Thorium-Brennstoffzyklus
Der Thorium-Brennstoffzyklus ist ein Nuklearbrennstoffzyklus, bei dem Thorium als Brennstoff verwendet wird. Thorium ist ein häufigeres Element als Uran und hat eine höhere Schmelztemperatur, was es weniger anfällig für kritische Unfälle macht. Der Thorium-Brennstoffzyklus erzeugt auch weniger radioaktive Abfälle als der Uran-Brennstoffzyklus.
Der Thorium-Brennstoffzyklus beginnt mit der Aufbereitung des Thoriumerzes. Das Erz wird gemahlen und mit Säuren behandelt, um das Thorium zu extrahieren. Das Thorium wird dann zu Thoriumdioxid (ThO2) oxidiert. Das Thoriumdioxid wird dann in eine Kugelform gepresst und zu einer Brennstabhülse hinzugefügt. Die Brennstäbe werden dann in einem Reaktor eingesetzt.
Im Reaktor wird das Thoriumdioxid durch Neutronen gespalten. Die Spaltung des Thoriums erzeugt Wärme, die zur Erzeugung von Strom verwendet wird. Die Spaltprodukte des Thoriums werden dann in einem Reaktorkern gesammelt.
Die Spaltprodukte des Thoriums können dann in einem Wiederaufbereitungswerk behandelt werden. Die Behandlung der Spaltprodukte beinhaltet die Trennung der verschiedenen Elemente und die Herstellung neuer Brennstäbe. Die neuen Brennstäbe können dann in einem Reaktor wiederverwendet werden.
Der Thorium-Brennstoffzyklus ist ein vielversprechender Ansatz für die Erzeugung von Kernenergie. Er ist sicherer, effizienter und nachhaltiger als der Uran-Brennstoffzyklus. Der Thorium-Brennstoffzyklus könnte dazu beitragen, die Abhängigkeit von fossilen Brennstoffen zu verringern und die Umwelt zu schützen.
Hier sind einige der Vorteile des Thorium-Brennstoffzyklus:
Thorium ist ein häufigeres Element als Uran. Thorium hat eine höhere Schmelztemperatur, was es weniger anfällig für kritische Unfälle macht. Der Thorium-Brennstoffzyklus erzeugt weniger radioaktive Abfälle als der Uran-Brennstoffzyklus. Der Thorium-Brennstoffzyklus ist sicherer und effizienter als der Uran-Brennstoffzyklus. Der Thorium-Brennstoffzyklus ist nachhaltiger als der Uran-Brennstoffzyklus. Der Thorium-Brennstoffzyklus ist jedoch noch nicht vollständig entwickelt. Es gibt noch einige Herausforderungen, die bewältigt werden müssen, bevor der Thorium-Brennstoffzyklus kommerziell eingesetzt werden kann. Diese Herausforderungen umfassen die Entwicklung neuer Reaktortypen, die Entwicklung neuer Brennstäbe und die Entwicklung neuer Wiederaufbereitungstechniken.
Trotz der Herausforderungen hat der Thorium-Brennstoffzyklus das Potenzial, ein wichtiger Teil der Zukunft der Kernenergie zu werden. Der Thorium-Brennstoffzyklus könnte dazu beitragen, die Abhängigkeit von fossilen Brennstoffen zu verringern, die Umwelt zu schützen und die Sicherheit der Kernenergie zu verbessern.
