ArticlePDF Available

Small-Scale Nuclear Energy

Authors:

Abstract

Ensuring an ongoing supply of power in a low carbon economy is one of the major national and international challenges that almost every country faces. Investments in alternative and renewable energy technologies have risen steadily over the last decade, particularly since the ratification of the 2030 Paris Agreement. Although reasonable progress has been made as a result of this, even the most developed renewable energy technologies, for example, solar, wind and hydro, cannot satisfy the rapidly growing energy demand of the world. Arguably a non-renewable energy source, nuclear energy may be one clean energy answer for the future. More specifically, small-scale nuclear energy holds considerable potential. Such potential exists in the form of light water small modular reactors (LW-SMRs). These SMRs have the capability to meet the energy independence and the energy security needs of many countries while reducing capital and operating expenditure and environmental and physical footprint. The modularity aspect of this technology allows for varied application, from large towns to rural regions that currently rely on individual generators. It also creates the opportunity of cogeneration with already existing conventional power generation technology to diversify power generation and increase grid stability. LW-SMRs are not a new idea; in fact, they have been used to power U.S. aircraft carriers and submarines for almost 60 years. This case study will address the advantages and disadvantages of the LW-SMR, using the market leader NuScale as an example. NuScale in Oregon, United States, is arguably the most experienced and influential LW-SMR nuclear energy company when it comes to the factory fabrication of LW-SMRs.
ARTICLE CASE
Small-Scale Nuclear Energy: Environmental and Other Advantages
and Disadvantages
LIAM DARBY
1
, AMANDA HANSSON
2
, AND CLEMENT TISDELL
3
1
School of Chemical Engineering University of Queensland, Queensland, Australia
2
School of Earth and Environmental Science, University of Queensland, Queensland, Australia
3
School of Economics, University of Queensland, Queensland, Australia
Email: liam.darby@uqconnect.edu.au
ABSTRACT Ensuring an ongoing supply of power in a low carbon economy is one of the major national and
international challenges that almost every country faces. Investments in alternative and renewable energy
technologies have risen steadily over the last decade, particularly since the ratification of the 2030 Paris
Agreement. Although reasonable progress has been made as a result of this, even the most developed renewable
energy technologies, for example, solar, wind and hydro, cannot satisfy the rapidly growing energy demand of the
world. Arguably a non-renewable energy source, nuclear energy may be one clean energy answer for the future. More
specifically, small-scale nuclear energy holds considerable potential. Such potential exists in the form of light water
small modular reactors (LW-SMRs). These SMRs have the capability to meet the energy independence and the
energy security needs of many countries while reducing capital and operating expenditure and environmental and
physical footprint. The modularity aspect of this technology allows for varied application, from large towns to rural
regions that currently rely on individual generators. It also creates the opportunity of cogeneration with already
existing conventional power generation technology to diversify power generation and increase grid stability. LW-
SMRs are not a new idea; in fact, they have been used to power U.S. aircraft carriers and submarines for almost 60
years. This case study will address the advantages and disadvantages of the LW-SMR, using the market leader
NuScale as an example. NuScale in Oregon, United States, is arguably the most experienced and influential LW-
SMR nuclear energy company when it comes to the factory fabrication of LW-SMRs. KEYWORDS small-scale
nuclear energy,small modular reactor,energy transition,gas and nuclear co-generation,small versus large nuclear
reactors,small modular reactor application
INTRODUCTION
Since the Paris Agreement was ratified in 2016 [1], the
aim of the Paris Agreement is to limit the global temper-
ature increase to below 2C, with a preference to keep the
warming below 1.5C. Significant changes will have to be
implemented to achieve this goal. While there has been
a minimal number of large projects executed since the
agreement due to time frame challenges, a large variety
of sustainable and renewable energy projects have been
put into motion all over the world. Global energy de-
mands are expected to increase rapidly due to strong
economic growth in many developing countries [2].
Owing to a range of issues such as intermittent energy
production, cost feasibility and scaling limitations, there
are inherent difficulties in transitioning to a grid system
where most of the electricity is supplied by renewables
[3]. This is worrisome, considering that it is predicted
that the world market for electricity generation is ex-
pected to increase by 80%over the next 25 years [4].
While these renewable energysystemsarecontinually
improving, baseload power generation must be achieved
by alternative means. The solution may just be nuclear
energy, specifically through the utilisation and optimisa-
tion of small modular reactors (SMRs).
