Powering the future – with no compromises

A molten salt reactor (MSR) is a class of nuclear fission reactor in which the primary nuclear reactor coolant and/or the fuel is a molten salt mixture. MSRs offer multiple advantages over conventional nuclear power plants, although for historical reasons, they have not been deployed.

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Molten Salt Reactors

(from World-Nuclear Association)

  • Molten salt reactors operated in the 1960s.
  • They are seen as a promising technology today principally as a thorium fuel cycle prospect or for using spent LWR fuel.
  • A variety of designs is being developed, some as fast neutron types.
  • Global research is currently led by China.
  • Some have solid fuel similar to HTR fuel, others have fuel dissolved in the molten salt coolant.

Molten salt reactors (MSRs) use molten fluoride salts as primary coolant, at low pressure. This itself is not a radical departure when the fuel is solid and fixed. But extending the concept to dissolving the fissile and fertile fuel in the salt certainly represents a leap in lateral thinking relative to nearly every reactor operated so far. However, the concept is not new, as outlined below.

MSRs may operate with epithermal or fast neutron spectrums, and with a variety of fuels. Much of the interest today in reviving the MSR concept relates to using thorium (to breed fissile uranium-233), where an initial source of fissile material such as plutonium-239 needs to be provided. There are a number of different MSR design concepts, and a number of interesting challenges in the commercialisation of many, especially with thorium.

The salts concerned as primary coolant, mostly lithium-beryllium fluoride and lithium fluoride, remain liquid without pressurization from about 500°C up to about 1400°C, in marked contrast to a PWR which operates at about 315°C under 150 atmospheres pressure.

The main MSR concept is to have the fuel dissolved in the coolant as fuel salt, and ultimately to reprocess that online. Thorium, uranium, and plutonium all form suitable fluoride salts that readily dissolve in the LiF-BeF2(FLiBe) mixture, and thorium and uranium can be easily separated from one another in fluoride form. Batch reprocessing is likely in the short term, and fuel life is quoted at 4-7 years, with high burn-up. Intermediate designs and the AHTR have fuel particles in solid graphite and have less potential for thorium use.

Graphite as moderator is chemically compatible with the fluoride salts.

Background

During the 1960s, the USA developed the molten salt breeder reactor concept at the Oak Ridge National Laboratory, Tennessee (built as part of the wartime Manhattan Project). It was the primary back-up option for the fast breeder reactor (cooled by liquid metal) and a small prototype 8 MWt Molten Salt Reactor Experiment (MSRE) operated at Oak Ridge over four years to 1969 (the MSR program ran 1957-1976). In the first campaign (1965-68), uranium-235 tetrafluoride (UF4) enriched to 33% was dissolved in molten lithium, beryllium and zirconium fluorides at 600-700°C which flowed through a graphite moderator at ambient pressure. The fuel comprised about one percent of the fluid.

The coolant salt in a secondary circuit was lithium + beryllium fluoride (FLiBe).* There was no breeding blanket, this being omitted for simplicity in favour of neutron measurements.

* Fuel salt melting point 434°C, coolant salt melting point 455°C. See Wong & Merrill 2004 reference.

The original objectives of the MSRE were achieved by March 1965, and the U-235 campaign concluded. A second campaign (1968-69) used U-233 fuel which was then available, making MSRE the first reactor to use U-233, though it was imported and not bred in the reactor. This program prepared the way for building a MSR breeder utilising thorium, which would operate in the thermal (slow) neutron spectrum.

According to NRC 2007, the culmination of the Oak Ridge research over 1970-76 resulted in a MSR design that would use LiF-BeF2-ThF4-UF4 (72-16-12-0.4) as fuel. It would be moderated by graphite with a four-year replacement schedule, use NaF-NaBF4 as the secondary coolant, and have a peak operating temperature of 705°C.

The R&D program demonstrated the feasibility of this system, albeit excluding online reprocessing, and highlighted some unique corrosion and safety issues that would need to be addressed if constructing a larger pilot MSR with fuel salt. Challenges would include processing facilities to remove the main fission products, though gaseous fission products come off readily in the gas purge system. It also showed that breeding required a different design, with a larger blanket loop and two fluids (heterogeneous). Tritium production was a problem (see below re lithium enrichment).

In 1980 Oak Ridge published a study to “examine the conceptual feasibility” of a denatured MSR (DMSR) fuelled with low-enriched uranium-235 “and operated with a minimum of chemical processing,” solely as a burner reactor. The main priority was proliferation resistance, avoiding use of HEU.

In the UK a large (2.5 GWe) lead-cooled fast spectrum MSR (MSFR) with the plutonium fuel dissolved in a molten chloride salt was designed, with experimental work undertaken over 1968-73. Funding ceased in 1974.

There is now renewed interest in the MSR concept in Japan, Russia, China, France and the USA, and one of the six Generation IV designs selected for further development is the MSR in two distinct variants, the molten salt fast reactor (MSFR) and the advanced high temperature reactor (AHTR) – also known as the fluoride salt-cooled high-temperature reactor (FHR) with solid fuel, or PB-FHR specifically with pebble fuel. The Generation IV international Forum (GIF) mentions ‘salt processing’ as a technology gap for MSRs, putting the initial focus clearly on burners rather than breeders.

Since the 2002 Generation IV selection process, significant changes in design philosophy have taken place, according to a 2015 report by Energy Process Developments Ltd (EPD). The first is to design simpler, less ambitious, molten salt reactors that do not breed new fuel, do not require online fuel reprocessing and which use the well-established enriched uranium fuel cycle. In this regard, both American researchers and the China Academy of Sciences/SINAP are working on solid fuel, salt-cooled reactor technology as a realistic first step into MSRs. In 2014, as part of an assessment of MSR activity internationally, proposals were made for pilot-scale implementation, where technical readiness was claimed. Six such specific proposals* were assessed over 12 months with commissioned expertise from established UK nuclear engineering firms. These proposals were all seen as credible for building a prototype, with one emerging in the EPD report as currently most suitable as a basis for UK MSR development, the Moltex SSR.

* from Flibe Energy, ThorCon, Moltex, Seaborg Technologies, Terrestrial Energy and Transatomic Power.

Function

In the normal or basic MSR concept, the fuel is a molten mixture of lithium and beryllium fluoride (FLiBe) salts with dissolved low-enriched uranium (U-235 or U-233) fluorides (UF4). The core consists of unclad graphite moderator arranged to allow the flow of salt at about 700°C and at low pressure. Much higher temperatures are possible but not yet tested. Heat is transferred to a secondary salt circuit and thence to steam or process heat. The basic design is not a fast neutron reactor, but with some moderation by the graphite is epithermal (intermediate neutron speed) and breeding ratio is less than 1.

However, this concept, with fuel dissolved in the salt, is further from commercialisation than solid fuel designs, where the ceramic fuel may be set in prisms, plates, or pebbles, or one design with liquid fuel in static tubes. Reprocessing that fuel salt online is even further from commercialization.

Considering liquid-fuel MSR designs, thorium can be dissolved with the uranium in a single fluid MSR, known as a homogeneous design. Two-fluid, or heterogeneous MSRs, would have fertile salt containing thorium in a second loop separate from the fuel salt containing fissile uranium or plutonium and could operate as a breeder reactor (MSBR). Here, the U-233 is progressively removed* and transferred to the primary circuit. However, graphite degradation from neutron flux limits the useful life of the reactor core with the fuel and breeding fluids in close juxtaposition, and in the 1960s it was assumed that the entire reactor vessel in the two-fluid design would be replaced after about eight years.**

e.g. by bubbling fluorine through the salt so that UF6 is formed and removed as a gas. The UF6 is reduced and added to the fuel stream.

** Graphite is used to slow neutrons in epithermal designs, and deteriorates in a high neutron flux environment. The rate of damage increases with temperature, which is a particular problem with MSRs at 700°C.

In liquid-fuel MSR designs the fission products dissolve in the fuel salt and are ideally removed continuously in an adjacent online reprocessing loop and replaced with fissile uranium, plutonium and other actinides or, potentially, fertile Th-232 or U-238. Meanwhile caesium and iodine in particular remain secure in the molten salt. Xenon is removed rapidly by outgassing, but protactinium-233 is a problem with thorium as a fuel source. (It is an intermediate product in producing U-233 and is a major neutron absorber.) Constant removal of fission products means that a much higher fuel burn-up could be achieved (> 50%) and the removal of fission products means less decay heat to contend with after reactor shutdown. Actinides are fully recycled and remain in the reactor until they fission or are converted to higher actinides which do so. Hence fissile plutonium is largely consumed, and contributes significant energy. The high-level waste would comprise fission products only, hence with shorter-lived radioactivity.

Compared with solid-fuelled reactors, MSR systems with circulating fuel salt are claimed to have lower fissile inventories*, no radiation damage constraint on fuel burn-up, no requirement to fabricate and handle solid fuel or solid used fuel, and a homogeneous isotopic composition of fuel in the reactor. Actinides are less-readily formed from U-233 than in fuel with atomic mass greater than 235. These and other characteristics may enable MSRs to have unique capabilities and competitive economics for actinide burning and extending fuel resources. Safety is high due to passive cooling up to any size. Also, several designs have freeze plugs so that if excessive temperatures are reached, the primary salt will be drained by gravity away from the moderator into dump tanks configured to prevent criticality.

* In particular, a small inventory of weapons-fissile material (Pu-242 being the dominant Pu isotope remaining), and low fuel use (the French self-breeding variant claims 50kg of thorium and 50kg U-238 per billion kWh).

MSRs have large negative temperature and void coefficients of reactivity, and are designed to shut down due to expansion of the fuel salt as temperature increases beyond design limits. The negative temperature and void reactivity coefficients passively reduce the rate of power increase in the case of an inadvertent control rod withdrawal (technically known as a ‘reactivity insertion’). When tests were made on the MSRE, a control rod was intentionally withdrawn during normal reactor operations at full power (8 MWt) to observe the dynamic response of core power. Such was the rate of fuel salt thermal expansion that reactor power levelled off at 9 MWt without any operator intervention.

