Why the LFTR is Still Needed

A new MiT report, The Future of the Nuclear Fuel Cycle, argues that

Uranium supplies will not limit the expansion of nuclear power in the US or around the world for the foreseeable futurer . . .

This should quiet the anti-nuclear power camp on that particular issue, but it won/t. Critics of nuclear power have a tin ear when it comes to evidence. Any evidence that discredits their position simply does not exist, in their minds, and thus they will discount the MiT Report, and continue to tell us that we are running out of uranium.

If we are not running out of uranium is their any justification for the LFTR, a reactor that operates on an alternative - Thorium - fuel cycle? The answer is that there are several good reasons for adopting LFTR technology, even though there may be a large supply of accessible uranium.

One major reason for choosing the LFTR is that it invites far lower fuel cycle related capital investments. If the future reactor fleet is to be entirely uranium fueled, very large capital investments will have to go into uranium mines, processing facilities, enrichment facilities, and spent fuel management. in addition all of these facilities have significant operation costs attached.

Now consider fuel related the capital costs associated with a fluoride salt thorium reactor deployment compared to that of a massive deployment of uranium fueled molten salt reactors. First thorium is a bye product of rare earth mining, and with increasing rare earth use in the economy, more and more thorium will be coming out of the ground anyway. Thus, unlike uranium which is often mined in costly uranium only mines, thorium basically comes out of the earth at no added cost, from mines that would exist whether or not we wanted to recover thorium.

Secondly, while the milling expenses for thorium and uranium would probably be similar, 200 times more uranium would have to be milled, because uranium reactors operate on a once through fuel cycle reactors, which consumes less than 0.5% of the milled uranium, while nearly 100% of the milled thorium will be consumed in closed fuel cycle LFTR.

Secondly, the uranium must be enriched, and this involves another costly, energy intense process. With thorium the enrichment process can be skipped. Following enrichment uranium oxide must be prepared fabricated into reactor fuel pellets. in contrast thorium would be prepared for reactor use by fluoridation, a simple, inexpensive and well understood chemical process. At that point the thorium would be inserted into a reactor blanket where it would be bombarded with neutrons. After thorium absorbs a neutron it is transformed into protactinium 233, which will be separated from the blanket salts by fluoride chemical processes, that will be performed by processing equipment that is directly attached to the reactor. Then the p
rotactinium is stored for a few months, while it undergoes nuclear transformation to fissionable U-233. Once that occurs, the U-233 is automatically inserted into the reactor core by another reactor mechanism. All of these processes are low cost.

The advantage of the Thorium Fuel cycle LFTR is that it requires a fuel infrastructure that is 200 times smaller than a fleet of once through uranium cycle reactors would require. The added cost of the uranium infrastructure is not the primary problem. Rather it is the enormous task of building the infrastructure. The LFTR will require a large infra structure as well, but the infrastructure that will be required to keep LFTRs fueled will be tiny compared to that of a once through uranium fueled reactor fleet.

If we draw the comparison between LFTRs and LWRs, even more U-235 has to be prepared per GWh of power delivered. LWRs waste about 17% of the U-235 that goes into the core, as well as an even larger percentage of the plutonium created in the core. These inefficiencies mean that more U-235 has to be produced relative to the fuel requirements of LFTRs.

LFTRs produce little or no nuclear waste, and indeed can be significant consumers of actinides, which are the most troubling components of LWR nuclear waste. LFTR waste products reach benign levels of radioactivity after 300 years, but many useful and valuable fission products become safe after a few years, and can be mined from the fission product stream for use in industry. Long half life fission products have uses in medicine, and industry. Thus the fission products from LFTRs can be viewed as material resources rather than nuclear waste.

Although Fast Breeder Reactors share many of the advantages of the LFTR, they are likely to be considerably more expensive to build and deploy in large numbers. In addition, FBRs require 10 times the fissile inventory of LFTRs or even more, thus limiting the size of the initial deployment of FBRs. FBR advocates argue that the higher breeding ratio of the FBR will make up for the disadvantage. But it will take time to breed up to the size of an initial LFTR deployment. Supplementing the FBR start up stock with freshly separated U-235 would require the same sort of uranium mining, processing and seperating facilities that would be required by a uranium fueled reactor deployment. Using the nuclear fuel inventory in existing LWR waste stockpiles, more than enough LFTRs could be started to provide 100% of American electricity. If the LFTRs simply replaced the fuel they consumed through nuclear breeding, no further reactors would only be required except to meet added electrical demand.

The LFTR offers both lower cost and significant deployment advantages over the FBR.

Thus the LFTR offers economic and deployment advantages over any of its competitors including Light Water Reactors, Uranium fueled Molten Salt Reactors, and fast breeder reactors. It would be far cheaper to invest in LFTR development and deployment than to build the new uranium mines, mills, isotope separation and fuel fabrications facilities that would be needed to support a uranium fueled reactor deployment. Clearly then even given adequate uranium supplies, the LFTR continues to offer significant advantages for a large scale nuclear deployment.

Thorium Remix 2009

Kirk Sorensen, Dr. Robert Hargraves, and Dr. Joe Bonometti explain the importance of Thorium as a potential nuclear fuel and the Liquid Fluoride Thorium Reactor (LFTR) in this digested version of their Google Tech Talks. 197 minutes of video have been digested into a 25 minute long video, which can serve as an introduction to these revolutionary ideas, and the talk is indexed for important ideas.

00:34	Thorium not fissionable, so how can it be a fuel?
01:30	Wartime perspective: Uranium vs Thorium. Uranium better suited for bombs.
02:48	Today’s light water reactors’ wasteful fuel cycles.
04:17	Nuclear criticality and self controlling reactors.
05:25	1944: A tale of two isotopes.
08:47	“We’ll build a fluid fueled reactor.” Easy removal of Xenon-135.
16:05	Alvin Wineberg fired. Program canceled.
18:48	Basic light water reactor problem: Incomplete combustion. LFTR solves problem of spent nuclear fuel.
20:58	What is LFTR’s biggest obstacle? LFTR is different and unknown.
23:11	U-238 Pu-239 chemical separation (fast breeder reactors): LFTR still better.

The video was prepared by Gordon McDowell who wrote:

If you are care about climate change, energy independence or nuclear fission byproducts (some take thousands of years to decay), then please check this out.

Aim High On Next Big Future.

Aim High got a good mention and a link on Brian Wang's blog Next Big Future. Aim High is he name Dr. Robert Hargraves gave to the plan to mas produce Liquid Fluoride Thorium Reactor. I have decided to endorse the "Aim High" name and of course I supported the plan before Bob coined the name. The Aim High plan is the only really viable plan to create a post carbon energy economy by 2050. The viability of the Aim High plan stems from its relatively low cost, and its potential to quickly build and set up large numbers of small safe, reliable and nuclear waste destroying LFTRs that can generate electricity anywhere 24 hours a day, 365 days a year.

