Pr 07 Environmental impact and cost analysis of coal versus nuclear power
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Environmental impact and cost analysis of coal versus nuclear power: The U.S. case
Jasmina Vuji c c Zorka Vukmirovi c
- Dragoljub P. Anti
a University of California, Berkeley, California, USA b
ENECONIT Center, Belgrade, Serbia a r t i c l e i n f o a b s t r a c t Article history:
With all energy production systems there are environmental issues to be considered, risks to be assessed,
Received 7 September 2011
and challenges to be addressed. It must be emphasized that an ideal energy source that is at the same
Received in revised form
time efﬁcient, cost-effective, environment-friendly, and risk-free does not exist. There are always some
necessary trade-offs to be made, in order to ensure optimal use of energy resources, while limiting
Accepted 4 February 2012
environmental and health impacts. Nuclear energy is currently the only technology with a secure base-
Available online 13 March 2012 load electricity supply and no greenhouse gas emissions that has the potential to expand at a large scale.
However, the spent fuel and safety issues must be addressed. Another base-load electricity source e the
fossil-burning power plants e although affordable, emits various air pollutants (chemical and radioactive
Sustainable energy sources
efﬂuents, dust, ash, etc.), which are dispersed from a power source and transported through various
Fossil-burning plants pathways that could lead to the general population exposure. This paper summarizes current status and
Environmental impact future trends in base-load electricity sources in the U.S., including environmental footprints, newCost estimates
regulatory requirements, and cost issues. It also presents an analysis of challenges that need to be overcome and opportunities that could us lead us closer to a sustainable energy future.
Ó 2012 Published by Elsevier Ltd.
1. Introduction coal-ﬁred generation will increase by an average of 2.3%, and nuclear power by 2.0% per year
The world is facing considerable energy and environmental The outlook for coal-ﬁred generation could be considerably challenges, having in mind that about one-third of the world’s modiﬁed depending on the future environmental legislation that population still does not have access to electricity, and that would substantially limit greenhouse gas emissions. Worldwide, underdeveloped and developing countries mostly use fossil fuels as hydropower and wind power are predicted to provide the largest the major source of energy. This trend will continue in the future, share of the projected increase in total renewable generations e unless more affordable and environment friendlier source of elec- other renewable generation technologies are not predicted to be tricity could be supplied to them. In the recently published inter- economically competitive with fossil fuels over the projection national energy projections through 2035 , an assessment was period. Electricity generation from nuclear power is predicted to given of the outlook for energy (including electricity) demand and increase from about 2.6 trillion kWh in 2007 to 3.6 trillion kWh in supply. Based on this study, the world net electricity generation will 2020 and to 4.5 trillion kWh in 2035. However, there is consider- increase by 87 percent (in the basic scenario), from 18.8 trillion able uncertainty with the predictions for nuclear power growth,
kWh (18.8 10 kWh) in 2007 to 25.0 trillion kWh in 2020 and to related to radioactive waste disposal, safety, non-proliferation 35.2 trillion kWh in 2035 issues, as well as rising construction cost and investment risk.
Speciﬁcally, the increase in non- OECD countries (82% of the 2010 world population) is predicted to Unless non-OECD countries introduce national policies that be 3.3 percent per year, and in OECD countries 1.1 percent. While would limit greenhouse gas emissions, or if binding international the renewable energy use for electricity generation will increase agreements are signed, the world coal consumption will continue from 18% in 2007 to 23% in 2035 (an average of 3.0% per year), the to increase. This study projects that the coal consumption will
increase form 132 quadrillion in 2007 to 206 quadrillion Btu in * Corresponding author.
1 E-mail addresses: The British thermal unit (Btu) is a traditional unit of energy equal to 1,055.056 J.
15 (D.P. Anti
c), (Z. Vukmirovi c). MMBtu represents one million Btu. A quadrillion Btu represents 10 Btu. 0360-5442/$ e see front matter Ó 2012 Published by Elsevier Ltd.
2035, with an average annual rate of increase of 1.6%. Non-OECD Asian countries including China (55% of the 2010 world pop- ulation) will account for 95% of the total net increase in world coal use from 2007 to 2035 ( ).
The cost of a new power plant consists of three major elements: capital cost (the cost of the equipment, materials, and labor required to build the plant), ﬁnancing costs, and operating costs. The capital and ﬁnancing costs make up the total project cost. provides the “overnight
Fig. 2. Coal consumption in selected world regions, 1990e2035 (quadrillion
Fig. 1. World net electricity generation by fuel, 2007e2035 (trillion kWh) .
