Nuclear power renaissance or demise?
Issue 2.4: Nuclear power renaissance or demise? By Umair Dossani Senior Technical Engineer / Systems Manager – Bruce Power Technical Paper for World Energy Congress
Abstract This paper attempts to explore the progress, innovation and renaissance of Nuclear Power that the world has seen in the past 70 years. In the middle of the 20th century right after World War II ended the world saw an emergence in a technology which was so powerful that its opponents feared it because of the dangers associated with it. The horrors which were evident after the destruction in Hiroshima and Nagasaki due to Nuclear Power could not be forgotten. But at the same time Nuclear scientists and physicists around the world had started to explore the possibilities that Nuclear Power could add to the energy mix in the world and solve the energy problems of the than emerging Industrialized world. It was decided that a Nuclear non Proliferation treaty will be formed under which countries will be subjected to restricted use of Nuclear technology for building war heads but this also meant that Nuclear Power plants could be built all around the world. But then the catastrophe of first the Three Mile Island in the USA and then Chernobyl in USSR led to the death of the emerging nuclear Power Industry. These two incidents shaped the image around the world that Nuclear Power generation is dangerous and should not be explored any longer and there were no new Nuclear generating Station built anywhere in the world after the incident of Chernobyl. But after primarily utilizing Fossil fuels for power generation; the world has seen the emerging issue of global warming and reduction in the sources of Fossil fuels. The world has once again started to brain storm about environmentally sustainable solutions for power generation and this has been the primary reason and focus for the renaissance of Nuclear Power. The factors that have contributed to the emergence of Nuclear Power once again are the environmental feasibility that Nuclear Power provides as opposed to other forms of generation, advances in Technology and at the same time the renovation in nuclear fuel production, reprocessing and disposal.
Introduction At the present time when the entire world is tackling a huge problem that is related to Global warming; Scientists around the world have been arguing and hinting towards the renewal in the interest the world is showing in Nuclear Power. With Asian Powers like China and India adding Nuclear Generating Stations to their arsenal with the help of developed countries such as the USA, France and Russia who not only have the technology to provide but also the operating experience to supplement the Nuclear Technology. Below is a snapshot showing the Nuclear Generating Stations all around the world.
Figure 1 – World Map of Nuclear Reactors in the World
Obviously the developed world is also once again starting projects for constructing new Nuclear Generating Stations. The interesting factor is that the pace in the Americas and Europe is less aggressive than in Asia and the reason is because of the emergence of Asian Powers and there growth which is leading towards more Energy Demand. But with the problem of Global warming a lot of focus has shifted to Nuclear Power plants to handle their growing Energy needs and demands. Another statistic shows that a lot of the developed world is already equipped very well with Nuclear Power to handle energy needs with the obvious example of France where more than 78% of all their energy needs are met through Nuclear Power. Below is a snapshot of the proportion of all sources of Electricity production in France as of 2006, and it is clear that Nuclear Power leads the way.
Figure 2 – Electricity Generation in France 2006
Does all the discussion mean that the resurgence of Nuclear Power is around the corner? For this a lot of factors need to be considered out of which the following form the basis for the argument that the renaissance of Nuclear Power has started once again: 1. First of all what has the developed world done to fight global warming on a Universal level – because this is the basis for the renaissance of Nuclear Power in the world energy mix once again 2. What is the percentage that nuclear Power contributes towards the energy mix in different parts of the developed and developing world 3. What advances have been made in the past 40 years since the last Nuclear Generating Station was made 4. Most importantly how has the nuclear fuel production, reprocessing and disposal cycle changed in the last 40 years or so.
Setup Global warming’s contribution to Nuclear Renaissa Renaissance Starting with the first factor – the steps World is taking towards fighting global warming. The developed world has been trying to curb carbon emissions through a lot of measures but nothing so far has seemed to exactly work. A Although the first such step which was taken in the world was in the 1990’s with the signing of the Kyoto protocol in which all the industrialized and developed nations pledged to cut emissions to save and preserve the world. Since then a lot has been said but actual measures havee been short of any actions. Even at the Copenhagen summit held in 2009 countries could not firmly agree to a number that should be considered a bench mark in curbing rbing emissions. A big factor for this failure is due to the less proactive approach that the USA U has shown being the biggest polluter in the world. In the USA Power production is dominated by Fossil fuels and that is a primary reason the USA has not been in the front running for curbing emissions. The graph below shows Electricity production in USA and it is clear that Fossil fuels lead the way.
Figure 3 – Electricity Generation in U.S 2008
But it is not only in the USA that Fossil fuels are used for Power Generation, most countries in the world rely on Fossil fuels. The issue at hand is twofold in that the Fossil fuels are the reason why we today are concerned with reducing carbon and green house gas emissions. Carbon and green house gas emissions have led to global warming and essentially to a lot of changes in our so rapidly advanced and develo developing ping world. This in essence has launched the renaissance of Nuclear Power once again. The graph from the World Nuclear Association below provides a snapshot of World electricity Generation and Fossil fuels can clearly be seen as the dominating force.
Figure 4 – World Electricity Generation
Nuclear Power Generating Capacity Going on to the next step in the journey to see how is the Renaissance of Nuclear Power shaping up is to analyze what is the breakdown of the Nuclear Generating capacity in the world and what is the breakdown of this in different regions in the world. It is worthwhile to note the following important facts and figures here: • • • •
The first commercial nuclear power stations started operation in the 1950s. There are now some 436 commercial nuclear power reactors operating in 30 countries, with 372,000 MWe of total capacity. They provide about 15% of the world's electricity as continuous, reliable base-load power, and their efficiency is increasing. 56 countries operate a total of about 250 research reactors and a further 220 nuclear reactors power ships and submarines.
In the 1950s attention turned to the peaceful purposes of nuclear fission, notably for power generation. Today, the world produces as much electricity from nuclear energy as it did from all sources combined in 1960. Civil nuclear power can now boast over 13,000 reactor years of experience and supplies almost 16% of global electricity needs, in 30 countries. Today, only eight countries are known to have a nuclear weapons capability. By contrast, 56 operate civil research reactors, and 30 have some 440 commercial nuclear power reactors with a total installed capacity of over 370 000 MWe. This is more than three times the total generating capacity of France or Germany from all sources. Some 30 further nuclear power reactors are under construction, equivalent to 8% of existing capacity, while over 90 are firmly planned,
equivalent to 27% of present capacity. The graph below shows the share of Nuclear Electricity Production and the share of total Electricity Production from 1971 to 2008.
Figure 5 – Nuclear Electricity Production in the World 1971 to 2008
It is also worthwhile to see the individual contribution from Nuclear Power in different regions of the world in graphical format to emphasize on the impact and importance it holds in different regions in the world. The graph below from World Nuclear Association shows Nuclear Electricity Generation based on 2007 figures.
Figure 6 – Nuclear Electricity Generation 2007
One final and very important factor that we need to look at when considering the influence that Nuclear Power Generation has in different regions of the world is to see how many new nuclear plants are currently being built. The table below has been taken from the World Nuclear Association database which shows all the plants that are under construction currently and will be in operation by 2030. The most important factor to analyze in the table is to see the regions where most of the Nuclear Power Generator Generatorss are being constructed currently. China leads the way in Asia with 20 plants, Russia 9 plants and India 5 plants. This figure again reiterates the emergence of the BRIC nations on the world stage and their growing Energy demands. Another indicator to consider ider is the number of proposed Nuclear Generating Stations in the world right now. Again China leads the ways in Asia with 120 proposed Nuclear Power Plants in the world, and then is Russia with 37 proposed Nuclear Power Plants and India with 15 Nuclear Po Power Plants. Also this is a clear indication that the Nuclear Renaissance is indeed taking shape. Although there is a strong resurgence of Nuclear Power Plants in Asia, the USA also has some 20 proposed plants in planning and this is once again a clear sign signal al that the world has seriously started to consider Nuclear Generation to fight with the issues of global warming and reducing carbon emissions.
COUNTRY (Click name for Country Profile)
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERABLE
REACTORS UNDER CONSTRUCTION
1 Feb 2010
1 Feb 2010
REACTORS PLANNED Feb 2010
REACTORS PROPOSED Feb 2010
URANIUM REQUIRED 2010
tonnes U
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
No.