Nuclear power plants generate flexible, continuous and
reliable energy with zero carbon emissions. Approximately
1
Case Studies in the Environment,2020, pps. 19. electronic ISSN 2473-9510.©2020 by the Regents of the University of California. All rights reserved.
Please direct all requests for permission to photocopy or reproduce article content through the University of California Press’s Reprints and Permissions
web page, www.ucpress.edu/journals.php?p¼reprints. DOI: https://doi.org/10.1525/cse.2020.1112327.
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
11%of the world’s electricity demand is met using nuclear
power. In some countries, up to 70%of the power
requirement is achieved using nuclear power [5]. The aim
of LW-SMRs is to reduce the problems associated with
conventional (large-scale) nuclear reactor plants, such as
the high capital and operational costs, safety issues and the
disposal of radioactive waste.
SMRs, as the name suggests, are a form of small-
scale nuclear energy production. They operate accord-
ing to the same fundamental principles as large-scale
nuclear reactors but have recently been deemed to be
more affordable and flexible while remaining equally
efficient as large-scale reactors. Owing to this, over the
last couple of decades, many new projects (50þ[6])
have been undertaken to facilitate the adoption of
SMRs. This case study will address the influential fac-
tors for such projects by taking into consideration the
advantages and disadvantages associated with the devel-
opment, implementation and optimisation of small-
scale nuclear energy. An SMR world leader, NuScale
Power, will be used as an important point of reference.
This report will focus primarily on LW-SMRs to allow
for direct comparison.
CASE EXAMINATION
What Are SMRs and What Are They Used For?
SMRs are defined as nuclear reactors producing 300 MW
(or less) of electrical power [5]. SMRs are designed around
the idea of modularisation, and their compact design al-
lows for their factory fabrication and manageable trans-
portation to destinations for installation. SMRs are
mainly used to produce heat energy from nuclear fission
for generating electrical power in a single or multi-module
(depending on energy requirement) nuclear power plant.
Most existing SMR operations are third-generation light
water reactors, while fourth-generation reactors with
inherent safety features such as NuScale are currently
being developed [7]. Safety features include having a small
nuclear fuel inventory, being a seismic category 1design,
utilising natural circulation and incorporating automatic
shut down and self-cooling features [8]. In extreme events
where power is disconnected from the facility, the
increased strength and number of safety barriers can pre-
vent a nuclear meltdown. Fission energy is used to heat
circulating high-pressured water to subcritical levels,
which is used to boil low-pressured water in a secondary
loop. Produced steam is passed through a turbine and
condensed in a recycled stream. While other thermo-
dynamic fluids have been investigated to replace the water
in the primary loop, water remains the most cost-efficient
option [9].
Existing SMR Operations
While the modularity component of the SMR is still in
development, there are a variety of different small reactors
under development, construction and in operation all
around the world. The most popular of these are the
pressurised light water reactors. Those in operation include
the CNP-300 (300 MW) pressurized water reactor
(PWR) in China, the pressurized water reactor
(PHWR)-220 (220 MW) in India and the EGP-6(11
MW) at Siberia. The EGP is a light water graphite reactor
and is essentially a pilot plant that will be decommissioned
in 2019 [10]. There are also 5SMRs under construction
(all PWRs) and 10 reactor projects ready for near term
deployment [10]. The CNP-300 and PHWR-220 have
been in operation since 1994 and 1973, respectively.
China has since exported their CNP-300 design to Paki-
stan for development and implementation [11]. India is
also now looking to export the PHWR-220 design. Coun-
tries such as Vietnam, Thailand and Malaysia have
expressed interest in the SMR design [11].
Case Study: NuScale
The goal of NuScale Power is to provide sustainable and
scalable advanced nuclear technology to produce electricity,
heat and water to improve the quality of life for people
around the world. Formed in 2007, NuScale has been
deemed the market leader in SMR fabrication tech-
nology since 2013 by the Department of Energy [4].
NuScale was established with the sole purpose of com-
pleting and commercialising the design for a small-scale
reactor that uses conventional light water-cooling
methods—the NuScale Power Module (NPM). The
design specification for the NPM will be determined
by 2020, with factory construction beginning in 2022
and the first NPM being delivered by 2025 [4]. This
time line was established over the course of 8.5years
following 130 meetings, 2million labour hours (800
people), 1,000 documents (12,000 pages) and a US$505
million total investment.