Vorteile des Thorium-Brennstoffzyklus Thorium ist ein häufigeres Element als Uran. Es gibt etwa 3-4-mal mehr Thorium in der Erdkruste als Uran. Thorium hat eine höhere Schmelztemperatur als Uran, was es weniger anfällig für kritische Unfälle macht. Der Thorium-Brennstoffzyklus erzeugt weniger radioaktive Abfälle als der Uran-Brennstoffzyklus. Thorium produziert nur eine kleine Menge an Plutonium, das als Abfallprodukt entsteht. Der Thorium-Brennstoffzyklus ist sicherer und effizienter als der Uran-Brennstoffzyklus. Thorium ist weniger anfällig für kritische Unfälle und erzeugt weniger radioaktive Abfälle. Der Thorium-Brennstoffzyklus ist nachhaltiger als der Uran-Brennstoffzyklus. Thorium ist ein häufigeres Element als Uran und hat eine längere Halbwertszeit. Herausforderungen des Thorium-Brennstoffzyklus Der Thorium-Brennstoffzyklus ist noch nicht vollständig entwickelt. Es gibt noch einige Herausforderungen, die bewältigt werden müssen, bevor der Thorium-Brennstoffzyklus kommerziell eingesetzt werden kann. Diese Herausforderungen umfassen die Entwicklung neuer Reaktortypen, die Entwicklung neuer Brennstäbe und die Entwicklung neuer Wiederaufbereitungstechniken. Thorium ist ein schwereres Element als Uran, was die Brennstäbe teurer macht. Thorium ist ein selteneres Element als Uran, was die Verfügbarkeit von Thorium einschränken könnte. Zukunft des Thorium-Brennstoffzyklus Trotz der Herausforderungen hat der Thorium-Brennstoffzyklus das Potenzial, ein wichtiger Teil der Zukunft der Kernenergie zu werden. Der Thorium-Brennstoffzyklus könnte dazu beitragen, die Abhängigkeit von fossilen Brennstoffen zu verringern, die Umwelt zu schützen und die Sicherheit der Kernenergie zu verbessern.
The Thorium-Brennstoffzyklus is a nuclear fuel cycle that uses an isotope of thorium, Vorlage:SimpleNuclide2, as the fertile material. In the reactor, Vorlage:SimpleNuclide2 is transmuted into the fissile artificial uranium isotope Vorlage:SimpleNuclide2 which is the nuclear fuel. Unlike natural uranium, natural thorium contains only trace amounts of fissile material (such as Vorlage:SimpleNuclide2), which are insufficient to initiate a nuclear chain reaction. Additional fissile material or another neutron source is necessary to initiate the fuel cycle. In a thorium-fuelled reactor, Vorlage:SimpleNuclide2 absorbs neutrons to produce Vorlage:SimpleNuclide2. This parallels the process in uranium breeder reactors whereby fertile Vorlage:SimpleNuclide2 absorbs neutrons to form fissile Vorlage:SimpleNuclide2. Depending on the design of the reactor and fuel cycle, the generated Vorlage:SimpleNuclide2 either fissions in situ or is chemically separated from the used nuclear fuel and formed into new nuclear fuel.
The thorium fuel cycle has several potential advantages over a uranium fuel cycle, including thorium's greater abundance, superior physical and nuclear properties, reduced plutonium and actinide production,[1] and better resistance to nuclear weapons proliferation when used in a traditional light water reactor[1][2] though not in a molten salt reactor.[3][4]
History
BearbeitenConcerns about the limits of worldwide uranium resources motivated initial interest in the thorium fuel cycle.[5] It was envisioned that as uranium reserves were depleted, thorium would supplement uranium as a fertile material. However, for most countries uranium was relatively abundant and research in thorium fuel cycles waned. A notable exception was India's three-stage nuclear power programme.[6] In the twenty-first century thorium's potential for improving proliferation resistance and waste characteristics led to renewed interest in the thorium fuel cycle.[7][8][9]
At Oak Ridge National Laboratory in the 1960s, the Molten-Salt Reactor Experiment used Vorlage:SimpleNuclide2 as the fissile fuel in an experiment to demonstrate a part of the Molten Salt Breeder Reactor that was designed to operate on the thorium fuel cycle. Molten salt reactor (MSR) experiments assessed thorium's feasibility, using thorium(IV) fluoride dissolved in a molten salt fluid that eliminated the need to fabricate fuel elements. The MSR program was defunded in 1976 after its patron Alvin Weinberg was fired.[10]