MWe
Argentina
6.8
6.2
2
935
1
692
2
767
1
740
Armenia
2.3
39.4
1
376
0
0
1
1060
Bangladesh
0
0
0
0
0
0
0
0
2
2000
0
Belarus
0
0
0
0
0
0
2
2000
2
2000
0
Belgium
43.4
53.8
7
5728
0
0
0
0
0
0
1052
Brazil
14.0
3.1
2
1901
0
0
1
1245
4
4000
311
Bulgaria
14.7
32.9
2
1906
0
0
2
1900
0
0
272
Canada
88.6
14.8
18
12652
2
1500
4
4400
3
3800
1675
China
65.3
2.2
11
8587
20
21880
37
41590
120
120000
2875
Czech Republic
25.0
32.5
6
3686
0
0
0
0
2
3400
678
Egypt
0
0
0
0
0
0
1
1000
1
1000
0
Finland
22.0
29.7
4
2696
1
1600
0
0
1
1000
1149
France
418.3
76.2
58
63236
1
1630
1
1630
1
1630
10153
Germany
140.9
28.3
17
20339
0
0
0
0
0
0
3453
Hungary
14.0
37.2
4
1880
0
0
0
0
2
2000
295
India
13.2
2.0
18
3981
5
2774
23
21500
15
20000
908
Indonesia
0
0
0
0
0
0
2
2000
4
4000
0
Iran
0
0
0
0
1
915
2
1900
1
300
148
Israel
0
0
0
0
0
0
0
0
1
1200
0
Italy
0
0
0
0
0
0
0
0
10
17000
0
Japan
240.5
24.9
54
47102
1
1373
13
17915
1
1300
8003
Kazakhstan
0
0
0
0
0
0
2
600
2
600
0
123 55
COUNTRY
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERABLE
REACTORS UNDER CONSTRUCTION
1 Feb 2010
1 Feb 2010
(Click name for Country Profile)
REACTORS PLANNED
REACTORS PROPOSED
Feb 2010
URANIUM REQUIRED 2010
Feb 2010 tonnes U
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
No.
MWe
0
0
0
0
0
0
1
950
0
0
0
Korea RO (South)
144.3
35.6
20
17716
6
6700
6
8190
0
0
3804
Lithuania
9.1
72.9
0
0
0
0
0
0
2
3400
0
Mexico
9.4
4.0
2
1310
0
0
0
0
2
2000
253
Netherlands
3.9
3.8
1
485
0
0
0
0
1000
107
Pakistan
1.7
1.9
2
400
1
300
2
600
2000
68
0
0
0
0
0
0
0
0
6000
0
Romania
7.1
17.5
2
1310
0
0
2
1310
655
175
Russia
152.1
16.9
31
21821
9
7130
8
8000
36680
4135
Slovakia
15.5
56.4
4
1760
2
840
0
0
1
1200
269
Slovenia
6.0
41.7
1
696
0
0
0
0
1
1000
145
South Africa
12.7
5.3
2
1842
0
0
3
3565
24
4000
321
Spain
56.4
18.3
8
7448
0
0
0
0
0
0
1458
Sweden
61.3
42.0
10
9399
0
0
0
0
0
0
1537
Switzerland
26.3
39.2
5
3252
0
0
0
0
3
4000
557
Thailand
0
0
0
0
0
0
2
2000
4
4000
0
Turkey
0
0
0
0
0
0
2
2400
1
1200
0
Ukraine
84.3
47.4
15
13168
0
0
2
1900
20
27000
2031
UAE
0
0
0
0
0
0
4
5600
10
14400
0
Korea DPR (North)
Poland
1
2
6
1
37
COUNTRY
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERABLE
REACTORS UNDER CONSTRUCTION
1 Feb 2010
1 Feb 2010
(Click name for Country Profile)
REACTORS PLANNED
REACTORS PROPOSED
Feb 2010
URANIUM REQUIRED 2010
Feb 2010 tonnes U
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
52.5
13.5
19
11035
0
0
4
6600
6
9600
2235
USA
809.0
19.7
104
101119
1
1180
11
13800
19
25000
19538
Vietnam
0
0
0
0
0
0
2
2000
8000
0
WORLD**
2601
15
436
372,693
53
51,114
142
156,422
343,000
68,646
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
MWe
tonnes U
United
No.
MWe
Kingdom
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERATING
REACTORS BUILDING
ON ORDER or PLANNED
8
327
No.
PROPOSED
URANIUM REQUIRED
Figure 7 – Table of new Nuclear Plants in Construction
Nuclear Reactors Past and Present The next important consideration that needs to be analyzed when looking at the resurgence of Nuclear Power in the world is to see the Nuclear reactors of the past and the present. Here the focus is to check what kind of reactors did we have when we first started and how has their performance been to date to make the case for the new generation of Nuclear reactors. Obviously it is equally important to see what have we actually learnt in the past 70 some years and what kind of improvements have been implemented to make the new generation of nuclear reactors more cost efficient, scalable and also more energy efficient. To this end than the first thing to see is how have the reactors that were constructed in the 1950’s done so far and that is exactly how we will start our analysis. Although fewer nuclear power plants are being built now than during the 1970s and 1980s, those now operating are producing more electricity. In 2007, production was 2608 billion kWh. The increase over the six years to 2006 (210 TWh) was equal to the output from 30 large new nuclear power plants. Yet between 2000 and 2006 there was no net increase in reactor numbers (and only 15 GWe in capacity). The rest of the improvement is due to better performance from existing units. In 2007 performance dropped back by 50 TWh due to plant closures in Germany, UK and Japan. In a longer perspective, from 1990 to 2006, world capacity rose by 44 GWe and electricity production rose 757 billion kWh (40%). The relative contributions to this increase were: new construction 36%, up rating 7% and availability increase 57%.
One quarter of the world's reactors have load factors of more than 90%, and nearly two tw thirds do better than 75%, compared with about a quarter of them in 1990. For 15 years Finnish plants topped the performance tables, but the USA now dominates the top 25 positions, followed by South Korea. US nuclear power plant performance has shown a ssteady teady improvement over the past twenty years, and the average load factor now stands at around 90%, up from 66% in 1990 and 56% in 1980. This places the USA as the performance leader with 12 of the top 25 reactors, the 25th achieving more than 97.5%. The U USA SA accounts for nearly one third of the world's nuclear electricity. In 2007 and 2008 ten countries averaged better than 80% load factor, while French reactors averaged 76-77%, 77%, despite many being run in load load-following following mode, rather than purely for basebase load power. Some of these figures suggest near near-maximum maximum utilization, given that most reactors have to shut down every 18-24 24 months for fuel change and routine maintenance. In the USA this used to take over 100 days on average but in the last decade it has aver averaged about 40 days. Another measure is unplanned capability loss, which in the USA has for the last few years been below 2%. Sixteen countries depend on nuclear power for at least a quarter of their electricity. France gets around three quarters of its power ower from nuclear energy, while Belgium, Hungary, Lithuania, Slovakia, South Korea, Sweden, Switzerland, Slovenia and Ukraine get one third or more. Japan, Germany and Finland get more than a quarter of their power from nuclear energy, while the USA gets almost one fifth. The graph from World Nuclear Association below shows fuel for electricity generation for th the year of 2006.
Figure 8 – Fuel Electricity Generation 2006
Now let’s begin to see what kind of reactors are actually in operation in the world. The following facts and figures have been taken from the World Nuclear Association archives and serve the basis for the discussion. Several generations of reactors are commonly distinguished. Generation I reactors were developed in 1950-60s and very few are still running today. They mostly used natural uranium fuel and used graphite as moderator. Generation II reactors are typified by the present US fleet and most in operation elsewhere. They typically use enriched uranium fuel and are mostly cooled and moderated by water. Generation III are the Advanced Reactors, the first few of which are in operation in Japan and others are under construction and ready to be ordered. They are developments of the second generation with enhanced safety. Generation IV designs are still on the drawing board and will not be operational before 2020 at the earliest, probably later. They will tend to have closed fuel cycles and burn the long-lived actinides now forming part of spent fuel, so that fission products are the only high-level waste. Many will be fast neutron reactors. More than a dozen (Generation III) advanced reactor designs are in various stages of development. Some are evolutionary from the PWR, BWR and CANDU designs above, some are more radical departures. The former include the Advanced Boiling Water Reactor, a few of which are now operating with others under construction. The best-known radical new design is the Pebble Bed Modular Reactor, using helium as coolant, at very high temperature, to drive a turbine directly. Most of today's nuclear plants which were originally designed for 30 or 40-year operating lives. However, with major investments in systems, structures and components lives can be extended, and in several countries there are active programs to extend operating lives. There are several different types of reactors as indicated in the following table.