The MSR thus has a significant load-following capability where reduced heat abstraction through the boiler tubes leads to increased coolant temperature, or greater heat removal reduces coolant temperature and increases reactivity. Primary reactivity control is using the secondary coolant salt pump or circulation which changes the temperature of the fuel salt in the core, thus altering reactivity due to its strong negative reactivity coefficient. The MSR works at near atmospheric pressure, eliminating the risk of explosive release of volatile radioactive materials.

One MSR developer, Moltex, has put forward a molten salt heat storage concept (GridReserve) to enable the reactor to supplement intermittent renewables. Hot nitrate salt at about 600°C is transferred to storage tanks which are able to hold eight hours of reactor output at 2.5 GW thermal (as used in solar CSP plants). The heat store is said to add only £3/MWh to the levelised cost of electricity.

In the MSBR, the reactor-grade U-233 bred in the secondary circuit needs to be removed, or it will fission there and contaminate that circuit with ‘hot’ fission products. Therefore in practice the protactinium (Pa-233) formed from the thorium needs to be removed before it decays to U-233*, but this process is unproven at any scale. It is relatively easy to remove the U-233 from the Pa-233 by fluorination to UF6 before reducing it to UF4 for adding to the primary fuel salt circuit. However, the U-233 is contaminated with up to 400 ppm U-232 which complicates processing, due to its highly gamma-active decay progeny.

* Th-232 gains a neutron to form Th-233, which soon beta decays (half-life 22 minutes) to protactinium-233. The Pa-233 (half-life of 27 days) decays into U-233. Some U-232 is also formed via Pa-232 along with Th-233, and a decay product of this is very gamma active.

MSRs would normally operate at much higher temperatures than LWRs – up to at least 700°C, and hence have potential for process heat. Up to this temperature, satisfactory structural materials are available. ‘Alloy N’ is a nickel-based alloy (Ni-Cr-Mo-Si) developed at ORNL specifically for MSRs with fluoride salts.

Primary and secondary cooling, the fluoride salts

Fluoride salts have very low vapour pressure even at red heat, carry more heat than the same volume of water, have reasonably good heat transfer properties, are not damaged by radiation, do not react violently with air or water, and are inert to some common structural metals. However having the fuel in solution also means that the primary coolant salt becomes radioactive, complicating maintenance procedures, and the chemistry of the salt must be monitored closely to maintain a chemically reduced state to minimise corrosion. Also the beryllium in the salt is toxic, which leads to at least one design avoiding it, though this requires higher temperatures to keep LiF liquid. LiF however can carry a higher concentration of uranium than FLiBe, allowing less enrichment. There are difficulties with plutonium and other TRU fluorides in fluoride solvents.

Lithium used in the salt must be fairly pure Li-7, since Li-6 produces tritium when (readily) fissioned by neutrons. Li-7 has a very small neutron cross-section (0.045 barns). This means that lithium must be enriched beyond its natural 92.5% Li-7 level to minimise tritium production. Lithium-7 is being produced at least in Russia and possibly China today as a by-product of enriching lithium-6 to produce tritium for thermonuclear weapons. See also Lithiumpaper.

LiF is exceptionally stable chemically, and the LiF-BeF2 mix (‘FLiBe’)* is eutectic (at 459°C it has a lower melting point than either ingredient – LiF is about 500°C). It boils at 1430°C. It is favoured in MSR and AHTR primary cooling and when uncontaminated has a low corrosion effect. The three nuclides (Li-7, Be, F) are among the few to have low enough thermal neutron capture cross-sections not to interfere with fission reactions.

* Approx. 2:1 molar, hence sometimes represented as Li2BeF4

LiF without the toxic beryllium solidifies at about 500°C and boils at about 1200°C. FLiNaK (LiF-NaF-KF) is also eutectic and solidifies at 454°C and boils at 1570°C. It has a higher neutron cross-section than FLiBe or LiF but can be used in intermediate cooling loops. Sodium-beryllium fluoride (BeF2-NaF) solidifying at 385°C is used as fuel salt in one design for cost reasons.

The hot molten salt in the primary circuit can be used with secondary salt circuit or secondary helium coolant generating power via the Brayton cycle as with HTR designs, with potential thermal efficiencies of 48% at 750°C to 59% at 1000°C, or simply with steam generators. In industrial applications molten fluoride salts (possibly simply cryolite – Na-Al fluoride) are a preferred interface fluid in a secondary circuit between the nuclear heat source and any chemical plant. The aluminium smelting industry provides substantial experience in managing them safely.

Most secondary coolant salts do not use lithium, for cost reasons. ZrF4-NaF-KF, ZrF4-KF, NaF-BeF2 eutectic mixes are usual, as well as LiF-NaF-KF (FLiNaK).

In the secondary cooling circuit of the AHTR concept, air is compressed, heated, flows through gas turbines producing electricity, enters a steam recovery boiler producing steam that produces additional electricity, and exits to the atmosphere. Added peak power can be produced by injecting natural gas (or hydrogen in the future) after nuclear heating of the compressed air to raise gas temperatures and plant output, giving it rapidly variable output (of great value in grid stability and for peak load demand where renewables have significant input). This is described as an air Brayton combined-cycle (ABCC) system in secondary circuit.

In the 1960s MSRE, an alternative secondary coolant salt considered was 8% NaF + 92% NaF-BeF2 with melting point 385°C, though this would be more corrosive.

Chloride salts, fast spectrum reactors

Chloride salts have some attractive features compared with fluorides, in particular the actinide trichlorides form lower melting point solutions and have higher solubility for actinides so can contain significant amounts of transuranic elements. PuCl3 in NaCl has been well researched. While NaCl has good nuclear, chemical and physical properties, its high melting point means it needs to be blended with MgCl2 or CaCl2, the former being preferred in eutectic, and allowing the addition of actinide trichlorides. The major isotope of chlorine, Cl-35 gives rise to Cl-36 as an activation product – a long-lived energetic beta source, so Cl-37 is much preferable in a reactor.

A British design contains the chloride fuel salt in vertical tubes and relies on convection to circulate the secondary salt coolant, which is a fluoride mix.

Fast spectrum MSRs (MSFRs) can have conversion ratios ranging from burner to converter to breeder. This may be within a single unit as the ratio of U-238 to transuranics (TRU) is varied – less U-238 giving more fission. They can be optimised for burning minor actinides, for breeding plutonium from U-238, or they may be open-cycle power plants without heavy metal separation from fission products. The fast neutron spectrum allows the possibility of not having onsite processing to remove TRUs. While fission products have relatively large neutron capture cross sections in the thermal energy range, the capture cross sections at higher energies is much lower, allowing much greater fission product build-up in an MSFR than in a thermal-spectrum MSR (gaseous fission products separate out of the liquid fuel). Eventually the fuel salt heavily loaded with fission products can be sent occasionally for batch processing or allowed to solidify and be disposed of in a repository. For full breeder configuration the fissile material needs to be progressively removed.
 
MSFRs have a negative void coefficient in the salt and a negative thermal reactivity feedback, so can maintain a high power density with passive safety. Freeze plugs to drain the fuel salt are a further passive safety measure as in other MSRs.

MSR research emphasis

American researchers and the China Academy of Sciences/SINAP are working primarily on solid fuel MSR technology. The main reason is that this is a realistic first step. In China this is focused on thorium-fuelled versions (see TMSR in China’s dual program section below). The technical difficulty of using molten salts is significantly lower when they do not have the very high activity levels associated with them bearing the dissolved fuels and wastes. The experience gained with component design, operation, and maintenance with clean salts makes it much easier then to move on and consider the use of liquid fuels, while gaining several key advantages from the ability to operate reactors at low pressure and deliver higher temperatures.

In the Generation IV program for the MSR, collaborative R&D is pursued by interested members under the auspices of a provisional steering committee. There will be a long lead time to prototypes, and the R&D orientation has changed since the project was set up, due to increased interest. It now has two baseline concepts:

  • The Molten Salt Fast Neutron Reactor (MSFR), which will take in thorium fuel cycle, recycling of actinides, closed Th/U fuel cycle with no U enrichment, with enhanced safety and minimal wastes. it is a liquid-fuel design.
  • The Advanced High-Temperature Reactor (AHTR) – also known as the fluoride salt-cooled high-temperature reactor (FHR) – with the same graphite and solid fuel core structures as the VHTR and molten salt as coolant instead of helium, enabling power densities 4 to 6 times greater than HTRs and power levels up to 4000 MWt with passive safety systems. A 5 MWt prototype is under construction at Shanghai Institute of Nuclear Applied Physics (SINAP, under the China Academy of Sciences) with 2015 target for operation.

The GIF 2014 Roadmap said that a lot of work needed to be done on salts before demonstration reactors were operational, and suggested 2025 as the end of the viability R&D phase.

Russia’s Molten Salt Actinide Recycler and Transmuter (MOSART) is a fast reactor fuelled only by transuranic (TRU) fluorides from uranium and MOX LWR used fuel. It is part of the MARS project (minor actinide recycling in molten salt) involving RIAR, Kurchatov and other research organisations. The 2400 MWt design has a homogeneous core of Li-Na-Be or Li-Be fluorides without a graphite moderator and has reduced reprocessing compared with the original US design. Thorium may also be used, though it is described as a burner-converter rather than a breeder.

The SAMOFAR (Safety Assessment of the Molten Salt Fast Reactor) project, based in the Netherlands and funded by the European Commission, aims to prove the safety concepts of the MSFR in breeding mode from thorium. It plans advanced experimental and numerical techniques, to deliver a breakthrough in nuclear safety and optimal waste management, and to create a consortium of stakeholders. “The use of the Th-U fuel cycle is of particular interest to the MSR, because this reactor is the only one in which the Pa-233 can be stored in a hold-up tank to let it decay to U-233.” The SAMOFAR consortium consists of 11 participants and is mainly undertaken by universities and research laboratories such as CNRS, JRC, CIRTEN, TU Delft and PSI, thereby exploiting each other’s expertise and infrastructure. It commenced in 2015.

