Nations with annual per capita electric power of 2, kwh per year achieve the necessary prosperity for population stability. The US number is 12, Economists study the balance between the economic damage of carbon taxes against the economic damage of global warming. Raising carbon taxes too swiftly damages the total economy and future world prosperity. Developing nations will not accept carbon taxes that limit their growth.
Yet even global warming skeptics can support the economic benefit of energy cheaper than from coal. The liquid fluoride thorium reactor solves these issues by. Liquid Fluoride Thorium Reactor History. The LFTR uses inexpensive thorium as a fuel, transforming it to uranium which fissions, producing heat and electric power. Innovatively, the thorium and uranium are dissolved in molten salt, simplifying fueling and waste removal compared to today's nuclear power plants. Prototype molten salt reactors were developed and tested by the US at Oak Ridge National Laboratories in the s and s.
President Ford stopped the project in Chine intends to build a prototype. Occasional theoretical papers are published by US scientists. In the Oak Ridge research papers were scanned and posted on the internet. A collaboration of scientists, engineers, and professional volunteers has begun developing an updated conceptual design for the LFTR. The LFTR produces energy cheaper than from coal, economically forcing closure of coal power plants and their CO2 emissions, checking global warming.
The low cost energy also advances prosperity in developing nations, creating a lifestyle that results in diminishing world population without increasing pollution and tragic competition for dwindling natural resources. It can consume spent fuel now stored outside existing nuclear power plants.
Ending atmospheric pollution from coal particulates would save 24, lives annually in the US and hundreds of thousands in China and worldwide. It uses an inexhaustible supply of inexpensive thorium fuel. LFTR has no refueling outages, with continuous refueling and continuous waste fission product removal. It can change power output to satisfy demand, satisfying today's need for both baseload coal or nuclear power and expensive peakload natural gas power. It is air cooled, critical for arid regions of the Western US and many developing countries where water is scarce.
LFTR has low capital costs because it does not need massive pressure vessels or containment domes, because of its compact heat exchanger and Brayton cycle turbine, because of intrinsic safety features, and because cooling requirements are halved. It will be factory produced, like Boeing airliners, lowering costs and time, enabling continuous improvement.
PHWRs was a natural choice for implementing the first stage because it had the most efficient reactor design in terms of uranium utilisation, and the existing Indian infrastructure in the s allowed for quick adoption of the PHWR technology. Most of the remaining Heavy water deuterium oxide , D 2 O is used as moderator and coolant. Indian uranium reserves are capable of generating a total power capacity of GWe-years, but the Indian government limited the number of PHWRs fueled exclusively by indigenous uranium reserves, in an attempt to ensure that existing plants get a lifetime supply of uranium.
US analysts calculate this limit as being slightly over 13 GW in capacity. The 2 units of MWe each PHWRs that are under construction at both Kakrapar   and Rawatbhata ,  and the one planned for Banswara  would also come under the first stage of the programme, totalling a further addition of MW.
These additions will bring the total power capacity from the first stage PHWRs to near the total planned capacity of 10 GW called for by the three-stage power programme. Time required for construction has improved over time and is now at about 5 years. Tariffs of the operating plants are in the range of Rs. In the second stage, fast breeder reactors FBRs would use a mixed oxide MOX fuel made from plutonium , recovered by reprocessing spent fuel from the first stage, and natural uranium.
In FBRs, plutonium undergoes fission to produce energy, while the uranium present in the mixed oxide fuel transmutes to additional plutonium Once the inventory of plutonium is built up thorium can be introduced as a blanket material in the reactor and transmuted to uranium for use in the third stage.
The surplus plutonium bred in each fast reactor can be used to set up more such reactors, and might thus grow the Indian civil nuclear power capacity till the point where the third stage reactors using thorium as fuel can be brought online, which is forecasted as being possible once 50 GW of nuclear power capacity has been achieved. A start date in has been suggested. In addition, the country proposes to undertake the construction of four FBRs as part of the 12th Five Year Plan spanning —17, thus targeting MW from the five reactors. Doubling time refers to the time required to extract as output, double the amount of fissile fuel, which was fed as input into the breeder reactors.
In Bhabha's papers on role of thorium, he pictured a doubling time of 5—6 years for breeding U in the Th—U cycle. This estimate has now been revised to 70 years due to technical difficulties that were unforeseen at the time. Despite such setbacks, according to publications done by DAE scientists, the doubling time of fissile material in the fast breeder reactors can be brought down to about 10 years by choosing appropriate technologies with short doubling time.
