Well you hit the (2) big reason why people have not become champions of Nuclear Power Stations. But here are a few facts about the concept (Benefits of Nuclear Power). However, we might not be mature enough as a society to utilize this process TODAY!
Summary
The audited environmental product statement of the Vattenfall Energy utility shows that their Nuclear Power Plants emit less than one hundreth the Greenhouse Gases of Coal or Gas fired power stations. If the Nuclear Power Industry lives up to it's promises for modern, 3rd generation plants, the total levelised cost of Nuclear Power including contruction, operational, waste disposal and decommissioning costs is in the range 3 - 5 cents per KiloWatt-Hour depending on the interest rate obtained for the construction. Nuclear Power plants pay back the energy required to build them in less than 2 months of operation. Current world proven reserves of Uranium are sufficient to supply current world demand for 50 years. Speculative reserves provide an additional 150 years of supply. The cost of Uranium Ore is a very small fraction of the operating costs of Nuclear Power. Fourth Generation Nuclear Plants can fully utilize all the energy in Natural Uranium. There is sufficient Uranium and Thorium on Earth for Fourth Generation reactors to supply the total World demand for energy for hundreds of centuries.
Greenhouse Emissions of Nuclear Power
There is world-wide concern over the prospect of Global Warming primarily caused by the emission of Carbon Dioxide gas (CO2) from the burning of fossil fuels. Although the processes of running a Nuclear Power plant generates no CO2, some CO2 emissions arise from the construction of the plant, the mining of the Uranium, the enrichment of the Uranium, its conversion into Nuclear Fuel, its final disposal and the final plant decommissioning. The amount of CO2 generated by these secondary processes primarily depends on the method used to enrich the Uranium (the gaseous diffusion enrichment process uses about 50 times more electricity than the gaseous centrifuge method) and the source of electricity used for the enrichment process. It has been the subject of some controversy. To estimate the total CO2 emissions from Nuclear Power we take the work of the Swedish Energy Utility, Vattenfall, which produces electricity via Nuclear, Hydro, Coal, Gas, Solar Cell, Peat and Wind energy sources and has produced credited Environment Product Declarations for all these processes.
Vattenfall finds that averaged over the entire lifecycle of their Nuclear Plant including Uranium mining, milling, enrichment, plant construction, operating, decommissioning and waste disposal, the total amount CO2 emitted per KW-Hr of electricity produced is 3.3 grams per KW-Hr of produced power. Vattenfall measures its CO2 output from Natural Gas to be 400 grams per KW-Hr and from coal to be 700 grams per KW-Hr. Thus nuclear power generated by Vattenfall, which may constitute World's best practice, emits less than one hundredth the CO2 of Fossil-Fuel based generation. In fact Vattenfall finds its Nuclear Plants to emit less CO2 than any of its other energy production mechanisms including Hydro, Wind, Solar and Biomass although all of these processes emit much less than fossil fuel generation of electricity.
Cost of Nuclear Power.
The cost of generating power via nuclear energy can be separated into the following components:
The construction cost of building the plant.
The operating cost of running the plant and generating energy.
The cost of waste disposal from the plant.
The cost of decommissioning the plant.
Quantifying some of these costs is difficult as it requires an extrapolation into the future.
Construction Costs
Construction costs are very difficult to quantify but dominate the cost of Nuclear Power. The main difficulty is that third generation power plants now proposed are claimed to be both substantially cheaper and faster to construct than the second generation power plants now in operation throughout the world. The Nuclear Industry says its learned the lessons of economy-of-volume demonstrated by the French Nuclear Program, and that these will be employed for the new power plants. Westinghouse claims its Advanced PWR reactor, the AP1000, will cost USD $1400 per KW for the first reactor and fall to USD $1000 per KW for subsequent reactors. They also claim these will be ready for electricity production 3 years after first pouring concrete. A more technical description is here. Proponents of the CANDU ACR and Gas Cooled pebble bed reactors make similar or stronger claims. This should be compared to second generation plants which, in the U.S.A., had construction costs up to $5000 per KW and generally took more than five years to complete.
The General Electric ABWR was the first third generation power plant approved. The first two ABWR's were commissioned in Japan in 1996 and 1997. These took just over 3 years to construct and were completed on budget. Their construction costs were around $2000 per KW. Two additional ABWR's are being constructed in Taiwan. However these have faced unexpected delays and are now at least 2 years behind schedule.