China’s dual program

China plans for the TMSR-SF to be an energy solution for the northwest half of the country, with lower population density and little water. The application of water-free cooling in arid regions is envisaged from about 2025.

The China Academy of Sciences in January 2011 launched an R&D program on LFTRs, known there as the thorium-breeding molten-salt reactor (Th-MSR or TMSR), and claimed to have the world’s largest national effort on it, hoping to obtain full intellectual property rights on the technology. The TMSR Centre at Shanghai Institute of Applied Physics (SINAP, under the Academy) at Jiading is responsible. In the 1970s SINAP worked towards building a 25 MWe MSR, but this endeavor gave way to the Qinshan PWR project.

SINAP has two streams of TMSR development – solid fuel (TRISO in pebbles or prisms/blocks) with once-through fuel cycle, and liquid fuel (dissolved in fluoride coolant) with reprocessing and recycle. A third stream of fast reactors to consume actinides from LWRs is planned. The aim is to develop both the thorium fuel cycle and non-electrical applications in a 20-30 year timeframe.

  • The TMSR-SF stream has only partial utilization of thorium, relying on some breeding as with U-238, and needing fissile uranium input as well. It is optimized for high-temperature based hybrid nuclear energy applications. SINAP aimed at a 2 MW pilot plant initially, though this has been superseded by a simulator (TMSR-SF0) to be followed by a 10 MWt prototype (TMSR-SF1) before 2025. A 100 MWt demonstration pebble bed plant (TMSR-SF2) with open fuel cycle would follow, then a 1 GW demonstration plant (TMSR-SF3). TRISO particles will be with both low-enriched uranium and thorium, separately.
  • The TMSR-LF stream claims full closed Th-U fuel cycle with breeding of U-233 and much better sustainability with thorium but greater technical difficulty. It is optimized for utilization of thorium with electrometallurgical pyroprocessing. SINAP aims for a 2 MWt pilot plant (TMSR-LF1) initially, then a 10 MWt experimental reactor (TMSR-LF2) by 2025, and a 100 MWt demonstration plant (TMSR-LF3) with full electrometallurgical reprocessing by about 2035, followed by 1 a GW demonstration plant. The TMSR-LF timeline is about ten years behind the SF one.
  • TMSFR-LF fast reactor optimized for burning minor actinides is to follow.

SINAP sees molten salt fuel being superior to the TRISO fuel in effectively unlimited burn-up, less waste, and lower fabricating cost, but achieving lower temperatures (600°C+) than the TRISO fuel reactors (1200°C+). Near-term goals include preparing nuclear-grade ThF4 and ThO2 and testing them in a MSR. It appears that the postponement of building the 2 MW test reactor may be due to inadequate supplies of pure lithium-7.

The TMSR-SF program is proceeding with preliminary engineering design in cooperation with the Nuclear Power Institute of China (NPIC) and Shanghai Nuclear Engineering Research & Design Institute (SNERDI). Nickel-based alloys are being developed for structures, along with very fine-grained graphite.

Two methods of tritium stripping are being evaluated, and also tritium storage.

The 10 MWt TMSR-SF1 will have TRISO fuel in 60mm pebbles, similar to HTR-PM fuel, and deliver coolant at 650°C and low pressure. Primary coolant is FLiBe (with 99.99% Li-7) and secondary coolant is FLiNaK. Core height is 3 m, diameter 2.85 m, in a 7.8 m high and 3 m diameter pressure vessel. Residual heat removal is passive, by cavity cooling. A 20-year operating life is envisaged. The TMSR-SF0 simulator is one-third scale, with FLiNaK cooling and a 400 kW electric heater.

The 2 MWt TMSR-LF1 is only at the conceptual design stage, but it will use fuel enriched to under 20% U-235, have a thorium inventory of about 50 kg and conversion ratio of about 0.1. FLiBe with 99.95% Li-7 would be used, and fuel as UF4. The project would start on a batch basis with some online refuelling and removal of gaseous fission products, but discharging all fuel salt after 5-8 years for reprocessing and separation of fission products and minor actinides for storage. It would proceed to a continuous process of recycling salt, uranium and thorium, with online separation of fission products and minor actinides. It would work up from about 20% thorium fission to about 80%.

Beyond these, a 373 MWt/168 MWe liquid-fuel MSR small modular reactor is planned, with supercritical CO2 cycle in a tertiary loop at 23 MPa using Brayton cycle, after a radioactive isolation secondary loop. Various applications as well as electricity generation are envisaged. It would be loaded with 15.7 tonnes of thorium and 2.1 tonnes of uranium (19.75% enriched), with one kilogram of uranium added daily, and have 330 GWd/t burn-up with 30% of energy from thorium. Online refuelling would enable eight years of operation before shutdown, with the graphite moderator needing attention.

The US Department of Energy is collaborating with the China Academy of Sciences on the program, which had a start-up budget of $350 million. TMSR commercial deployment is anticipated in the 2030s.

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144 thoughts on “Powering the future – with no compromises

    • Brilliant list and well written summary!

      23. No need to be sited near a large body of water or river… areas typically densely settled and jealously guarded by humans. This gives nuclear energy something it has never had before, the ability to site plants in the West or as far away from population centers as desired. LFTR designs may even be compact enough to place directly within existing right-of-way corridors of HV pylons, yielding many site choices and eliminating the need for branching feeders.

    • “although for historical reasons, they have not been deployed.” Give me a break. The historical reason is regulatory capture of the NRC, and anyone who could do anything about it are to chicken or interested to challenge it.

  1. Still the best all around introduction.

    https://www.youtube.com/watch?v=lG1YjDdI_c8

    THORIUM REMIX 2011 [2:23:49], INDEX OF CONTENT: LFTR in 5 minutesDialogue on Energy sources & conservationElizabeth May (Green Party of Canada) on why nuclear ‘fails’, responseKirk Sorensen’s time at NASA, discovering molten salt researchOn Glenn Seaborg’s discovery of Thorium’s fissile properties in 1942What nuclear fission is, decay chains, half lifeNeutron absorption, cross section, Xenon poisoning at HanfordIsotopic enrichment, Thorium/u233 rejected for weaponsAtoms for Peace, absorption propensity and performance of nuclear fuels, thermal & fast spectrum, Thorium/Plutonium debateAlvin Weinberg focuses on Thorium and liquid fuels, Oak Ridge Labs, Aircraft Reactor Experiment, the Molten Salt Reactor Experiment, Fluoride SaltsTwo-fluid molten salt reactorLight water reactors, Watts Bar, reactor safety and containment systems, issues with water, Fukushima Daiichi hydrogen explosionsSolid fuel & rod assemblies, Eugene Wigner & liquid fuelsPWR efficiency, Weinberg’s quest for near-100% utilization, AEC’s choice to pursue Plutonium fast breedersWeinberg’s concerns about LWR safety, Congressman Chet Hollifeld’s inquiry, Weinberg leaves Oak Ridge, WASH-1222, Integral Fast Reactor, Traveling WaveFusion is hardThorium in a CANDUColonel Paul Roege on military reactors, Robert Hargraves: prosperity is related to energy, Robert F. Kennedy on mercury from coalTransuranics, LFTR active processing, electricity & isotope production from LFTR, Pu-238 and RTGs, Molybdenum-99 & Bismuth-213 in medicineCost to build LFTRProliferation concernsHysterical news coverage of radiation, LNTCoal & natural gas radioactive emissions, Thorium & Uranium decay in the Earth, magnetosphere, Hargraves on CO2 emissions & ocean acidification & energy density, one-sided press coverage for ‘renewables’Various approaches to nuclear power, the ‘reason why not’ (LFTR), LWR business modelChina and LFTR, Sorensen’s visit to Oak Ridge to obtain access to LFTR documents, the Chinese visit Oak RidgeThorium and rare earths, China’s domination of rare earths market, China’s LFTR programTransitioning energy sources, without plentiful energy we will revert to slavery, energy cheaper than from coalProcess heat applications, desalinization, synfuels, Brayton Cycle, managing transuranics, gas & oil working against nuclear, closing remarks and recap.

    • And… my April 2016 letter to candidate Donald Trump promoting all this stuff. I also sent Energy Secretary Perry a letter in 2017 warning of grid vulnerability from natural gas plants with little or no local storage.

      The Trump Administration has done more to protect our nuclear fleet than any recent president, though are met with resistance. The DOE has begun issuing grants to fund nuclear research again. Their proposed “90-day rule” would have granted some easement in the market to grid suppliers able to ‘stockpile’ 90 days’ worth of fuel on site (coal and nuclear), in an effort to prevent plants capable of doing so from being retired due to the cents-per-kWh volatility market now dominated by natural gas. I believe this is a matter of National Security with all that implies. That proposal was voted down by FERC who saw “no issue with grid reliability.” Time will tell.

    • If my memory serves me correctly, I posted that video on this website either in 2011 or 2012. I have been advocating it on this board ever since. I am almost ashamed to say that I have watched that video so many times I have the dialogue nearly memorized.

      I also have been posting Oak Ridge’s video of the reactor since Oak Ridge put it on line. I would post it again but it always gets flagged by the moderation crew and takes hours to post.

      This website has always seemed like a fossil fuel cheer-leading rag with a few of us nuclear supporters caught in the cross-hairs. I don’t have disdain for the fossil fuel industry. Far from it — most of my retirement is in Exxon stock and I was an attorney for Exxon for a couple years after law school. But fossil fuel just can not compete with the energy density of nuclear fuel. Full stop.

      • It has that effect on you too? You can thank Gordon McDowell who is an editing genius. The way he intersperses speakers, diagrams, slides and even simple text annotations that are deliberately crude so they pop out against the background and you can read them in an instant. And get the point! McDowell’s audio post-production is no less a marvel. He takes various lectures and stitches them together — snips as short as a word — with the perfect cadence of normal speech. Sorensen and McDowell have moved along since 2011 and may be uncomfortable that some are promoting this old thing. Newer edits are just as slick and up to date in many ways, and they have incorporated an incredible amount of NASA and space related material which will surely pull in a more Millennial audience. But I consider the TR2011 2-hour edit to be McDowell’s Mona Lisa.