Another report prepared for U. Department of Energy suggests a doubling time of 22 years for oxide fuel, 13 years for carbide fuel and 10 years for metal fuel. A Stage III reactor or an Advanced nuclear power system involves a self-sustaining series of thorium — uranium fuelled reactors. This would be a thermal breeder reactor , which in principle can be refueled — after its initial fuel charge — using only naturally occurring thorium.
As there is a long delay before direct thorium utilisation in the three-stage programme, the country is looking at reactor designs that allow more direct use of thorium in parallel with the sequential three-stage programme. Of the options, the design for AHWR is ready for deployment. It will take another 18 months to get clearances on regulatory and environmental grounds. Construction is estimated to take six years. India's Department of Atomic Energy and US's Fermilab are designing unique first-of-its-kind accelerator driven systems. No country has yet built an Accelerator Driven System for power generation.
Dr Anil Kakodkar, former chairman of the Atomic Energy Commission called this a mega science project and a "necessity" for humankind. In spite of the overall adequacy of its uranium reserves, Indian power plants could not get the necessary amount of uranium to function at full capacity in the late s, primarily due to inadequate investments made in the uranium mining and milling capacity resulting from fiscal austerity in the early s.
It was estimated that after attaining 21 GW from nuclear power by , further growth might require imported uranium. This is problematic because deployment of third stage requires that 50 GW be already established through the first and second stages. In such a scenario, the third stage could be made operational following the fast breeder implementation, and nuclear power capacity could grow to GW.
Imports of fissile material from outside would considerably speed up the programme. As per research data, the U—Pu cycle has the shortest doubling time by a large margin, and that technology's compounded yearly fissile material growth rate has been calculated as follows, after making some basic assumptions about the operating features of the fast breeder reactors. Indian power generation capacity has grown at 5.
This conclusion is mostly independent of future technical breakthroughs, and complementary to the eventual implementation of the three-stage approach. It was realised that the best way to get access to the requisite fissile material would be through uranium imports, which was not possible without ending India's nuclear isolation by U. Tellis argues that the Indo—US nuclear deal is attractive to India because it gives it access to far more options on its civil nuclear programme than would otherwise be the case, primarily by ending its isolation from the international nuclear community.
These options include access to latest technologies, access to higher unit output reactors which are more economical, access to global finance for building reactors, ability to export its indigenous small reactor size PHWRs,  better information flow for its research community, etc. This is possible due to the continuous feeding process. All other components of the salt are not touched and stay in the reactor. Additionally, the integral heavy metal content decreases significantly in the deep burn phase see Fig 6.
The process of changing the fissile component which is fed into the system has already been applied in the MSRE [ 13 ]. From safety point of view or better from authority point of view, the change of the fissile material is expected to require a special operational permission.
This task should be comparable to the operational permission which has to be received for a new loading of a LWR, when MOX fuel assemblies are foreseen to be inserted. Therefore, some additional safety analysis could be required. The U is bred in the blanket during the whole operation time. Thus it has to be stored, partly for a long time period. Thus, the methods for handling this kind of problem are already developed and demonstrated. However, this fact is a challenge for the safeguarding of the International Atomic Energy Agency.
The detailed analysis of the isotopic composition of the heavy metal content in the reactor core see Fig 6 during the whole operation is given in Fig 8. Almost all TRUs are accumulated during the transmuter operation. The slight changes in the feeding of the TRUs can be observed by the slow oscillations of the Pu content, and on a lower extent all other isotopes which are fed. Additionally, there are very short oscillations visible for all isotopes which are fed into the system PU, Am, and Cm , which can even not be resolved in the figure increased thickness of the lines.
These oscillations are created by the feeding and burning of the TRUs in each calculation cycle.
The only exceptions are Pu, Np, and partly Am The content of these isotopes decreases even though additional amounts of the isotopes are fed into the core at the beginning of each cycle. In the following deep burn phase, all TRUs are burnt very efficiently. First the Pu isotopes, followed by the Am isotopes, and finally by the Cm and the higher isotopes. However, this should not lead to the conclusion that the transmutation is not efficient during the transmuter operation.
The observed accumulation during the transmuter operation is only an indicator that not all TRUs which are fed into the system at the beginning of each time step are burnt in the time period of the cycle. In the deep burn phase, the uranium isotopes are accumulated see black curve in Fig 8 , left , but the main contribution is always U, only small amounts of even uranium isotopes are created. All TRU isotopes are burnt very efficiently during the deep burn phase, but at strongly different burning rates.