In 1993, Carlo Rubbia proposed the concept of an energy amplifier or "accelerator driven system" (ADS), which he saw as a novel and safe way to produce nuclear energy that exploited existing accelerator technologies. Rubbia's proposal offered the potential to incinerate high-activity nuclear waste and produce energy from natural thorium and depleted uranium.[11][12]
Kirk Sorensen, former NASA scientist and Chief Technologist at Flibe Energy, has been a long-time promoter of thorium fuel cycle and particularly liquid fluoride thorium reactors (LFTRs). He first researched thorium reactors while working at NASA, while evaluating power plant designs suitable for lunar colonies. In 2006 Sorensen started "energyfromthorium.com" to promote and make information available about this technology.[13]
A 2011 MIT study concluded that although there is little in the way of barriers to a thorium fuel cycle, with current or near term light-water reactor designs there is also little incentive for any significant market penetration to occur. As such they conclude there is little chance of thorium cycles replacing conventional uranium cycles in the current nuclear power market, despite the potential benefits.[14]
Nuclear reactions with thorium
BearbeitenIn the thorium cycle, fuel is formed when Vorlage:SimpleNuclide2 captures a neutron (whether in a fast reactor or thermal reactor) to become Vorlage:SimpleNuclide2. This normally emits an electron and an anti-neutrino (Vorlage:SubatomicParticle) by [[beta decay|Vorlage:SubatomicParticle decay]] to become Vorlage:SimpleNuclide2. This then emits another electron and anti-neutrino by a second Vorlage:SubatomicParticle decay to become Vorlage:SimpleNuclide2, the fuel:
![{\displaystyle {\ce {{\overset {neutron}{n}}+{^{232}_{90}Th}->{^{233}_{90}Th}->[\beta ^{-}]{^{233}_{91}Pa}->[\beta ^{-}]{\overset {fuel}{^{233}_{92}U}}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/f54ed9ab9c12691aba01cc0f642fa9b5ac661ea3)
Fission product wastes
BearbeitenNuclear fission produces radioactive fission products which can have half-lives from days to greater than 200,000 years. According to some toxicity studies,[15] the thorium cycle can fully recycle actinide wastes and only emit fission product wastes, and after a few hundred years, the waste from a thorium reactor can be less toxic than the uranium ore that would have been used to produce low enriched uranium fuel for a light water reactor of the same power. Other studies assume some actinide losses and find that actinide wastes dominate thorium cycle waste radioactivity at some future periods.[16]
Actinide wastes
BearbeitenIn a reactor, when a neutron hits a fissile atom (such as certain isotopes of uranium), it either splits the nucleus or is captured and transmutes the atom. In the case of Vorlage:SimpleNuclide2, the transmutations tend to produce useful nuclear fuels rather than transuranic wastes. When Vorlage:SimpleNuclide2 absorbs a neutron, it either fissions or becomes Vorlage:SimpleNuclide2. The chance of fissioning on absorption of a thermal neutron is about 92%; the capture-to-fission ratio of Vorlage:SimpleNuclide2, therefore, is about 1:12 – which is better than the corresponding capture vs. fission ratios of Vorlage:SimpleNuclide2 (about 1:6), or Vorlage:SimpleNuclide2 or Vorlage:SimpleNuclide2 (both about 1:3).[5][17] The result is less transuranic waste than in a reactor using the uranium-plutonium fuel cycle. Vorlage:Thorium Cycle Transmutation Vorlage:SimpleNuclide2, like most actinides with an even number of neutrons, is not fissile, but neutron capture produces fissile Vorlage:SimpleNuclide2. If the fissile isotope fails to fission on neutron capture, it produces Vorlage:SimpleNuclide2, Vorlage:SimpleNuclide2, Vorlage:SimpleNuclide2, and eventually fissile Vorlage:SimpleNuclide2 and heavier isotopes of plutonium. The Vorlage:SimpleNuclide2 can be removed and stored as waste or retained and transmuted to plutonium, where more of it fissions, while the remainder becomes Vorlage:SimpleNuclide2, then americium and curium, which in turn can be removed as waste or returned to reactors for further transmutation and fission.
However, the Vorlage:SimpleNuclide2 (with a half-life of Vorlage:Val) formed via (n,2n) reactions with Vorlage:SimpleNuclide2 (yielding Vorlage:SimpleNuclide2 that decays to Vorlage:SimpleNuclide2), while not a transuranic waste, is a major contributor to the long-term radiotoxicity of spent nuclear fuel.