Figure 9 – Nuclear Power Plants in Commercial Operation
The most common type of reactors currently in operation fall into one of the following categories and the table above shows the quantities of each kind, which are in service: Pressurized Water Reactor (PWR), Boiling Water Reactor (BWR), Pressurized Heavy Water Reactor (PHWR or CANDU), Advanced Gas Cooled Reactors (AGR) and Light Water Graphite Moderated Reactor (RBMK). Just to show an example a PHWR or CANDU reactor is depicted in the pictorial below.
Figure 10 – Pressurize Heavy Water Reactor
Now it’s time to look at what kinds of technologies are being worked on in terms of Nuclear Reactors of the future. The nuclear power industry has been developing and improving reactor technology for more than five decades and is starting to build the next generation of nuclear power reactors to fill orders now materializing. About 85% of the world's nuclear electricity is generated by reactors derived from designs originally developed for naval use. These and other second-generation nuclear power units have been found to be safe and reliable, but they are being superseded by better designs. Reactor suppliers in North America, Japan, Europe, Russia and elsewhere have a dozen new nuclear reactor designs at advanced stages of planning, while others are at a research and development stage. Fourth-generation reactors are at concept stage. Third-generation reactors have: •
A standardized design for each type to expedite licensing, reduce capital cost and reduce construction time,
•
A simpler and more rugged design, making them easier to operate and less vulnerable to operational upsets,
•
Higher availability and longer operating life - typically 60 years,
•
Further reduced possibility of core melt accidents,
•
Resistance to serious damage that would allow radiological release from an aircraft impact,
•
Higher burn-up to reduce fuel use and the amount of waste,
•
Burnable absorbers ("poisons") to extend fuel life.
The greatest departure from second-generation designs is that many incorporate passive or inherent safety features which require no active controls or operational intervention to avoid accidents in the event of malfunction, and may rely on gravity, natural convection or resistance to high temperatures. A lot of the effort in developing Nuclear Reactors of the future is being conducted on the basis of joint ventures in which countries have partnered to share cost, technology and get the maximum output from the projects in an efficient manner. The table below has been taken from World Nuclear Association and lists the current reactors that are being marketed. Country and developer
Reactor
Size MWe
Design Progress
Main Features (improved safety in all) • •
US-Japan (GE-Hitachi, Toshiba)
USA (Westinghouse)
ABWR
AP-600 AP-1000 (PWR)
EPR France-Germany US-EPR (Areva NP) (PWR)
USA (GE- Hitachi)
ESBWR
1300
Commercial operation in Japan since 1996-7. In US: NRC certified 1997, FOAKE.
600 1100
AP-600: NRC certified 1999, FOAKE. AP-1000 NRC certification 2005, first units being built in China, many more planned
1600
Future French standard. French design approval. Being built in Finland and France, planned for China. US version developed.
1550
Developed from ABWR,
•
Evolutionary design. More efficient, less waste. Simplified construction (48 months) and operation.
• •
Simplified construction and operation. 3 years to build. 60-year plant life.
• • •
Evolutionary design. High fuel efficiency. Flexible operation
• •
Evolutionary design. Short construction
•
Country and developer
Reactor
Size MWe
Design Progress
Main Features (improved safety in all)
under certification in USA, likely construction there. Japan (utilities, Mitsubishi)
APWR USAPWR EUAPWR
1530 1700 1700
Basic design in progress, planned for Tsuruga US design certification application 2008.
time.
• •
Hybrid safety features. Simplified Construction and operation.
• • •
Evolutionary design. Increased reliability. Simplified construction and operation.
APR-1400 1450 (PWR)
Design certification 2003, First units expected to be operating c 2013.
Germany (Areva NP)
SWR1000 (BWR)
1200
Under development, pre-certification in USA
• •
Innovative design. High fuel efficiency.
Russia (Gidropress)
VVER1200 (PWR)
1200
Replacement under construction for Leningrad and Novovoronezh plants
• • •
Evolutionary design. High fuel efficiency. 50-year plant life
• •
Evolutionary design. Flexible fuel requirements. C-9: Single standalone unit.
South Korea (KHNP, derived from Westinghouse)
CANDU6 750 Canada (AECL) CANDU- 925+ 9
Canada (AECL) ACR
South Africa (Eskom, Westinghouse)
PBMR
700 1080
Enhanced model Licensing approval 1997
undergoing certification in Canada
prototype due to start 170 building (Chinese 200 (module) MWe counterpart under const.)
Under development in USA-Russia et al 285 Russia by (General Atomics - GT-MHR (module) multinational joint OKBM)
•
• • •
Evolutionary design. Light water cooling. Low-enriched fuel.
•
Modular plant, low cost. High fuel efficiency. Direct cycle gas turbine.
• •
• •
Modular plant, low cost. High fuel efficiency.
Country and developer
Reactor
Size MWe
Design Progress
Main Features (improved safety in all)
venture
•
Direct cycle gas turbine.
Figure 11 – Table of Advanced Nuclear Reactors
Moving on next to the Generation IV Nuclear reactors which are in the design phase at the present time and are expected to be available for commercial use anywhere in between 2020 and 2030. An international task force selected six Nuclear reactor Technologies, all of which operate at higher temperatures than the current breed of reactors available. Most of the six systems employ a closed fuel cycle to maximize the resource base and minimize high-level wastes to be sent to a repository. Three of the six are fast neutron reactors (FNR) and one can be built as a fast reactor, one is described as epithermal, and only two operate with slow neutrons like today's plants. The sizes range from 150 to 1500 MWe (or equivalent thermal) , with the lead-cooled one optionally available as a 50-150 MWe "battery" with long core life (15-20 years without refueling) as replaceable cassette or entire reactor module. This is designed for distributed generation or desalination. neutron temperature spectrum pressure* fuel coolant (fast/ (°C) thermal) Gas-cooled fast reactors
fast
helium
850
high
Lead-cooled fast reactors
fast
lead or Pb-Bi
480-800
low
Molten salt fast reactors
fast
fluoride salts
700-800
low
Molten salt reactor Advanced Hightemperature reactors
thermal
fluoride 750-1000 salts
fuel cycle
size(s) uses (MWe)
electricity & 1200 hydrogen 20180** electricity closed, 300& U-238 + regional 1200 hydrogen 6001000 electricity UF in closed 1000 & salt hydrogen closed, U-238 + on site
UO2 particles in prism
open
1000hydrogen 1500
neutron spectrum temperature pressure* fuel coolant (fast/ (°C) thermal)
fuel cycle
size(s) uses (MWe) 30-150
Sodiumcooled fast reactors
fast
Supercritical water-cooled reactors
thermal or fast
Very high temperature gas reactors
sodium
water
thermal helium
550
510-625
900-1000
low
very high
high
U-238 & closed MOX
UO2
UO2 prism or pebbles
open (thermal) closed (fast)
open
300electricity 1500 10002000 300700 electricity 10001500 250300
hydrogen & electricity
Figure 12 – Generation IV Nuclear Reactors
Nuclear Fuel Production Cycle The last stage in completing the analysis of the Nuclear Power renaissance in the world is to consider the nuclear fuel cycle which includes fuel production, reprocessing and disposal. The Nuclear fuel cycle is imperatively one of the most important factors to consider because obviously it determines the source of the fuel to begin with, than how it will be processed to be used as fuel in the reactor and last but not least the disposal of the used fuel that comes from the reactor. The most crucial part of the nuclear fuel cycle is the disposal of the used fuel because the fuel coming out of a nuclear reactor is highly radioactive and needs to be disposed off in a very safe manner. The biggest consideration from a safety standpoint is to make sure that the radioactive used fuel does not impact the environment and the humans. In fact how much productivity can be achieved is dependent on how much fuel quantity is required to operate the reactor at full capacity. Also very importantly the nuclear fuel cycle is an ongoing cost that is incurred on a daily basis of the productive life cycle of a Nuclear reactor. Because there are many different kind of reactors that can be considered, one of the determining factors in deciding the type of reactor that will be used is the nuclear fuel cycle. So, the main challenge is to look at the nuclear fuel cycle as it exists today and how it has evolved for the nuclear reactors of the future. The next several decades could witness sizable changes in nuclear fuel cycles implemented in various countries and regions throughout the world. The transition from current open or partially
closed fuel cycles to ones offering long long-term nuclear energy sustainability ainability on the one hand or to phase-out out of nuclear energy on the other will most likely involve the set of issues discussed in this paper. The issues potentially involved in fuel cycle transitions have seen relatively little focus, as most studies of nuclear clear fuel cycles have been made under equilibrium operation and mass flow assumptions. While fuel cycle transition issues are in the end country country--specific, a set of generic issues can be identified that provide a general framework for further technical ana analyses. Such issues produce a set of overarching conditions and constraints that overlay results obtained from purely technology-based based analyses. A pictorial representation of a nuclear fuel cycle is shown here.