        As to the force that drives us to promote it, I’ll just quote and link an excerpt of my 2016 letter to Trump again, in the hope that the mods do not think I’m trying to sell vacuum cleaners,

        A dusty book.

        As Dr. Sorensen tells it, he learned the details of these molten salt experiments some years past from a dusty old book. Imagine that. You make your way through the modern world with a sense of confidence that everything that is worth knowing is part of the curriculum you have been taught — or at least, there are experts out there young like yourself, who grasp these things fully. Some one somewhere is on-task. And surely there is an investor or two behind it. And then one day you open this dusty yellowed book and start to glimpse a future, a great future, that should have been but never was.

        You’re asking yourself… why? And you research it further to discover that the rest of the story is kept in a file cabinet at Oak Ridge, and of those who did this work few now survive, they are in their 80s and 90s. You seek them out to discover that they are still convinced theirs was the best approach. They are bitter that the road was not taken.

        If this quest had happened to me it would be a moving, even shocking experience. It would shake all confidence that our survival as a species was in any way ‘assured’. It would coalesce into a keen sense of desperation to carry on this work, to realize the dream Weinberg laid out. That is where Sorensen is, and he tells the story so well I experience a touch of it myself, which is why I write these letters.

    • You’ve got a better chance of being struck by lighting,…. Twice, before a commie government actually develops anything. Because the only thing sticking your neck out gets you is having it chopped off..

      • Chinese innovation presents a complicated picture. By the same token, scientific research in America is experiencing Eroom’s Law where “discovery is becoming slower and more expensive over time, despite improvements in technology”.

        We have the replication crisis where most published research findings are false, and therefore can’t be replicated. It’s a kind of corruption driven by the way grants are given out.

        So, China has problems but America has to deal with its own elephant in the room which can be described as the bureaucracy of the granting agencies and academia in general. For pure, or curiosity driven, research, there is no evidence that private industry is doing better than academia.

        There is a wonderful little book Why Greatness Cannot be Planned: The Myth of the Objective. It points out that incrementalism rarely leads to scientific breakthroughs and “search for novelty” is a much better approach. In other words, breakthroughs are usually the result of accident and we need the prepared minds to take advantage of those accidents. That requires a radical re-think of the way we fund and administer basic research.

        • Your first comment is more correct. The second about needing more research is not; the research and even testing has been done. All we need to do is get the bureaucrats, politicians and Lawyers out of the way.

      • The Chinese are building conventional reactors at a high rate and have not been stymied like the Westinghouse AP1000 reactors were – the U.S. has no ability to produce large reactor cores.

    • I don’t think that’s an accurate description. As I understand the history the MSR work in the USA was stopped at the orders of President Nixon who favoured the PWR technology for a variety of reasons, some political and some to do weapons grade materials. At the close of th program all laboratory and research reports were handed in and destroyed. Nobody was allowed to keep any documentation of any kind.

      Later the Chinese decided MSR was the way to go and got started several years before thee USA showed any significant interest. Once they got underway they stated they hoped to own the technology and, more importantly, the patents. It’s interesting to see that the USA and China now have some degree of cooperation.

      • I fairly sure you’re wrong. Nixon knew nothing about reactors nor technology. The Atomic Energy Commision stopped molten salt reactor development because they wanted to concentrate resources on the sodium-cooled fast reactor.

        • Nixon’s voice is on tape saying that the solid fuel reactors were selected to locate the nucleat development programs in California…and NOT in Tennessee.

      • That is not how patents work.
        It is not who first files for a patent, though that does happen both accidently and deceitfully.

        It is who first defines/describes/illustrates the concepts.
        All it takes to prove ownership of the concept is paperwork, whitepapers, images, simulations, tests developed before competitors.

        Even the article above describes historical development and advances, that is sufficient to prevent others claiming they patented the concept and own all rights.

        Leaving, what the Chinese can legitimately patent are any distinctly new or novel processes or portions of processes. When all of the main processes have already been defined, described, tested, etc.; that leaves variations of processes or additional processes open to patents.

        • In most of the world it is indeed first-to-file. Until recently, in the US it was first-to-invent. The US recently changed it’s laws, and 200-plus year tradition, to be in line with the rest of the world.

          • Thanks for beating me to it. You are correct. The vast majority, if not all, countries are First To File.

            People can say what they want about the Chinese system (and I don’t like it) but they have 700 scientists (plus engineers & technologists) working on the LFTR project and that is only one of 5 designs they are working on with those type of resources assigned to them.

            China thinks big and long term. They want to be the OPEC of electricity. They will get it to work, lock up the IP, mass manufacture them and sell them to countries with loans they provide. They will make money coming and going.

          • It varies but most patents have a 20 year span but the effective lifespan in technology is much less than that due to the complexity of going from discovery to deployment.

          • 20 years from date of filing. A patent will not publish until 18 months from the date of filing. A patent typically takes 3 to 5 years to prosecute. A patent does not give the assignee the right to practice, but rather a patent is the right to exclude others from practicing. A granted patent could be superseded by other, existing patents and prior art.

      • Some errors in your statements (:
        Major is Admiral Rickover wanted a ballast-heavy pressurized water system for ships and submarines, not the MSR, originally conceived for airplane use, and many people have been granted open access to Oak Ridges original information, and it continues:
        https://www.ornl.gov/news/nuclear-advancing-molten-salt-reactors

        Biggest -lack-of-news- is restarting Thorium production and use would free up IS major sources of rare earths, whose mining is uneconomical because of cost of storing the slightly radioactive Thorium byproduct.

          • Measuring total radioactivity is misleading because it fails to distinguish between gamma rays (relatively benign because they pass through lots of stuff before getting absorbed) and alpha and beta particle emitters (much more dangerous because they are absorbed by tissue. Potassium (i.e. bananas) only emits gamma rays.

            It’s also extremely misleading to compare refined thorium (the same is true of refined uranium BTW) with thorium (and uranium) in the natural environment. In the wild, those elements build up multiple generations of daughter products until finally producing stable lead isotopes. Many of these daughters are strong emitters of alpha, beta and gamma radiation.

            That’s how we find them when doing exploration. If it wasn’t for the daughter products, they would be almost impossible to discover.

            I notice the posted article used the word “progeny” instead of the traditional “daughter”. Nuclear industry eliminates a sexist word! That ought to make the whole concept palatable the social progressives who rule us. /sarc

            Radon gas is particularly noxious because it’s a gas and can get out of its host mineral, seep into your basement where it can decay. If you breathe in a radon 222 atom at the moment it decays, it will likely leave an atom of polonium 218 (IIRC) which will further decay in a cascade of short-lived isotopes, emitting energetic alpha particles, and cause tissue damage. Radon 222 is part of the uranium decay chain. Thorium produces another radon isotope, radon 220 (also called thoron) which has similar deleterious effects. All of which can be more or less avoided by good ventilation and a vapour barrier. And all of which are 100% natural and unrelated to mining of uranium or thorium, or the nuclear industry.

            I have long argued that uranium mining removes a natural hazard from the environment and sequesters it in a secure industrial process (and the same would apply to thorium mining) but uninformed objectors (i.e. all of them) don’t care.

          • Can’t disagree, SR. Indeed we are all gamma emitters because of our 40 K content, but it’s interesting that we are taught that alpha particles cannot fight their way out of a paper bag, yet 210 Po is a chosen weapon of certain state assassins. Deadly when ingested in small quantities.

    • I don’t think that’s an accurate description. As I understand the history the MSR work in the USA was stopped at the orders of President Nixon who favoured the PWR technology for a variety of reasons, some political and some to do with the production of weapons grade materials. At the close of the program all laboratory and research reports were handed in and destroyed. Nobody was allowed to keep any documentation of any kind.

      Later the Chinese decided MSR was the way to go and got started several years before the USA showed any significant interest. Once they got underway they stated they hoped to own the technology and, more importantly, the patents. It’s interesting to see that the USA and China now have some degree of cooperation.

    • Take a lesson from the Chinese method; let them develop the technology, then steal it.

      The problem in the United States is that Chinese patents that wash up on the US shoreline are gathered by the government to be used to complicate our own indiscriminate use of technology, while US patents that wash up on Chinese shores are Xeroxed, then recycled into pulp to make toilet paper.

    • As I’ve heard (per video by Sorenson), the Chinese already “stole” US MSR technology when a Chinese delegation visited Oak Ridge (OR) for a tour and at the end of the tour explained that they were there for documentation on OR’s MSR technology, which apparently was given to them.

      Also, a, or the, key factor in stopping the MSR program was because of the development of inflight fueling. Apparently, MSR research only got funding because the government desired nuclear powered bombers for unlimited flight range. Inflight fueling obviated that need, so the MSR project was terminated.

    • I think the last line makes your point:

      The US Department of Energy is collaborating with the China Academy of Sciences on the program, which had a start-up budget of $350 million. TMSR commercial deployment is anticipated in the 2030s.

      They already are.

  2. Molten salt reactors are an interesting concept and may become commercial as early as 2040. However, we need to begin deploying NuScale Small Modular Reactors in 2027 as a “carbon free” alternative to wind/solar junk power. Suggesting that molten salt reactors are near commercial viability is a distraction from the increasing economic damage and grid instability that renewables are causing.
    copy excerpts from above:
    “……this concept, with fuel dissolved in the salt, is further from commercialisation than solid fuel designs, where the ceramic fuel may be set in prisms, plates, or pebbles, or one design with liquid fuel in static tubes. Reprocessing that fuel salt online is even further from commercialization…..”

    “…full electrometallurgical reprocessing by about 2035, followed by 1 a GW demonstration plant”.

    • I used to feel very good about the push for those cute water cooled solid fuel Small Modular Reactors (say less then 1GWe/unit). They were originally fronted to solve the nuclear industry’s most pressing problem at the time, to develop familiar technology that anti-nuke false-environmentalists might fear and hate less. Well the joke’s on them! Turns out that seething hatred of all things nuclear is not scalable. You have to route around it the old fashioned way, by starting to ignore people.