It is also clear that renewable electricity generation (excluding hydro) suffers from higher “overnight” cost, and low capacity availability factors particularly for solar and wind generation plants. The capacity factor is usually used as a measure of power plant operating efﬁciency. It is deﬁned as the total amount of energy produced during a period of time divided by the amount of energy that the plant would have produced at full capacity (times
From it is clear that coal and nuclear power plants have compatible “overnight” cost, particularly when the cost of carbon capture and sequestration is included for coal power plants. There is also a trend of rising cost of capital-intensive power technologies, commodities, construction materials, and cost increase due to regulatory requirements with respect to pollution and waste. In addition, there are very few companies in the world that have ability and expertise for complex engineering project such as construction of nuclear or advanced coal power plants.
The estimated capital cost in (e.g., the total project engineering, procurement and construction) includes the following categories: civil/structural material and installation, mechanical equipment supply and installation, electrical instrumentation and controls supply and installation, project indirect cost, fees and contingency, and owner’s cost (insurance, property taxes, asset management fees, excluding project ﬁnancing costs). Fixed opera- tion and maintenance (O&M) expenses include: stafﬁng and monthly fees under pertinent operating agreements, typical bonuses paid to the given plant operator, plant support equipment, plant-related general and administrative expenses, routine preventive and predictive maintenance performed during opera- tions, maintenance of structures and grounds. Variable O&M (VOM) expenses are production-related costs which vary with electrical generation and might include: raw water, waste and wastewater disposal expenses, purchase power, demand charges and related utilities, chemicals, catalysts and gases, lubricants, consumable materials and supplies.
generic plants ranges from a 7 MW solar plant to a 2236 MW advanced dual-unit nuclear power plant. Environmental footprint for each generic plant is included, with the cost increase due to implementations of particular technology for reduction of green- house gas emissions. includes the following power plant options: a generic nuclear power plant consisting of two 1117 MWe Westinghouse AP1000 nuclear power units build in a “brownﬁeld” (existing nuclear facility site), a nominal 650 MWe or 1300 MWe dual unit coal-ﬁred supercritical steam-electric generating plant built in a “greenﬁeld” location, and various other plants.
. The nominal capacity of the
cost estimates that were developed for a list of generic facilities of speciﬁc size and conﬁguration
In this paper, we are mostly interested in environmental impact of nuclear and coal-based electricity production under regular (not accidental) situations. Section
Several detailed studies were published recently that provide the newest capital cost and production cost estimates for electricity generation plants in the U.S.
2. Comparative cost estimates for new generating capacity in the U.S.
situation in nuclear electricity generation in the U.S. Having in mind that nuclear power is currently the only technology with a secure base-load electricity supply and no greenhouse gas emissions that has the potential to expand at a large scale, we will discuss what role nuclear power should play in meeting increased energy demands in a safe and proliferation resistant manner, and with minimal waste production through recycling. In conclusion, we point out what are some of the challenges that the base-load electric power sources (coal and nuclear) need to be overcome to stay as a part of energy mix for a sustainable energy future.
gives the current
ronmental impact of coal electricity generation in the U.S. and discusses the new environmental regulations proposed by the U.S. Environmental Protection Agency. Section
analyses the envi-
electricity sources, including the average fuel consumption per year and the amount of waste generated. Section
, we discuss general environmental footprint of various
comparative costs of new power generating plants, and various factors that will shape it in the future: changing national and international regulatory requirements for environmental protec- tion, changes in demand from developing countries, the cost of carbon capture and its storage, the uncertainty in commodities and construction costs, the electricity market deregulations, etc. In Section
includes the discussion about
2 “Overnight” cost is an estimate of the cost at which a plant could be constructed assuming that the entire process from planning through completion could be accomplished in a single day. c et al. / Energy 45 (2012) 31e42 coal and nuclear are 85% and 90%, respectively, the capacity avail- ability factor for hydro is 52%, for offshore wind 34%, for solar- thermal 18%, and for photovoltaic 24% The average capacity factors of power plants by fuel type in the U.S. are presented in
92 $5,578 $84.27 $9.64 Hydroelectric Hydro 500,000 52 $3,076 $13.44 Hydro-pumped storage Hydro 250,000 $5,595 $13.03
Biomass 50,000 83 $3,860 $100.50 $5.00 Geothermal dual ﬂash Geothermal 50,000
83 $7,894 $338.79 $16.64 Biomass BFB e
Gas 400,000 87 $1,003 $14.62 $3.11 A-NGCC/CCS Gas 340,000 87 $2,063 $30.25 $6.45 Fuel cells Gas 10,000 60 $6,835 $350.00 Dual unit nuclear Uranium 2,236,000 90 $5,339 $88.75 $2.04 Biomass combined cycle Biomass 20,000
Coal 520,000 85 $5,343 $69.30 $8.04 Conventional NGCC Gas 540,000 87 $978 $14.39 $3.43 Advanced NGCC d
Coal 1,300,000 85 $4,579 $63.21 $9.05 Single unit APC/CCS Coal 650,000 85 $5,099 $76.62 $9.05 Single unit IGCC/CCS c
Coal 1,300,000 85 $2,844 $29.67 $4.25 Dual unit APC/CCS b
Variable O&M ($/kW-yr) Dual unit APC a
Capital cost ($/kW) Fixed O&M ($/kW-yr)
Technology Fuel Nominal capacity (kW) Capacity factor (%)
8.9 Fig. 3. U.S. electricity production cost in 2009 cents per kWh Table 1 Estimates of power plant capital and operating costs
12.9 Oil (steam turbine)
17.7 Gas (steam turbine)
This means that the estimated power plant capital and oper- ating costs need to be increased (in some cases, several times) in order to offset the smaller capacity availability factors and deter- mine the “real” cost to investors.
