per MW*d


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PostPosted: Mar 09, 2009 4:19 pm 
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thorium87 wrote:
... ie how much U-233 do I need to leave behind to use in a future reactor?

Estimates of requirements per reactor range as low as 400 kg U233 for a 1GWe plant. 1000 kg is certainly plenty for a variety of designs operating in a thermal or epithermal neutron spectrum. Fast spectrum/high breeding rate reactors need ~6000 kg. However, this doesn't enter into calculations about long term sustainability. Even for a fast reactor, it's only ~6 years worth of fuel, and it isn't lost when a reactor reaches the end of its life. If the reactor is replaced, you either transfer over the whole fuel salt mixture to the new reactor, or if the salt composition required for the replacement 'Gen VI' reactor is too different from what was used before, you can run the entire salt mixture through the treatment plant and remove all the fissile isotopes, transfer them over, and dispose of the rest

thorium87 wrote:
.... a value of 3.6 TWh/tonne Th based on the Atom Versuchs HTGR. Is this fair? How does it compare to other net breeder reactors that would be most suited for a uranium-free fission economy? Essentially I am trying to work out the best energy/mass value to use to calculate the very long term sustainability of thorium.


All solid fuel reactors have limited burnup, due to neutron damage to the fuel and fission product neutron absorbers building up. MSRs don't have these limits, as a liquid fuel cannot get damaged by radiation, and the fission products are removed continuously.

Luke


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PostPosted: Mar 09, 2009 4:50 pm 
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The burnup numbers refer to thermal power not electrical power.
You can use 20 GWth-hrs/ tonne as a good estimate for thorium consumption over the long haul.
You will never run out of thorium - even after thousands of years of running the worlds energy needs on LFTRs.

A liquid fuel reactor gets to continuously clean out the fission products so they do not build up and limit how long the fuel can remain in the reactor. The HTGR is a pebble-bed, solid fuel design. As such the fuel is not cleaned and the fission products build up sufficiently over time that the pebbles do not contribute neutrons anymore. The burnup number referenced is considerably better than todays LWRs but much worse than an LFTR. Considering that the design is also inbetween in terms of maturity perhaps this isn't a surprising result.


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PostPosted: Apr 04, 2009 3:16 pm 
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I was reading that Saskatchewan wants to revive Nuclear Energy based on the fact that
they have Uranium mines.

Quote:
Enterprise Saskatchewan, the provincial agency that is examining options for uranium development.

Page 4 says a priority of the government is to grow the economy. It goes on to talk about a report on uranium development.

It says a "key action" for Enterprise Saskatchewan will be to "advance recommendations of the Uranium Development Partnership report after public consultation to increase value-added processing of Saskatchewan's uranium resources."

The report, which is expected to be released on Friday, has already been criticized by the Opposition as likely favouring more development.

Lyle Stewart, minister responsible for Enterprise Saskatchewan. Lyle Stewart, minister responsible for Enterprise Saskatchewan. (CBC) But the minister responsible says he will take his cue from the public.

"I can honestly tell the people of Saskatchewan that we are committed to only developing the nuclear cycle in a fashion that meets with the approval of the majority of Saskatchewan people," Lyle Stewart, the minister responsible for Enterprise Saskatchewan said on Tuesday. "The public consultation process will be one of the ways we have of determining how the majority feel in this province."

Calvert, however, doubted the process would provide anything meaningful considering the nature of the topic and the government's desire to conclude discussions by the end of the summer.

"We are going to decide and debate and give the public an opportunity to talk about a nuclear reactor — the generation of electricity with a nuclear reactor — costing $8-10 billion.… We're going to talk about the whole future of the uranium industry. We're going to do all this in a matter of a few weeks and expect the people of Saskatchewan to have an adequate opportunity to participate?" Calvert said.

"That alone tells me this is a sham."

Stewart countered that people will be able to make their views known in various ways, including by letter and at public meetings.

He said a schedule for dates and locations would be announced at the end of the week.


So again the greed factor for Uranium mining investment is the driving force for a Nuclear Power Plant and they're talking $8-10 billion. Where's the Canadian representation for LFTR.
Someone should get in there.

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JUST ONE LFTR PROTOTYPE WOULD BE A HUGE BOOST


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PostPosted: Apr 04, 2009 3:24 pm 
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rmaltese wrote:
Where's the Canadian representation for LFTR.

There is no LFTR.