      But then the absurdity of populating the landscape with 3MW wind turbines — and folks taking the idea seriously — made me think, What is the nuclear equivalent of this? The point at which per-unit overhead turns a good idea into an unworkable one? The NuScale is a nice commercial product that would make a few billionaires happy, they could pool their wealth to acquire a few and power their survival enclaves in New Zealand in style. In a post-collapse society a thriving Medieval barony could be built around one. One that shoots strangers on sight.

      If your nuclear reactor is surrounded by an area of ‘debt’ that extends beyond the earning power of the area for which it could supply electricity, you have done the modern equivalent of creating a tyrannical Egyptian water-province around the Nile. And there’s more than one kind of ‘debt’. You could substitute unreasonable/misrepresented construction time, fair-weather assumptions about the economy that turn sour, and the worst kind of debt: delivering a half-ass solution that requires people to borrow money to build gas plants while paying down the debt.

      So I go for at least 1 gigawatt electric per unit with a few per plant as the baseline for feasible scalaling of any technology that is destined to become a grid solution. And sadly those AP1000 and CAP1400 are best of breed for safety but for the amount they will produce, they are MONSTERS of debt. Too great in capital and especially time. As in (brace yourself) will not happen.

      If you’re looking for an interim solution you have to just try harder to draw the future into to the present, not extend the past further into the present. ThorCon burners of uranium are a nice way to tap the possibilities of salts sooner. though Weinberg’s two fluid LFTR and its DO-ABLE ~300 waste profile is the best option yet.

      And the idea is now 50 years old. Oh, the embarrassment.

    • The timeline will be much shorter than 21 years for commercialization of MSRs. Look for the first commercial reactors by the end of the next decade.

      • commercial reactors by the end of the next decade

        How many and what size will be operating in 2029?
        Pick a number: 3, 13, 23, 43, …, 173. 563?
        What percent of electrical power will they be providing?

        • Tough questions (but good). The Chinese have moved their schedule up twice so far so I’d say they will have at least one of their 5 NG nuke designs providing electricity by 2025 and a few more by 2029. After that they evaluate their performances and costs then move to mass manufacturing (or as close as they can get) for the best of the designs.

          Not much percentage wise (less than 1% IMHO) to start but probably 10% by 2050.

        • Of course nobody knows the answers to your questions with any kind of precision. How fast MSRs are adopted will depend a great deal on where – as in which nations, which affects things like licensing requirements that have been a huge roadblock in the USA for the last 60 years, but is not a big deal in China, or France which is all in on nukes.

          Changes to the NRC’s licensing rules were enacted in a law passed last year by Congress, with the purpose of speeding up the licensing of Gen 4 nuke plants … perhaps that will speed things up, we’ll see.

  3. “I have seen the enemy and he is us!”
    – Churchy la Femme

    The greens had better be careful what they wish for. If the US does not proceed with the development of nuclear we could be all learning Mandarin in the next century.

  4. I had thought that using certain non radioactive isotopes as fissionable materiel would get around the problem of radioactive waste. I read a column in a Toronto paper about 20 years ago but have forgotten the references.

  5. I’m less of a fan of MSRs than I used to be.

    I once had to put together an education module on handling fluorine products, notes written by educators so they could provide a safety course to people who fluoridate drinking water.

    Fluorine is really horrible stuff. Compounds of fluorine are deadly toxic. Splashing yourself with hydrofluoric acid or exposure to fluorine gas can easily be fatal. The poison is insidious, you don’t know if you are a walking dead person for minutes or even hours after exposure. Even sublethal exposure has really horrible consequences, your body literal crumbles inside – fluorine is attracted to calcium, so it rips your bones apart, and heavily disrupts biological processes such as brain and nerve cells which use calcium chemistry.

    If MSRs become common, I suspect there will be far more deaths from handling fluorine than radiological incidents.

    • It is true that LFTR advocates gloss over present lack of method for producing lithium fluoride and beryllium fluoride salts safely in industrial quantity. And why shouldn’t they? Weinberg’s vision of active processing and the fact that the salts can be reused between reactors should push safety issues into the workable realm of occupational safety. The fluorine is bound just as is sodium in table salt, and the result is not reactive with air or water.

      This is a big win, especially for worst case scenarios. If someone blows up a LFTR and shatters its containment, the area affected is the blast radius. No need to evacuate people over the hill. Could there ever be a bigger win?

      No, LFTR’s chemistry is not edible. Solving the world’s energy problems cannot be accomplished using a Play-Doh Fun Factory.

      • … e.g. by bubbling fluorine through the salt so that UF6 is formed and removed as a gas. The UF6 is reduced and added to the fuel stream. …

        Seriously I’m a fan of nuclear power, I think the risks can be managed. But I’m terrified of fluorine. Corrosive, toxic, insidious. Very dangerous stuff.

        Maybe I’m making too big a deal of the problems. But I’m not keen on the fluorine chemistry component of MSRs.

        • Sorry if I was too cheeky there, worthy WUWT contributor. The Play-Doh (do you have it in Britain?) remark is stuck in my brain from a time when I was arguing with someone who thought all energy problems could be solved altogether without radioactivity, without even mythical fusion. I think they wanted to de-populate me first.

          I agree that in a working reactor the bubbling column might be the most terrifying kills you before you know it thing. It is my hope that the volume of elemental fluorine not bound to salt at any given time will be low enough that it only kills working blokes like me who would love to be gainfully employed to ‘tickle the dragon’, and not such volume and longevity as to risk another “Union Carbide”.

          Sadly, when Weinberg’s career was cut short he had just completed the base MSRE without even a Thorium blanket and had not progressed to the processing stage, so even though fluoridation columns are presently in use, there is no direct LFTR experiment to draw on.

        • All of the uranium that went into a gaseous diffusion plant, or centrifuge, was uf6 when it was enriched. Seals are made with Teflon. UF6 is a solid at room temperature and that limits how much Florine can be released in a breach. No special protection needed around the equipment.

        • Kirk Sorensen goes ballistic when people raise this issue. LFTR’s use fluoride not fluorine. Huge difference.

    • ” I suspect there will be far more deaths from handling fluorine “
      The Hall-Heroult process for producing aluminium, which has been used for 140 years, electrolyses Al₂O₃ dissolved in molten fluoride, at near 1000°C. Fluorine is evolved, and probably HF. It is done on a massive scale, but the handling issues seem to be managed.

    • Except they are using Fluoride solutions and NOT Fluorine solutions…. Completely different chemistry Eric. Fluoride is not reactive like Fluorine.

      • I knew a guy who worked at a place that processed depleted uranium. They had to work in moon suits when servicing the equipment because of UF6. He said his suit malfunctioned once and he got a whiff, which he described as horrible, but he lived. The only thing that could come out of my mouth at that time was “You’re effing crazy”.

    • Thanks for resume of the dangers of flourine , now remind me why goverments want to put it in the water supply. So we don’t need to brush our teeth ?

    • Eric, I, also, can see some reasons not to develop conventional nuclear…even the MSR. However, if you look at the abysmal performance of the US Department of Energy, originally conceived to reduce US dependence on foreign energy sources, (and ignore that the shale revolution was not a DOE or NREL project), I think an (optimistic) reading of the self-confined plasma efforts in https://e-catworld.com/ and the fact that DOE expenditures on alternate sources of energy has been minuscule compared to the totally non-successful billions poured into the heavy-magnet Tokamaks, says the money might be spread around a lot more profitably.
      I say this even after decades of seeing that political or governmental involvement trashes many things it touches. Please don’t jump on Rossi. He May or May Not have something of value.

    • Eric, relative to Fluorine: I am a Registered Professional Chemical Engineer and have done design work for plants producing hydrogen fluoride (talk about nasty!).

      The biggest problem with the MSR is nuclear poisons that hinder smooth operation and must be chemically remove. Yes, even Tantalum is subject to corrosion by fluorides, but these problems are soluble. Best solution is multiple reaction cells that can be easily removed and recycled to a central rebuilding facility every seven years or so.
      I also like the pebble-bed concept, where if the pebbles get too hot, the expansion interferes with the geometry required to keep the chain reaction going.

    • We handle stuff as dangerous as fluorine and much more so every day in typical industrial processes. No big deal. Establish safety guidelines and follow them.

    • Fluorine is best described as “evil”. It is truly one of the nastiest elements to deal with on a chemical level.

      That said, it is used at an industrial scale in making Teflon (PTFE) and Viton (FKM). These products also often involve the use of fluoroantimonic acid (pH equivalent to -18). I think that this particular hurdle isn’t all that terrible.

    • While I agree with your prediction, the refrigerant industry handles a lot of fluorine and HF every year without serious incidents. I have worked with HF for about ten years without any accidents. Liquid chlorine is used all over the country for both manufacturing chemicals (PVC, etc.) and drinking water. I think the technological aspects of handling these materials can be safely developed.

  6. There’s also interest in Denmark, Holland and UK.

    The molten salt used can also be sodium chloride. UK company Moltex use NaCl as the coolant and have an agreement with Fermi Energia of Estonia to build molten salt reactors. Moltex want to build a fast reactor. Fast reactors have advantages:

    1) preferred choice as breeders
    2) almost all actinides fission when exposed to fast neutrons; including uranium-238. Few actinides fission when exposed to thermal neutrons. Only really: U-233, U-235, Pt-239.
    3) they are the preferred choice as ex-nuclear-fuel disposal reactors. Used nuclear fuel can be used as fuel for fast reactors will minimal reprocessing.

    and disadvantages:

    3) they wear out faster because fast neutrons are generally more damaging to reactor components
    4) we haven’t as much experience with them.

    Up to now the great majority of fast reactors used liquid sodium as a coolant. But this scares a lot of people. Sodium metal is very chemically reactive because it has only one electron in its outer shell. In contrast: sodium chloride, is very chemically stable, so offers an whole new range of possibilities for fast reactors.

    • Your summary is not correct.

      You do not understand the fundamental weakness of fuel rod reactors which is the fuel rods can melt down and water is the fundamental weakness of the pressure water reactors.

      A molten salt, liquid fuel, no fuel rod, no water thermal spectrum reactor is the most fuel efficient (six times more fuel efficient than a pressure water reactor), safest reactor possible for fundamental engineering reasons that cannot be changed by technology.