End Game: Answering the World's Energy Needs from Nuclear Waste

Lars Jorgensen is an Electrical Engineer who is Chief Technologist for Radio Products for Texas Instruments. In his spar time Lars has an unusual hobby. He is doing unpaid work on the development of the Liquid Fluoride Thorium Reactor, in a project that Rod Adams describes as the Nuclear equivalent of the Open Source movement in computing. The goal of the project, is to develop viable LFTR designs including the design tools that would be useful for Nuclear Engineers. In addition Lars is doing research on the use of LFTRs to solve the problem of the nuclear waste from other reactors. At the same time, Jorgensen's concept will cause produce vast amounts of electricity from the waste destroying process through the use of the LFTRs involved in the electrical generation process.

The idea of "burning" transuranium elements, the principle toxic wastes in nuclear waste, in molten salt type reactors is not new. During the 1950's my father verified that plutonium was compatible with a molten salt fuel carrier, and thus was suitable for use as a nuclear fuel in molten salt reactors. The idea of Using LFTRs to destroy nuclear weapons was pioneered by a group of nuclear scientists and Engineers at ORNL. In 1991, Uri Gat, and J. R. Engel of ORNL, and C. H. Dodds, of the University of Tennessee, proposed burning fissile fuel from dismantled nuclear weapons in LFTRs, as a means of nuclear deproliferation. That is the process of destroying the raw materials of nuclear weapons.

V. V. Ignatiev, S. A. Konakov, S. A. Subbotine, and R. Y. Zakirov of the Kurchatov Institute in Moscow, and K. Grebenkine proposed the use of Molten Salt Reactors as a means of disposing of nuclear waste. They noted that LFTRs had advantages over Liquid Metal reactors for nuclear waste disposal. The Russian research has lead to the development of the MOSART reactor design. The MOSART is a liquid salt fuel reactor concept intended to burn nuclear waste.
A similar proposal has come from Charles W. Forsberg of ORNL.

Forsberg noted that the development of

Brayton power cycles (rather than steam
cycles) that eliminate many of the historical challenges in building MSRs and (2) the conceptual development of several fast-spectrum MSRs that have large negative temperature and void coefficients, a unique safety characteristic not found in solid-fuel fast reactors.

Forsberg pointed to the potential of LFTRs to both produce electricity and destroy the dangerous components of nuclear waste.

In a draft paper titled. "An Improved End Game for the Non-Moderated Thorium Molten Salt Reactor", Lars Jorgensen has determined that by combining the disposal of nuclear waste and the generation of electricity in LFTRs vast amounts of electricity can be generated. Jogensen foresees a world wide demand for 7,500 GWe, nearly 20 times the current electrical consumption in the United States. With the use of electricity for water desalinization, Jorgensen further foresees electrical demand increasing to as much as 20,000 GWe.

Jorgensen, drawing on work by French nuclear scientists, H. Nifenecker, D. Heuer, J.M. Loiseaux, O. Meplan, A. Nuttin, S. David, and J.M. Martin, offers plans

to simultaneously reduce the current TRU wastes 15-fold (with onsite recycling) to 15,000 fold reduction (with the best offsite recycling), while also supplying 9000 GWe electricity for an energy-hungry world.

This is surely an ambitious undertaking.

Despite his ambition, Jorgenson's plan is simple. He reference the French Non Moderated Thorium Molten Salt Reactor, a Liquid Fluoride Thorium Reactor, as the his waste burning power generation reactor. By 2046 enough fissionable transuranium elements will be present in American Light Water Reactor Waste to start enough TMSRs to produce 125 billion watts of electricity. The TMSR is a breeder, that is it will produce more fuel than it burns. Other reactors will be started with U-233 from original TMSR fleet.

Jorgensen believes that his concept would work world wide to get rid of nuclear waste. As many as 1000 large TMSR could be built to use the word wide supply of 8842 tons LWR TRU waste as nuclear fuel. Each reactor would produce 1 billion watts of electricity. From that initial fleet enough U-233 would be produced to start another 8000 reactors. Enough to supply the entire wolds electrical demands 100 years from now.

Jorgensen plans for the TRUs from light water reactors to remain in TMSR cores until they are used up, a process that would take several hundred years. After 200 years more that 56% of the original LWR TRU inventory will have been used up. If there is a desire to shut down the TMSR fleet, as the amount of TRU drops inside the TMSRs, the TRUs can be withdrawn from the core by batch chemical processing of the fuel, Fission products and U-233 would of course be processed out of the fuel salts at the same time. The withdrawn TRUs would be transfered to the cores of other reactors, and the reactor whose TRUs are processed out can be shut down.

According to Jorgensen:

We can virtually eliminate the inventory TRUs in the reactor cores by gradually shutting down the reactors and fissioning the residual inventory off. The optimization goals of the shutdown procedure are:
1) minimize the final inventory of TRUs disposed as waste;
2) shut down the vast majority of reactors, as quickly as possible, consistent with the first goal.

Eventually the TRU's and U-233 involved in the process can be "burned down" to a tiny amount of waste. as much as an 11,000 fold reduction in the amount of waste. The final waste will come from two sources: a very small leak of TRU and U-233 into the fission product stream, and the TRU and U-233 inventory left over when the final, very small TMSR no longer contains enough fissionable material to maintain a chain reactor.

Jorgensen concludes:

The deployment not only provides 1,800,000 GW-yr (1.8 PW-yr) of electricity, but eliminates 90 to 99.99% of the world’s predicted transuranic waste inventory. The NM-TMSR’s fuel flexibility allows virtual elimination of the waste inventory arising from shutting down the reactor fleet. This sort of flexibility is much more difficult to achieve with any proposed solid fuel reactor. The Th-U233 cycle operates with TRU inventories only 5% of those for U238-Pu239 based breeder reactors. While much R&D needs to be funded and completed to bring this reactor to fruition, it is far less than the projected costs for Yucca Mountain, and solves both the TRU waste and energy generation challenges facing our society today.

For those concerned about nuclear proliferation, the TMSR and similar LFTRs are wonderful deproliferation tools. Uranium and plutonium from nuclear weapons and weapons available stockpiles can be used as starter charges for LFTRs and burned up by the nuclear process. LFTR can be designed to produce no more U-233 than is burned up in its chain reaction. Thus far from being a nuclear proliferation menace, the LFTR can becomes a prime tool for lowering the possibility of nuclear war.

Greener Than A Thousand Suns

The wikipedia notes several definitions of Green Power:

An alternate term for renewable energy.
Energy generated from sources which do not produce pollutants (e.g., solar, wind, and wave energies).
Energy generated from sources that are considered environmentally friendly (e.g., hydro (water), solar (sun), biomass (landfill), or wind)
Energy generated from sources that produce low amounts of pollution.
Energy that is produced and used in ways that produce relatively less environmental impacts.

To these definitions we ought to add to further green dimensions, energy return on energy invested, and green land and water use principles.
Thus the green potential of LFTR technology can be illustrated by comparing its "greenness" to the the "greenness" of solar electrical generation systems.

Surprisingly the greenness of solar power cannot be taken for granite. The Energy Return on Energy Invested (EROEI) of solar cells is at best about 10 over their life time, and when you add the energy consumed in the manufacture of materials used in large scale solar cell arrays and during the construction of those arrays, the EROEI of PV generated energy becomes even lower. Indeed it has been argued that the EROEI of PV technology may be as low as 1 to 1. There is some debate whether PV technology produces more energy than it consumes. It is quite clear that at present PV technology is not economically viable and would not be used for electrical production were in not for a system of generous state subsidies there would be PV would not be in play at all as an electrical producing technology. If we add to the discussion about the question of green land use practices, the greenness of widespread use of PV electrical generation technologies clearly can be questioned.