Uranium-232 contamination
BearbeitenVorlage:SimpleNuclide2 is also formed in this process, via (n,2n) reactions between fast neutrons and Vorlage:SimpleNuclide2, Vorlage:SimpleNuclide2, and Vorlage:SimpleNuclide2:
![{\displaystyle {\begin{aligned}{}\\{\ce {{^{232}_{90}Th}->[+n]{^{233}_{90}Th}->[\beta ^{-}]{^{233}_{91}Pa}{\text{ }}->[\beta ^{-}]{^{233}_{92}U}->[+n-2n]{^{232}_{92}U}}}\\{\ce {{^{232}_{90}Th}->[+n]{^{233}_{90}Th}->[\beta ^{-}]{^{233}_{91}Pa}{\text{ }}->[+n-2n]{^{232}_{91}Pa}->[\beta ^{-}]{^{232}_{92}U}}}\\{\ce {{^{232}_{90}Th}->[+n-2n]{^{231}_{90}Th}->[\beta ^{-}]{^{231}_{91}Pa}{\text{ }}->[+n]{^{232}_{91}Pa}->[\beta ^{-}]{^{232}_{92}U}}}\\{}\end{aligned}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c082ef8785480b488370fecb974943fbc7bff08f)
Unlike most even numbered heavy isotopes, Vorlage:SimpleNuclide2 is also a fissile fuel fissioning just over half the time when it absorbs a thermal neutron.[18] Vorlage:SimpleNuclide2 has a relatively short half-life (Vorlage:Val), and some decay products emit high energy gamma radiation, such as Vorlage:SimpleNuclide2, Vorlage:SimpleNuclide2 and particularly Vorlage:SimpleNuclide2. The full decay chain, along with half-lives and relevant gamma energies, is:
.PNG)
Vorlage:SimpleNuclide2 decays to Vorlage:SimpleNuclide2 where it joins the [[thorium series|decay chain of Vorlage:SimpleNuclide2]]
![{\displaystyle {\begin{aligned}{}\\{\ce {^{232}_{92}U ->[\alpha] ^{228}_{90}Th}}\ &\mathrm {(68.9\ years)} \\{\ce {^{228}_{90}Th ->[\alpha] ^{224}_{88}Ra}}\ &\mathrm {(1.9\ year)} \\{\ce {^{224}_{88}Ra ->[\alpha] ^{220}_{86}Rn}}\ &\mathrm {(3.6\ day,\ 0.24\ MeV)} \\{\ce {^{220}_{86}Rn ->[\alpha] ^{216}_{84}Po}}\ &\mathrm {(55\ s,\ 0.54\ MeV)} \\{\ce {^{216}_{84}Po ->[\alpha] ^{212}_{82}Pb}}\ &\mathrm {(0.15\ s)} \\{\ce {^{212}_{82}Pb ->[\beta^-] ^{212}_{83}Bi}}\ &\mathrm {(10.64\ h)} \\{\ce {^{212}_{83}Bi ->[\alpha] ^{208}_{81}Tl}}\ &\mathrm {(61\ m,\ 0.78\ MeV)} \\{\ce {^{208}_{81}Tl ->[\beta^-] ^{208}_{82}Pb}}\ &\mathrm {(3\ m,\ 2.6\ MeV)} \\{}\end{aligned}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/84159d783a87a794a657d34a04f5e151e74f207f)
Thorium-cycle fuels produce hard gamma emissions, which damage electronics, limiting their use in bombs. Vorlage:SimpleNuclide2 cannot be chemically separated from Vorlage:SimpleNuclide2 from used nuclear fuel; however, chemical separation of thorium from uranium removes the decay product Vorlage:SimpleNuclide2 and the radiation from the rest of the decay chain, which gradually build up as Vorlage:SimpleNuclide2 reaccumulates. The contamination could also be avoided by using a molten-salt breeder reactor and separating the Vorlage:SimpleNuclide2 before it decays into Vorlage:SimpleNuclide2.[3] The hard gamma emissions also create a radiological hazard which requires remote handling during reprocessing.