65.4 Gas (combined cycle)
71.6 Coal (steam turbine)
Fuel Type Average capacity factors (%) Nuclear
Table 2 The U.S. average capacity factors by fuel type (2010)
This model shows that a merchant nuclear power plant with an 80% debt and 20% equity capital structure, supported by a federal loan guarantee, could produce electricity in the range of $84/MWh
The following assumptions were made in the model: the nuclear cases assume 48-month construction, 6-month start-up, owner’s cost of $300/kWe and 10% contingency, 6.5% interest rate on commercial debt for unregulated entities, 6.0% interest rate on commercial debt for regulated entities, 4.5% interest rate on government-guaranteed debt, 15% return on equity for project ﬁnance and 12% allowed rate of return for rate base, 2% loan guarantee cost, 90% capacity factor, O&M cost of $9.50/MWh and fuel cost of $6.50/MWh. The capital cost estimate for supercritical pulverized coal (SCPC) and integrated gasiﬁcation combined cycle (IGCC) are from
A detailed analysis of cost of electricity, including various ﬁnance options is presented in
The levelized cost of electricity production from new baseload generation of electricity (nuclear, coal-ﬁred, and gas-ﬁred plants) has been studied many times, and the results of the most recent study . It is shown that nuclear elec- tricity production is cost-competitive at 6.6 cents/kWh as compared to 6.2 cents/kWh for coal and 6.5 cents/kWh for gas. This is valid if the technology risk premium is removed from ﬁnancing assumptions. Also, it is shown that nuclear electricity generation is increasingly competitive if the cost of carbon capture and seques- tration is included for coal and gas. In , it is shown that a $25/ ton carbon tax would increase the price of coal-ﬁred generation to 8.3 cents/kWh and gas-ﬁred generation to 7.5 cents/kWh, while nuclear generation remains at 6.6 c/kWh.
Important factor is the cost of fuel. While the percentage of fuel cost for nuclear power is only 28%, the cost of fuel for gas-powered plant is 89%, and for coal-burning plant 78% of overall production cost in 2009 The nuclear fuel cost consists of following components: the cost of conversion (4%), fabrication (8%), waste fund (15%), enrichment (31%), and uranium (42%).
production cost in the period from 1995 to 2009, in 2009 cents per kWh. The production cost is deﬁned as the sum of O&M costs and fuel costs .
shows the U.S. electricity
Onshore wind Wind 100,000 25 $2,438 $28.07 Offshore wind Wind 400,000 34 $5,975 $53.33 Solar thermal Solar 100,000 18 $4,692 $64.00 Photovoltaic Solar 7,000 24 $6,050 $26.04 a Advanced pulverized coal. b Advanced pulverized coal with carbon capture and sequestration. c Integrated gasiﬁcation combined cycle with carbon capture and sequestration. d Advanced natural gas combined cycle. e Bubbling ﬂuidized bed. c et al. / Energy 45 (2012) 31e42 to $91/MWh. The conclusions from this analysis suggest that “although nuclear project costs are undeniably large, total project cost does not measure a project’s economic viability. The relevant metric is the cost of the electricity produced by the nuclear project relative to alternative sources of electricity and relative to the market price of the electricity at the time the nuclear power comes into service.”
2.1. Impact of deregulation and consolidation on nuclear electricity generation
7.00 Levelized cost (cents/kWh)
period from 1971 to 2010 . It gives the clear evidence of efﬁciency gains from deregulation and consolidation of nuclear power reac- tors. The companies that now own large number of the U.S. power reactors (namely Exelon and Entergy) succeeded in achieving the highest levels of nuclear reactor operating efﬁciency in history (over 90.1%), and proﬁted from it.
Over the last several decades, market deregulations were the way (at least in theory) to force industry to increase efﬁciency, cut costs, make new investments and support technological innova- tions. Some cases of market deregulations were more successful that others, and in many cases deregulation lead to industry consolidation. Having in mind that the U.S. nuclear power industry was for decades owned by regulated utilities, there was a wide- spread concern how would nuclear electricity generation compete in deregulated markets. Recently published paper gives a detailed analysis of impact of market deregulation and consoli- dation on nuclear electricity generation efﬁciency and cost. We will present a brief summary of the ﬁndings presented in that paper.
shows the U.S. Nuclear Industry Capacity Factors for the
production of more that 40 billion kWh annually (valued at $2.5 billion annually), without any new plant construction.