Meanwhile the Chinese Nuclear Power Industry has won contracts to build new plants of their own design at capital costs reported to be $1500 per KW and $1300 per KW at sites in South-East and North-East China. If completed on budget these facilities will be formidable competitors to the Western Nuclear Power Industry.
Given the history of Nuclear Plant construction in the U.S.A., the financial industry sees the construction of the new generation of reactors as a risky investment and demands a premium on captial lent for the purpose. The Energy Bill recently passed by the US Congress assumes this risk and provides production credits of 1.8 cents per KW-Hr for the first 3 years of operation. This subsidy is equivalent to what is paid to Wind Power companies and is designed to encourage new nuclear reactor construction in the USA.
If the AP1000 lives up to its promises of $1000 per KW construction cost and 3 year construction time, it will provide cheaper electricity than any other Fossil Fuel based generating facility, including Australian Coal power, even with no sequestration charges.
Construction Cost Over-Runs
There were massive cost overruns for plants built in the USA in the 1970's and 1980's.
There were several reasons for these.
Design Flaws. There were significant design flaws which led to the reactor leak and operator confusion that caused the Three Mile Island accident. After these were exposed, the US Nuclear Regulatory Commission (NRC), undertook an extensive review of Nuclear Plant designs and in many cases ordered changes. These changes were both expensive and time consuming to fix. They led to extensive construction delays at a time of very high interest rates and so significantly increased the cost of the Capital required to build the plant.
Two hurdle licensing. Up until the mid-1990's developers of nuclear power plants had to obtain both a license to build a Nuclear Power then a subsequent license to operate the plant. This also delayed the start of plant operation which significantly increased the cost of the plant. The worst situation was that of the Shoreham Plant which was completed on Long Island in New York State at a cost of 5 Billion dollars but was never allowed to operate.
Non-uniform designs. The US Nuclear Power Industry never achieved economies of volume because every reactor design was different. Each developer put in their own tweaks and much of the equipment was custom built for each plant. This compounded the difficulties of obtaining NRC licensing approval since the NRC had to evaluate each individual design.
In contrast the French Nuclear Power program settled on a standard design which satisfied the French Regulatory Commission. Industry was able to achieve economies of volume in the production of plants and to complete construction on time.
Operating Costs
These costs are much easier to quantify and are independently verified as they relate directly to the profitability of the Utilities which operate them. Any discrepancies are soon discovered through accounting audits. Company's that operate the USA's nuclear power reactors have made excellent profits over the last five years. The US Nuclear Power industry has at last lived up to its promise made in in 1970's to produce electricity reliably and cheaply. Since 1987 the cost of producing electricity from has decreased from 3.63 cents per KW-Hr to 1.68 cents per KW-Hour in 2004 and plant availability has increased from 67% to over 90%. The operating cost includes a charge of 0.2 cents per KW-Hr to fund the eventual disposal of waste from the reactor and for decommissioning the reactor. The price of Uranium Ore contributes approximately 0.05 cents per KW-Hr.
Management of Nuclear Plant Operations
It's clear from both the French and US experience that pro-active Industry organisations are vital in obtaining efficient plant utilisation and in minimising running costs. In the US in the late 1980's and early 1990's there was little pooling of knowledge and experience amongst Nuclear Power Operators. This was caused by a combination of industry inexperience, the lack of standardised designs and the fragmentation of the industry. Once again this was in contrast to the French experience where the uniform design and the single state-owned organisation allowed knowledge to be more easily shared.
The US industry has has since gone through several cycles of consolidation and the operation of the USA's fleet of Nuclear Reactors has mostly been taken over by specialist companies that specialize in this activity. In addition the industry has learned the benefits of pooling knowledge. This combination has demonstrably improved the performance of the US reactor fleet and is reflected in the share price of the nuclear operation companies.
Waste Disposal
In the USA, Nuclear Power operators are charged 0.1 cents per KW-Hr for the disposal of Nuclear Waste. In Sweden this cost is 0.13 US cents per KW-Hr. These Countries have utilized these funds to pursue research into Geologic disposal of waste and both now have mature proposals for the task. In France the cost of waste disposal and decommissioning is estimated to be 10% of the construction cost. So far provisions of 71 billion Euros have been acquired for this from the sale of electricity.
Decommissioning Costs
The US industry average cost for decommissioning a power plant is USD $300 million. The funds for this activity are accumulated in the operating cost of the plant. The French and Swedish Nuclear Industries expect decommissioning costs to be 10 -15 % of the construction costs and budget this into the price charged for electricity. On the other hand the British decommissioning costs have been projected to be around 1 Billion pounds per reactor. Cleaning up the Hanford Nuclear Weapons reactor is budgeted at 5.6 Billion dollars but may cost 2 to 3 times this much.