Nuclear fuel
BearbeitenAs a fertile material thorium is similar to Vorlage:SimpleNuclide2, the major part of natural and depleted uranium. The thermal neutron absorption cross section (σa) and resonance integral (average of neutron cross sections over intermediate neutron energies) for Vorlage:SimpleNuclide2 are about three and one third times those of the respective values for Vorlage:SimpleNuclide2.
Advantages
BearbeitenThe primary physical advantage of thorium fuel is that it uniquely makes possible a breeder reactor that runs with slow neutrons, otherwise known as a thermal breeder reactor.[5] These reactors are often considered simpler than the more traditional fast-neutron breeders. Although the thermal neutron fission cross section (σf) of the resulting Vorlage:SimpleNuclide2 is comparable to Vorlage:SimpleNuclide2 and Vorlage:SimpleNuclide2, it has a much lower capture cross section (σγ) than the latter two fissile isotopes, providing fewer non-fissile neutron absorptions and improved neutron economy. The ratio of neutrons released per neutron absorbed (η) in Vorlage:SimpleNuclide2 is greater than two over a wide range of energies, including the thermal spectrum. A breeding reactor in the uranium - plutonium cycle needs to use fast neutrons, because in the thermal spectrum one neutron absorbed by Vorlage:SimpleNuclide2 on average leads to less than two neutrons.
Thorium is estimated to be about three to four times more abundant than uranium in Earth's crust,[19] although present knowledge of reserves is limited. Current demand for thorium has been satisfied as a by-product of rare-earth extraction from monazite sands. Notably, there is very little thorium dissolved in seawater, so seawater extraction is not viable, as it is with uranium. Using breeder reactors, known thorium and uranium resources can both generate world-scale energy for thousands of years.
Thorium-based fuels also display favorable physical and chemical properties that improve reactor and repository performance. Compared to the predominant reactor fuel, uranium dioxide (Vorlage:Chem), thorium dioxide (Vorlage:Chem) has a higher melting point, higher thermal conductivity, and lower coefficient of thermal expansion. Thorium dioxide also exhibits greater chemical stability and, unlike uranium dioxide, does not further oxidize.[5]
Because the Vorlage:SimpleNuclide2 produced in thorium fuels is significantly contaminated with Vorlage:SimpleNuclide2 in proposed power reactor designs, thorium-based used nuclear fuel possesses inherent proliferation resistance. Vorlage:SimpleNuclide2 cannot be chemically separated from Vorlage:SimpleNuclide2 and has several decay products that emit high-energy gamma radiation. These high-energy photons are a radiological hazard that necessitate the use of remote handling of separated uranium and aid in the passive detection of such materials.
The long-term (on the order of roughly Vorlage:Val to Vorlage:Val) radiological hazard of conventional uranium-based used nuclear fuel is dominated by plutonium and other minor actinides, after which long-lived fission products become significant contributors again. A single neutron capture in Vorlage:SimpleNuclide2 is sufficient to produce transuranic elements, whereas five captures are generally necessary to do so from Vorlage:SimpleNuclide2. 98–99% of thorium-cycle fuel nuclei would fission at either Vorlage:SimpleNuclide2 or Vorlage:SimpleNuclide2, so fewer long-lived transuranics are produced. Because of this, thorium is a potentially attractive alternative to uranium in mixed oxide (MOX) fuels to minimize the generation of transuranics and maximize the destruction of plutonium.[20]
Disadvantages
BearbeitenThere are several challenges to the application of thorium as a nuclear fuel, particularly for solid fuel reactors:
In contrast to uranium, naturally occurring thorium is effectively mononuclidic and contains no fissile isotopes; fissile material, generally Vorlage:SimpleNuclide2, Vorlage:SimpleNuclide2 or plutonium, must be added to achieve criticality. This, along with the high sintering temperature necessary to make thorium-dioxide fuel, complicates fuel fabrication. Oak Ridge National Laboratory experimented with thorium tetrafluoride as fuel in a molten salt reactor from 1964–1969, which was expected to be easier to process and separate from contaminants that slow or stop the chain reaction.
In an open fuel cycle (i.e. utilizing Vorlage:SimpleNuclide2 in situ), higher burnup is necessary to achieve a favorable neutron economy. Although thorium dioxide performed well at burnups of 170,000 MWd/t and 150,000 MWd/t at Fort St. Vrain Generating Station and AVR respectively,[5] challenges complicate achieving this in light water reactors (LWR), which compose the vast majority of existing power reactors.