The NPM produces 60 MWe of power, and like
most SMRs, it is small enough to be manufactured in
a factory and transported and installed on-site. The
design allows for flexible and independent power
2CASE STUDIES IN THE ENVIRONMENT 2020
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
production and can be operated in parallel to achieve
demand (up to 12 modules providing 600 MWe gross
output) [4]. These modules are predicted to have
a60-year lifetime [4].
NuScale Licensing
NuScale’s SMR is the first and only SMR under design
certification review by the U.S. Nuclear Regulatory Com-
mission (NRC). The 12th of December 2019 marked the
completion of Phase 4of the review of the Design Cer-
tification Application. The final phase, Phase 6,istar-
geted for completion in early September [12]. NuScale
has also applied to Canada’s nuclear regulator for a pre-
licensing vendor design review [13]. This is not a step in
the NRC application process but is an optional service to
assess the vendor’s (NuScale) reactor technology. This
additional submission allows the NuScale design to be
reviewed by another highly experienced nuclear regulator.
ADVANTAGES OF THE SMR
The design and development of SMRs are taking place in
many parts of the world. There are many reasons for this,
and those include, but are not limited to, their ability to
be fabricated in a factory, their small environmental foot-
print, the ease of their transportation, their flexible opera-
tions, their economies of installation and maintenance
and their low associated greenhouse gas emissions.
Environmental Benefits
Nuclear power is a key player in decarbonising the energy
production system [14]. While SMRs might be more
expensive per unit of power produced compared to large
nuclear reactors, they can play a vital role in providing
electricity in conjunction with renewables [14]. Owing to
the intermittent nature of many renewable energy sources,
combining renewables with nuclear power can constitute
one of the cheapest ways of achieving a low-carbon energy
production system, and it can reduce emissions more
compared to energy production systems relying entirely
on renewable sources [15]. While renewable energy, as
well as nuclear, typically has a low carbon footprint, many
renewable sources generally produce less power output per
MW of installation, are less reliable, and require transmis-
sion, storage and backup generation capacity [15].
The carbon emission from nuclear power generation
across its full life cycle is approximately 23 gCO
2
/kWh
[16], which is around 4times higher than wind power
plants [17] but at the same time significantly less than
that of many solar power plants [18]. However, when
comparing this to coal-fired power plants, which make
up approximately 30%of the world’s energy production
[19], there are significant emission reductions to be made
by replacing these with nuclear power plants considering
the emission intensity of coal-fired plants can be as large
as 1,000 gCO
2
/kWh [20]. While efforts are underway
to reduce emissions associated with fossil fuel systems by
introducing technologies such as carbon capture and stor-
age (CCS) [19], the average emission associated with
these technologies today and in the near future still ranges
from 400 to 970 gCO
2
/kWh, [19,21]. Therefore, uti-
lising SMRs to replace fossil fuel-driven power plants, and
especially those of low efficiency, could be one of the
quickest ways to reduce carbon emissions associated with
energy production.
Factory Fabrication
Being a relatively small module, the SMR can be fabri-
cated in a streamlined manner in a factory. By being
manufactured off-site, not only can economies of scale
be taken advantage of, but the burden of on-site construc-
tion can be significantly reduced. The median construc-
tion time for large-scale reactors in 2018 was 8.5years.
This is slower than previous years, which can largely be
attributed to the high number of first of a kind (FOAK)
reactors being constructed [22]. This involves a consider-
able amount of time and resource investment. As these
statistics were retrieved from data obtained for 441 oper-
ational reactors, it is deemed to be a representative aver-
age. SMRs, however, can be built on-site in under 4years
(excluding module construction at the factory). This is
considerably less than the time required to construct large
reactors. There is further potential to reduce the construc-
tion time of SMRs to 3years following the FOAK [6].
Small Footprint
In comparison to other forms of energy generation tech-
nologies, nuclear power plants occupy significantly less
land area [23]. While large-scale nuclear power plants
occupy around 25%of the area of coal-fired power plants,
small-scale nuclear power reactors have an even smaller
footprint. Their modular form allows for installation
underground, underwater, or on ships [5]. The NuScale
module weighs 590 tons, has a 2.7m diameter and is 20
m long [24], making transportation via railcar, barge, or
special trucks and on-site installation relatively easy. The
overall footprint of the facility (720 MW) has been
Small-Scale Nuclear Energy 3
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
predicted to be only 34.5acres [25]. A conventional large-
scale reactor (550 MW production) on the other hand
requires over 500 acres [26]. The difference in these
physical footprints is immense, with SMR sites requiring
significantly less land clearing.