In the case of concentrated solar power (CSP), the potential for a positive return on energy invested is clearer. Although it cannot be said that there is a great deal of evidence, the EROEI of concentrated solar is reported to be about 10. Thus CSP is green by EROEI standards. But what about land use? Austra calculates that by using its technology a 92 by 92 mile square or 8464 square miles or 5.4 million acres would be sufficient to supply the entire United States with electricity at its current rate of consumption. David Rutledge, using real world data from Navada Solar One project land use asserts that it would take 11,600 square miles to supply current US electrical requirements. Bernadette Del Chiaro, Sarah Payne and Tony Dutzik claim about 10,000 square miles.

It should be noted that the general replacement of fossil fuels by electricity in economic sectors like transportation and process heating, could easily double solar land use requirements. Del Chiaro, Sarah Payne and Tony Dutzik claim that the land area disturbed by solar installations would be comparable to that disturbed by coal mining:

more than 9,000 square miles of the United States has been disturbed by coal mining over the nation’s history. And at least 1,644 square miles are disturbed by current mining operations

We may not have an entire picture of the land use impact of solar installations. In addition to the installations themselves, land would be occupied by electrical gathering systems, electrical substations, and high voltage electrical lines. 

There is little doubt then that at least 10,000 square miles of fragile desert habitat and quite possible twice that amount could be impacted by a full blown national solar electric scheme. Thus from a land use point of view, some "Greens" would seem willing to sacrifice green land use valuse in the cause of solar generated electricity, while others are not. Sandy Bahr of the Sierra Club states,

"We support solar power, but it is an industrial activity and putting it next to a wilderness area just is not a good idea".

There you have the Green dilemma.

Water conservation is a green value. Water use in concentrated solar power systems is almost completely ignored, but Joe Gelt points out that water use in concentrated solar is greater than that of coal and similar to nuclear per MWh generated:

a coal fired plant uses 110 to 300 gallons per megawatt hour; a nuclear plant uses between 500 and 1100 gallons/MWh; and a solar parabolic trough plant uses 760 -920 gallons/MWh.

Gelt adds:

Efforts to increase water efficiency in solar energy operations involve modifying the conventional cooling tower. For example, dry desert air could be used instead of water to cool the operation. This, however, would greatly increase building costs because enormous cooling towers would need to be constructed. Also relying on air to cool would not cool the water circulating through the plant to a low enough temperature for peak performance, decreasing the efficiency of the plant.

The Southwest has already has a significant water shortage, and climate projections are for the Southwest to become even dryer during the coming years. The only possible source of enough water for desert based solar thermal power facilities would be to withdrawal water from agricultural use and to transfer it to power production. This would in turn raise food prices in the southwest, and thus would paradoxically constitute a subsidy paid by poor food consumers who would pay higher food prices, to solar electrical producers who would profit from from nation wide electrical sales. Social justice is presumably a Green goals.   

Within the Southwest, concentrated solar power is not environment friendly.  It does not conform to green land and water use principles, and CSP water use requirements would indirectly make the life of the poor in the Southwest worst rather than better.  

Moving concentrated solar electrical production out of the Southwest is not an option, because solar electrical generation is highly dependent on cloudless skies.  There is ample reason then to view there hither to unquestioned "greenness" of concentrated solar generated electricity as open to question.  

In contrast as I have already pointed out there are many aspects of LFTR greenness.  Thorium is a sustainable energy source, with the potential to provide people all of the energy they need for millions of years.   There is already a great deal of Thorium above ground in the form of mine tailings, enough to supply human demands for hundreds of years.  Thorium energy conversion is 100 to 200 time more efficient, that current uranium reactor technology.   LFTR reactor designs use materials more efficiently than conventional reactor designs to.  Recycling of existing coal fired power plants sites for LFTR use has the potential to create energy savings of 50% to 75% compared to start from scratch power plant construction.  LFTR produce little   
to no nuclear waste, thus greatly diminishing energy inputs into waste control.  Material outputs from nuclear daughter products would be an energy savings, that would be unique to LFTR technology.  It is clear then that the LFTR EROEI would from somewhere in the three figures at its lowest on up. From the EROEI stand point, the LFTR would be the ultimate in energy efficiency.

Since most of the chemical output of the LFTR is already recyclable, and some materials processing and separation is expected to be a normal part of reactor operation, the LFTR is expected to produce little unused byproduct.  There are existing markets for some radioactive byproducts and other markets can be developed.  Molten Salt Reactors have been proposed for the disposal of transuranium nuclear waste.  Thus the potential exists to completely eliminate 

not only their own nuclear waste, but also the nuclear waste of conventional reactors  through the use of LFTRs.  Thus the LFTR hasthe potential to be a 100% pollution free technology.

The LFTR has the potential to be very parsimonious in its land use. First I have proposed the recycling of existing coal power plant sites. It should also be noted that much of the landused by nuclear power facilities is actually used as a land buffer for the mitigation of accidental release of radioactive products. Thus up to 95% of the land occupied by a LFTR facility may actually be set aside for conservation purposes. Compared to CSP facilities, LFTRs would have a very modest land use footprint.  Underground placement of the reactor would further restrict visual intrusions, as well as add to reactor safety defenses.  

The LFTR would typically runs at a far higher temperature than conventional reactors. This higher temperature could be used to improve energy efficiency in electrical output. Thus a smaller percentage of the heat produced by LFTR would need to be dissipated by water cooling, In addition most potential LFTR sites are located in areas which do not experience chronic water shortages. Water conservation measure could be applied if needed, and water conservation facilities would already exist at some coal fired plant sites. If needed LFTRs could be air cooled. In the Southwest, LFTRs could be located near the sea coast, an option not available for CSP..

The Liquid Fluoride Thorium Reactor is by definitions green. The LFTR is green by the principles of green engineering. The LFTR conforms to the goal of green chemistry by not producing polluting waste. There is little doubt that the LFTR is greener than CSP in terms of energy efficiency, land use and water conservation, and could potentially be as pollution free as well. The LFTR thus is by conventional definitions of green, greener than all forms of solar power.

Long Green

The primary goal of Nuclear Green, and for that matter of Energy from Thorium is and has been the relaunching of the development of the Liquid Fluoride Thorium Reactor/Molten Salt Reactor approach to reactor design. I believe that the LFTR represents the best long term energy option for human society, and its eventual adoption is inevitable. The success of the LFTR is not a matter of if but when.

The LFTR is clearly the best of reactor options. It has inherent safety features, which when coupled with a defense in depth safety system, will make serious accidents very, very unlikely, and will always protect the public from the consequences of any serious accident. It is more likely that the human race will die off as a result of an extinction event, than there would be a LFTR accident that would produce a single casualty among the general public.