Model of Projected Costs
The following simple model gives a reasonable guideline to the cost in US cents of electricity per KW-Hr based on various assumptions for construction cost, interest rate and construction time. The model assumes that the capital for the entire project is delivered up-front before construction commences. This is a conservative approach. A better financing deal would to acquire capital as it needs to spent during construction. A 40-year lifetime is assumed. The operating costs are assumed to be 1.3 cents per KW-Hr in line with the second best-quartile of the American Nuclear Plant average. The plant availability is assumed to be 90% in-line with the full American average since 2000. The plant is assumed to have a 1 GW capacity.
The current discount interest rate in the USA is about 5%. China appears to be taking the Nuclear Power industry at its word that it can deliver generating power at USD$1500 per KW of capacity. As of August 30th, 2005, reports state that China expects to pay USD$6 Billion dollars for 4 GW worth of Nuclear Plant and that this will come on-line by 2010. Reports from December, 2006 state that the Chinese have contracted to buy 4 Westinghouse AP1000's with start up expected in 2013. The final price of the contract is unclear this time. If the Nuclear Power Industry delivers generating capacity at $1500 per kilowatt it will likely place the price of electricity produced at around 3 US cents per KW-Hr. This would be similar to the price of electricity generated by Eastern Australian Coal-Power which is in the range of 2.2 - 4.5 AUD cents per KW-Hr. It will be well worth watching to see if the Industry can deliver this outcome.
The construction costs expected by the Chinese are far lower than what the Nuclear Industry delivered in the 1980's. For example the ill-fated Shoreham facility, which was never allowed to operate, cost 5 Billion dollars for a plant rated at 1 GW. Case 5, shown below, shows the what our model predicts for this scenario.
Case 1, Construction Cost = $1 Billion. (Westinghouse claim for it's AP1000 reactor after volume production.)
The performance of Nuclear Power can also be measured by calculating the total energy required to build and run a Nuclear Power plant and comparing it to the total energy it produces. The following set of calculations is also taken from the independently audited, Vattenfall Environmental Product Declaration for its 3090 MW Forsmark power plant.
The following table displays the source and the amount of energy required to produce 1 KW-Hr of electricity from the Forsmark power plant. The table includes the energy used in construction of the plant, mining the Uranium, enriching it, converting it to fuel, disposing the waste and decommissioning the plant. The Forsmark plant is assumed to run for 40 years. There is an additional 0.026 grams of Uranium consumed in generating this one KW-Hr of electricty. This 0.026 grams includes the Uranium used to generate power at Forsmark and the Uranium consumed by the French Nuclear Power plants that produced the electricity that enriched the Forsmark Fuel.
So the Forsmark Plant produces 93 times more energy than it consumes. Or put another way, the non-nuclear energy investment required to generate electricity for 40 years is repaid in 5 months. Normalized to 1 GigaWatt electrical capacity, the energy required to construct and decommission the plant, which amounts to 4 Peta-Joules (PJ), which is repaid in 1.5 months. The energy required to dispose of the waste is also 4 PJ and repaid in 1.5 months. In total this is less than 0.8% of the all the electrical energy produced by the plant.
The calculations of the operating energy costs include the energy required to mine and mill the Uranium. In the case of the Forsmark power plant some of the Uranium is sourced from the Olympic Dam mine in South Australia. This mine has a rather low Uranium concentration (0.05% by weight). A detailed and audited environmental description of the Olympic Dam mine and a succinct description of the energy inputs of the mine is available. These data show that the Olympic Dam mine supplies enough Uranium for the generation of 26 GigaWatt-years of electricity each year (including the Uranium needed to run the power plants for enrichment). The energy consumed by the the mine is equivalent to 22% of a GigaWatt-Year. The energy gain is over a factor of 100. The Olympic Dam mine energy cost includes the energy required for mining and smelting it's huge Copper prodcution.
Another Uranium source for Forsmark is the Rossing Mine in Nambia. A description of the operations of the mine is available. The Rossing mine produced 3037 tonnes of Uranium in 2004, which is sufficient for 15 GigaWatt-years of electricity with current reactors. The energy used to mine and mill this Uranium was about 3% of a Giga-Watt-year. Thus the energy producd is about 500 times more than the enrgy required to operate the mine.