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PostPosted: Apr 04, 2009 3:35 pm 
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I know but that's no excuse. Are we suppose to ignore stupid decisions to spend billions when we know they can be done more efficiently and much cheaper. They have lunatics ready to hang bankers yet we can't get one lobbyist pushing for LFTR.

Also Mining Uranium is fine but should not be the reason to design a Power Plant.

When you say there is no LFTR are you saying that they need Billions in research before
they can be started. Is it not now the time to get financial backing?

Maybe if we had 5 years more time to research it all then we could press for LFTR?

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JUST ONE LFTR PROTOTYPE WOULD BE A HUGE BOOST


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PostPosted: Apr 04, 2009 4:16 pm 
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rmaltese wrote:
Are we suppose to ignore stupid decisions to spend billions when we know they can be done more efficiently and much cheaper.

What's so stupid about Saskatchewan making loads of money from uranium mining, while at the same time helping about a dozen countries reduce their dependence on coal, oil and gas, by using nuclear power ?

Note the following quote in the Saskatoon Star Phoenix editorial article copied below:
"a province that for 50 years has profited from the sale of the commodity and used the cash to fund its progressive social programs".

rmaltese wrote:
Also Mining Uranium is fine but should not be the reason to design a Power Plant.

Thorium does not contain any fissile material.
Consequently, to start an LFTR program, you will need either U235 from natural uranium, or plutonium produced using uranium in current reactors.

rmaltese wrote:
When you say there is no LFTR are you saying that they need Billions in research before they can be started. Is it not now the time to get financial backing?

Maybe if we had 5 years more time to research it all then we could press for LFTR?

More like 15 to 25 years.
Western society -- and investors in particular -- have grown enormously risk averse.
Nobody wants to try anything new & different.
Just look at the PBMR project : They've given up on developing the helium gas Brayton turbine cycle, hoping to stave off death by switching to steam and process heat applications....

Here's that article I mentioned above:
Quote:
Forum - Anti-nukes dragging NDP back to past
Saskatoon Star Phoenix
2 April 2009

After three decades of grappling with the issue of uranium development and nuclear power, the inability of many New Democrats to get beyond fearmongering and pandering to ignorance continues to threaten the progress of Saskatchewan.

The attempt this week in the legislature by departing NDP Leader Lorne Calvert to suggest untoward government meddling in a $2.5 million consultant's report to be released on Friday by the Uranium Development Partnership only underlines the silliness that pervades the party's ranks on matters nuclear.

There's little doubt that the governing Saskatchewan Party is supportive of pursuing the nuclear power option if it's viable. However, Enterprise and Innovation Minister Lyle Stewart has provided assurances that public sentiment will determine whether Saskatchewan builds a reactor or adopts measures to add value to the uranium that's mined here but is now shipped elsewhere to be refined and processed.

What's nearly incomprehensible about Mr. Calvert's theatrics in the house is that they come from a man who, as premier, said his government might consider a proposal to build a small reactor if there was a business case for it -- a prospect made all the slimmer by his NDP predecessor's decision to send packing AECL from Saskatoon, where it was researching the development of just such a reactor.

As premier, Mr. Calvert was in Europe to pitch the idea of the French company, Areva, choosing Saskatchewan as the site for a uranium refinery that would create jobs, and vowed that his government would press the federal government to ease regulatory burdens and duplication in order to stimulate more uranium exploration and development. He even claimed that public opinion in Saskatchewan had changed since the bad old days of the 1970s, when agitators riled up Warman area residents against locating a uranium refinery, and identified the Battlefords and Shellbrook as communities that were interested in hosting such a facility now.

Of course, with the anti-nuke forces again hard at work in the province now that Premier Brad Wall's government has picked up where Mr. Calvert's left off, the NDP leader seemingly sees the need to retrench from adopting a technology that's been safely delivering electricity to Ontario, many U.S. jurisdictions, China, India, Japan and several European nations for decades.

Apparently, the NDP out of office has reverted to form, with the agitators and fear-mongers seeking to crowd out party members who dare to consider a pragmatic approach to nuclear power and uranium development in a province that for 50 years has profited from the sale of the commodity and used the cash to fund its progressive social programs.

Two contenders to replace Mr. Calvert as the party leader, Ryan Meili and Yens Pedersen, released statements on Tuesday that condemned any notion of building a nuclear reactor, with Mr. Pedersen reportedly eschewing any further development of uranium mining. Meanwhile, the acknowledged front-runner Dwain Lingenfelter, who had taken a decidedly pro-nuclear stance by touting it as "clean, safe and affordable energy to power oilsands development," lately has become more circumspect, saying that the cost of building a reactor can only be justified if the excess power can be exported to the United States.