First, the very good fissile materials and the low weighted isotopes disappear due to fission and capture processes. Especially, the higher curium isotopes like Cm to stay constant, or even grow slightly in the first five years of the deep burn phase.
Also what are the barriers legal or regulatory to higher enrichment, do laws need to be changed, or just regulations, or nothing? Progress on fission product cross sections to improve LWR cycle length prediction, D. Salvatores, February J Dean. Sublet, J. Additionally, this finding leads to the conclusion that the parameters for the optimization of the salt configuration should not only be the melting point of the salt and the demands for reprocessing. This fact leads to the request of the optimization of the length of the deep burn phase.
However, after about 5 years, these isotopes are burnt efficiently, too. A comparable behavior can be found for the very heavy curium isotopes. The amount grows in the beginning of the deep burn phase due to breeding processes from lighter isotopes. Finally, even the californium isotopes are burnt, since the built up of new californium isotopes decreases due to the reduced breeding potential. This is caused by the burning of the lighter precursor isotopes which could act as precursors for breeding. An overview of the main operational results separated for the transmuter operation and for different options of the deep burn phase is given in Table 3.
The most remarkable numbers are: in each of the requested three reactors This amount is inserted over an operational period of nearly 45 years transmuter operation. The remaining loading at the end of the transmuter operation is burnt in the deep burn phase. The time period for the deep burn phase depends on the requested burnout of the TRU isotopes. Any extension of the deep burn phase leads to counteracting consequences.
On the one hand, the reduction of the TRUs improves up to On the other hand, the TRU burning rate decreases. This is caused by the extension of the deep burn phase. It leads to a shift of the energy production from the TRUs to the U However, it has to be kept in mind that this very small remaining TRU amounts have to be put to the deep geological final disposal. Thus, the decision on the length of the deep burn phase is an optimization problem with boundary conditions which have finally to be defined by the public.
This result confirms the quality of the calculation procedure. In first order approximation, the amount of energy set free by the fission of the TRUs during transmuter operation will be the same for each fertile free reactor configuration since it is determined by physical constants. Thus, it is only the question if the fertile free configuration will be acceptable from safety, technological, and operational point of view. These requests are fulfilled in the MSFR due to the very special safety characteristics and the much simpler fuel production compared to solid fuels.
The detailed composition at the very end of the deep burn phase, after cycles is given in Table 4. This process is already well established for the blending of weapon grade Uranium [ 40 ]. Finally, a general remark concerning radiotoxicity: the radiotoxicity content in the reactor is significantly reduced in the deep burn phase since the major carriers of the radiotoxicity are the TRUs. Transmutation is a process which is generally driven by different nuclear reactions.
To illustrate the process, a detailed analysis of the, into the system inserted and the in core resident masses of the, TRUs are given in Figs 9 — The figures and the detailed discussion are given to deepen the understanding of the processes driving the transmuter operation and the deep burn phase. The major nuclear reactions are the fission reactions and the capture reactions. On the one hand, there are the fission reactions which lead immediately to a reduction of the TRU inventory in the core. On the other hand, there are the capture reactions which lead to breeding processes.
In both processes the observed isotope disappears, but as long as no fission takes place the isotope only forms a higher TRU isotope.
Thus, the TRU mass is not reduced and often the radiotoxicity of the unwanted higher isotope is even higher than the one of the precursor. Even a net built up of a specific isotope can appear, if the capture processes leading to an isotope predominates over the fission and the capture processes in the special isotope.
The TRU mass inserted into the core are significantly higher than the TRU mass resident in the molten salt in the core over the operation time see Fig 9. In the initial phase, an accumulation of TRUs in the core takes place. However, even in this starting period more TRU is burnt than accumulated. This indicates that the TRU amount inserted into the system after this time is immediately burnt in the same cycle, while the TRU content in the salt stays constant.
The amount of burnt TRU can be read at each point of the operation as the yellow marked difference only along the y-direction. No TRUs are added in the following deep burn phase anymore. The amount of inserted TRUs stays constant there. However, the TRU mass resident in the core decreases rapidly. Thus, in the deep burn phase, the amount of resident TRUs in the core is eliminated.
source link This can be read from the figure due to the extension of the yellow area down to the x-axis. A net built up of TRUs does not appear during the whole operation period neither in the transmuter operation, nor in the deep burn phase. The values at the end of the deep burn phase reflect the mass of burnt material which is given by the distance between the dotted line inserted TRU and the solid line TRU resident in the core.