Figure 13 – Nuclear Fuel Cycle
From what is depicted in the diagram shown above of the existing nuclear fuel cycle, there are several challenges that lie ahead in progressing to the next generation fuel cycle. The incentive to implement advanced fuel cycle options and their benefits depends on the evolution of nuclear capacity and electricity generation. Depending on the country considered, the role of nuclear energy in national supply may increase, remain stable or decrease towards an eventual phase phase-out in the coming decades. Next for discussion pu purposes rposes the transition scenarios for reactors in Canada are considered here.
The Canadian nuclear power program is based on CANDU® technology, which provides unequalled flexibility for the use of different fuel cycles. Its inherent high neutron economy, fu fuel channel design, on-power power refueling capability and simple fuel bundle design allow for the optimization of an assortment of different nuclear fuel cycles. Atomic Energy of Canada Limited (AECL) is actively examining CANDU fuel cycles that exploit synergi synergies es between heavy-waterheavy moderated CANDU reactors (HWRs) and light light-water water reactors (LWRs), as well as fast reactors. Optimization of thermal-to-fast fast reactor transition scenarios involves the exploitation of these synergies. Canadian research has shown that th there ere are unique and valuable roles for heavy water
reactors in thermal-to-fast reactor transition scenarios. Heavy water reactors could be used to match the size of the reactor fleet to electricity demands, make efficient use of fissile resources and to manage the minor actinide inventory in the fuel cycle. Transition to fast reactors with low breeding ratios
Heavy water reactors can efficiently supply fissile material for a fast reactor fleet. In a transition scenario where there is a limited supply of available fissile material, and where the fast reactors have low breeding ratios, the rate at which the fast reactor fleet can be increased is limited by the large fissile requirement for the initial fast reactor core load. In these scenarios, a small fleet of HWRs would be the most resource-efficient way to convert natural uranium into fissile material for use in the initial core load for next-generation fast reactors. In scenarios where a supply of plutonium comes from reprocessing spent LWR fuel, the addition of a small number of HWRs would allow the reprocessed uranium from the LWR spent fuel to be converted to both fissile plutonium and depleted uranium for use in the fast reactors, while generating valuable electricity. As mentioned earlier, a combination of LWRs and HWRs could provide an extremely efficient supply of both fissile material and depleted uranium by exploiting the low fissile requirements of HWRs. An example of such a fuel cycle is shown in Figure below.
Figure 14 – Fast Reactors with Low Breeding Ratios
Transition to fast reactors with high breeding ratios
The high neutron economy of HWRs allows them to produce a large amount of energy from a small amount of fissile material. In fuel cycle scenarios involving fast reactors with high breeding ratios, net plutonium production would exceed the demand for increases in the size of the fast reactor fleet. Here, an HWR could efficiently convert the excess plutonium production to electricity with minimal impact on uranium resource utilization through either a plutoniumuranium MOX fuel cycle, or a plutonium-thorium fuel cycle. The introduction of 233U recycle in a plutonium-thorium fuel cycle would significantly increase the amount of energy produced from the initial plutonium feed. In these fuel cycles, HWRs would make much more efficient use of plutonium, uranium and thorium resources than LWRs and, in the extreme, an HWR-based thorium fuel cycle with 233U recycle could produce a large amount of energy from a very small amount of plutonium input.
Figure below shows a comparison of a simple uranium-plutonium, mixed-oxide (MOX) fuel cycle implemented with LWRs or HWRs. The mass flows are based on a comparison of plutonium burning in LWRs and HWRs and assumes that both reactor types are capable of running with a full core load of MOX fuel. If the LWRs were capable of running with only, for example, a one-third core load of MOX, this would increase the LWR fleet of a factor of three, but would require a dramatic increase in the natural uranium requirements to produce enriched uranium fuel for the remaining two-thirds core load.
Figure 15 – Fast Reactors with High Breeding Ratios
Conclusions The emerging issue in the world at this time is the exponential growth in global warming and the effects it has on the planet and humanity. There is a huge need and a lot is being said to control carbon and green house gas emissions and a lot of countries are expeditiously trying to come up with carbon trade programs. But the success rate has been limited because the biggest polluters in the world the USA and China have not given their complete go ahead and are not sailing in the same boat as others. On the other hand the world is seeing a rise in the demand of energy consumption and especially in the developing world and in countries which are the next generation super powers like China and India. To meet these energy requirements the countries need to find solutions that are sustainable over long time, cost effective and also provide the means to fight carbon emissions caused by the conventional methods of Power generation. In such a situation the options that the countries are considering are either to shift to renewable energy sources but with most of the technology in its design or just testing phases renewable cannot fill the gap of the energy demand factor currently existing in the world. In such a situation the attention has once again shifted to Nuclear Power and a lot of progression is being made in directions to see if Nuclear Power once again can be considered because it serves a lot of grand purposes which are: nuclear power is clean and provides the possibility of fighting the carbon emissions problem causing global warming, they can provide base load power at a continuous rate and at the same time the power generating capacity from Nuclear Power can be far greater than any other source. Also with advances in technology the cost related to operation of Nuclear Stations can be reduced. So, it is feasible to conclude that Nuclear Power can be a solution to meet the growing energy demands in the world and its renaissance is evident by the facts explored in this paper.
References [1] John F. Ahearne, Nickolay P. Laverov “Internationalization of the Nuclear Fuel Cycle: Goals, Strategies and Challenges”, The National and Academic Press Washington D.C. 2009. [2] Robert G. Cochran, W.F. Miller, Nicholas Tsoulfanidis “Nuclear Fuel Cycle Analysis and Management”, Amer Nuclear Society 1993. [3] James D. Duderstadt, Louis J. Hamilton “Nuclear Reactor analysis”, Wiley 1976. [4] John R. Lamarsh, Anthony J. Baratta “Introduction to Nuclear Engineering” Prentice Hall 2001. [5] P.D. Wilson “The Nuclear Fuel Cycle: From Ore to Waste”, Oxford 1996. [6] Ian Hore-Lacy “Nuclear Energy in the 21st Century”, Academic Press 2006. [7] Gwyneth Cravens, Richard Rhodes “Power to Save the World: The Truth about Nuclear Energy”, Vintage Books USA 2008. [8] Janet Wood “Nuclear Power”, Institute of Engineering and Technology 2006. [9] Geoffrey F. Hewitt, John G. Collier “Introduction to Nuclear Power”, Taylor and Francis 2000. [10] W. J. Nuttall “Nuclear Renaissance: Technologies and Policies for the Future of Nuclear Power”, Taylor and Francis 2004. [11] David Elliot “Nuclear or Not?: Does Nuclear Power Have a Place in a Sustainable Energy Future”, Palgrave Macmillan 2009. [12] Colin Bayliss, Kevin Langley “Nuclear Decommissioning, Waste Management, and Environmental Site Remediation”, A Butterworth-Heinemann 2003. [13] International Nuclear Safety Center. Maps of Nuclear Power Reactors: World Map. Accessed at http://www.insc.anl.gov/pwrmaps/map/world_map.html, February 2010. [14] Wikipedia. Electricity Generation: Sources of Electricity in France 2006. Accessed at http://en.wikipedia.org/wiki/File:Sources_of_Electricity_in_France_in_2006.PNG,February 2010. [15] Wikipedia. Electricity Generation: 2008 U.S. Electricity Generation by Source. Accessed at http://en.wikipedia.org/wiki/File:2008_US_electricity_generation_by_source_v2.png, February 2010.