In a once-through thorium fuel cycle, thorium-based fuels produce far less long-lived transuranics than uranium-based fuels, some long-lived actinide products constitute a long-term radiological impact, especially Vorlage:SimpleNuclide2 and Vorlage:SimpleNuclide2. [15] On a closed cycle,Vorlage:SimpleNuclide2 and Vorlage:SimpleNuclide2 can be reprocessed. Vorlage:SimpleNuclide2 is also considered an excellent burnable poison absorber in light water reactors. [21]
Another challenge associated with the thorium fuel cycle is the comparatively long interval over which Vorlage:SimpleNuclide2 breeds to Vorlage:SimpleNuclide2. The half-life of Vorlage:SimpleNuclide2 is about 27 days, which is an order of magnitude longer than the half-life of Vorlage:SimpleNuclide2. As a result, substantial Vorlage:SimpleNuclide2 develops in thorium-based fuels. Vorlage:SimpleNuclide2 is a significant neutron absorber and, although it eventually breeds into fissile Vorlage:SimpleNuclide2, this requires two more neutron absorptions, which degrades neutron economy and increases the likelihood of transuranic production.
Alternatively, if solid thorium is used in a closed fuel cycle in which Vorlage:SimpleNuclide2 is recycled, remote handling is necessary for fuel fabrication because of the high radiation levels resulting from the decay products of Vorlage:SimpleNuclide2. This is also true of recycled thorium because of the presence of Vorlage:SimpleNuclide2, which is part of the Vorlage:SimpleNuclide2 decay sequence. Further, unlike proven uranium fuel recycling technology (e.g. PUREX), recycling technology for thorium (e.g. THOREX) is only under development.
Although the presence of Vorlage:SimpleNuclide2 complicates matters, there are public documents showing that Vorlage:SimpleNuclide2 has been used once in a nuclear weapon test. The United States tested a composite Vorlage:SimpleNuclide2-plutonium bomb core in the MET (Military Effects Test) blast during Operation Teapot in 1955, though with much lower yield than expected.[22]
Advocates for liquid core and molten salt reactors such as LFTRs claim that these technologies negate thorium's disadvantages present in solid fuelled reactors. As only two liquid-core fluoride salt reactors have been built (the ORNL ARE and MSRE) and neither have used thorium, it is hard to validate the exact benefits.[5]
Reactors
BearbeitenThorium fuels have fueled several different reactor types, including light water reactors, heavy water reactors, high temperature gas reactors, sodium-cooled fast reactors, and molten salt reactors.[23]
List of thorium-fueled reactors
BearbeitenFrom IAEA TECDOC-1450 "Thorium Fuel Cycle – Potential Benefits and Challenges", Table 1: Thorium utilization in different experimental and power reactors.[5] Additionally, Dresden 1 in the United States used "thorium oxide corner rods".[24]
| Name | Country | Reactor type | Power | Fuel | Operation period |
|---|---|---|---|---|---|
| AVR | Germany (West) | HTGR, experimental (pebble bed reactor) | 15 MW(e) | Th+Vorlage:SimpleNuclide2 Driver fuel, coated fuel particles, oxide & dicarbides | 1967–1988 |
| THTR-300 | Germany (West) | HTGR, power (pebble type) | 300 MW(e) | Th+Vorlage:SimpleNuclide2, Driver fuel, coated fuel particles, oxide & dicarbides | 1985–1989 |
| Lingen | Germany (West) | BWR irradiation-testing | 60 MW(e) | Test fuel (Th,Pu)O2 pellets | 1968–1973 |
