Everything else is a slide thread. Thorium Power is the single most important issue of our time.
Benefits of Thorium Power:
-Reactors cannot melt down
-Abundant fuel
-No risk of nuclear proliferation
-No carbon or air pollution
-Cheaper than even coal or natural gas
Imagine a world where the US is producing power for 1-2c/kwh. Most energy intensive manufacturing has now returned to the US. Food can be grown indoors without pesticides at a lower cost than outdoor agriculture. Economy enters a sustained economic boom of 10%+ gdp growth for an entire generation.
One of the biggest benefits of Thorium reactors is that they are passively safe. They cannot melt down, even if attacked. If they overheat, the freeze plug would melt, the fuel falls into a containment vessel, and the reactor shuts itself down.
I would be thrilled if you could link me to an article of a net positive thorium reactor
Sebastian Morgan
>There have been several significant demonstrations of the use of thorium-based fuels to generate electricity in several reactor types. Many of these early trials were able to use high-enriched uranium (HEU) as the fissile ‘driver’ component, and this would not be considered today.
>The 300 MWe Thorium High Temperature Reactor (THTR) at Hamm-Uentrop in Germany operated with thorium-HEU fuel between 1983 and 1989, when it was shut down due to technical problems. Over half of its 674,000 pebbles contained Th-HEU fuel particles (the rest comprised graphite moderator and some neutron absorbers). These were continuously moved through the reactor as it operated, and on average each fuel pebble passed six times through the core.
>The 40 MWe Peach Bottom HTR in the USA was a demonstration thorium-fuelled reactor that ran from 1967-74.2 It used a thorium-HEU fuel in the form of microspheres of mixed thorium-uranium carbide coated with pyrolytic carbon. These were embedded in annular graphite segments (not pebbles). This reactor produced 33 billion kWh over 1349 equivalent full-power days with a capacity factor of 74%.
Cont.
Chase White
>The 330 MWe Fort St Vrain HTR in Colorado, USA, was a larger-scale commercial successor to the Peach Bottom reactor and ran from 1976-89. It also used thorium-HEU fuel in the form of microspheres of mixed thorium-uranium carbide coated with silicon oxide and pyrolytic carbon to retain fission products. These were embedded in graphite ‘compacts’ that were arranged in hexagonal columns ('prisms'). Almost 25 tonnes of thorium was used in fuel for the reactor, much of which attained a burn-up of about 170 GWd/t.
>A unique thorium-fuelled light water breeder reactor operated from 1977 to 1982 at Shippingport in the USA3 – it used uranium-233 as the fissile driver in special fuel assemblies that had movable ‘seed’ regions which allowed the level of neutron moderation to be gradually increased as the fuel agede. The reactor core was housed in a reconfigured early PWR. It operated with a power output of 60 MWe (236 MWt) and an availability factor of 86% producing over 2.1 billion kWh. Post-operation inspections revealed that 1.39% more fissile fuel was present at the end of core life, proving that breeding had occurred. A 2007 NRC report quotes a breeding ratio of 1.01. Chemically reprocessing the fuel was not attempted.
>Indian heavy water reactors (PHWRs) have for a long time used thorium-bearing fuel bundles for power flattening in some fuel channels – especially in initial cores when special reactivity control measures are needed.
>Research into the use of thorium as a nuclear fuel has been taking place for over 50 years, though with much less intensity than that for uranium or uranium-plutonium fuels. Basic development work has been conducted in Germany, India, Canada, Japan, China, Netherlands, Belgium, Norway, Russia, Brazil, the UK & the USA. Test irradiations have been conducted on a number of different thorium-based fuel forms.
>Noteworthy studies and experiments involving thorium fuel include:
>Heavy water reactors: Thorium-based fuels for the ‘Candu’ PHWR system have been designed and tested in Canada at AECL's Chalk River Laboratories for more than 50 years, including the irradiation of ThO2-based fuels to burn-ups to 47 GWd/t. Dozens of test irradiations have been performed on fuels including: mixed ThO2-UO2, (both LEU and HEU), and mixed ThO2-PuO2, (both reactor- and weapons-grade). The NRX, NRU and WR-1 reactors were used, NRU most recently. R&D into thorium fuel use in CANDU reactors continues to be pursued by Canadian and Chinese groups as part of joint studies looking at a wide range of fuel cycle options involving China's Qinshan Phase III PHWR units. Eight ThO2-based fuel pins have been successfully irradiated in the middle of a LEU Candu fuel bundle with low-enriched uranium. The fuels have performed well in terms of their material properties.
>Closed thorium fuel cycles have been designed4 in which PHWRs play a key role due to their fuelling flexibility: thoria-based HWR fuels can incorporate recycled U-233, residual plutonium and uranium from used LWR fuel, and also minor actinide components in waste-reduction strategies. In the closed cycle, the driver fuel required for starting off is progressively replaced with recycled U-233, so that an ever-increasing energy share in the fuel comes from the thorium component. AECL had a Thoria Roadmap R&D project.