It is worth noting that the widely quoted paper by Jan Willem Storm van Leeuwen and Philip Smith (SLS), which gives a rather pessimistic assessment of the Energy Lifecycle of Nuclear Power, assumes a far larger energy cost to construct and decommission a Nuclear Power plant (240 Peta-Joules versus 8 Peta-Joules(PJ)). The difference is that Vattenfall actually measured their energy inputs whereas Willem Storm van Leeuwen and Smith employed various theoretical relationships between dollar costs and energy consumed. This paper also grossly over-estimates the energy cost of mining low-grade Ores and also that the efficiency of extraction of Uranium from reserves would fall dramatically at ore concentrations below 0.05%. Employing their calculations predicts that the energy cost of extracting the Olympic Dam mine's yearly production of 4600 tonnes of Uranium would require energy equivalent to almost 2 one-GigaWatt power plants running for a full year (2 Giga-Watt years). This is larger than the entire electricity production of South Australia and an order of magnitude more than the measured energy inputs.
The Rossing mine has a lower Uranium concentration (0.03% vs 0.05% by weight) than Olympic Dam and the discrepency is even larger in the case of Rossing. Here SLS predict Rossing should require 2.6 Giga-Watt-Years of energy for mining and milling. The total consumption of all forms of energy in the country of Namibia is equivalent to 1.5 GigaWatt-Years, much less than the prediction for the mine alone. Furthermore, yearly cost of supplying this energy is over 1 billion dollars, yet the value of the Uranium sold by Rossing was, until recently, less than 100 million dollars per year. Since Rossing reports it's yearly energy usage to be 0.03 Giga-Watt-years, SLS overestimates the energy cost of the Rossing mine by a factor of 80.
Additionally SLS predict that the yield of of Uranium extracted from low grade Ores will fall to 0 at concentrations of 0.0002% (2 ppm). The Olympic Dam mine extracts gold at high efficiency at concentrations of 0.0005% (5 ppm (parts per million)) and there are many other gold mines which produce gold profitably at this concentration. Given the huge Uranium reserves present at 5 ppm, it unlikely we will ever need mines that operate lower than this.
The energy cost of the Olympic Dam mine is the sum of all the operations for mining Copper, Uranium, Gold and other minerals. It is therefore the upper limit of the energy cost of extracting the Uranium alone. The Rossing mine which only produces Uranium, is a better measure of the energy cost future Uranium mines.
It is interesting to see what effect using the correct energy cost of 8 PJ for the construction, decommissioing and waste disposal of a power plants and the measured energy consumption of the Rossing mine has within the methodolgy of Willem Storm van Leeuwen and Smith. If we assume that the energy cost of extraction scales inversely with concentration and employ the Rossing experience as a benchmark, ore concentrations as low as 0.001% (10 ppm) provide an energy gain of 16. This also (and very unrealistically) assumes no further progress in mining technology or efficiency improvements in Nuclear Power operations over the course of hundreds of years. There is an estimated 1 trillion tonnes of Uranium at concentrations of 10 ppm or higher within the Earth's crust. This provides a resource over a factor of 300 times greater than predicted by Willem Storm van Leeuwen and Smith to be recoverable. So once the correct energy cost for plant construction and mining operations are used, the work of Willem Storm van Leeuwen and Smith imply that resource exhastion will not be a problem for Nuclear Power for the foreseeable future.
Storm and Smith have released a rebuttal of this argument, but that is more than we can discuss today. Due some additional investigations and you will be able to stengthen a conclusion that there is far more minable Uranium than predicted by Storm and Smith.
Availability of Usable Uranium
Uranium is present at an abundance 2 - 3 parts per million in the Earth's crust which is about 600 times greater than gold and about the same as tin. The amount of Uranium that is available is mostly a measure of the price that we're willing to pay for it. At present the cost of Natural Uranium ($100 per kg) is a small component in the price of electricity generated by Nuclear Power. At a price of $US50 per pound the known reserves amount to about 85 years supply at the current level of consumption with an expected further 500 years supply in additional or speculative reserves. The price of Uranium would have to increase by over a factor of 3 before it would have an impact of the cost of electricity generated from Nuclear Power. Such a price rise would stimulate a substantial increase in exploration activities with a consequent increase in the size of the resource (as has been the case with every other mineral of value). Currently the price of Uranium is increasing and this trend is projected to continue [1]. The world reserves of Uranium have increased by around 50% since the end of 2003.