      There are two types of fission reactors.

      1) Thermal spectrum (All current civilian reactors)
      In these reactors the neutrons are slowed down to roughly the speed of the moving fuel atoms which greatly increases the chance of neutron absorption.

      Thermal spectrum reactors are allowed to use by law a maximum U235 enrichment of 5%.

      Thermal spectrum reactors when they fail do not produce a dirty fission bomb.

      The water/fuel rod reactors explode due to low water/water flash boiling/too low flow rate, rupture of pressure vessel/piping which then results in fuel meltdown and due to water reacting with zircon and gamma radiation/neutrons to produce hydrogen.

      Fuel rod reactors are dangerous because of the meltdown problem, massive release of steam, and the hydrogen gas explosions.

      Fission reactors are stopped by injecting a neutron absorbing liquid.

      The problem is there is still heat generated by highly radioactive fission products (7% of the thermal output of the reactor or 20% of the electrical output of a PWR) particularly for the first 8 hours after reactor shutdown.

      In a melted salt reactor, the short lived radioactive elements are mixed evenly in the vessel which enables that type of reactor to be convection cooled. There are no catastrophic failure modes.

      Molten salt no fuel rod reactor are the only thermal spectrum reactors that can be used for breeding.

      Getting rid of fuel rods removes the melt down problem.

      Fast Spectrum Reactors
      These reactors do not slow down the neutrons so they hence need more neutrons to start fission. Fast spectrum required highly enriched U235 20% and Platinum for fuel.

      A cooling failure for a fast spectrum reactor can result in dirty fission explosion of equivalent to 710 kg of high explosive.

  7. then a 10 MWt experimental reactor

    I have absolutely no faith in someone writing about energy in a scientific context who does not even know how to write the units. This shows total ignorance of basic science.

    Would you take a lesson in English literature from someone who consistently writes their instead of there ??

  8. Our Mission

    World Nuclear Association is the international organization that represents the global nuclear industry. Its mission is to promote a wider understanding of nuclear energy among key international influencers by producing authoritative information, ….

    power levels up to 4000 MWt

    “authoritative information” from folks who do not even know the symbol for the unit of power ??

    • See above, the “t” stands for “thermal”. You’ll only convert about 40% of the thermal energy to electrical energy in a complete power plant. Since no one is hooking up generators yet, this is the best way to make comparisons among designs. Come to think of it, it’s the best way period. The electricity side of things basically just hangs on the thermal side anyway.

    • Be careful commenting in the absence of actual knowledge.

      The “t” is “thermal” power … i.e. the thermal energy output produced by the primary reactor loop. The actual electrical energy of a nuclear power plant is substantially less due to the inefficiencies of the secondary steam plant (per the “rankine cycle” of a steam turbine plant) which actually powers the electrical generators.

      Pressurized water reactors operate at approximately 250 deg C, sufficient only to create saturated (vs. superheated) steam, and therefore the total plant efficiency (thermal power divided by motive or electrical power output) at that temperature is only in the low 30s percent. PWRs are so limited because it is impractical to pressurize the primary coolant sufficiently to operate at a much higher temperature. Typical pressure in a PWR is around 100+ atmospheres. That makes everything in the primary coolant loop very heavy and expensive and subject to excessive stresses due to thermal shock.

      MSRs can easily operate at 700 deg. C at just one atmosphere of pressure, which enables the steam plant to operate at superheated temperatures which increases thermal efficiencies in the mid to upper 50s percent … and therefore allows all of the primary coolant loop components to be made much lighter and thinner and less subject to thermal shock, An atmospheric operating pressure also eliminates the risk of primary loop steam explosions in a loss of cooling accident as happened at Fukushima and Three Mile Island.

      So with an PWR, a 1 GWt reactor can only produce about 320-330 MWe (electrical power) … whereas a 1 GWt MSR can produce about 550-590 MWe.

      • “MSRs can easily operate at 700 deg. C at just one atmosphere of pressure.” What steam pressure in the primary loop do you recommend?

        Be careful commenting in the absence of actual knowledge.

        • “MSRs can easily operate at 700 deg. C at just one atmosphere of pressure.”

          Nothing wrong with that statement.

          PWRs operate at 300+ degrees C and 150-200 bar.

          Nothing wrong with that statement either.

        • Knowledge gained from being a trained and qualified reactor operator for both the US Navy and DOE, as well as degreed and licensed engineer.

        • There is no “steam pressure” in the primary loop of a MSR. Molten salts don’t boil at even one atmosphere until somewhere in the 1,100 plus degree temperature range, depending upon which salt is used.

          That is what enables the MSR to easily operate at around 700 deg C at just one atmosphere, which enables peak efficiency in the secondary steam plant capable of producing thermal efficiencies in the mid to upper 50 percent range. Theoretically a MSR could operate at much higher temps than 700 deg C, but doing so would complicate the materials engineering for the plant and would not much improve the thermal efficiency. 700 deg C is considered the optimal operating temp for a MSR.

  9. Another “true believer”. I think this is exactly how wind and solar became dominent. Enough “true believers” and you can sell real unicorns.

  10. MSRs offer multiple advantages over conventional nuclear power plants, although for historical reasons, they have not been deployed.

    This sounds like a bad excuse. If they have such significant advantages they would have been deployed. We are not being told about the disadvantages. This is a significant problem as most articles always present only one side of the story and finding the other side is not easy for a technology that so far is just an experiment.

    • The main “disadvantage” would be the disestablishment of the players who have massive (multi billion dollar) stakes in the designs of the current generations of operating reactors. By ensuring over-regulation of the industry, start-ups without government subsidy or sponsorship have too long a period of research and licensing before operating profit for private financing alone.
      Having said that, I am watching closely the Moltex design (mentioned briefly several times by Anthony). The design is unique in containing the fission materials and products as liquid crystal in fuel tubes, obviating the need for inline fluoride processing. The current design would utilise previous waste fuel (still 95% “unburnt” in the solid pellet form) and decommissioned military materials eliminating the need for most of the reprocessing, the end products having half lives measured in decades rather than millenia. With modification future SMRs of this type would be able to use the Thorium cycle. The fast breeder design does have disadvantages, but these should be easier to overcome than those resulting from attempting to process the liquid crystal fuel medium inline.
      Having previously won the British Government selection process the company are now engaged in licensing in New Brunswick.
      I have no personal/ business relationship with Moltex other than taking an interest in their progress.

      • I don’t buy that excuse either. This is a global planet with multiple companies from many countries. If a technology has a clear advantage it would be being deployed at many places right now.

        Forgive me for being an skeptic. I’ve being around and I’ve read about lots of miraculous technologies that never make it to commercial products, from magic algae that produce oil, to wondrous nanocarbon batteries that will have us all in EVs in no time. Too many snake oil sellers.

        I’ll believe it when I see it and not a moment before.

    • A PWR coolant leak is benign compared to a leak of molten reactive metal salt.

      I cleaned up many a coolant spill and prevented many many more.

      Now tell me how molten salt coolant doesn’t leak as demonstrated at Monju.

      • The humongous difference in favor of MSRs over PWRs, with respect to leakage, is that MSRs operate at 1 atmosphere, whereas PWRs operate at 100+ atmospheres. If you think on that for about 1 millisec, the obvious winner is the MSR.

  11. Mentioned (but glossed over in this article) is another really big benefit of MSR’s is the higher (than light water reactors) operating temperatures. Temperatures are high enough to generate power AND to do industrial processing in the same thermal cycle.

    These industrial processes could include:
    • water desalination
    • production of liquid transportation fuels (using CO2 to make lefties happy)
    • hydrogen production (to make lefties happy)
    • ammonia production for fertilizers (to keep us all fed)

  12. We don’t have “energy problems” except for the fantasy ones carbonistas have made up. By all means, we should investigate other ways of producing energy, but not present them as energy solutions or panaceas. In order for MSRs or any type of energy production to be viable for the grid, it has to be relatively safe, scalable, competitive in price to other energy production types, and help provide grid stability. Good luck to MSRs meeting those criteria. I hope they do someday, but I’m not holding my breath.

    • These facts (among others) are reasons enough to pursue the technology, IMO:

      * most US reactors will reach end of life in the next few decades
      * building new PWRs will just add to the growing waste problem
      * MSRs can consume existing waste

    • While we have lots of available combustible energy available here, nuclear power will be vital for asteroid mining operations. There are some valuable metals up there that our technologies require.

  13. We have 60 years of speculation on MSRs. We have double ought zero operating commercially. Until we do, this is all just tiresome speculation.

      • How much electricity did it produce? None.

        It was not operating. The whole generating part was missing. By the way, that’s what caused problems at the Crescent Dunes solar plant – and their molten salt was not radioactive.

        Don’t get me wrong, I would love to see it work – but we should not lie. Not about the past, not about the future. Leave that to alarmists.

        • The electrical generating part isn’t nuclear and does not involve nuclear technology. Superheated steam turbine systems have been in use for more than a century in both ships and non-nuclear power plants.

          • Head fake. That we know how to use steam to generate electricity has nothing to do with it. The apparent difficulty is getting steam from an MSR. We know what to do with the steam once we get it.

            Where has integrating MSR and steam generation been done?

          • Wholly phuck, Batman! Are we seriously having this conversation. Heat produces steam which generates electrical power. Duh!

        • As for operating pressures of a superheated steam plant, that is dictated by the steam plant design which, as I also stated here, has nothing to do with reactor plant design.

          All that matters, as far as the steam secondary plant, is the temperature at which the primary heat source operates. The higher the operating range of the primary heat source, the more efficient the secondary plant is in terms of operating on the Rankine curve.

          As for Crescent Dunes, the molten salt is merely a heat sink, designed to store energy collected by the solar collector.

          In MSRs, the molten salt does not operate primarily as a heat sink or storage mechanism. Rather, it operates to either cool a solid fuel reactor (such as a pebble bed thorium reactor) and transfer that heat to a secondary superheated steam plant … or it operates as the solvent carrying the liquified nuclear fuel in which the reaction actually takes place, and at the same time transfers its heat to the superheated secondary steam plant.