Flexible Operation and Dispatchability
Load following refers to situations in which a power plant
ramps electricity production up or down to meet supply
and demand. The flexibility of a power system is deter-
mined by its load-following capability. The “long-term
future of nuclear power will depend on its ability to adapt
to the new world of flexible power systems and low mar-
ginal cost renewable electricity” [27]. A significant down-
side to large reactors and most forms of renewable energy
is their lack of flexibility to do exactly that. Their power
supply is often surplus, and demand exceeding their
design capacity cannot be met. Conversely, SMRs have
been shown to load follow effectively with a 57 MW wind
farm, proving their ability to play a crucial role in cogen-
eration with both renewable and non-renewable energy
generation [28]. The number of modules connected to
the grid can also vary [27]. During peak demand, more
modules can be initialised and connected to the grid.
While this reaction-driven process is not instant and can-
not react to sudden changes in demand, forecasted
demand can be met. For example, one or more additional
modules can be connected during the summer period.
The number of modules installed at the nuclear power
plant should be determined according to scenario cash
flow modelling. For a city to be entirely dependent on
the modules, the output must satisfy the peak demands. It
may prove to be more economical for a combination of
energy generation methods to be utilised. When the
SMRs are introduced to an established electricity supply
network, existing technology can be incorporated into the
new combination grid supply.
While still achieving cost parity, SMRs can produce
anywhere between 5MW and 300 MW of electricity [6].
The lower this production, the more flexible the capacity
becomes. Taking the case of NuScale, one 60 MWe alone
can provide enough power for up to 60,000 homes [29].
The number of modules implemented can be quickly
increased according to the electricity demand of the city.
This makes it a convenient option for either rural or
urban areas, particularly those with poor resource avail-
ability and storage possibilities for solar and wind
operations. Hydro storage in the form of dams, lakes and
reservoirs is currently the most prevalent economic and
environmental storage technology. Hydro storage is built
on water flowing between two bodies of different eleva-
tion, where water is released from the upper water body to
generate electricity and then pumped back with surplus
electricity produced from intermittent technologies [30].
However, many towns and cities do not have topographic
environment for this technology and therefore cannot
economically store energy generated from intermittent
renewable technology. It is these locations where SMR
technology would be most suitable.
DISADVANTAGES OF SMRS
Most of the issues that follow the SMR proposals are
closely linked with those of large-scale nuclear energy.
This includes the substantial initial costs, particularly
those related to a continuous SMR production factory,
the issue of nuclear waste and the finite amount of recov-
erable uranium.
High Initial Costs
In 20132014, NuScale projected their overnight capital
cost (OCC, a standard concept used to compare construc-
tion costs of power plants) for a 540 MWe plant to
US$5,078/kWe. The levelized cost of electricity (LCOE,
typically measured as $/MWh) was furthermore esti-
mated at US$100/MWh [31]. At that time, NuScale,
which was one of the first producers to receive grants
from the Department of Energy in the United States to
develop SMRs, was one of the pioneers in producing
SMRs commercially. Typically, FOAK development is
usually significantly more expensive, and costs are expected
to decrease as technologies mature and components, sys-
tems and facilities can be shared [32]. As technological
development has advanced, the OCC has been significantly
lowered, and in 2018, NuScale estimated their OCC to
have reduced by more than 50%and for the LCOE to be
18%less than originally thought [31]. This can be com-
pared to the OCC of commercial large-scale reactors,
which, when constructed in the United States between
1968 and 1978, ranged from 1,800 kW to 11,000/kW
[33], and is currently estimated to average at US$6,317 kW
[34]. It is important to note that like large-scale reactors,
large SMR facilities also have an added risk of construction
overruns. Rural single module applications however may
not incur this economic barrier. Nuclear reactors, regardless
4CASE STUDIES IN THE ENVIRONMENT 2020
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
of their kind, are currently being outperformed by some
types or renewables such as wind power (1,319/kW) and
solar PV ($1,331/kW) [34].