| Dragon (OECD-Euratom) | UK (also Sweden, Norway and Switzerland) | HTGR, Experimental (pin-in-block design) | 20 MWt | Th+Vorlage:SimpleNuclide2 Driver fuel, coated fuel particles, oxide & dicarbides | 1966–1973 |
| Peach Bottom | United States | HTGR, Experimental (prismatic block) | 40 MW(e) | Th+Vorlage:SimpleNuclide2 Driver fuel, coated fuel particles, oxide & dicarbides | 1966–1972 |
| Fort St Vrain | United States | HTGR, Power (prismatic block) | 330 MW(e) | Th+Vorlage:SimpleNuclide2 Driver fuel, coated fuel particles, Dicarbide | 1976–1989 |
| MSRE ORNL | United States | MSR | 7.5 MWt | Vorlage:SimpleNuclide2 molten fluorides | 1964–1969 |
| BORAX-IV & Elk River Station | United States | BWR (pin assemblies) | 2.4 MW(e); 24 MW(e) | Th+Vorlage:SimpleNuclide2 Driver fuel oxide pellets | 1963–1968 |
| Shippingport | United States | LWBR, PWR, (pin assemblies) | 100 MW(e) | Th+Vorlage:SimpleNuclide2 Driver fuel, oxide pellets | 1977–1982 |
| Indian Point 1 | United States | LWBR, PWR, (pin assemblies) | 285 MW(e) | Th+Vorlage:SimpleNuclide2 Driver fuel, oxide pellets | 1962–1980 |
| SUSPOP/KSTR KEMA | Netherlands | Aqueous homogenous suspension (pin assemblies) | 1 MWt | Th+HEU, oxide pellets | 1974–1977 |
| NRX & NRU | Canada | MTR (pin assemblies) | 20 MW; 200 MW (see) | Th+Vorlage:SimpleNuclide2, Test Fuel | 1947 (NRX) + 1957 (NRU); Irradiation–testing of few fuel elements |
| CIRUS; DHRUVA; & KAMINI | India | MTR thermal | 40 MWt; 100 MWt; 30 kWt (low power, research) | Al+Vorlage:SimpleNuclide2 Driver fuel, ‘J’ rod of Th & ThO2, ‘J’ rod of ThO2 | 1960–2010 (CIRUS); others in operation |
| KAPS 1 &2; KGS 1 & 2; RAPS 2, 3 & 4 | India | PHWR, (pin assemblies) | 220 MW(e) | ThO2 pellets (for neutron flux flattening of initial core after start-up) | 1980 (RAPS 2) +; continuing in all new PHWRs |
| FBTR | India | LMFBR, (pin assemblies) | 40 MWt | ThO2 blanket | 1985; in operation |
| Petten | Netherlands | High Flux Reactor thorium molten salt experiment | 45 MW(e) | ? | 2024; planned |
See also
BearbeitenVorlage:Portal inline Vorlage:Portal inline Vorlage:Colbegin
References
BearbeitenFurther reading
Bearbeiten- Kasten, P. R. (1998). "Review of the Radkowsky Thorium reactor concept" Science & Global Security, 7(3), 237–269.
- Duncan Clark (9 September 2011), "Thorium advocates launch pressure group. Huge optimism for thorium nuclear energy at the launch of the Weinberg Foundation", The Guardian
- A. T. Nelson: Thorium: Not a near-term commercial nuclear fuel. In: Bulletin of the Atomic Scientists. 68. Jahrgang, Nr. 5, 2012, S. 33–44, doi:10.1177/0096340212459125, bibcode:2012BuAtS..68e..33N (zenodo.org).
- B.D. Kuz'minov, V.N. Manokhin, (1998) "Status of nuclear data for the thorium fuel cycle", IAEA translation from the Russian journal Yadernye Konstanty (Nuclear Constants) Issue No. 3–4, 1997
- Thorium and uranium fuel cycles comparison by the UK National Nuclear Laboratory
- Fact sheet on thorium at the World Nuclear Association.
- Annotated bibliography for the thorium fuel cycle from the Alsos Digital Library for Nuclear Issues
External links
Bearbeiten- ↑ a b Robert Hargraves, Ralph Moir: Liquid Fuel Nuclear Reactors. In: American Physical Society Forum on Physics & Society. Januar 2011, abgerufen am 31. Mai 2012.
- ↑ Carey Sublette: Nuclear Materials FAQ. In: http://nuclearweaponarchive.org. 20. Februar 1999, abgerufen am 23. Oktober 2019.