          Either way (solid fuel or liquid fuel), the molten salt has a boiling point at one atmosphere of pressure that is vastly higher than water has at 100+ atmospheres, and thus delivers all the advantages of high temperature/low pressure operations as I describe elsewhere in this thread.

    • We know the details on amount of heat produced etc from the experiments in the 60s. I’m pretty sure we know how to use it to create steam and drive a turbine. That part of the engineering is pretty much solid. There may be problems with LFTRs but turning heat into electricity is not one of them.

      • Then why hasn’t it been done? Until someone gets one running, making electricity economically, you have NOTHING.

        In three generations – 60 years – it hasn’t happened.

        But y’all say, “It can be done!”

        Do it, then talk about it.

  14. What if Fukushima has this tech instead of the one that was overcome by a tsunami? Would the end results be comparable or would liquid salt tech have reduced the amount of radiation leakage? If so, this could offer an alternative to those who live in dangerous earthquake zones, maybel?

    • Once the containment vessel is breached you would have a big mess but it would cool and stop reacting once out. The containment vessel (where the reaction occurs) is designed to keep the heat in to the reaction can continue. Lose that and the reaction stops.

      It would still be a huge mess but no where near what 3 Mile Island, Chernobyl & Fukushima produced.

      • Actually, there would be no mess at all with a liquid fuel MSR in the event of a loss of cooling accident as happened at Fukushima. Lose all cooling for an extended period and the freeze plugs melt and gravity sends the liquid salt solution to dispersion chambers where the reaction stops. There is nothing to melt down, and no high pressure steam or hydrogen to explode. It just sits there until cooling is restored and the freeze plug is reestablished.

        With a solid fuel MSR, again, no steam or H2 to explode, the molten salt primary coolant has a failsafe negative coeficient of activity, and essentially nothing happens at all.

        MSRs are inherently failsafe, unlike PWRs.

  15. One MSR developer, Moltex, has put forward a molten salt heat storage concept (GridReserve) to enable the reactor to supplement intermittent renewables. Hot nitrate salt at about 600°C is transferred to storage tanks which are able to hold eight hours of reactor output at 2.5 GW thermal (as used in solar CSP plants). The heat store is said to add only £3/MWh to the levelised cost of electricity.

    Somebody please explain to me why we need “intermittent renewables” if we have MSRs? Why would we not leave wilderness areas free of hideous bird choppers and dispense with solar panels if MSRs are available to generate cheap reliable power 24×7?

    Sorry to say, it looks like another technology that might be commercialized in 20-40 years if we pour billions into research. Not sure why they fret about tritium production, it can just be used in the co-located fusion reactor, both of which will apparently be ready around the same time. (T+30yrs and holding)

    • “Somebody please explain to me why we need “intermittent renewables” if we have MSRs? ”

      Obviously (to you and me) we don’t. But in the current political climate in the west the only way to get progress of any sort is to pander to the greenthink. Hopefully, by the time these are being commissioned, mankind will have come to its collective senses and the pandering to “intermittent renewables” will have been eliminated.

    • Why they “fret” about tritium production:
      http://moltensalt.org/references/static/downloads/pdf/ORNL-MIT-117.pdf

      Tritium can permeate many metals, plastics, and forms of rubber and actually “leak” out into the surrounding area, making it radioactive (half-life of 12 years). Hydrogen (including tritium) has a habit of combining into molecules with other elements forming, say, water that has tritium in it. Tritium inside the human body can actually harm you. (Tritium produces Helium-3 through beta-decay).

      The difference in MSR and Fusion is that we can already BUILD the MSR, we just need to fine tune it for the highest possible safety and efficiency. We cannot even build a working fusion reactor that produces more energy than it consumes, let alone start capturing the energy and producing electricity from it.

      With a program to develop the MSR (and assuming the government doesn’t interfere) we could have a standardized working MSR in around 10 to 12 years. With activists starting lawsuits and the ever-present government interference, it will likely take 30 or more years and then be canceled for cost overruns.

      • Tritium is a problem. The Daiichi plant at Fukushima has over a quarter of a billion gallons of highly radioactive tritiated water stored onsite, that will eventually be dumped into the ocean (either purposely or because of earthquake damage). The tanks are so radioactive they emit x-rays throughout the area because of bremsstrahlung radiation. They were able to filter out most other radionuclides, but not tritium.

      • Of course I’m aware that tritium is a problem. If it wasn’t obvious, my comment about using it in a co-located fusion reactor was sarcasm.

        I’m not against MSRs, especially LFTRs (thorium), but so far only pilot plants to demonstrate concepts have been built. There are quite a few difficult (read expensive) technical problems left to resolve before a commercially-viable power plant would be on line. There aren’t ANY technical problems to resolve with gas turbines.

        The probability that a complex, unproven technology opposed by whacko activists is going to end up producing electricity cheaper than natural gas any time soon must be very low.

        So why should it be a priority for spending more borrowed tax money? If it’s a good idea that will make money for private investors, then let them invest. Let the market decide. So far it has decided that the time is not right yet. I agree with the market.

        Maybe it’s a good idea as a way to get rid of nuclear waste? Again, if this is the cheapest, safest way to deal with the problem, (and presuming that it is a problem and that regulators require it to be addressed), then the market will drive private investment in it. Where I am extremely wary is in pouring more government money down the crony capitalist drain as we have done with wind and solar already.

        Maybe it’s a way to appease the CAGW fanatics without despoiling every last wilderness area with bird choppers? Are you serious? CAGW fanatics are riding their climate change meme to destroy capitalism. They aren’t going to be tricked into accepting a capitalist solution to their fake problem.

        • The various elements of the MSRs have been proven. The generate heat. The one at Oak Ridge also generated steam, part of the power cycle for generaing electricity. That nuclear generated power has been ‘tested’ since the 1950’s is not under dispute. Replacing a uranium cycle PWR with an thorium cycle MSR to generate electrical power is a no-brainer. Unless there are seriously misunderstood concepts and factors in regards to MSRs, I doubt there will be any major “gotcha’s”.

          But as an engineer I too want to see a complete MSR/power generation plant built and tested. Will it take 20 years as someone above suggested? Only if we let the rabid anti-nuclear warmists dictate the terms or file endless lawsuits to delay any progress in this area. Let’s build some and test the heck out of them. It didn’t take this long to develop nuclear reactors for the Navy or for commercial power generation.

          • Is it going to give us cheaper electricity than natural gas? If so, why do we need government spending on it? If not, same question.

  16. Once again:

    How ’bout electricating the entire transportation sector?

    As Mencken observed, for every complex problem there is an easy solution – and wrong.

  17. I like the concept of MSR’s, but several key points make me nervous until worked out:

    1) They use graphite as moderators, and graphite catches on fire. I know the heat in most designs is SUPPOSED to be fairly low, but sticking a combustible element into a nuclear reactor just sounds over-dangerous to me. They need to find a more stable moderator.
    2) Depending on the salts used, you get new kinds of corrosion inside the system. This also worries me deeply, as corrosion has a NASTY habit of getting out of control in unforeseen ways and causing leaks and damage to systems.
    3) Without advanced recycling techniques, preferably inline to the system so that it can run continuously (so no shutdown for refueling would be needed), these systems lose most of their value. Recycling nuclear fuel in the U.S. is banned, so first we would need Congress, for just a few days, to act coherently and lift the ban.
    4) There may still be a need for vast quantities of water for cooling – this needs to be addressed. Newer nuclear reactors need to be able to be built anywhere without impacting large amounts of fresh water. This allows reactors to be located closer to electric consumers – a distributed power system will be inherently more stable than one depending on long transmission lines.

    The advantages of a MSR is a long list already covered in the article. With breeder reactors capable of burning waste and thorium, and efficient recycling, our nuclear fuel problems (future ones) would be over. The entire baseline electrical output could be provided by nuclear power plants.

    Once this is achieved, we can start disassembling these outbreaks of wind-warts (wind turbines) that mar the countryside and kill birds and bats. Gas-powered electric generation plants can supply all the variable loads.

    • Robert, your points 1, 2, and 3 are largely negated in the Moltex design mentioned several times by Anthony and commenters above – worth a look on their site! The water requirements are no more than for a conventional steam generating plant of similar thermal output.

    • The modern molten salt, no fuel rod, no water reactor design does not have the graphite stored energy problem.

      The graphite energy stored, that when released caused a fire is only a problem for low temperature graphite moderated reactors that use water for cooling.

      The Terrestrial integral reactor operates at 600C, hundreds of degree celsius above the problem temperature for graphite.

      The molten salt reactor is six times more fuel efficient than a fuel rod reactor as the liquid fuel moves in and out of the core of the reactor.

      Molten salt reactor is in addition to being six times more fuel efficient 20% more thermal efficient as it produces heat at 600C (46% thermal efficiency) as compared to a pressure water reactor that operates at only 320C 36% efficient.

  18. MSRs are going to be a major element in the rebirth of the nuclear power industry throughout the world. Bet on it.

    MSRs solve nearly all the problems associated with PWRs, most specifically safety (impossible to “melt down”), activity of the spent fuel products (half lives of hundreds of years vs. tens of thousands of years, and actually uses spent PWR fuels as fuel, so eliminates the many decades of spent fuel products now languishing in cooling pools), and of course is a breeder reactor so creates new fuel as it burns.

    The other factor that wasn’t mentioned in this post is that high temperature reactors like MSRs operate at a much more efficient temperature range in the steam plant … existing PWR plant thermal efficiencies are only in the low 30s percent, while MSR reactors operating at approx. 700 C with superheated/reheated steam plants achieve thermal efficiencies in the mid to upper 50s percent.

    Because of the above, MSRs also make a great deal of sense for naval reactor plants, significantly reducing the size of the required steam plant for a given mechanical/electrical power output.

    • replace MSR with Unicorn farts and your post still reads the same. Lots of hype. Get back to us when they get one (just one, is that too much to ask?) in commercial operation so that hype can be compared to reality.