The LFTR destroys nuclear waste rather than produces them. In fact Molten Salt Reactors have been repeatedly proposed as the solution to the nuclear waste problem. Because the fuel of the LFTR can be continuously reprocessed, Molten Salt Reactor offer a good environment for the fission of transuranium elements. While ideally the LFTR would always operate with U-233 as its nuclear fuel, and would produce more U-233 through the thorium breeding cycle, it has been proposed to start LFTR operations by initially fueling it with plutonium from nuclear waste. That would kill two birds with one stone, booth initiating LFTR operations and destroying the most dangerous element in nuclear waste. Thus the LFTR, far from being a tool for nuclear proliferation, is a singular tool for nuclear deproliferation, for destroying nuclear weapons building materials.

Finally because of the absolute abundance of Thorium in the earths crust, and the prodigious amount of energy that LFTRs can release by the LFTR, that the human population of the earth will never use up all of the available thorium. Thorium this prodigious gift to human energy needs is now waisted. It is quite literally thrown away. More energy could be extracted from thorium in the coal ash piles of power plants, than from burning the original coal. Thorium can be extracted from mine tailings, enough to power the United States for hundreds and perhaps thousands of years without ever turning a shovel of earth to mine more thorium.

The abundance of thorium, its energy potential, and the benefits of the thorium fuel cycle all point to thorium as the major source of future energy. The most significant competitor to thorium will be not the sun or the wind but uranium. Yet the uranium fuel cycle will be more expensive to operate because of the cost advantages of liquid salt reactors. Only liquid salt uranium fueled reactors could compete with the LFTR on costs, and fuel efficiency.

Why then don't we have the LFTR now? It all boils down to a question of money and politics. In his autobiography Alvin Weinberg wrote:

In 1962, the AEC issued a report to the president on civilian nuclear power. Lee Haworth, a superbly responsible physicist-administrator, was in charge of drafting the report. He projected a nuclear deployment by 2000 of about 700 gigawatts (compared with the actual deployment in 1993 of 102 gigawatts), which seemed at the time quite reasonable. Both the fast breeder based on the 239Pu-238U cycle and the thermal breeder based on the 233U-232Th cycle figured prominently in the report. Indeed, the report implied that both systems should be pursued seriously, including large-scale reactor experimentation. It particularly favored molten uranium salts for the thermal breeder. But the molten-salt system was never given a real chance. Although the AEC established an office labeled "Fast Breeder," no corresponding office labeled "Thermal Breeder" was established. As a result, the center of gravity of breeder development moved strongly to the fast breeder; the thermal breeder, as represented by the molten-salt project, was left to dwindle and eventually to die.

The fast-breeder project in the United States centered around the Clinch River Breeder, a 250-megawatt sodium-cooled breeder to be built in Oak Ridge by Westinghouse. But, by this time, objections to the breeder were being voiced, ostensibly because the breeder, with its coupled chemical reprocessing system, lent itself to the clandestine diversion of plutonium for nuclear weapons. But in my view the real aim of some of the more dedicated opponents of Clinch River was the extirpation of nuclear energy. The Clinch River Breeder was a handy and vulnerable target, particularly since it could not produce power at a competitive cost. And the opponents eventually won—Clinch River was killed in 1975.

Although the molten-salt system was never allowed to show its full capability as a breeder, a 233U-232Th thermal breeder was demonstrated in Admiral Rickover's Shippingport reactor. Operating with 233U fuel and a thorium blanket, this reactor actually demonstrated a breeding ratio of 1.03—i.e., for every 233U burned, 1.03 new 233U was produced. This accomplishment has gone unnoticed since the cost of power from Shippingport is much higher than from other sources. Whether, as cheap uranium becomes scarce, other reactors will be fueled with 233U and thorium remains to be seen. Thus, as Wigner once said, breeders may emerge from incremental improvements of existing light-water or heavy-water reactors, or may spring from entirely new technologies specifically designed for the breeder. As for fast uranium breeders, the latter path is being followed in France, Japan, India, and Russia. (The French fast breeder PHENIX has demonstrated a breeding ratio of 1.13.) But as for thermal thorium breeders, it seems that these will emerge from the existing nonbreeder LWR or CANDU rather than from molten-salt technology.

Why didn't the molten-salt system, so elegant and so well thought-out, prevail? I've already given the political reason: that the fast breeder arrived first and was therefore able to consolidate its political position within the AEC. But there was another, more technical reason. The molten-salt technology is entirely different from the technology of any other reactor. To the inexperienced, molten-salt technology is daunting. This certainly seemed to be Milton Shaw's attitude toward molten salts—and he after all was director of reactor development at the AEC during the molten-salt development. Perhaps the moral to be drawn is that a technology that differs too much from an existing technology has not one hurdle to overcome—to demonstrate its feasibility—but another even greater one—to convince influential individuals and organizations who are intellectually and emotionally attached to a different technology that they should adopt the new path. This, the molten-salt system could not do. It was a successful technology that was dropped because it was too different from the main lines of reactor development. But if weaknesses in other systems are eventually revealed, I hope that in a second nuclear era, the molten-salt technology will be resurrected.

Weinberg thus points to the AEC role of Molten Salt Reactor foe Milton Shaw during the 1960's and early 1970's. Beyond Milton Shaw was the politics of nuclear power, with coal interests and anti nuclear activists forming a tacit alliance against nuclear power. From the beginning of the Nixon administration onward the fortunes of nuclear research declined in the United States. Jimmy Carter maded the disasterous decision to turn to coal for electrical generation at the very time scientists led by Alvin Weinbery were warning off the dangers of CO2 triggered global warming. Oponants of nuclear power, lead by psudo-physicist Amory Lovins, were perfectly willing to go on burning fossil fuels, as long as it was burned in small, allededly more efficient generators. Lovins, Ralph Nader, and Helen Caldicott, willingly served as fronts for the coal barons, and seldom even mentioned CO2 or global warming. In fact, in 1989 Amory Lovins blamed part of the CO2 problem on Nature, and argued that energy efficiency was cheap and indeed the only needed solution to the CO2/Global Warming problem. In the mean time the coal fired power plants dumped billions of tons of CO2 into the atmosphere every year, and the coal barons banked their money. Amory Lovins banked his money too.

Coal now is in decline, and Amory Lovins is fighting a rearguard action against nuclear power. The story is now being told that energy will be very expensive in the post-carbon age. As I argued yesterday, there are potentially innovative ways to lower LFTR cost to a fraction of the cost of conventional nuclear technology. The potential of cheap power through LFTR technology needs to be explored in ways that only money can bring about. The route to green power begins with long green.

Three Technologies That Can Save Civilization

I am setting aside, for the moment, my history of the Molten Salt Reactor to focus on a question raised by Robert Hargraves on "Energy From Thorium". Dr. Hargraves asked:

If we were to try to convince the US to pursue MSR technology, what would we propose? to whom? Who would carry out the work? How much would it cost? How long would it take? Can we argue for long-term funding, by treaty, as supplied to the CERN supercollider? What university professors and research laboratory scientists would support such a proposal and also have credibility and influence?

I've met with my congressman and senator on the subject of energy in the past, but I don't know what I would ask for on the subject of the thorium MSR.

This question poses a dilemma for the sort of innovative project that can reasonably expected to contribute to our post carbon energy future. If no funding is available, and past attempts to secure funding have been discouraged, then there is no incentive to to continue to develop projects, even on a conceptual level. Thus we get caught in a vicious circle, that no funding leads to a lack of interest, and the lack of interest then becomes the excuse for no funding.