- ↑ a b J. Kang, F. N. Von Hippel: U‐232 and the proliferation‐resistance of U‐233 in spent fuel. In: Science & Global Security. 9. Jahrgang, Nr. 1, 2001, S. 1–32, doi:10.1080/08929880108426485, bibcode:2001S&GS....9....1K. Archived copy. Archiviert vom am 3. Dezember 2014; abgerufen am 2. März 2015.
- ↑ "Superfuel" Thorium a Proliferation Risk? 5. Dezember 2012.
- ↑ a b c d e f g IAEA-TECDOC-1450 Thorium Fuel Cycle – Potential Benefits and Challenges. International Atomic Energy Agency, Mai 2005, abgerufen am 23. März 2009.
- ↑ Ganesan Venkataraman: Bhabha and his magnificent obsessions. Universities Press, 1994, S. 157.
- ↑ IAEA-TECDOC-1349 Potential of thorium-based fuel cycles to constrain plutonium and to reduce the long-lived waste toxicity. International Atomic Energy Agency, 2002, abgerufen am 24. März 2009.
- ↑ Brett Evans: Scientist urges switch to thorium ( des vom 28. März 2010 im Internet Archive), ABC News, April 14, 2006. Abgerufen am 17. September 2011
- ↑ Richard Martin: Uranium Is So Last Century – Enter Thorium, the New Green Nuke In: Wired, December 21, 2009. Abgerufen am 19. Juni 2010
- ↑ Daniel Miller: Nuclear community snubbed reactor safety message: expert. In: ABC News. März 2011, abgerufen am 25. März 2012.
- ↑ Tim Dean: New age nuclear. In: Cosmos. April 2006, abgerufen am 19. Juni 2010.
- ↑ David J. C. MacKay: Sustainable Energy – without the hot air. UIT Cambridge Ltd., 20. Februar 2009, S. 166 (cam.ac.uk [abgerufen am 19. Juni 2010]).
- ↑ Flibe Energy. Flibe Energy, abgerufen am 12. Juni 2012.
- ↑ Vorlage:Cite report
- ↑ a b C. Le Brun, L. Mathieu, D. Heuer, A. Nuttin: Impact of the MSBR concept technology on long-lived radio-toxicity and proliferation resistance. Technical Meeting on Fissile Material Management Strategies for Sustainable Nuclear Energy, Vienna 2005, abgerufen am 20. Juni 2010.
- ↑ Brissot R., Heuer D., Huffer E., Le Brun, C., Loiseaux, J-M, Nifenecker H., Nuttin A.: Nuclear Energy With (Almost) No Radioactive Waste? Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Juli 2001, archiviert vom am 25. Mai 2011: „according to computer simulations done at ISN, this Protactinium dominates the residual toxicity of losses at Vorlage:Val“
- ↑ Interactive Chart of Nuclides. In: Brookhaven National Laboratory. Abgerufen am 2. März 2015: „Thermal neutron cross sections in barns (isotope, capture:fission, f/f+c, f/c) 233U 45.26:531.3 92.15% 11.74; 235U 98.69:585.0 85.57% 5.928; 239Pu 270.7:747.9 73.42% 2.763; 241Pu 363.0:1012 73.60% 2.788.“
- ↑ 9219.endfb7.1. In: atom.kaeri.re.kr.
- ↑ The Use of Thorium as Nuclear Fuel. American Nuclear Society, November 2006, abgerufen am 24. März 2009.
- ↑ Thorium test begins, World Nuclear News, 21 June 2013. Abgerufen im 21 July 2013
- ↑ Protactinium-231 –New burnable neutron absorber. 11. November 2017.
- ↑ Operation Teapot. 11. November 2017.
- ↑ IAEA-TECDOC-1319 Thorium Fuel Utilization: Options and trends. International Atomic Energy Agency, November 2002, abgerufen am 24. März 2009.
- ↑ Spent Nuclear Fuel Discharges from U. S. Reactors. Energy Information Administration, 1995, ISBN 978-0-7881-2070-1, S. 111 (google.com [abgerufen am 11. Juni 2012] [1993]). They were manufactured by General Electric (assembly code XDR07G) and later sent to the Savannah River Site for reprocessing.