[16] World Nuclear Association. Nuclear Power in the World Today. Accessed at http://www.world-nuclear.org/info/inf01.html, February 2010. [17] World Nuclear Association. World Nuclear Power Reactors & Uranium Requirements. Accessed at http://www.world-nuclear.org/info/reactors.html, February 2010. [18] World Nuclear Association. Nuclear Power Reactors. Accessed at http://www.worldnuclear.org/info/inf32.html, February 2010. [19] World Nuclear Association. Advanced Nuclear Power Reactors. Accessed at http://www.world-nuclear.org/info/inf08.html, February 2010. [20] World Nuclear Association. Generation IV Nuclear http://www.world-nuclear.org/info/inf77.html, February 2010.
Reactors.
Accessed
at
[21] World Nuclear Association. The Nuclear Fuel Cycle. Accessed at http://www.worldnuclear.org/info/inf03.html, February 2010.
Abstract This paper attempts to explore the progress, innovation and renaissance of Nuclear Power that the world has seen in the past 70 years. In the middle of the 20th century right after World War II ended the world saw an emergence in a technology which was so powerful that its opponents feared it because of the dangers associated with it. The horrors which were evident after the destruction in Hiroshima and Nagasaki due to Nuclear Power could not be forgotten. But at the same time Nuclear scientists and physicists around the world had started to explore the possibilities that Nuclear Power could add to the energy mix in the world and solve the energy problems of the than emerging Industrialized world. It was decided that a Nuclear non Proliferation treaty will be formed under which countries will be subjected to restricted use of Nuclear technology for building war heads but this also meant that Nuclear Power plants could be built all around the world. But then the catastrophe of first the Three Mile Island in the USA and then Chernobyl in USSR led to the death of the emerging nuclear Power Industry. These two incidents shaped the image around the world that Nuclear Power generation is dangerous and should not be explored any longer and there were no new Nuclear generating Station built anywhere in the world after the incident of Chernobyl. But after primarily utilizing Fossil fuels for power generation; the world has seen the emerging issue of global warming and reduction in the sources of Fossil fuels. The world has once again started to brain storm about environmentally sustainable solutions for power generation and this has been the primary reason and focus for the renaissance of Nuclear Power. The factors that have contributed to the emergence of Nuclear Power once again are the environmental feasibility that Nuclear Power provides as opposed to other forms of generation, advances in Technology and at the same time the renovation in nuclear fuel production, reprocessing and disposal.
Introduction At the present time when the entire world is tackling a huge problem that is related to Global warming; Scientists around the world have been arguing and hinting towards the renewal in the interest the world is showing in Nuclear Power. With Asian Powers like China and India adding Nuclear Generating Stations to their arsenal with the help of developed countries such as the USA, France and Russia who not only have the technology to provide but also the operating experience to supplement the Nuclear Technology. Below is a snapshot showing the Nuclear Generating Stations all around the world.
Figure 1 – World Map of Nuclear Reactors in the World
Obviously the developed world is also once again starting projects for constructing new Nuclear Generating Stations. The interesting factor is that the pace in the Americas and Europe is less aggressive than in Asia and the reason is because of the emergence of Asian Powers and there growth which is leading towards more Energy Demand. But with the problem of Global warming a lot of focus has shifted to Nuclear Power plants to handle their growing Energy needs and demands. Another statistic shows that a lot of the developed world is already equipped very well with Nuclear Power to handle energy needs with the obvious example of France where more than 78% of all their energy needs are met through Nuclear Power. Below is a snapshot of the proportion of all sources of Electricity production in France as of 2006, and it is clear that Nuclear Power leads the way.
Figure 2 – Electricity Generation in France 2006
Does all the discussion mean that the resurgence of Nuclear Power is around the corner? For this a lot of factors need to be considered out of which the following form the basis for the argument that the renaissance of Nuclear Power has started once again: 1. First of all what has the developed world done to fight global warming on a Universal level – because this is the basis for the renaissance of Nuclear Power in the world energy mix once again 2. What is the percentage that nuclear Power contributes towards the energy mix in different parts of the developed and developing world 3. What advances have been made in the past 40 years since the last Nuclear Generating Station was made 4. Most importantly how has the nuclear fuel production, reprocessing and disposal cycle changed in the last 40 years or so.
Setup Global warming’s contribution to Nuclear Renaissa Renaissance Starting with the first factor – the steps World is taking towards fighting global warming. The developed world has been trying to curb carbon emissions through a lot of measures but nothing so far has seemed to exactly work. A Although the first such step which was taken in the world was in the 1990’s with the signing of the Kyoto protocol in which all the industrialized and developed nations pledged to cut emissions to save and preserve the world. Since then a lot has been said but actual measures havee been short of any actions. Even at the Copenhagen summit held in 2009 countries could not firmly agree to a number that should be considered a bench mark in curbing rbing emissions. A big factor for this failure is due to the less proactive approach that the USA U has shown being the biggest polluter in the world. In the USA Power production is dominated by Fossil fuels and that is a primary reason the USA has not been in the front running for curbing emissions. The graph below shows Electricity production in USA and it is clear that Fossil fuels lead the way.
Figure 3 – Electricity Generation in U.S 2008
But it is not only in the USA that Fossil fuels are used for Power Generation, most countries in the world rely on Fossil fuels. The issue at hand is twofold in that the Fossil fuels are the reason why we today are concerned with reducing carbon and green house gas emissions. Carbon and green house gas emissions have led to global warming and essentially to a lot of changes in our so rapidly advanced and develo developing ping world. This in essence has launched the renaissance of Nuclear Power once again. The graph from the World Nuclear Association below provides a snapshot of World electricity Generation and Fossil fuels can clearly be seen as the dominating force.
Figure 4 – World Electricity Generation
Nuclear Power Generating Capacity Going on to the next step in the journey to see how is the Renaissance of Nuclear Power shaping up is to analyze what is the breakdown of the Nuclear Generating capacity in the world and what is the breakdown of this in different regions in the world. It is worthwhile to note the following important facts and figures here: • • • •
The first commercial nuclear power stations started operation in the 1950s. There are now some 436 commercial nuclear power reactors operating in 30 countries, with 372,000 MWe of total capacity. They provide about 15% of the world's electricity as continuous, reliable base-load power, and their efficiency is increasing. 56 countries operate a total of about 250 research reactors and a further 220 nuclear reactors power ships and submarines.
In the 1950s attention turned to the peaceful purposes of nuclear fission, notably for power generation. Today, the world produces as much electricity from nuclear energy as it did from all sources combined in 1960. Civil nuclear power can now boast over 13,000 reactor years of experience and supplies almost 16% of global electricity needs, in 30 countries. Today, only eight countries are known to have a nuclear weapons capability. By contrast, 56 operate civil research reactors, and 30 have some 440 commercial nuclear power reactors with a total installed capacity of over 370 000 MWe. This is more than three times the total generating capacity of France or Germany from all sources. Some 30 further nuclear power reactors are under construction, equivalent to 8% of existing capacity, while over 90 are firmly planned,
equivalent to 27% of present capacity. The graph below shows the share of Nuclear Electricity Production and the share of total Electricity Production from 1971 to 2008.
Figure 5 – Nuclear Electricity Production in the World 1971 to 2008
It is also worthwhile to see the individual contribution from Nuclear Power in different regions of the world in graphical format to emphasize on the impact and importance it holds in different regions in the world. The graph below from World Nuclear Association shows Nuclear Electricity Generation based on 2007 figures.