Dr. Hargraves has been a brilliant advocate for Pebble Bed Reactor technology, and the dilemma effects PBR development in the United States no less than it does MSR/LFTR technology.

I would contend that PBR technology, MSR/LFTR technology can play critical roles in future resolutions of our energy crisis. Both reactor types are very safe and highly efficient, and can be manufactured at much lower costs than traditional reactor designs, they have great potential for reducing the cost of nuclear generated electricity. Because of their low cost, both LFTRs and PBRs can serve as peak electrical generators as well as well as base load generators. In addition MSRs have excellent load following characteristics. Indeed load following can extend the core life of graphite cored LFTRs, by lessening the intensity of neutron radiation the core is exposed too. The load following ability of LFTRs also makes them candidates to support wind electrical generating systems, since the ability of LFTRs to quickly respond to rapidly changing electrical currents from wind generators.

Renewables advocates often suggest the use of fossil fuel plants for load following and generation back up, but this option is not sustainable, is expensive, generates CO2, and outs European nations at risk for energy blackmail by natural gas suppliers. Therefore the flexibility of the LFTR makes it an ideal candidate to be paired with wind generation systems, and thus a prime candidate to replace coal and gas burning electrical plants. The rub is that a system of LFTRs would be a low cost alternative to a system of unreliable windmills with LFRT backup. This no doubt rests at the heart of the opposition to nuclear power, by renewables advocates.

At any rate either with or without renewables, the

There are several advantages of LFTRs over PBRs. However PBR's may have some advantageous in the area of proliferation resistance. Thus it is possible to sell PBR's to countries that are a considered a proliferation risk with MSRs. PBRs can be produced cheaply, do not require containment structures, do not require elaborate and expensive containment structures, can replace coal, natural gas, and oil fired generators, are extremely safe, can be operated by simple low cost computers, can provide industrial process heat, heat for space heating, and heat for desalinization in addition to electricity. There low cost makes them attractive options for peak load generators. There are several disadvantages of PBRs vis-à-vis LFTRs. PBRs don't breed or convert their own nuclear fuel. While LFTRs can burn up to 98% of the thorium in their system, PBRs can only burn a tiny fraction of their potential nuclear fuel. As a consequence PBRs produce several orders of magnitude more nuclear waste than LFRTs. The difficulty and expense of reprocessing PBR fuel is a key to their proliferation resistance.

A second disadvantage of PBRM's is that they are not good load followers. In order to follow loads, PBR operators would have to be dumped heat rather than running it through the generating system. This is not efficient use of nuclear power.

Despite these disadvantageous PBR's are destined to play a significant role in the replacement of fossil fuel power plants with nuclear reactors. Like LFTRs, PBRs can be quickly and inexpensively built in very large numbers in factories. Thus, for example, the Chinese, who are developing their own PBR technology, could build thousands of PBRs between 2020 and 2050. Reportedly the Chinese have already offered Canada PBRs to be used in processing Alberta tar sands into crude oil. The rub would be that the oil would then go to China.

South Africa is developing its own PBR which is a little more technologically advanced than the Chinese concept. The South Africans probably can project a very large market for the sale of these reactors. Both the under developed countries of Africa, and Latin America, as well as the more advanced nations of Europe, North America and Asia, would be included in the South African target markets. Thus it can be foreseen that PBRs will play a major role in the replacement of carbon based electrical and energy sources between 2020 and 2050.

LFTRs, because of their superior fuel efficiency, the major reduction of the problem of nuclear wast that LFTR technology brings, their safety, their ability to serve as base load generators, peak load generators, and effect load followers, and there low manufacturing cost, would be the preferred power generation technology for nuclear capable nations. A nuclear capable country is a nation which posses the capacity to produce nuclear weapons, without new technological transfers from external sources. An illustration of nuclear capacity would be South Africa, which developed its own centrifuge Uranium enrichment technology in the 1970's and 80's and managed to produce 6 nuclear weapons. Other nations which are nuclear capable include Argentina, Australia, Canada, the Ukraine, Japan, Taiwan, Egypt, Turkey, Iran, Brazil, Poland, the Czech Republic, Germany, Spain and other European nations. All of these countries could produce nuclear weapons if they chose too.

The low cost of LFRT factory manufacture, plus their many attractive features, and the abundance of recoverable thorium, will mean that in many situations LFTRs will be preferred to PBRs for both power and heat, in many situations. Like PBRs, relatively small (100 MWe to 300 MWe) LFTRs can be built in factories and transported to their long term sites. While LFTR technology is not being developed at the same pace as as PBR technology is proceeding, a large knowledge base was developed in Oak Ridge between 1960 and 1976. In addition other recent technological breakthroughs, for example the development of high temperature gas turbine technology, have technological problems that were unresolved when ORNL stopped working on MSR development in 1976.

Given the current state of LFTR development, a Manhattan Project style development program commenced by 2012, could have LFTRs moving out factory doors by 2020. There are no insurmountable barriers to large scale production.

With their potential for easy, quick and low cost manufacture, PBRs and LFTRs will play a major role in the future of energy, and will be by 2050 the predominant source of electricity world wide.

If reactors are to be the major form by which future energy is produced, more attention needs to be paid to how energy gets stored for transportation. At present Lithium-ion batteries represent the preferred technology for the electrification of transportation in the near future, however, lithium Ion technology brings with it a number of draw backs. First is safety related issues, that are caused by battery heating due to rapid discharge. The second serious problem is Lithium-ion batteries costs which are anticipate to run in the neighborhood of $30,000 for the first Lithium-ion powered EVs. For that price Lithium Ion Batteries offer uninspiring performance. The trip range of the GM Volt is expected to be about 30 miles with our backup from internal combustion engine. That is good for drives to work, and errands, but not for trips out of town.

It is highly desirable then, if carbon based technology is to be replaced in transportation that better electrical storage technology must emerge. Lithium-Sulfur batteries appear to have potential as one such technology. According to a recent Insyncworld report,

in theory, Lithium-Sulfur potentially offers over 50% more Watt-hours/liter than Lithium-Ion batteries, and over four times the Watt-hours/Kg. That allows for smaller, lighter, or longer lasting (pick two) portable devices. Those are theoretical maximums that have not yet been reached, but current Li_S batteries already have a better power/weight ratio than conventional Lithium Ion.

The potential of Li_S technology is illustrared by this recent BBC story.

Li_S technology is newly emerging, but appears to hold great potential including greatly extended battery powered driving ranges, and lower costs. Although personal transportation would seem to be a lower priority on the energy problems list, in fact it is very important, because the physical structure of civilization in countries like the United States is highly dependent on personal mobility. Without personal transportation, the ability of workers to travel from home to work would be significantly compromised in spread out cities. Were workers to be foprced to move closer to their jobs, enormous values would be lost in home, infrastructure and commercial suburban investments. The loss of value in these investments would produce significant investment losses, that could not be easily recovered from.

Thus two reactor technologies, the LFTR and the PBR hold enormous promise as sources of low cost electrical energy and industrial heat. In addition a recently emerging battery technology, the Lithium-Sulfur battery, holds promise to improve the post-carbon transportation picture.

The development of these technologies must be given the highest priorities by our society, during the next few years, if your civilization is not to be seriously wounded. We must not allow Dr. Hargraves dilemma to inhibit that development.