Until fabrication has stabilised and production is well
understood, the LCOE of SMR-generated power will be
30%more costly than that of the energy produced by
a large-scale nuclear reactor [14]. Furthermore, current
cash flow modelling suggests that the cost of a natural gas
plant with CCS is less than that of an SMR plant on a per
output basis [14]. Cost parity, however, is expected to be
achieved once 10 units are deployed on a yearly basis [6].
This cost parity is a result of high learning rates (810%
[6]) and moving the building activity away from the plant
site, where the time and resource-consuming construction
of the SMR is external to the plant. The cost of achieving
such an output is expected to be several hundred billion
dollars [14]. Manufacturers need promised investors, with
approximately 3050 ordered modules [35]. Such invest-
ment requires a U.S. national, and more importantly,
a worldwide commitment to decarbonise the energy sys-
tem. Such investors will arise if the direct or indirect cost
of emitting carbon dioxide grows from US$40 to
US$100 over the next decade [35,36].
Water Use
The large water requirements for all thermoelectric plants
arise from the cooling and condensing stages of the process.
After passing through the turbine, the remaining steam and
saturated water need to be cooled before recirculating
through the reactor. This is achieved using large heat
exchangers with a counterflow of cool service water. The
more heat that needs to be removed, the more service water
will be required, and the more water-intensive the whole
process becomes. NuScale has estimated a water require-
ment rate of 740 gallons/MWh [36], comparable to large-
scale nuclear energy, coal, oil and gas-fired plants which
range from 580 to 850 gallons/MWh [37]. As this water
does not come into contact with the reactor water, the
effluent is pollutant-free, with the reactor water remaining
inside the reactor [36]. Nuclear reactors have a high-water
use compared to most renewable energy sources, such as
wind and solar, which both require an almost insignificant
amount of water during their life cycle [23]. The high
consumption of water associated with nuclear reactors is
primarily due to the considerable evaporation occurring
during the cooling process, resulting in water being lost
from the system.
Nuclear Waste
Like large nuclear reactors, a significant issue involving
SMRs is the management of spent fuel (often referred
to as nuclear waste). While many safety controls are in
place, the removal of a single expired module from a set
involves more risk than removing spent fuel from a large
nuclear reactor due to the added complexity of refuelling
multiple modules. In each case, the power plant is shut
down, but the SMR facility will need to have a variety of
additional decommissioning steps that can isolate the
expired reactor from those that remain. The upfront costs
of such are substantial but reduce the cost of decommis-
sioning at the end of the module’s life cycle [38]. Being
a relatively new technology, reliable data on SMR de-
commissioning costs are scarce. The average price of de-
commissioning Nuclear Energy Agency (NEA)-
membered nuclear reactors in 2003 was found to be
US$320/kWe [39], or US$480/kWe in today’s terms
according to the rise in the Chemical Engineering Plant
Cost Index [40]. This cost per input is comparable to
those of recently decommissioned large-scale U.S. nuclear
power plants (1,358,527 and US$266/kWe) [41]. This
translates to US$24 million per PWR NPM. This is
considerably larger than the decommissioning costs of
coal- (US$100/kWe) and gas-powered plants
(US$200/kWe). All decommissioning costs are relative
to a plant size of 500 MW [42].
Once removed from the immediate power generation
facility, the spent nuclear fuel follows one of two path-
ways. It is prepared for long-term storage, or the danger-
ous fission products, such as 90Sr, 137Cs, 99Tc and 129I,
can be separated and the remaining elements reprocessed
[43]. Regardless, nuclear waste needs to be disposed of. By
reprocessing the spent fuel, not only can a portion be
reused, but the half-life of the remnant is reduced signif-
icantly [44]. Owing to the high cost of reprocessing and
relatively low cost of nuclear fuel, however, the spent
uranium is usually stored in underground concrete bun-
kers, where transportation is completely automatic [45].
Although there are many suitable geological locations for
safe storage of spent fuel, the question of where this fuel
should be stored remains a highly political issue.
Proliferation of Nuclear Weapons
The issue of proliferation of radioactive material will
always be a concern for the nuclear energy industry. It
has been argued that having SMRs at more sites increases
Small-Scale Nuclear Energy 5
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
security and proliferation risks, particularly due to stag-
gered refuelling. Each underground module is individually
refuelled every 2years to ensure energy security [46].