Figure 6 – Nuclear Electricity Generation 2007
One final and very important factor that we need to look at when considering the influence that Nuclear Power Generation has in different regions of the world is to see how many new nuclear plants are currently being built. The table below has been taken from the World Nuclear Association database which shows all the plants that are under construction currently and will be in operation by 2030. The most important factor to analyze in the table is to see the regions where most of the Nuclear Power Generator Generatorss are being constructed currently. China leads the way in Asia with 20 plants, Russia 9 plants and India 5 plants. This figure again reiterates the emergence of the BRIC nations on the world stage and their growing Energy demands. Another indicator to consider ider is the number of proposed Nuclear Generating Stations in the world right now. Again China leads the ways in Asia with 120 proposed Nuclear Power Plants in the world, and then is Russia with 37 proposed Nuclear Power Plants and India with 15 Nuclear Po Power Plants. Also this is a clear indication that the Nuclear Renaissance is indeed taking shape. Although there is a strong resurgence of Nuclear Power Plants in Asia, the USA also has some 20 proposed plants in planning and this is once again a clear sign signal al that the world has seriously started to consider Nuclear Generation to fight with the issues of global warming and reducing carbon emissions.
COUNTRY (Click name for Country Profile)
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERABLE
REACTORS UNDER CONSTRUCTION
1 Feb 2010
1 Feb 2010
REACTORS PLANNED Feb 2010
REACTORS PROPOSED Feb 2010
URANIUM REQUIRED 2010
tonnes U
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
No.
MWe
Argentina
6.8
6.2
2
935
1
692
2
767
1
740
Armenia
2.3
39.4
1
376
0
0
1
1060
Bangladesh
0
0
0
0
0
0
0
0
2
2000
0
Belarus
0
0
0
0
0
0
2
2000
2
2000
0
Belgium
43.4
53.8
7
5728
0
0
0
0
0
0
1052
Brazil
14.0
3.1
2
1901
0
0
1
1245
4
4000
311
Bulgaria
14.7
32.9
2
1906
0
0
2
1900
0
0
272
Canada
88.6
14.8
18
12652
2
1500
4
4400
3
3800
1675
China
65.3
2.2
11
8587
20
21880
37
41590
120
120000
2875
Czech Republic
25.0
32.5
6
3686
0
0
0
0
2
3400
678
Egypt
0
0
0
0
0
0
1
1000
1
1000
0
Finland
22.0
29.7
4
2696
1
1600
0
0
1
1000
1149
France
418.3
76.2
58
63236
1
1630
1
1630
1
1630
10153
Germany
140.9
28.3
17
20339
0
0
0
0
0
0
3453
Hungary
14.0
37.2
4
1880
0
0
0
0
2
2000
295
India
13.2
2.0
18
3981
5
2774
23
21500
15
20000
908
Indonesia
0
0
0
0
0
0
2
2000
4
4000
0
Iran
0
0
0
0
1
915
2
1900
1
300
148
Israel
0
0
0
0
0
0
0
0
1
1200
0
Italy
0
0
0
0
0
0
0
0
10
17000
0
Japan
240.5
24.9
54
47102
1
1373
13
17915
1
1300
8003
Kazakhstan
0
0
0
0
0
0
2
600
2
600
0
123 55
COUNTRY
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERABLE
REACTORS UNDER CONSTRUCTION
1 Feb 2010
1 Feb 2010
(Click name for Country Profile)
REACTORS PLANNED
REACTORS PROPOSED
Feb 2010
URANIUM REQUIRED 2010
Feb 2010 tonnes U
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
No.
MWe
0
0
0
0
0
0
1
950
0
0
0
Korea RO (South)
144.3
35.6
20
17716
6
6700
6
8190
0
0
3804
Lithuania
9.1
72.9
0
0
0
0
0
0
2
3400
0
Mexico
9.4
4.0
2
1310
0
0
0
0
2
2000
253
Netherlands
3.9
3.8
1
485
0
0
0
0
1000
107
Pakistan
1.7
1.9
2
400
1
300
2
600
2000
68
0
0
0
0
0
0
0
0
6000
0
Romania
7.1
17.5
2
1310
0
0
2
1310
655
175
Russia
152.1
16.9
31
21821
9
7130
8
8000
36680
4135
Slovakia
15.5
56.4
4
1760
2
840
0
0
1
1200
269
Slovenia
6.0
41.7
1
696
0
0
0
0
1
1000
145
South Africa
12.7
5.3
2
1842
0
0
3
3565
24
4000
321
Spain
56.4
18.3
8
7448
0
0
0
0
0
0
1458
Sweden
61.3
42.0
10
9399
0
0
0
0
0
0
1537
Switzerland
26.3
39.2
5
3252
0
0
0
0
3
4000
557
Thailand
0
0
0
0
0
0
2
2000
4
4000
0
Turkey
0
0
0
0
0
0
2
2400
1
1200
0
Ukraine
84.3
47.4
15
13168
0
0
2
1900
20
27000
2031
UAE
0
0
0
0
0
0
4
5600
10
14400
0
Korea DPR (North)
Poland
1
2
6
1
37
COUNTRY
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERABLE
REACTORS UNDER CONSTRUCTION
1 Feb 2010
1 Feb 2010
(Click name for Country Profile)
REACTORS PLANNED
REACTORS PROPOSED
Feb 2010
URANIUM REQUIRED 2010
Feb 2010 tonnes U
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
52.5
13.5
19
11035
0
0
4
6600
6
9600
2235
USA
809.0
19.7
104
101119
1
1180
11
13800
19
25000
19538
Vietnam
0
0
0
0
0
0
2
2000
8000
0
WORLD**
2601
15
436
372,693
53
51,114
142
156,422
343,000
68,646
billion kWh
%e
No.
MWe
No.
MWe
No.
MWe
MWe
tonnes U
United
No.
MWe
Kingdom
NUCLEAR ELECTRICITY GENERATION 2008
REACTORS OPERATING
REACTORS BUILDING
ON ORDER or PLANNED
8
327
No.
PROPOSED
URANIUM REQUIRED
Figure 7 – Table of new Nuclear Plants in Construction
Nuclear Reactors Past and Present The next important consideration that needs to be analyzed when looking at the resurgence of Nuclear Power in the world is to see the Nuclear reactors of the past and the present. Here the focus is to check what kind of reactors did we have when we first started and how has their performance been to date to make the case for the new generation of Nuclear reactors. Obviously it is equally important to see what have we actually learnt in the past 70 some years and what kind of improvements have been implemented to make the new generation of nuclear reactors more cost efficient, scalable and also more energy efficient. To this end than the first thing to see is how have the reactors that were constructed in the 1950’s done so far and that is exactly how we will start our analysis. Although fewer nuclear power plants are being built now than during the 1970s and 1980s, those now operating are producing more electricity. In 2007, production was 2608 billion kWh. The increase over the six years to 2006 (210 TWh) was equal to the output from 30 large new nuclear power plants. Yet between 2000 and 2006 there was no net increase in reactor numbers (and only 15 GWe in capacity). The rest of the improvement is due to better performance from existing units. In 2007 performance dropped back by 50 TWh due to plant closures in Germany, UK and Japan. In a longer perspective, from 1990 to 2006, world capacity rose by 44 GWe and electricity production rose 757 billion kWh (40%). The relative contributions to this increase were: new construction 36%, up rating 7% and availability increase 57%.
One quarter of the world's reactors have load factors of more than 90%, and nearly two tw thirds do better than 75%, compared with about a quarter of them in 1990. For 15 years Finnish plants topped the performance tables, but the USA now dominates the top 25 positions, followed by South Korea. US nuclear power plant performance has shown a ssteady teady improvement over the past twenty years, and the average load factor now stands at around 90%, up from 66% in 1990 and 56% in 1980. This places the USA as the performance leader with 12 of the top 25 reactors, the 25th achieving more than 97.5%. The U USA SA accounts for nearly one third of the world's nuclear electricity. In 2007 and 2008 ten countries averaged better than 80% load factor, while French reactors averaged 76-77%, 77%, despite many being run in load load-following following mode, rather than purely for basebase load power. Some of these figures suggest near near-maximum maximum utilization, given that most reactors have to shut down every 18-24 24 months for fuel change and routine maintenance. In the USA this used to take over 100 days on average but in the last decade it has aver averaged about 40 days. Another measure is unplanned capability loss, which in the USA has for the last few years been below 2%. Sixteen countries depend on nuclear power for at least a quarter of their electricity. France gets around three quarters of its power ower from nuclear energy, while Belgium, Hungary, Lithuania, Slovakia, South Korea, Sweden, Switzerland, Slovenia and Ukraine get one third or more. Japan, Germany and Finland get more than a quarter of their power from nuclear energy, while the USA gets almost one fifth. The graph from World Nuclear Association below shows fuel for electricity generation for th the year of 2006.