MSR/LFTR development: WASH-1222 and Beyond

Where is the LFTR on the product development cycle?

A proof of concept MSR prototype was built in the 1950's. It was regarded as highly successful. A more advanced MSRE prototype was built and tested between 1965 and 1969. It was, like the first prototype, considered an outstanding successes. The MSRE accomplished all experimental objectives The MSRE, tested many advanced technologies, including

* Online reactor refueling
* First reactor to use U-235, U-233, and Pu-239 as nuclear fuel
* The longest reactor runs between shutdowns at the time
* Verified MSR safety features
* Successfully use of the liquid LiF-BeF2-UF4 fuel/coolant formula.

Several developmental problems emerged from the test:
1. Tritium, a radioactive form of hydrogen, was found to have escaped the reactor. This was considered highly undesirable, but not entirely unexpected. ORNL researchers believed that a tritium control system had to be developed. They later accomplished this task.
2. Cracking on the surface of Metal alloys that came in contact with liquid salts was observed. Later research identified the cause of the of the cracking, a fission product, and methods of preventing the problem.
3 Prolonged and heavy neutron radiation exposure of graphite, lead to changes of graphite internal structure. This produced swelling of the graphite moderators which also served as the inner plumbing of the reactor. The swelling of the graphite structure weakened it. This problem has not yet been solved, but it can be worked around. One work around would involve the floating of hundreds of graphite pebbles, that is small graphite balls in and out of the MSR core. The pebbles would not have any structural function, but would serve as a moderator. When the pebbles swell from excessive radiation, they can be captured sas they flote out of the reactor core, and removed from the reactor.

Upon completion of the MSRE, ORNL staff began to design a large (1000 MWe) LFTR, the MSBR. It was designed to serve as a thorium fuel cycle breeder. The jump from the 10MW MSRE to a 3000 MW MSBR was in hindsight overly ambitious, but was necessitated by AEC requirements. The solution to the graphite problem was particularly unsatisfactory. A two fluid core design, that is a core design in which fuel salts and fertile blanket salts were intended to be kept separate, required a graphite core structure. Graphite swelling lead to problems with graphity 2 fluid core structures, and one solution was to periodically remove the core graphite removed and replace it. There are several less drastic alternatives.

Wash-1222 listed a number of developmental issues facing the MSBR design and development team. Wash-1222 stated, "the development of these larger components along with their special handling and maintenance equipment is probably one of the most difficult and costly phases of MSBR development. However, reliable, safe, and maintainable components would need to be developed in order for any reactor system to be a success".

WASH-1222 also noted, "The salt valves for large MSBR's represent another development problem, although the freeze valve concept which was employed successfully in the MSRE could likely be scaled up in size and utilized for many MSBR applications. Mechanical throttling valves would also be needed for the MSBR salt systems, even though no throttling valve was used with the MSRE. Mechanical shutoff valves for salt systems, if required, would have to be developed". This would seem to be a simple developmental task.

WASH-1222 also noted that an integrated fuel reprocessing system would have to be tested, and a design for system integration for the entire MSBR was also required.

Many of the developmental tasks listed by WASH-1222 apply primarily or entirely to the MSBR. Other developmental tasks appeared to be routine and not likely to pose a challenge.

WASH also noted the MSBR "requirement for remote maintenance will significantly affect the ultimate design and performance of the plant system". It then pointed to one of the significant problems with the MSBR design, "the removal and replacement of core internals, such as graphite, might pose difficult maintenance problems because of the high radiation levels involved and the contamination protection which would be required whenever the primary system is opened". This pointed to the most significant problem of the MSBR design, the resolution of the graphite problem by periodic core removal. French MSR researchers, have recently made the choice to follow a developmental track that eliminates graphite from the core of their proposed MSR. There analysis of the difficulties posed by the graphite core of the MSRE, lead them to conclude that despite some significant disadvantages, the a graphite free core offered more advantages.

WASH-1222 raised questions about the safety of the MSBR. Subsequent MSR safety analysis by Uri Gat, and Gat and Dodds, would seem to resolve most safety questions on a conceptual level. Recent discussions in the "Energy from Thorium" raised questions about assurances that the "salt freeze safety valve would operated in a timely fashion in the event of an emergency shut down. My rather brief review of ORNL reports did not shed light on the question. In absence of devinitive evidence from ORNL reports, the proper functioning of the emergency reactor drain system including the freeze valve, should be verified, and any short comings rectified.

Thus the major MSBR developmental problems noted by WASH-1222 were the tritium problem, and the problem of core graphite. The tritium problem requires a technological fix that is clearly not impossible. Several work around ideas have been proposed for the graphite problem, and a French MSR design team has adopted one.

In addition to the developmental issues noted by WASH-1222, the problem of protactinium extraction, a problem that bedeviled my father from the late 1950's to the mid 1960's, has been the subject of continuing discussions on "Energy from Thorium". The tennor of the discussion seems to be as follows, protactinium extraction is difficult and probably should be avoided if possible.

I mentioned alternative approaches to the graphite problem. Again some available options have been discussed on "Energy from Thorium". These include the big pot approach which has attracted french interest. The reactor core is simply a open chamber into which liquid salt coolant/fuel is poured. No moderator is used although the liquid coolant/fuel does have some moderating effect. There are disadvantages to this approach. The amount of fissionable fuel required to sustain a chain reaction would be much greater that in a moderated MSR.

One interesting option would be to put graphite pebbles into the pot in order to provide a moderator. The graphite pebbles would float in the liquid salt and could be periodically removed for replacement. This system was actually suggested at ORNL in 1970.

"Jaro" suggested the use of self-cleansing carbon nanotubes as MSR moderators. Another "jaro" suggestion involved the use of heavy water being piped through the MSR core. There would probably be safety concerns about this design, although heavy water would work even better as a moderator that graphite.

It would appear then that the graphite problem is no deal killer for the MSR. Solutions and work arounds exist for the graphite problem, but reactor developers have to decide which one to choose.

Finally, research on the tritium problem was problem was continued at ORNL into the mid 1970's. Tritium (H-3) is a radioactive isotope of hydrogen that primarily is produced from lithium-6 isotopes. If pure lithium-7 is used in the fuel, then the LFTR tritium problem would be greatly reduced, but not entirely eliminated. Tritium hike the other forms of hydrogen diffuse through metal barriers. Tritium is most likely to escape the MSR/LFTR through the thin walls the heat exchange. ORNL researchers in 1977 later reported that they were making progress toward a solution to the tritium problem when their funding was cut off by the United States government energy bureaucracy. Again the tritium problem seems no deal breaker. The ORNL researchers who were trying to solve the tritium problem stated:
"Although a complete understanding of the behavior of tritium in sodium fluoroborate could not be developed from this series of experiments due to the termination of the Molten-Salt Reactor- Program, the effectiveness of sodium fluoroborate to trap tritium was demonstrated. Furthermore, use of sodium fluoroborate as a secondary coolant in an MSBR would be expected t:o adequately limit the transport of tritium to the reactor steam system and environment".