6.5 Levelized cost (Cents/kWh) with $25/tCO
7.5 c et al. / Energy 45 (2012) 31e42
Technology Nuclear with risk premium Nuclear without risk premium Coal Gas
Capital cost ($2007/kW) 4000 4000 2300 850Fuel cost ($2007/MMBtu)
Due to the large size of nuclear power plants in the U.S., even small improvements in operating efﬁciency imply substantial
20% equity 50% Debt 50% equity 50% Debt
Table 4 Cost of electricity from various generating technologies (in 2010 dollars) a .
By late 1990s electricity markets in many U.S. states were deregulated. Majority of the U.S. nuclear power plants were sold to independent power producers selling power in competitive wholesale markets, which lead to consolidation, and today the three largest companies control more than one-third of all U.S. nuclear capacity. Between 1999 and 2002, a total of 36 reactors were divested and reclassiﬁed as independent power producers. An additional 12 reactors were divested between 2004 and 2007. The main ﬁnding in this paper
is that “deregulation and consoli-
dation were associated with a 10 percent increase in operating efﬁciency, achieved primarily by reducing the frequency and duration of reactor outages,” which lead to an increase in electricity
amounts of additional electricity produced. The following example is illustrative a typical two-reactor 2000 MWe nuclear plant, that operates at 80% capacity produces electrical energy worth approximately $840 million dollars annually, at typical wholesale electricity prices ($60 per MWh). An increase in capacity factor from 80% to 85% increases revenues by $52 million dollars annually, $120,000 for each additional hour that the plant is operating. Having in mind that the average fuel cost for nuclear plants (about $7 per MWh) is low compared to wholesale prices of electricity, any increase in capacity factors will directly generate proﬁt for the plant owner.
The paper also points out: “because the increased electricity
production displaces mostly coal and natural gas ﬁred power, these gains in efﬁciency also have substantial implications for the environ- ment, implying an annual decrease of 38 million metric tonnes of carbon dioxide emissions. Using a conservative estimate for the social cost of carbon dioxide ($20 per ton) this is an additional $760 million in beneﬁts annually. To put this into perspective, this is more carbon abatement than was achieved by all the U.S. wind and solar generation combined during the same period.”
Technology Nuclear Coal (SCPC) Coal (IGCC) Gas (combined cycle) Project Structure Project ﬁnance with loan guarantee
50% equity 50% Debt 50% equity 80% Debt
Rate base with CWIP b
Rate base with CWIP Project ﬁnance with loan guarantee
Rate base with CWIP Project ﬁnance 80% Debt 20% equity 50% Debt
Estimated Total Cost values from the NEI Financial Model include EPC cost, owner’s costs, decommissioning funding (nuclear units only), and ﬁnancing. Values are rounded to nearest hundred. Table 3 Levelized cost of baseload electricity
NA NA Add $25.00 Add $25.00 Add $18.00
Notes: The nuclear Cases assume 48-month construction, 6-month start-up; owner’s cost of $300/kWe and 10% contingency; 6.5% Interest rate on commercial debt for
unregulated entities, 6.0% interest rate on commercial debt for regulated entities, 4.5% interest rate on government-guaranteed debt, 15% return on equity for project ﬁnance
and 12% allowed rate of return for rate base; 2% loan guarantee cost; 90% capacity factor; O&M cost of $9.50/MWh and fuel cost of $7.50/Mm. The capital cost estimates forsupercritical pulverized coal (SCPC) and integrated gasiﬁcation combined cycle (IGCC) are from the Energy Information Administration a Estimates calculated using the NET Financial Model Version 8.10, August 2010. b CWIP ¼ Construction Work In Progress. c
2 price at $30/Ton ($/MWh)
(coal/gas e $/mmBtu) $7.50 $2.00 $2.00 $5.00 $7.00 Capacity (MWe) 1400 800 600 400 First Year Busbar ($/MWh) $84-91 $115-$126 $99 $81 $113 $63 $77 Levelized Busbar ($/MWh) NA $86-$93 $75 NA $85 NA NA Impact of CO
($/kWe) S6000e$6600 $5300e$5800 $3500 $4500 $4000 $1200 $1200 Fuel cost (nuclear e $/WYVh)
50% equity EPC cost ($/kWe) $4500 5000 $3200 $3600 $1000 Total cost c
Since the majority of coal-ﬁred power plants represent old and less efﬁcient techniques, average emissions of greenhouse gases will
remain high. Although natural gas is less polluting than coal, it has other important uses in chemical and petrochemical industry, and as non-renewable resource should not be used as the primary source for electricity production.