While Saskatchewan indeed needs to have an intelligent debate on nuclear power that considers everything from its immediate and long-term costs to safety and environmental considerations, with a similar analysis of conventional coal- and gas-fired plants that will be needed to ensure secure base-load capacity even under the alternative power generation options touted by "green" advocates, what the province doesn't need is anti-nuclear rhetoric that panders to ignorance.

As the province awaits the consultant's report, which minister Stewart has promised to make public in its entirety, the findings of a new poll are instructive. Despite the anti-nuclear sentiments that seem pervasive enough in the NDP's ranks that Mr. Lingenfelter appears somewhat cowed, he remains the preferred candidate by far among members of the general public who stated a choice.

Granted, it's members of the NDP who have the say in choosing their next leader, but it's the general public that decides whether that person provides the vision and leadership required to oust the current government and premier, who rank highly in the polls. With nuclear power destined to become a major political issue, it would be interesting to see if the NDP can put its internal divisions aside to address Saskatchewan's needs in a realistic way.


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PostPosted: Apr 04, 2009 4:36 pm 
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Hi Jaro

You give a thoughtful answer. I wonder how many here agree with you? I am starting to see some interesting questions for a poll to be done here. Do you mind if I quote you in the new thread I just posted? The one on should we have an official position. I mean some people first reading about Thorium will want some timeline and cost estimates. Does EnergyFromThorium want to set itself up as some kind of body that is shooting for specific goals. Or are we more of a discussion forum just happy to engage in discussion and let that be enough in itself?

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JUST ONE LFTR PROTOTYPE WOULD BE A HUGE BOOST


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PostPosted: Apr 04, 2009 5:02 pm 
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rmaltese wrote:
I wonder how many here agree with you?

I don't believe its a question of anyone agreeing with me: The above posts just give background & media reports -- even if they may not always be bracketed by quotation marks.
When I wish to express an opinion, I usually include a caveat to that effect.
rmaltese wrote:
Do you mind if I quote you in the new thread I just posted?

No -- but you might be better off quoting a source directly.
If you think I failed to cite a source at any point, one that you think you might want to quote, let me know & I'll see if I can get you one...
rmaltese wrote:
Does EnergyFromThorium want to set itself up as some kind of body that is shooting for specific goals. Or are we more of a discussion forum just happy to engage in discussion and let that be enough in itself?

A poll might be interesting.
But I suspect that each of the nearly 300 forum members (few of whom are regular participants) has a different view.
Personally, I think that just getting informed is Job #1.

As for modalities for the eventual goal of getting MSRs going commercially, I think I would agree with David L., that a few different concepts/designs may be required, in order to address suitability factors (not just technical ones) in various regions around the world.

Beyond that, it seems pretty obvious that while some folks are more interested in technical aspects, others prefer to look at the business & political questions.


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PostPosted: Apr 04, 2009 5:10 pm 
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Jaro and anybody else interested

Do you see how being non-specific as a group works against us?

I'm thinking a 4th page when first entering the energy from thorium site.

Something like: "Here's what we propose so far."

And if necessary get a Creative Commons license
for alternative concepts that are more fully realized.

Quote:
More like 15 to 25 years.
Western society -- and investors in particular -- have grown enormously risk averse.
Nobody wants to try anything new & different.

I guess the 15 to 25 years part does not sit well with me.

_________________
JUST ONE LFTR PROTOTYPE WOULD BE A HUGE BOOST


Last edited by rmaltese on Apr 04, 2009 5:52 pm, edited 1 time in total.

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PostPosted: Apr 04, 2009 5:45 pm 
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rmaltese wrote:
Jaro and anybody else interested

Do you see how being non-specific as a group works against us?

I'm thinking a 4th page when first entering the energy from thorium site.

Something like here's what we propose so far.

And if necessary get a Creative Commons license
for alternative concepts that are more fully realized.

Quote:
More like 15 to 25 years.
Western society -- and investors in particular -- have grown enormously risk averse.
Nobody wants to try anything new & different.

I guess the 15 to 25 years part does not sit well with me.


I fully expect gov support for LFTR development to have some kind of demo plant in 7-10yrs with a commercial roll out in 10-15yrs (well before I die). Many in this forum are working with congress to make this happen.

I don't expect private investment until the regulatory path is made clear at least. Private investment is not a priority for me at least.

If you want to help make this happen, start briefing all your local congress persons on LFTR.


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