The ORNL researchers further summarized their findings:

The tritium addition experiments conducted in the CSTF demonstrated sodium fluoroborate’s effectiveness for sequestering tritium. However, further experimentation and research would be required to yield a better understanding of tritium behavior in sodium fluoroborate, to better define
basic parameters, and to explain some of the observed phenomena as a result
of conducting the experiments in the CSTF.

If the MSR program were to be continued, further investigation relating to the following would be desirable:
1. The chemistry of sodium fluoroborate and the trapping process by which tritium is retained by the salt,
2. Permeability values for Hastelloy N.
3. Solubility data for the dissolution of elemental hydrogen (tritium) in sodium fluoroborate.
4. Data on gas-liquid equilibria in the pump bowl in an effort to
explain behavior such as that observed in experiment T4 when, upon increasing the off-gas flow rate to 4 liters/min, equilibrium conditions in the pump bowl between the gas and liquid were altered drastically.
5. Identification of the sink that required saturating before steady state conditions could be established.
6. Determination of the existence of an extraneous source of hydrogen in the off-gas system and its effect (if present) on the behavior and distribution of tritium in the CSTF".

Thus the obstacles to successful development of the MSR/LFTR mentioned by the WASH-1222, can be. Design choices and promising research avenues known since the 1970's are still available.

Hidden in a Dusty Government Warehouse

In my recent case study of EEStor, I pointed to the importance of a working “proof of concept” prototype as the most telling means of demonstrating the credibility of a technology. EEStor faces critics who argue that . Capacitor experts have repeatedly argued that EEStor technology claims contradict the postulates conventional science. From the viewpoint of philosophy of science, the postulates of conventional science become the null hypothesis, for the EEStor capacitor theory. A small working EESU prototype that performed would be all that would be required to quiet skeptics like me. Alas, to date no prototype has been produced, despite the claim of EEStor to have passed all of the technological milestones standing in the way of building the prototype.

Now let us consider another story. Let us suppose that there is a substance, which we can call “element T”. Now “element T” has so much energy locked into it, that a single mine located on the Idaho-Montana border could produce enough energy to sustain the American economy to over a thousand years. Suppose that the power of this “element T” was so great that simply by excavating rocks from the crust of the earth, and chemically extracting a few atoms from every ton would produce enough “element T” to generate far more power than the extraction of “element T” required. Now further suppose that the purity of “Element T” coming from the mine located on the Idaho-Montana border was of such purity that 4 guys with shovels and a pickup truck could dig up enough in a day, to power a huge electrical generating plant for a year.

Fantastic, you say, there is more.

Sixty years ago, some brilliant scientists discovered a simple but radical technology that could the energy from “element T”. Let’s call it the “T” machine. Scientists developed two proof of concept prototype “T” machine in the 1950’s and 1960’s. The “T” machines impressed the scientist with their success. The scientist research showed that the “T” machines could alter “element T” in to a form of matter from which the energy of “element T” could be extracted. The “T” machine was judged by scientist to be amazingly safe. Unlike coal fired power plants and conventional reactors, the “T” machine produced very little little waste, at most only a few hundred pounds a year.

And geologists found enough “element T” in Vermont to power the United States for tens of thousands of years.

Then when scientists proposed building a “T” power plant, A shadowy government bureaucrat named Milton Shaw, who fought against improving nuclear safety during the Nixon Administration, order the MSR research project shut down.

Thousands of pages of documents reporting the scientists research successes on the “T Machine” are now buried dusty government archives, like the Ark of the Covenant in “Raiders of the Lost Ark”.

“Where did you come up with such a fantastic story,” you say.

All of the story I just told is true. The promise of sustainable virtually unlimited power from thorium is laid out in dozens of research reports and proposals, and in the virtually reports of geologists.

I knew the story because my father, Dr. C.J. Barton, Sr., was one of the scientists who worked on the “T machine” between 1950, and 1969. My father, and the other scientists called the machine they were creating the Molten Salt Reactor (MSR). “Element T” is really called Thorium. The “T machine,” is now called the Liquid Fluoride Thorium Reactor (LFTR). The late Alvin Weinberg, the brilliant and charismatic Director of Oak Ridge National Laboratory described the MSR/LFTR as "elegant and so well thought-out".

Dr. Weinberg, who invented the Light Water Reactor design, that is now use world wide in nuclear power plants as well as in nuclear powered Navy ships. Weinberg said, "The molten-salt technology is entirely different from the technology of any other reactor. To the inexperienced, molten-salt technology is daunting. . . I hope that in a second nuclear era, the molten-salt technology will be resurrected.”

Kirk Sorensen and I have separately told the story. Kirk on “Energy from Thorium” and I on both “Nuclear Green” and Energy from Thorium. (For those who prefer to listen, Kirk tells the story to fellow nuclear blogger Rod Adams here.) /

Shortly before he died, Nobel Prize winning physicist, Dr. Edward Teller, began working on a paper on MSR/LFTRs. Teller died before the paper was finished, but the paper was finished by a colleague, Dr. Ralph Moir.

In their joint paper, Teller and Moir told of “advantages [ of the MSR/LFTR] that include utilization of ,an abundant fuel, inaccessibility of that fuel to terrorists or for diversion to weapons use, together with good economics and safety features . . .”

Dr. Moir told me, “[Teller] believed building a small molten salt reactor . . .was most urgent because our energy options are running out (especially natural gas).”

Dr. Moir said that the MSR/LFTR “holds the promise of being more economical than our present reactors while using less fuel. . . It can come in small sizes without as much of a penalty as is usually the case and can be in large sizes. It can burn thorium thereby getting away from so much buildup of plutonium and higher actinides.”

Other scientists, including world famous reactor scientist, Dr. Alvin Weinberg, who invented the Light Water Reactor design, that is now use world wide in nuclear power plants as well as in nuclear powered Navy ships. Weinberg said, The molten-salt technology is entirely different from the technology of any other reactor. To the inexperienced, molten-salt technology is daunting. . . I hope that in a second nuclear era, the molten-salt technology will be resurrected.”

Oak Ridge scientist, Uri Gat considered the MSR/LFTR to potentially be, the ultimately safe reactor. Gat notes that the MSR design features a high level of passive safety, that is safety features that operate automatically by taking advantage of the laws of nature. Gat, along with many other scientists, have pointed out that because the fuel in the MSR/LFTR is already suspended in a hot liquid, core meltdown is not a problem.

Scientist agree that Three Mile Island and Chernobyl type accidents would be impossible with MSR/LFTR type reactors.

Gat and two associates J. R. Engel of Oak Ridge National Laboratory, and Dr. H. L. Dodds pf the University of Tennessee, have argued that the MSR is the good tool for disposing of uranium and plutonium from nuclear weapons. They also argue that MSR's can burn nuclear waste as fuel, meaning that the problem of nuclear waste can almost be eliminated. Other scientists agree with them.

Another Oak Ridge scientist, Dr. Herbert G. MacPerson , also pointed to the cost advantages of MSR/LFTRs. MacPerson said that the real reason that the MSR was not developed was a lack of political support.

Alvin Weinberg explained why research on the the MSR/LFTR was stopped by saying, “the moral to be drawn is that a technology that differs too much from an existing technology has not one hurdle to overcome—to demonstrate its feasibility—but another even greater one—to convince influential individuals and organizations who are intellectually and emotionally attached to a different technology."