3. Environmental impact of electricity generation Environmental impact of various electricity generation sources could be characterized as follows: (a) Use of natural resources
The life-cycle greenhouse gas emission for a photovoltaic (PV) system is not zero, as some believe. It is shown to be 39 tonnes CO
Wind power requires use of large amounts of land, which is not desirable in many cases. It requires installations of concrete foun- dation, roads, transformers, cables and communication equipment. Green house gas emissions are generated during the manufacturing and construction, as well as during the decommissioning. Some disadvantages included the use of a reserve power during the low- productive periods, and a short lifetime of about 25 years. However, wind power is essentially a clean energy source and will remain as a power generation option particularly if the electricity production cost is reduced.
Using coal to generate electricity affects the environment in a number of ways, producing air and water pollution, and gener- ating solid waste residuals. The main drawback with the use of coal is the emission of carbon dioxide to the atmosphere, which is difﬁcult to control. Other emissions are more easily controlled by the use of the modern ﬁltering techniques but could be very costly.
- equivalent per GW
Two main baselode electricity generating sources, coal and nuclear, produced more than 50% of world’s electricity in 2007 (World: 41.6% and 13.8%; OECD 37.2% and 21.4%; U.S. 45% and 20%, respectively), as shown in .
Fig. 5. Electricity generation by source. (a) Worldwide and OECD (2007) .Fig. 4. The U.S. Nuclear Industry Capacity Factors (1971e2010) c et al. / Energy 45 (2012) 31e42
Nuclear power emissions of greenhouse gases are minimal, and nuclear power is the only baseload electricity source that could effectively replace fossil-burning pants and help in reduction of global warming threat. It is estimated that nuclear power currently reduces carbon dioxide emissions by about 2.5 billion tonnes per year.
per kWh In addi- tion, the collapse of dams has caused more immediate casualties worldwide than any other power generation options .
emissions range between 4 and 410 g CO
The hydropower uses water and as such is a renewable source. It remains the cheapest electricity generation source. However, the hydropower has a list of environmental issues . The dam construction and operation of hydropower plants directly inﬂuence the river systems, surrounding land use, resettlement of pop- ulation, and water and ﬁsh resources management. It may inﬂu- ence local climate, geological stability, groundwater conditions, and water quality. Under certain conditions, decomposition of organic matter in reservoirs will result in methane formation, while the CO
e h) .
h) or coal-burning plant (974 tonnes CO
Life Cycle Assessment (LCA) is a technique for assessing the envi- ronmental aspects and potential impacts associated with a product from the cradle to the grave.
h), but signiﬁcantly lower than the emissions from natural gas plant (469 tonnes CO
(fossil fuel and ore, land, water or air), (b) Thermal pollution, (c) Emission of chemical pollutants (in atmosphere, hydrosphere and lithosphere), (d) Emission of radionuclides (in atmosphere, hydrosphere and lithosphere), and (e) Various social an economical impacts. Effect on people could be direct (inhalation, ingestion or exposure to emitted pollutants) or indirect (through impact on food chains, climate effects, changes of ﬂora and fauna). The societal risk perception and even aesthetic aspects should not be neglected. Short- and long-term environmental impact studies are very complex because of many interactions in the ecosystems. A detailed multidisciplinary analysis and modelling of physical, chemical and biological processes is necessary for reliable estimations, taking into account many uncertainties. A life cycle analysis methodology should be used to compare different electricity generation options.
h) and wind (14 tonnes CO
h, which is higher than nuclear (15 tonnes CO
/GW It is estimated that carbon dioxide emissions will more than double by 2050 shows the amount of CO
Dust, particles, ashes 25,000 Coal 2,000,000 CO
. It is
estimated that an annual average radiation dose to an indi-
Table 5 Fuel consumption and waste generation from various generation plants for 1 GWe year .
Fuel consumption (t) Waste generation (t)
Crude oil 1,400,000 CO
2 5,000,000 SO
2 40,000 NO x 25,000
2 6,000,000 SO
Ra) in ﬂy ash is about 210 Bq/kg and upper limit for dissolved radium in drinking water is 0.2 Bq/l Thus, there are serious concerns of radioactive nuclides reaching the drinking water. There is also a possibility of uranium, in form of the ﬁne-size particles, concentrating on ﬂy ash surfaces as a condensate, and ﬂying into the atmosphere together with about 1% of ﬂy ash that is accrualy released in the air. shows that inhalation of ﬁne particles of uranium or thorium might increase a probability of lung and bone cancer, and dissolution of uranium and thorium in drinking water might cause kidney disease.
2 120,000 NO x 25,000
Dust, particles, ashes 300,000 Liqueﬁed natural gas 1,000,000 CO
2 3,000,000 SO
20 NO x 13,000 Nuclear
30 Uranium (not waste) (28.8) Plutonium
(not waste) (0.3) Fission products
0.9 Fig. 6. CO
Solid coal combustion products (ﬂy ash, bottom ash, boiler slag, etc.) are suitable for different uses: 35% of it is used in agriculture, blasting grit, cement, mine backﬁll, road base, wallboards
emissions from various power sources, both direct and indirect (from life-cycle). Another important issue in any comparative analysis of various electricity generation plants is the amount of fuel consumed and waste generated per unit energy generated. shows fuel consumption and waste generation comparison for energy that
1 GWe plants of various types will produce within one year (1 GWe year) There is huge difference in the amount and type of waste generated by a coal-burning pant (millions of tonnes) and nuclear power (less that 30 tonnes) per year.