  19. While I’m not qualified to evaluate the pros or cons of the topic of this posting I do much appreciate the article that has offered insight as to the concept of MSR research, design and operation. It is the most informative that I have read.

    I noted the mention of the use of super-critical CO2 as was discussed in an earlier WUWT posting a week or so ago that I found interesting. https://wattsupwiththat.com/2019/04/08/weekly-climate-and-energy-news-roundup-355/

    For those of us ‘outside the loop’ these type of discussions are most welcome. At least we know that technological advances are being made or at least evaluated. Wind turbines are not the solution for future energy supplies even though Josh showed one way to overcome the lack of wind.

  20. The reason molten salt reactors were never commercialized in the past was due to the lack of advanced metal alloys which could resist the corrosive effects of molten salt and also the lack of a moderators small enough to allow sufficient molten salt fuel at non-weapons grade radioactivity in the moderating area. The first problem has apparently been solved in two ways : Moltex Energy simply encases molten salt fuel in conventional fuel statinless steel rods and uses them in a sacrificial fashion – at around 5 years of inclusion in the fuel pak , the 5 year old rods are sikmply withdrawn and replaced with a new fuel rod. There is no need to vent and capture toxic gases, which remain encased in the rod and are removed when the rod is removed. The other solution is the use of very expensive corosion resistent metal allows for the reactor core.
    There are at least half a dozen private development efforts and apparently commercialization may appear as early as mid-late 2020s.

    • As long as it is privately funded, I wish them great success and support efforts to eliminate unreasonable regulations designed to cripple nuclear power as well. But we don’t need another government research project on which to waste borrowed money.

    • Kent, you report:
      ….There are at least half a dozen private development efforts and apparently commercialization may appear as early as mid-late 2020s.
      Note: Maybe commercial in China in the 2020’s. How long will it be before USA regulators approve an extremely hot and extremely corrosive radioactive liquid in a nuclear reactor that needs to be operational for about 40 years to be economically viable? The required metallurgy development is still ongoing…Hastelloy N can not withstand the temperatures. Can you imagine regulatory approval prior to a government monitored pilot plant operating for at least 20 years without a corrosion incident? (We’ll go broke installing worthless wind and solar long before MSR approval).

  21. Thanks Anthony.
    My thought on this story: MSRs offer multiple advantages
    but even if widely adopted will not be a big disruptor.

    If I were a young person, and if I thought about it, I would start a notebook
    with a short summary of concept stories (global warming, flying cars, future power sources …).
    Then I would make note of my thoughts on the concept, say 50 years out.
    My problem is, I will be checking out about 2030 — all things considered.
    In my lifetime, the innovations that were big disruptors in a very short
    time were cell phones and Jeff Bezos’ book business. What’s the next disruptor?

    Truth: I think WUWT has been a disruptor. You deserve a standing ovation – take a bow.

    • Actually, MSRs WILL be a huge disrupter. They provide the only means of operating a nuclear reactor that is both completely failsafe and which can use a wide variety of fuels including thorium (of which there is four times as much recoverable as uranium), U-235, U-233, depleted uranium, and previously-depleted reactor fuels. Its cost will be much less, both to build and to maintain .. and it nearly doubles the actual power output of today’s PWR power plants due to its far higher thermal efficiency.

      If that doesn’t constitute a “disrupter”, then nothing does.

      • Nice thought, Duane, but a different source of electricity is not going to disrupt an existing modern society. Most of the people in, say Wash. DC, do not know where their electricity comes from nor from what. Swap out the current sources for MSRs and those folks won’t know the difference.

        Your example is of interest to those within the power industries, that’s fair enough.

        • a different source of electricity is not going to disrupt an existing modern society.

          Consider this, taken from my 2016 letter to candidate Trump,

          Years ago I became convinced that our grid should grow to become 500% nuclear. The silly percentage is not hyperbole; it is an arbitrary guess as to what we may need to scale beyond present consumption in order to supplant petroleum in most things, and do new things. Call it my green dream. In my dream we are using nuclear electricity for all ground transportation and a renaissance of electric rail. To support air and sea travel and feed hydrocarbon chemistry we are manufacturing the synthetic fuel, fertilizer and plastics that are now by-products of natural petroleum and methane — by processes which are known today, though they are laughably energy-intensive and inefficient. Even ludicrous ideas like purifying seawater and pumping it upstream or importing fresh water from the far North to restore depleted aquifers. But in my dream no one is laughing because there is such a grand surplus of available energy these things can be done ‘right’ with careful engineering and calm deliberation.

          […] Imagine what might happen if the cost of putting electrical energy onto the grid levels off and begins to decrease steadily over time, approaching zero until it is practically infinitesimal compared to the amount of energy produced. What could this do for our economy? The cost of heating in winter, cooling in summer, municipal water treatment, lighting, charging electric vehicles, manufacturing, and a thousand little things with ripple effects… not in the least, a renewed interest in Big Projects. All this with no uncertainty in obtaining fuel that is the incidental byproduct of small footprint mining operations which are profitable in their own right. Thorium energy could do this.

          The problem with free money is that it affects all the other money in a bad way. I may be a dreamer, but I do not see the same problem with almost-free energy. I see a revitalized money economy where all things that are technically possible, even fantastic things, become more feasible because human ingenuity is ever-increasing. I see reduction in cost of living, cost of manufacture and cost of fossil fuel extraction that is so pervasive its positive effect may exceed any economic strategy ever devised. And on that day far in the future when the last hydrocarbon is extracted, it will be just cause for a quiet celebration. We’ll already be well into the next great thing.

          What would the future hold, and what wonders could we achieve — if energy was simply not an issue?

          Think of me as the Trix Rabbit of Thorium.

      • Thorium doesn’t require the enrichment that uranium requires. Uranium oxide fueled reactors use fuel enriched to ~5%. It takes a lot of processing to get uranium to 5%. Thorium requires no enrichment as we understand it.

        Another plus: We have far more thorium than uranium. A lot more.

  22. I dream of nuclear power supplying our electricity and some of that electricity being used to make hydrogen for fuel cell usage, which will power our trucks and cars. We are wasting time, money and brainpower chasing after wind, solar and other “renewables.”

    But I studied aviation and meteorology in school. 🤷‍♂️

  23. A revolution in fission power requires discussing the black hat information concerning fission power, the facts that are hidden from us.

    The pubic would not allow the fuel rod, water cooled reactors to be built if they knew there was a six times more fuel efficient, sealed, atmospheric pressure design, that cannot have a fuel meltdown, and that has no catastrophic failure modes, and that can be mass produced.

    The design in question produces heat at 600C as opposed to the PWR which produces heat at 320C. The 600C molten salt heat output which opens up trillions of dollars of heat applications. Heat requirement for industry is roughly the same energy requirement as electricity requirement.

    In all other industry, the safest most fuel-efficient design is required by regulation to be used. In the nuclear industry the breakthrough to a safe cheap design has been hidden.

    There is something fundamentally wrong with every country’s nuclear ‘management’ and design selection when there is a six times more fuel-efficient design, that can be mass produced, that can produce power as cheap as coal, that does not any catastrophic failure modes, and that was built and tested 50 years ago.

    We do not have a nuclear industry.
    We have a fuel rod industry.

    There are roughly 50,000 fuel rods in a pressure water reactor. The fuel rods in the core of the reactor have a life in the reactor of roughly 2 years before they crack and release radioactive gases and water soluble radioactive elements into the flowing water. Every two years roughly 1/3 of the fuel rods are removed. The cost of the fuel rods is hundreds of millions of dollars.

    Rather than changing reactor designs to eliminate the catastrophic failure modes by a change in design, the ‘nuclear’ industry added more technology to the pressure water reactor.

    There is red book 80 years of uranium. U235 is the only naturally occurring element that can be used for fission.

    All of the breeding schemes require using U235.

    We are wasting uranium by ‘burning’ it in pressure water reactors rather than using it in a six times more fuel efficient molten salt, no fuel rod, reactor?

  24. Just a quick thought, aren’t molten halide salts NaCl, flourides, etc. very corrosive. Is this, apart from other factors, also a reason preventing the development of these reactor cycles? I certainly like these things.

    • quite probably. One of the findings of the Oak Ridge experiments was the discovery of shallow, inter-granular cracking in all metal surfaces exposed to the fuel salt. Post-operation examination of pieces of a control-rod thimble, heat-exchanger tubes and pump bowl parts revealed the ubiquity of the cracking. The crack growth was rapid enough that it would be a problem over the planned thirty-year life of a follow-on thorium breeder reactor.

  25. Nice informative video explaining the basics but I take exception to mentioning “no CO2”. It only strengthens the theory that CO2 is a problem.

  26. Thorium is NOT A FUEL.

    It is a fertile material and has to be converted into fuel but it doesn’t do so perfectly reliably.

    So anybody who sells you the concept of a “thorium molten salt reactor” is a fucking psychopath with no understanding of the nuclear physics of a MSR.

    You can turn a pile of cleaned thorium into a bomb with a little dose of high fissile Uranium and the MSR is useless on large scale because the fluid has to be mixed on a fine scale to maintain even and safe reaction.

    It is NOT a commercial power generating option. As the parts wear the internal volume of the system increases and reactions start to occur in places you do not want reactions occurring. There is no reliable non-laboratory infusion system for the fertile material to be converted to fissile in an MSR while there IS in a classic rod breeder reactor.

    We can get the benefits of Thorium without having to make monstrous amounts of varietal isotope waste: Thorium can be bombarded into isotopes of Plutonium and can also fissile instead of convert to Uranium. In order to make the system able to generate power it has to be operated at a rather high temperature and the specific heat of the molten salt is nowhere near as good as water. The whole process is very very inefficient.

    Their entire “drain to safe” plan has never been tested and will NOT stop a reaction.

    The project was terminated because it would proliferate reactors all across the country and requires nearly as many people to operate for a 1Mw as you’d need for a 30Gw plant. Additionally the MSR produces a nearly never-ending stream of metal junk which cannot be recycled or re-used as part of the reactor – to the tune of literally replacing the mass of the entire system every 18 months.

    The plants we HAVE are the best option. MSR brings nothing to the table… but uneducated people with psychoses.

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