Figure 8 – Fuel Electricity Generation 2006
Now let’s begin to see what kind of reactors are actually in operation in the world. The following facts and figures have been taken from the World Nuclear Association archives and serve the basis for the discussion. Several generations of reactors are commonly distinguished. Generation I reactors were developed in 1950-60s and very few are still running today. They mostly used natural uranium fuel and used graphite as moderator. Generation II reactors are typified by the present US fleet and most in operation elsewhere. They typically use enriched uranium fuel and are mostly cooled and moderated by water. Generation III are the Advanced Reactors, the first few of which are in operation in Japan and others are under construction and ready to be ordered. They are developments of the second generation with enhanced safety. Generation IV designs are still on the drawing board and will not be operational before 2020 at the earliest, probably later. They will tend to have closed fuel cycles and burn the long-lived actinides now forming part of spent fuel, so that fission products are the only high-level waste. Many will be fast neutron reactors. More than a dozen (Generation III) advanced reactor designs are in various stages of development. Some are evolutionary from the PWR, BWR and CANDU designs above, some are more radical departures. The former include the Advanced Boiling Water Reactor, a few of which are now operating with others under construction. The best-known radical new design is the Pebble Bed Modular Reactor, using helium as coolant, at very high temperature, to drive a turbine directly. Most of today's nuclear plants which were originally designed for 30 or 40-year operating lives. However, with major investments in systems, structures and components lives can be extended, and in several countries there are active programs to extend operating lives. There are several different types of reactors as indicated in the following table.
Figure 9 – Nuclear Power Plants in Commercial Operation
The most common type of reactors currently in operation fall into one of the following categories and the table above shows the quantities of each kind, which are in service: Pressurized Water Reactor (PWR), Boiling Water Reactor (BWR), Pressurized Heavy Water Reactor (PHWR or CANDU), Advanced Gas Cooled Reactors (AGR) and Light Water Graphite Moderated Reactor (RBMK). Just to show an example a PHWR or CANDU reactor is depicted in the pictorial below.
Figure 10 – Pressurize Heavy Water Reactor
Now it’s time to look at what kinds of technologies are being worked on in terms of Nuclear Reactors of the future. The nuclear power industry has been developing and improving reactor technology for more than five decades and is starting to build the next generation of nuclear power reactors to fill orders now materializing. About 85% of the world's nuclear electricity is generated by reactors derived from designs originally developed for naval use. These and other second-generation nuclear power units have been found to be safe and reliable, but they are being superseded by better designs. Reactor suppliers in North America, Japan, Europe, Russia and elsewhere have a dozen new nuclear reactor designs at advanced stages of planning, while others are at a research and development stage. Fourth-generation reactors are at concept stage. Third-generation reactors have: •
A standardized design for each type to expedite licensing, reduce capital cost and reduce construction time,
•
A simpler and more rugged design, making them easier to operate and less vulnerable to operational upsets,
•
Higher availability and longer operating life - typically 60 years,
•
Further reduced possibility of core melt accidents,
•
Resistance to serious damage that would allow radiological release from an aircraft impact,
•
Higher burn-up to reduce fuel use and the amount of waste,
•
Burnable absorbers ("poisons") to extend fuel life.
The greatest departure from second-generation designs is that many incorporate passive or inherent safety features which require no active controls or operational intervention to avoid accidents in the event of malfunction, and may rely on gravity, natural convection or resistance to high temperatures. A lot of the effort in developing Nuclear Reactors of the future is being conducted on the basis of joint ventures in which countries have partnered to share cost, technology and get the maximum output from the projects in an efficient manner. The table below has been taken from World Nuclear Association and lists the current reactors that are being marketed. Country and developer
Reactor
Size MWe
Design Progress
Main Features (improved safety in all) • •
US-Japan (GE-Hitachi, Toshiba)
USA (Westinghouse)
ABWR
AP-600 AP-1000 (PWR)
EPR France-Germany US-EPR (Areva NP) (PWR)
USA (GE- Hitachi)
ESBWR
1300
Commercial operation in Japan since 1996-7. In US: NRC certified 1997, FOAKE.
600 1100
AP-600: NRC certified 1999, FOAKE. AP-1000 NRC certification 2005, first units being built in China, many more planned
1600
Future French standard. French design approval. Being built in Finland and France, planned for China. US version developed.
1550
Developed from ABWR,
•
Evolutionary design. More efficient, less waste. Simplified construction (48 months) and operation.
• •
Simplified construction and operation. 3 years to build. 60-year plant life.
• • •
Evolutionary design. High fuel efficiency. Flexible operation
• •
Evolutionary design. Short construction
•
Country and developer
Reactor
Size MWe
Design Progress
Main Features (improved safety in all)
under certification in USA, likely construction there. Japan (utilities, Mitsubishi)
APWR USAPWR EUAPWR
1530 1700 1700
Basic design in progress, planned for Tsuruga US design certification application 2008.
time.
• •
Hybrid safety features. Simplified Construction and operation.
• • •
Evolutionary design. Increased reliability. Simplified construction and operation.
APR-1400 1450 (PWR)
Design certification 2003, First units expected to be operating c 2013.
Germany (Areva NP)
SWR1000 (BWR)
1200
Under development, pre-certification in USA
• •
Innovative design. High fuel efficiency.
Russia (Gidropress)
VVER1200 (PWR)
1200
Replacement under construction for Leningrad and Novovoronezh plants
• • •
Evolutionary design. High fuel efficiency. 50-year plant life
• •
Evolutionary design. Flexible fuel requirements. C-9: Single standalone unit.
South Korea (KHNP, derived from Westinghouse)
CANDU6 750 Canada (AECL) CANDU- 925+ 9
Canada (AECL) ACR
South Africa (Eskom, Westinghouse)
PBMR
700 1080
Enhanced model Licensing approval 1997
undergoing certification in Canada
prototype due to start 170 building (Chinese 200 (module) MWe counterpart under const.)
Under development in USA-Russia et al 285 Russia by (General Atomics - GT-MHR (module) multinational joint OKBM)
•
• • •
Evolutionary design. Light water cooling. Low-enriched fuel.
•
Modular plant, low cost. High fuel efficiency. Direct cycle gas turbine.
• •
• •
Modular plant, low cost. High fuel efficiency.
Country and developer
Reactor
Size MWe
Design Progress
Main Features (improved safety in all)
venture
•
Direct cycle gas turbine.