In the following sections we will focus on the environmental impacts of two base-load electricity generations sources, coal and nuclear power plants, and analyze the current situation in the U.S.
4. Environmental impact of coal electricity generation in the U.S.
Important issue in electricity generation is emission of green- house gases and other pollutants. Fossil fuels (mainly coal, oil, and natural gas), biomass, municipal and industrial wastes that were used, for example, to generate 71% of electricity in the U.S. in 2009, emit: carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, particulate matter, heavy metals such as mercury, and radioactive nuclides such as uranium and thorium
In the United States the coal power accounts for about 45% of the electricity production which is a drop from 53% in 1997 In 2009, there were 1436 coal power plants with the total nominal capacity of 338.732 GW. In 2006, the U.S. consumed 1,026,636,000 short tonnes (931,349,000 metric tonnes) of coal, generating 227.1 GWh, which represented the highest electrical energy generated from coal in the world
Carbon dioxide is considered to be the main contributor to global warming, while sulfur dioxide causes acid rain, and may cause respiratory illnesses and heart diseases, particularly in chil- dren and the elderly. Nitrogen oxides contribute to ground level ozone, which irritates and damages the lungs. Particular matter
(PM) results in hazy conditions in cities, contributes to asthma and chronic bronchitis. Very small, or «ﬁne PM» could also cause emphysema and lung cancer. Heavy metals such as mercury can cause damage to brain, nervous system, kidneys and liver, as well as developmental birth defects
Table 6 details health and environmental issues associated with hazardous air pollutants (HAPs): acid gases, benzene, toluene, dioxins and furans, mercury, arsenic, beryllium, cadmium and other heavy metals, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds, and radioactive uranium and thorium, that are emitted by coal-burning plants. It is estimated that coal-ﬁred power plants in the U.S. emit 386,000 tonnes of 84 different
During coal combustion, 100% of the radon gas is released in the air. Uranium, thorium and most of their decay products are almost entirely retained in the solid waste. Having in mind that ash presents a 10% of the original coal, it means that the concentrations of radionuclides in ash will be larger 10 times. Average activity of radium (
HAPs, and are responsible for emission of over 50% of mercury, over 50% of acid gases, 60% of arsenic, 60% of SO
, 13% of NO
, 30% of nickel, 20% of chromium, etc. Coal contains naturally occurring radioisotopes such as radio- active potassium (
40 K), uranium (U), thorium (Th) and their numerous decay products, including radium (Ra) and radon (Rn).
The U.S. Geological Survey (USGS) maintains the largest database on chemical composition of U.S. coal . Concentration of uranium and thorium in the U.S. coal is between 1 to 4 parts per million (ppm) although there are coals with much larger concentrations. shows typical range of uranium concentra- tion in coal, ﬂy ash, and rocks
2 emissions from various power sources . Source: Mitigation of climate change, Intergovernmental panel on climate change, 2007. c et al. / Energy 45 (2012) 31e42 construction materials, would increase by 135 m Sv. It might also increase emissions of radon and thoron from the building walls. Overall, based on the data presented in , the radiation exposure levels to population living close to coal-burning plants are about 100 times larger than in the case of nuclear power plants.
4.1. The U.S. Environmental Protection Agency proposed regulations
Class of HAP Notable HAP Human health hazards Environmental hazards Acid gases Hydrogen Chloride, HCl Irritation of skin, eyes, nose, throat, breathing passages Acid precipitation, damage to corps and forests. Hydrogen Fluoride, HF Dioxins and furans 2,3,7,8-tetrachlorodioxin (TCDD) Probable Carcinogen: Stomach and immune system. Affects reproductive endocrine and
Aldehydes including formaldehyde Probable Carcinogen: lung and nasopharyngeal cancer. Eye, nose, throat irritation, respiratory
Accumulates in soil and sediments.
Irritation of the skin, eyes, nose, throat; difﬁculty in breathing; impaired function of the lungs; delayed response to visual stimulus; impaired memory; stomach discomfort; and effects to the liver and kidneys. May also cause adverse effects to the nervous system. Benzene is a carcinogen.
Kidney diseaseVolatile organic compounds Aromatic hydrocarbons including benzene, xylene, ethylbenzene and toluene.
Exists in vapor or particulate phase. Accumulates in soil and sediments
Radioisotopes Radium Carcinogen: lung and bone. Deposits into rivers, lakes and oceansand is taken up by ﬁsh and wildlife. Accumulates in soils and sediments and in the food chain. Bronchopneumonia, anemia, brain abscess. Uranium Carcinogen: lung and lymphatic system.