And so the secret of the MSR/LFTR has remained hidden in dusty government warehouses for almost 40 years.

Advice to the New Thorium Industry

Blogging can be an adventure.  A week and a half ago, I wrote about the abundance of uranium and thorium.  The evidence pointed to uranium being so abundant as to be all practical purposes, a renewable resource. In contrast the USGS reported thorium reserves seemed rare.  Yet it was universally acknowledged that thorium was at least three times as plentiful as uranium.  This made no sense.  Then I found a report by Conrad Windham on thorium  resources.  Conrad Windham is a speculator, not a geologist, but Windham reported a tremendous geological find at Lemhi Pass in Idaho.  According to Windham, there was enough thorium in the ground there to power the United States for several centuries, and quite possibly enough to power the United States for over 2000 years.  Subsequently I found similar statements from Jack Loften. Loften had attended a meeting of geologists at which a paper on the Lemhi Pass find was read and discussed. Finally I located a confirmation of the Lemhi Pass find on the the Web pages of Thorium Energy, the owner of the Lemhi Pass stake.  So It is beyond reasonable doubt Thorium Energy is the owner of a very large thorium find.  

The implication of the Lemhi Pass are staggering.  There are many advantages to the use of thorium rather than uranium in the nuclear fuel cycle.  The thorium fuel cycle largely solves the problem of nuclear waste, it is proliferation resistant, and  inherently safe thorium fueled reactors have been designed and tested.

The problem for Thorium Energy is not going to be getting the thorium out of the ground, indeed they are claiming a potential of "25 to 63 percent thorium oxide (ThO 2) per ton of raw ore. Thus one ton of thorium ore could potentially yield as much as 500-1,200 lbs. of high grade thorium oxide (ThO2)." The problem then will be finding the reactors into which the thorium will go.

There are several obstacles to the massive potential sale of thorium that are possible given the extent of the Lemhi Pass resources. The Light Water Reactor (LWR), the type of reactor used by the nuclear industry is extremely expensive. There are are numerous inefficiencies associated with the LWR concept.  The LWR uses its fuel very inefficiently, and indeed most of the potential energy in its fuel is not extracted by the LWR.  The inefficiency of the LWR fuel cycle in turn creates the problem of nuclear waste.  

A second inefficiency has to do with reprocessing nuclear fuel.  The solid reactor fuel in light water reactors must be broken down into a liquid soluble form, and chemically processed.  This chemical processing of highly radioactive fuels is highly expensive.  A more efficient reactor design would use fuel in a form that would me more easily to process chemically.  

Finally, the LWR is inefficient in its use of the heat it produces. The LWR is limited by the use of water as a heat transfer medium. Water is not a very efficient means of transferring the heat nuclear fuel is capable of producing. Yet the higher output heat leads to greater the output heat from a reactor, the greater its thermal efficiency. Thus a more efficient reactor would use a heat transport fluid that is more efficient than water.

Paradoxically the inefficiencies of LWR contribute to the expense of building them, and create many of their problems. The inefficiencies of the light water reactor are the greatest obstacle to the the sale of thorium.

The 19th century economist, William Stanley Jevons provides us with a central clue: "It is the very economy of its [coal's] use which leads to its extensive consumption."

Jevons added: "It needs but little reflection to see that the whole of our present vast industrial system, and its consequent consumption of coal, has chiefly arisen from successive measures of economy."

"Civilization, says Baron Liebig, is the economy of power, and our power is coal. It is the very economy of the use of coal that makes our industry what it is; and the more we render it efficient and economical, the more will our industry thrive, and our works of civilization grow."

The lesson to the thorium produces is clear, if you want to sell more thorium, greater reactor economies are required. Those efficiencies are to be found in the management of heat, and in the processing of fuel, as well as in other aspects of reactor design that can lower reactor cost.
Reactor scientist at Oak Ridge National Laboratory, during the 1950's, looked at the problem of reactor design. They had invented the light water reactor, but were acutely aware of its limitations. They believed that reactors could be more efficient if the nuclear fuel were suspended in a fluid, rather than inserted into the reactor in a solid form. By suspending the fuel in a fluid, it became more easily accessible for chemical processing. After some research, they determined that the best fluid for this purpose was hot liquid fluoride salts. A test reactor was built, and it performed well. The liquid fluoride approach was seen to work well with a thorium fuel process, because there was the potential to continuously process the fuel and blanket salts. Much of the chemical processing would be relatively inexpensive, because much of the chemistry for the process was fairly simple and well understood within the nuclear industry.

As Oak Ridge scientists studied the potential of a reactor used nuclear fuel suspended in liquid fluoride salts, they found more and more to like about it. It was far far safer than LWR. It could produce from thorium, an atom of fissionable U233, for every atom of U233 it burned. Some fission products could be easily removed from the reactor, while others radioactive isotopes could remain in the reactor salts fluid, until the reactor was removed from service. At that point they could be processed out of the salt fluid, and after loosing their radioactivity, the many valuable materials that had been produced by the nuclear process, could be recycled into industry. Thus the supposed problem of nuclear waste could be solved.

Political opposition by government bureaucrats and powerful members of Congress eventually killed research into a Liquid Fluoride Thorium Reactor (LFTR). Many scientist, however, continued to believe that the LFTR has many unique advantages.  In his last paper (Thorium fueled underground power plant based on molten salt technology, ), Edward Teller wrote, 

"Our economic goal is to achieve a cost of electrical energy averaged over the life of the power station to be no more than that from burning fossil fuels at the same location. Past studies have shown a potential for the molten salt reactor to be somewhat lower in cost of electricity than both coal and LWRs. There are several reasons for substantial cost savings: low pressure operation, low operations and maintnance costs, lack of fuel fabrication, easy fuel handling, low fissile inventory, use of multiple plants at one site allowing sharing of facilities, and building large plant sizes. The cost of undergrounding the nuclear part of the plant obviously needs to be determined and will likely not offset the cost advantages of a liquid-fueled low-pressure reactor." 

In a separate research proposal (Deep-Burn Molten-Salt Reactors ), Ralph Moir of Lawrence Livermore National Laboratory, who co-authored Teller's last paper, togeather with T. J. Dolan, of Idaho National Engineering and Environmental Laboratory, Sean M. McDeavitt of Argonne National Laboratory, D. F. Williams and C. W. Forsberg of Oak Ridge National Laboratory, and E. Greenspan and J. Ahn of the University of California, Berkeley wrote,

"Molten salt reactors have the potential of meeting the goals of Generation IV reactors
better than solid fuel reactors. They also have the potential of meeting the goals of the
high-level waste transmutation program better than solid fuel reactors. In fact, they may
enable doing most if not all of the transmutation planned for accelerator-driven
subcritical reactors."

They stated:

We know qualitatively that there are many benefits of MSRs relative to other fission power plants:
reliable low pressure operation
no solid fuel fabrication
online refueling
negative temperature coefficient
negative void coefficient
low radioactive source term
potential for large unit size
thorium resource utilization
high fuel burnup
high temperature and thermal efficiency
LWR actinide burnup
proliferation resistance
low HLW mass and repository requirements
low capital cost.

Clearly then the LFTR-Molten salt reactor has significant economical advantages that bring the reactor economies that will in turn promote thorium sales.