Figure 11 – Table of Advanced Nuclear Reactors
Moving on next to the Generation IV Nuclear reactors which are in the design phase at the present time and are expected to be available for commercial use anywhere in between 2020 and 2030. An international task force selected six Nuclear reactor Technologies, all of which operate at higher temperatures than the current breed of reactors available. Most of the six systems employ a closed fuel cycle to maximize the resource base and minimize high-level wastes to be sent to a repository. Three of the six are fast neutron reactors (FNR) and one can be built as a fast reactor, one is described as epithermal, and only two operate with slow neutrons like today's plants. The sizes range from 150 to 1500 MWe (or equivalent thermal) , with the lead-cooled one optionally available as a 50-150 MWe "battery" with long core life (15-20 years without refueling) as replaceable cassette or entire reactor module. This is designed for distributed generation or desalination. neutron temperature spectrum pressure* fuel coolant (fast/ (°C) thermal) Gas-cooled fast reactors
fast
helium
850
high
Lead-cooled fast reactors
fast
lead or Pb-Bi
480-800
low
Molten salt fast reactors
fast
fluoride salts
700-800
low
Molten salt reactor Advanced Hightemperature reactors
thermal
fluoride 750-1000 salts
fuel cycle
size(s) uses (MWe)
electricity & 1200 hydrogen 20180** electricity closed, 300& U-238 + regional 1200 hydrogen 6001000 electricity UF in closed 1000 & salt hydrogen closed, U-238 + on site
UO2 particles in prism
open
1000hydrogen 1500
neutron spectrum temperature pressure* fuel coolant (fast/ (°C) thermal)
fuel cycle
size(s) uses (MWe) 30-150
Sodiumcooled fast reactors
fast
Supercritical water-cooled reactors
thermal or fast
Very high temperature gas reactors
sodium
water
thermal helium
550
510-625
900-1000
low
very high
high
U-238 & closed MOX
UO2
UO2 prism or pebbles
open (thermal) closed (fast)
open
300electricity 1500 10002000 300700 electricity 10001500 250300
hydrogen & electricity
Figure 12 – Generation IV Nuclear Reactors
Nuclear Fuel Production Cycle The last stage in completing the analysis of the Nuclear Power renaissance in the world is to consider the nuclear fuel cycle which includes fuel production, reprocessing and disposal. The Nuclear fuel cycle is imperatively one of the most important factors to consider because obviously it determines the source of the fuel to begin with, than how it will be processed to be used as fuel in the reactor and last but not least the disposal of the used fuel that comes from the reactor. The most crucial part of the nuclear fuel cycle is the disposal of the used fuel because the fuel coming out of a nuclear reactor is highly radioactive and needs to be disposed off in a very safe manner. The biggest consideration from a safety standpoint is to make sure that the radioactive used fuel does not impact the environment and the humans. In fact how much productivity can be achieved is dependent on how much fuel quantity is required to operate the reactor at full capacity. Also very importantly the nuclear fuel cycle is an ongoing cost that is incurred on a daily basis of the productive life cycle of a Nuclear reactor. Because there are many different kind of reactors that can be considered, one of the determining factors in deciding the type of reactor that will be used is the nuclear fuel cycle. So, the main challenge is to look at the nuclear fuel cycle as it exists today and how it has evolved for the nuclear reactors of the future. The next several decades could witness sizable changes in nuclear fuel cycles implemented in various countries and regions throughout the world. The transition from current open or partially
closed fuel cycles to ones offering long long-term nuclear energy sustainability ainability on the one hand or to phase-out out of nuclear energy on the other will most likely involve the set of issues discussed in this paper. The issues potentially involved in fuel cycle transitions have seen relatively little focus, as most studies of nuclear clear fuel cycles have been made under equilibrium operation and mass flow assumptions. While fuel cycle transition issues are in the end country country--specific, a set of generic issues can be identified that provide a general framework for further technical ana analyses. Such issues produce a set of overarching conditions and constraints that overlay results obtained from purely technology-based based analyses. A pictorial representation of a nuclear fuel cycle is shown here.
Figure 13 – Nuclear Fuel Cycle
From what is depicted in the diagram shown above of the existing nuclear fuel cycle, there are several challenges that lie ahead in progressing to the next generation fuel cycle. The incentive to implement advanced fuel cycle options and their benefits depends on the evolution of nuclear capacity and electricity generation. Depending on the country considered, the role of nuclear energy in national supply may increase, remain stable or decrease towards an eventual phase phase-out in the coming decades. Next for discussion pu purposes rposes the transition scenarios for reactors in Canada are considered here.
The Canadian nuclear power program is based on CANDU® technology, which provides unequalled flexibility for the use of different fuel cycles. Its inherent high neutron economy, fu fuel channel design, on-power power refueling capability and simple fuel bundle design allow for the optimization of an assortment of different nuclear fuel cycles. Atomic Energy of Canada Limited (AECL) is actively examining CANDU fuel cycles that exploit synergi synergies es between heavy-waterheavy moderated CANDU reactors (HWRs) and light light-water water reactors (LWRs), as well as fast reactors. Optimization of thermal-to-fast fast reactor transition scenarios involves the exploitation of these synergies. Canadian research has shown that th there ere are unique and valuable roles for heavy water
reactors in thermal-to-fast reactor transition scenarios. Heavy water reactors could be used to match the size of the reactor fleet to electricity demands, make efficient use of fissile resources and to manage the minor actinide inventory in the fuel cycle. Transition to fast reactors with low breeding ratios
Heavy water reactors can efficiently supply fissile material for a fast reactor fleet. In a transition scenario where there is a limited supply of available fissile material, and where the fast reactors have low breeding ratios, the rate at which the fast reactor fleet can be increased is limited by the large fissile requirement for the initial fast reactor core load. In these scenarios, a small fleet of HWRs would be the most resource-efficient way to convert natural uranium into fissile material for use in the initial core load for next-generation fast reactors. In scenarios where a supply of plutonium comes from reprocessing spent LWR fuel, the addition of a small number of HWRs would allow the reprocessed uranium from the LWR spent fuel to be converted to both fissile plutonium and depleted uranium for use in the fast reactors, while generating valuable electricity. As mentioned earlier, a combination of LWRs and HWRs could provide an extremely efficient supply of both fissile material and depleted uranium by exploiting the low fissile requirements of HWRs. An example of such a fuel cycle is shown in Figure below.
Figure 14 – Fast Reactors with Low Breeding Ratios
Transition to fast reactors with high breeding ratios
The high neutron economy of HWRs allows them to produce a large amount of energy from a small amount of fissile material. In fuel cycle scenarios involving fast reactors with high breeding ratios, net plutonium production would exceed the demand for increases in the size of the fast reactor fleet. Here, an HWR could efficiently convert the excess plutonium production to electricity with minimal impact on uranium resource utilization through either a plutoniumuranium MOX fuel cycle, or a plutonium-thorium fuel cycle. The introduction of 233U recycle in a plutonium-thorium fuel cycle would significantly increase the amount of energy produced from the initial plutonium feed. In these fuel cycles, HWRs would make much more efficient use of plutonium, uranium and thorium resources than LWRs and, in the extreme, an HWR-based thorium fuel cycle with 233U recycle could produce a large amount of energy from a very small amount of plutonium input.
Figure below shows a comparison of a simple uranium-plutonium, mixed-oxide (MOX) fuel cycle implemented with LWRs or HWRs. The mass flows are based on a comparison of plutonium burning in LWRs and HWRs and assumes that both reactor types are capable of running with a full core load of MOX fuel. If the LWRs were capable of running with only, for example, a one-third core load of MOX, this would increase the LWR fleet of a factor of three, but would require a dramatic increase in the natural uranium requirements to produce enriched uranium fuel for the remaining two-thirds core load.
Figure 15 – Fast Reactors with High Breeding Ratios
Conclusions The emerging issue in the world at this time is the exponential growth in global warming and the effects it has on the planet and humanity. There is a huge need and a lot is being said to control carbon and green house gas emissions and a lot of countries are expeditiously trying to come up with carbon trade programs. But the success rate has been limited because the biggest polluters in the world the USA and China have not given their complete go ahead and are not sailing in the same boat as others. On the other hand the world is seeing a rise in the demand of energy consumption and especially in the developing world and in countries which are the next generation super powers like China and India. To meet these energy requirements the countries need to find solutions that are sustainable over long time, cost effective and also provide the means to fight carbon emissions caused by the conventional methods of Power generation. In such a situation the options that the countries are considering are either to shift to renewable energy sources but with most of the technology in its design or just testing phases renewable cannot fill the gap of the energy demand factor currently existing in the world. In such a situation the attention has once again shifted to Nuclear Power and a lot of progression is being made in directions to see if Nuclear Power once again can be considered because it serves a lot of grand purposes which are: nuclear power is clean and provides the possibility of fighting the carbon emissions problem causing global warming, they can provide base load power at a continuous rate and at the same time the power generating capacity from Nuclear Power can be far greater than any other source. Also with advances in technology the cost related to operation of Nuclear Stations can be reduced. So, it is feasible to conclude that Nuclear Power can be a solution to meet the growing energy demands in the world and its renaissance is evident by the facts explored in this paper.
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