May have adverse affects to the liver, kidney, and testes. May damage sperm cells and cause impairment of reproduction.
Polycyclic Aromatic Hydrocarbons (PAHs) Benzo-a-anthracene, Benzo-a-pyrene, Fluoranthene, Chrysene, Dibenzo-aanthracene Probable carcinogens. May attach to small particulate matter and deposit in the lungs.
May adversely affect land and water ecosystems. May adversely affect learning, memory and behavior. May cause cardiovascular and kidney effects, anemia, weakness of ankles, wrists and ﬁngers.
Accumulates in soil and sediments. Soluble forms may contaminate water systems. Lead Damages developing nervous system. Harms plants and wildlife; accumulates in soils and sediments.
Cadmium, Chromium Nickel, Selenium, Manganese Carcinogens: lung, bladder, kidney, skin. May adversely affect nervous, cardiovascular, dermal, respiratory and immune systems
Non-mercury metals and metalloids (excluding radioisotopes) Antimony, Arsenic, Beryllium,
Taken up by ﬁsh and wildlife. Accumulates in the food chain.
Deposits into rivers, lakes and oceans and is taken up by ﬁsh and wildlife. Accumulates in the food chain. Mercury Methylmercury Damage to brain, nervous system, kidneys and liver. Causes neurological and developmental
Table 6 Health and environmental issues associated with hazardous air pollutants (HAP) emitted by electric generation stations fueled by coal
Having all above in mind, the U.S. Environmental Protection Agency (EPA), has been trying for decades to regulate hazardous emissions from coal-burning plants. It had difﬁculties in imposing stricter regulations, due to the opposition from the coal-burning industry, and various challenges in courts. The majority of electric utilities in the U.S. burn high-sulfur bituminous coal, which contributed to an acid rain problem. To address this, the U.S.
proposed rules are passed, the average household electric bill in the
$10.9 billion, but EPA also estimates that the health and environ- mental beneﬁts would be more than $100 billion a year
The total annual cost of compliance is estimated to be about
EPA estimates that due to toxic emissions from fossil burning plants, there are: up to 17,000 of premature deaths; 11,000 heart attacks; 120,000 asthma attacks; 12,200 hospital admission and emergency room visits; 4500 cases of chronic bronchitis; 850,000 missed work or «sick» days; and 5,100,000 days when people must restrict their activities each year
control technology. Thus, EPA in March of 2011 decided to propose more stringent regulations in order to reduce toxic pollution from coal-burning plants
electric power plants decreased to less that 45% from almost 65%. More that 20 years after the CAAA was passed, still 44% of all coal- burning plants (1200 units) do not use advanced SO
It caused electric utilities to start switching to alternative fuels, especially natural gas, and the share of coal used in the U.S.
Congress passed Clean Air Act Amendments of 1990 (CAAA) (Public Law 101-549) with stringent restrictions on sulfur oxide emissions
Fig. 7. Typical range of uranium concentration in coal, ﬂy ash, and a variety of common rocks . c et al. / Energy 45 (2012) 31e42
There is a large opposition to the new EPA’s rules from the utilities that own and operate coal-burning power plants. For example, the Texas Public Utility Commission recently expressed the concern that this new federal air quality rule will cause disruption in electricity service, will cause shut down of some coal- ﬁred plants, and could lead to rolling blackouts in Texas
Country Percent France
FGD e Flue Gas Desulfur- ization; SCR e Selective Catalytic Reduction. Source: Sue Tierney, “EPA Proposed Utility Air Toxics Rule e Managing Compliance in Reliable Ways”, Congressional Staff Brieﬁng, May 9, 2011, p. 4.
37.4 Czech Rep.
33.0 Korea Rep.
Table 7 Nuclear generation (%).
Fig. 8. Coal-ﬁred plants by age and emission controls
The U.S. EPA will not have an easy road ahead regarding the proposed environmental regulations. One example of how the politics and lobbying by special interest groups could undermine the EPA’s work is an announcement by President Obama in September 2011, that he overruled the Environmental Protection Agency e and the unanimous opinion of its independent panel of scientiﬁc advisers, regarding the draft Ozone National Ambient Air Quality Standards due to “the importance of reducing regulatory burdens and regulatory uncertainty, particularly as our economy continues to recover.”
the various industry groups are warning that new EPA regulations will cost utilities up to $129 billion, and force them to retire one- ﬁfth of coal plant capacity, the environmental groups praise the EPA work, and point out that the new rules will have large public health and environment beneﬁts.