This value has to be compared to the negligible distance between the solid line and the x-axis which reflects the remaining TRUs in the core. A comparable process can be observed for the Pu mass inserted into the core. The inserted mass is always significantly higher than the Pu mass resident in the molten salt in the core see Fig This behavior is characteristic for isotopes with a comparably high fission cross section in the fast neutron spectrum. The characteristic for these isotopes is the immediate decrease of the contents from begin of operation on.
No accumulation takes place at all, since the inserted amount of these isotopes is immediately burnt in the cycle when they are inserted. Typical representatives are Pu, Np, and partly Pu This type of isotopes disappears very rapidly at the beginning of the deep burn phase. Both effects can be explained by the high fission cross section. Pu is the main fissile isotope in the starting phase. During the operation, other fissile isotopes are created in breeding processes.
A part of the required fissile content is shifted to other isotopes and less Pu is required to sustain the energy production. Finally, the excellent fissile material is fissioned very rapidly in the deep burn phase. New Pu is not bred, since the typical precursor would be U which is almost not available in the core. The comparison between the Cm mass inserted into the core and the Cm mass resident in the molten salt in the core over the operation time indicates a completely different behavior.
This behavior is characteristic for isotopes which are inserted with the TRU loading and which have a comparably low fission cross section in the fast neutron spectrum. All these isotopes undergo a net built up to an asymptotic value, which can even be higher than the overall inserted amount of the isotope e. Thus, for these isotopes it is possible to find amounts in the salt which are higher than the amount inserted with the feeding material.
This is one of the major challenges of the transmutation process. The isotopes are formed by breeding inside the TRU material which is fed into the core to be burnt. The major reason for this behavior is that the isotopic composition of the TRU feed is not the asymptotic one. The asymptotic composition will be formed specific for any kind of reactor and neutron spectrum. This is the situation at the end of the transmuter operation. This effect confirms that Cm can be transmuted. The Cm amount in the core decreases rapidly in the deep burn phase.
This is caused by two effects, no new Cm is fed into the core anymore and the amount of precursors for the creation of Cm is decreased. Additionally, the relations between different isotopes should be kept in mind. Pu is given in tons and Cm is given kilograms. There is nearly a factor of 50 more Pu inserted than the maximum mass of Cm in the core. The very heavy isotopes which are not inserted with the TRU loading are characterized by a comparably low fission cross section in the fast neutron spectrum.
These isotopes accumulate during the transmuter operation see Fig Typical representatives of this group are the higher Cm- isotopes, the Bk- and Cf- isotopes. These isotopes accumulate by breeding processes in the TRU. Breeding processes are more or less unavoidable due to the competition of the fission and capture processes. The formation of Cf starts with a time delay of roughly five years, since the precursor isotopes for the breeding of Cf have to be built first.
In the following period, the mass increases to an asymptotic value which is not completely approached in the time of the transmuter operation.
Uranium , (). Plutonium n0. U U*?? n0. x Nuclear Most plants use %. Most US permits are for 5%. Some reactors use nat. U. All PowerPoint presentation slides and similar materials are open to misinterpretation . When U is used as a nuclear fuel, it is inevitably contaminated with.
The increase of the Cf amount becomes even stronger in the first five years of the deep burn phase. Obviously, the system tends to a new asymptotic value which would be higher for a system with less plutonium. This increase is stopped due to the reduction of breeding which is caused by the reduction of the precursor isotopes for breeding. The time for approaching the maximum value becomes longer, the higher the californium isotope is.
However, after 30 years of deep burn phase, all Cf isotopes have almost disappeared. The different isotopes appearing in the core at the end of the transmuter operation require significantly different time horizons for the burning of in the deep burn phase see Fig 13 , left.
This information has to be seen in conjunction with the corresponding maximum amounts of the different isotopes during the deep burn phase see Fig 13 , right. Both parts of the figure form the correlation for the evaluation of the efficiency of the deep burn phase.
The left part of the figure helps to understand how much time is required in the deep burn phase to burn each specific isotope. Negative values in the burning rate indicate breeding of an isotope. A process which obviously only appears for Bk and for Cf isotopes. The figure on the right indicates the relevance of these isotopes via the maximum amount of the specific isotope which is appearing during the deep burn phase. There, it is obvious that the Bk and Cf isotopes appear only in a very limited amount during the whole deep burn phase.
In comparison it is clear to see, the isotope appearing in the highest mass Pu is already mostly burnt after only ten years of deep burn. In this way every isotope can be studied. It has almost disappeared after 25 years.