Gavin Bennett
This stuff has been around since the 60s. Not gonna happen
Christopher Smith
peepee
Matthew Thompson
>India’s nuclear developers have designed an Advanced Heavy Water Reactor (AHWR) specifically as a means for ‘burning’ thorium – this will be the final phase of their three-phase nuclear energy infrastructure plan (see below). The reactor will operate with a power of 300 MWe using thorium-plutonium or thorium-U-233 seed fuel in mixed oxide form. It is heavy water moderated (& light water cooled) and will eventually be capable of self-sustaining U-233 production. In each assembly 30 of the fuel pins will be Th-U-233 oxide, arranged in concentric rings. About 75% of the power will come from the thorium. Construction of the pilot AHWR was envisaged in the 12th plan period to 2017, for operation about 2022. As of 2020, however, no site or construction schedule for the demonstration unit has been announced.
>For export, India has also designed an AHWR300-LEU which uses low-enriched uranium as well thorium in fuel, dispensing with plutonium input. About 39% of the power will come from thorium (via in situ conversion to U-233, c. two-thirds in AHWR), and burn-up will be 64 GWd/t. While closed fuel cycle is possible, this is not required or envisaged, and the used fuel, with about 8% fissile isotopes can be used in light water reactors. (See also information page on India).
Lincoln Fisher
Silence fed
Zachary Martinez
>High-temperature gas-cooled reactors: Thorium fuel was used in HTRs prior to the successful demonstration reactors described above. The UK operated the 20 MWth Dragon HTR from 1964 to 1973 for 741 full power days. Dragon was run as an OECD/Euratom cooperation project, involving Austria, Denmark, Sweden, Norway and Switzerland in addition to the UK. This reactor used thorium-HEU fuel elements in a 'breed and feed' mode in which the U-233 formed during operation replaced the consumption of U-235 at about the same rate. The fuel comprised small particles of uranium oxide (1 mm diameter) coated with silicon carbide and pyrolytic carbon which proved capable of maintaining a high degree of fission product containment at high temperatures and for high burn-ups. The particles were consolidated into 45mm long elements, which could be left in the reactor for about six years.
>Germany operated the Atom Versuchs Reaktor (AVR) at Jülich for over 750 weeks between 1967 and 1988. This was a small pebble bed reactor that operated at 15 MWe, mainly with thorium-HEU fuel. About 1360 kg of thorium was used in some 100,000 pebbles. Burn-ups of 150 GWd/t were achieved.
>Pebble bed reactor development builds on German work with the AVR and THTR and is under development in China (HTR-10, and HTR-PM).
Austin Garcia
>Light water reactors: The feasibility of using thorium fuels in a PWR was studied in considerable detail during a collaborative project between Germany and Brazil in the 1980s5. The vision was to design fuel strategies that used materials effectively – recycling of plutonium and U-233 was seen to be logical. The study showed that appreciable conversion to U-233 could be obtained with various thorium fuels, and that useful uranium savings could be achieved. The program terminated in 1988 for non-technical reasons. It did not reach its later stages which would have involved trial irradiations of thorium-plutonium fuels in the Angra-1 PWR in Brazil, although preliminary Th-fuel irradiation experiments were performed in Germany. Most findings from this study remain relevant today.
>Thorium-plutonium oxide (Th-MOX) fuels for LWRs are being developed by Norwegian proponents (see above) with a view that these are the most readily achievable option for tapping energy from thorium. This is because such fuel is usable in existing reactors (with minimal modification) using existing uranium-MOX technology and licensing experience.
>Various groups are evaluating the option of using thorium fuels in an advanced reduced-moderation BWR (RBWR). This reactor platform, designed by Hitachi Ltd and JAEA, should be well suited for achieving high U-233 conversion factors from thorium due to its epithermal neutron spectrum. High levels of actinide destruction may also be achieved in carefully designed thorium fuels in these conditions. The RBWR is based on the ABWR architecture but has a shorter, flatter pancake-shaped core and a tight hexagonal fuel lattice to ensure sufficient fast neutron leakage and a negative void reactivity coefficient.
Ethan Walker
>The so-called Radkowsky Thorium Reactor design is based on a heterogeneous ‘seed & blanket’ thorium fuel concept, tailored for Russian-type LWRs (VVERs)6. Enriched uranium (20% U-235) or plutonium is used in a seed region at the centre of a fuel assembly, with this fuel being in a unique metallic form. The central seed portion is demountable from the blanket material which remains in the reactor for nine yearsf, but the centre seed portion is burned for only three years (as in a normal VVER). Design of the seed fuel rods in the centre portion draws on experience of Russian naval reactors.
>The European Framework Program has supported a number of relevant research activities into thorium fuel use in LWRs. Three distinct trial irradiations have been performed on thorium-plutonium fuels, including a test pin loaded in the Obrigheim PWR over 2002-06 during which it achieved about 38 GWd/t burnup.
>A small amount of thorium-plutonium fuel was irradiated in the 60 MWe Lingen BWR in Germany in the early 1970s. The fuel contained 2.6 % of high fissile-grade plutonium (86% Pu-239) and the fuel achieved about 20 GWd/t burnup. The experiment was not representative of commercial fuel, however the experiment allowed for fundamental data collection and benchmarking of codes for this fuel material.
>n 2020 a consortium was formed to develop Advanced Nuclear Energy for Enriched Life (ANEEL) fuel, a mixture of high-assay low-enriched uranium (HALEU) and thorium. This can be used in BWR and PWRs but seems best suited for PHWR reactors such as CANDU where fuel would remain in the core for about eight times longer than usual. It has a high burn-up to 55 GWd/t. The consortium comprises the DOE's Idaho National Laboratory and the Nuclear Engineering & Science Center at Texas A&M University with Clean Core Thorium Energy (CCTE).