The Congressional Research Service (CRS), which conducts non- partisan policy research for members of the U.S. Congress, issued its analysis in August 2011 in order to rebuff the Edison Electric Institute (EEI) report on negative impacts of EPA’s environmental regulations on the U.S. generation ﬂeet
In its report, EEI claims
that new EPA regulations “would cause the unplanned retirement of 17e59 GW of coal-ﬁred electric capacity (5.4% to 18.8% of the total current coal-ﬁred capacity of about 315 GW) by 2015, and would require incremental capital expenditures of $85 billion to $129 billion.”
EEI, which represents investor-owned electric
utilities in the U.S., nicknamed the EPA’s rules as “EPA’s Regulatory Train Wreck”.
In its report, CRS points out that many of the coal-ﬁred plants that might need to be shut down are the oldest, the least economic and/or are those that currently operate with minimal pollution control. As shown in , the prime target for retirement are the plants that began operating between 1940 and 1969, and that do not have scrubbers.
This decision will be welcomed by
The newest Westinghouse AP1000 and GE’s ESBWR designs that feature passive safety systems belong to the Generation IIIþ. These reactors are yet to be built e the ﬁrst four AP1000s are under construction in China. For example, the AP1000 reactor design has passive safety features, simpliﬁed plant design and modular construction, and short engineering and construction schedule. It was the ﬁrst and only Generation IIIþ reactor to receive Design Certiﬁcation form the U.S. Nuclear Regulatory Commission. Some of the features include: dramatically safer and simpler design, smaller footprint (needs less concrete and steel per MWe), no safety-grade pumps, less maintenance required, much less reliance on operator action to mitigate accidents, independence of off-site AC power to
industry but will most likely alienate the president’s environ- mental base as his administration backs away from key anti- pollution initiatives. It is to be seen if the other important envi- ronmental rules proposed by EPA will survive in the U.S. election year.
5. Environmental impact of nuclear electricity generation in the U.S As of September 2011, 29 countries world wide are operating 439 nuclear power reactors for electricity generation (with a total net installed capacity of 374,042 MWe), 5 nuclear power reactors are in long term shutdown, and 66 new nuclear power reactors are under construction in 15 countries . The largest number of reactors under construction is in China (27) and Russia (11). The percentage of electricity generation by nuclear power in the world is 13.8% and in the OECD countries is 21.4% summarize the nuclear generation in the world by percentage and by total energy production in kWh.
The United States, with 104 currently operating nuclear power reactors in 31 states (with the total installed net capacity of about 101,000 MWe, and the capacity factor of 92%) that produce about 20% of the total electricity production in the U.S., is the country with the largest number of operating NPPs There is only one NPP under construction in the U.S. at this moment, and the last order for NPP was in 1979. Out of 104 operating nuclear reactors, 35 are Boiling Water Reactors (BWR), and 69 are Pressurized Water Reactors (PWR), manufactured by Westinghouse (48), General Electric (35), Combustion Engineering (14), and Babcock and Wil- cox (7).
Since the beginning in the early 1950s, nuclear power tech- nology has evolved through the following generations of system designs (
): Generation I e mostly early prototypes and ﬁrst-of- a-kind reactors built between 1950s and 1970s; Generation II e reactors built from 1970s to 1990s, most of which are still in operation today (such as PWR, BWR, CANDU); and Generation III e evolutionary advanced reactors with active safety systems built by the turn of the 20
century (such as General Electric’s Advanced BWR and Framatom’s EPR). In the U.S., 2 reactors began commercial operation in the1960s, 50 in the 1970s, 46 in the 1980s and 5 in the 1990s
27.3 c et al. / Energy 45 (2012) 31e42 operate reactor safety systems, ultimate hear sink is ambient air. The most important improvement is that the reactor safety func- tions are achieved without using any safety-related AC power.
Instead, the following processes are used: battery powered valve actuation, natural circulation, condensation, evaporation and compressed gases (nitrogen and air)
U cannot be considered as “real” waste, particularly when advanced fuel cycles and fast reactors are con- cerned. In a fast reactor, depleted uranium can be placed around the core in a “blanket”, to breed new fuel. If we continue with a once- through thermal fuel cycle, there are enough uranium resources to last until the end of century, and switching to the thorium cycle
For the “open” or “once-through” fuel cycle SNF is waste, which needs to be stored for several decades to reduce radioactivity and radioactive decay heat, and eventually needs to be disposed of in a geological repository. Currently, there is no central permanent geological repository in the U.S.; high-level radioactive waste (HLW) is stored temporarily in spent fuel pools and in dry cask storage facilities at NPP sites.
However, only 3% of SNF can be considered as “real” waste, while uranium and plutonium are extracted and recycled in a “closed” fuel cycle. The “real” HLW is separated out for further treatment followed by interim storage, pending ﬁnal disposal in a geological repository.
summarizes primary waste resulting from “once- through” and “closed” fuel cycles from a 1 GWe nuclear power plant . It should be emphasized that over 99% of natural and depleted uranium consists of
U, which is a “fertile” isotope. It does not ﬁssion at thermal neutron energies, but “breeds” a new fuel e