However advanced technologies are being developed which are far more efficient in their use of Uranium or which utilize Thorium which is 3 times more abundant than Uranium. If perfected these technologies can make use of both the spent fuel from current nuclear reactors and the depleted Uranium stocks used for enrichment. Taken together these provide enough fuel for many centuries of energy production. This will mitigate the demand for newly mined Uranium.
Size of the Uranium Resource
Uranium is a dense metal found at an abundance of 2.8 parts per million in the Earth's crust. It is a highly reactive metal that does not occur in a free state in nature, commonly occuring as an oxide U3O8. Prices for Uranium in the world market are quoted in $US per pound of U3O8. The amount of Uranium commercially recoverable depends upon the market price of the metal. The current market price is around US$20/pound, coming off historical lows of less than US$10/pound in the early 1990s [1]. The cost of mining Uranium is a very small factor in the cost of running a nuclear power station and so movements in the price have little effect on the price of the power produced.
The sources of uranium are: mining, commercial inventories (from earlier periods of oversupply), reprocessing of spent full rods from nuclear power plants and down blending (mixing of enriched uranium with natural or depleted uranium) of highly enriched uranium from dismantled nuclear weapons. Consumption of uranium at the end of 1999 was 61600 tonnes of Uranium metal (tU) per annum [2] of which 56% is sourced from uranium mining. The majority of the balance comes from stockpiles and down blending in former Soviet countries as they reduce or eliminate their stock of nuclear weapons. The importance of this source and that of commercial inventories is expected to diminish over the next ten years.
Reasonably assured reserves (or proven reserves) refers to known commercial quantities of Uranium recoverable with current technonology and for the specified price. As well there are estimates of additional and speculative reserves in extensions to well explored deposits or in new depoists that are thought to exist based on well defined geological data. These are necessarily subject to a larger uncertainty, however, the historically low price of uranium over the past ten years has provided a disincentive to exploration. This is beginning to be rectified as the price recovers. Further exploration will reduce the uncertainty in the estimates of additional reserves. There are around 4000 million tU in sea water at a concentration of approximately 3 parts per billion.
Extracting this Uranium is a significant challenge [3] but substantial progress has been demonstrated by Seko et al.
These researchers recovered approximately 1 kg of Uranium in a 16 square meter cage submerged for 240 days off the coast of Japan. A patent related these efforts has been granted.
As of the beginning of 2003 World Uranium reserves were
Reasonable Assured Reserves recoverable at less than $US130/kgU (or $US50/lb U3O8) [4] = 3.10 - 3.28 million tU [2,5].
Additional reserves recoverable at less than $US130/kgU (or $US50/lb U3O8) = 10.690 million tU [2].
As of the beginning of 2005 World Uranium reserves were
Reasonable Assured Reserves recoverable at less than $US130/kgU (or $US50/lb U3O8) = 4.7 million tU [6].
Additional recoverable Uranium is estimated to be 35 million tU [6].
The substantial increase (almost 50%) from 2003 shows the reults of the world-wide renewed exploration effort spurred by the increase in Uranium prices which commenced in 2004. This increase in activity has continued through to 2006. Thus, the provable uranium reserves amount to approximately 85 years supply at the current level of consumption with current technology, with another 500 years of additional reserves. Around 24% of the proven reserves are in Australia.
With current technology, 235U is the only fuel for nuclear reactors. Uranium-235 represents 0.72% of natural uranium. Future technological developments could allow other elements to fuel nuclear reactors. Thorium-232 is a possible nuclear fuel and has a similar abundance to uranium, though there are as yet no commercial reactors operatoring or planned that would utilize thorium. Fast breeder reactors could utilize both 235U (Uranium-235) and 239Pu (Plutonium-239) as a fuel. Plutonium-239 is created when 238U (99.27% of naturally occuring uranium) is bombarded with neutrons. Plutonium-239 is a by product of nuclear power generation with the current mix of 235U and 238U. It is currently a waste product of concern due to its extreme toxicity and link to nuclear weapons. If reactors could be made to utilize 239Pu the potential of known reserves of uranium would be greatly extended since 238U could then be turned into a fuel. The Super Phoenix fast breeder reactor in France has demonstrated the technology. Currently electricity from such a plant would cost around three times the amount per kilowatt as that from conventional nuclear power plants. Fast breeder reactors have a higher risk profile due to the need to handle large quantities of Plutonium, and so present a different balance between utility and risk than the other types of reactors.
Also by using raw materials from the USSR the European and US fuel costs will decrease significantly!
2007-08-05 00:06:05
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answer #1
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answered by Freeman 2
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