While the uranium fuel is transported and handled much
more frequently than that of a large reactor, the miniscule
quantity and enrichment significantly reduces the attrac-
tion of an attack or sabotage. NuScale’s enrichment of 5%
is considerably lower than that of other reactors that
operate using high-assay low-enriched uranium that can
be enriched up to 20%[47]. This resilient plant design is
achieved through the application of defence in-depth
principles which reduce vulnerability to site and transport
sabotage [48].
A Finite Supply of Nuclear Fuel
While somewhat abundant now, it was initially forecasted
in the early 2000s that the world’s uranium supply would
approach depletion around the mid to late 21st century.
This prediction has since been re-evaluated due to the
substantial overestimation of uranium demand and
increased reactor efficiencies. It was initially predicted that
a much larger number of reactors would be in operation
by now. This assumption was made before the Treaty on
the Prohibition of Nuclear Weapons was signed (2017)
and the Fukushima disaster. This disaster created the
impression that using nuclear energy was very dangerous.
The reputation of nuclear power has since improved as it
is one of the only feasible methods of combating climate
change [14]. Opinions differ about how much uranium is
likely to be mined in the future. Bedford [49] has pre-
dicted that its rate of production will increase for at least
the next 200 years. On the other hand, Dittmar [50] has
estimated that its level of production has already peaked
and that there will be a significant shortage in production
by 2030. This highlights the considerable uncertainty
surrounding future uranium availability, thereby also
questioning the future market price of the commodity.
RECOMMENDATIONS
Electrification of remote areas remains an issue, and re-
newables such as solar, wind and hydro have the potential
to fill parts of this gap. Diversification of energy produc-
tion methods can be useful in many areas due to the risks
associated with the reliance on a single source of energy.
However, not all locations have the potential to utilise
these technologies due to a lack of the required natural
resources for their operation. SMRs have the potential to
replace non-renewable energy production systems in geo-
graphically and geologically suitable location, which can
both diversify and lower the carbon emission associated
with the traditional grid system [51].
Remote high latitudinal areas without potential for
hydropower may be a suitable target market for NuScale
and other SMR producers due to the dispatchability of
the technology as well as its capacity to produce baseload
power. Many existing smaller off-grid systems are cur-
rently powered by diesel generators, which are associated
with high emissions and are exposed to price fluctuations
occurring in the global oil market [52]. Although the NuS-
cale facility is not applicable, the implementation of single
module in these low-demand areas could reduce the reli-
ance on individual generators, as mini grids can be imple-
mented at a local scale as an alternative to an expensive
expansion of the existing regional network to remote loca-
tions. This can reduce costs associated with grid develop-
ment and maintenance and reduces the transmission loss.
One of the main drawbacks of LW-SMRs and other
water-dependent nuclear power plants is the high water
consumption, making this type of technology unsuitable
in locations of water scarcity [51]. This can, however, be
worked around by installing coastal or floating SMRs,
which can use seawater as a means of cooling. An example
of such an SMR is the floating nuclear reactor constructed
in Murmansk, Russia, that was shipped to Pevek, Chu-
kotka, in late 2019 [53]. Although operating costs for the
plant in Pevek are high, it has been estimated to be sig-
nificantly cheaper compared to that of extending the grid
network to this remote region [51].
SMRs can furthermore be combined with other gen-
eration sources that are better suited for peak generation
or alternatively can be used alone in remote industrial
areas where there is little temporal variance in energy
demand. Cogeneration with gas-fired power plants has
been deemed the most suitable energy generation combi-
nation due to the high economic returns and low envi-
ronmental impact [54]. Rural mini grids can be self-
sufficient with cogeneration where demand that exceeds
the electricity supply from SMRs can be met by firing up
these additional small-scaled power plants. Besides, SMR
technology can be coupled with storage in the form of
hydro-storage or possibly batteries. This provides greater
flexibility in meeting energy and emission requirements
and can be useful in areas where environmental condi-
tions do not support solar and wind power.
6CASE STUDIES IN THE ENVIRONMENT 2020
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
CONCLUSION
With a rapidly growing demand for energy and a quickly
approaching global emission target, new alternative power
production technologies must be developed and put into
immediate action. While considerable improvements in
innovative renewable technologies such as solar and wind
energy have been made, they cannot combat global warm-
ing on their own. Instead, a clean, reliable and carbon-free
energy source to satisfy baseload power needs to be
adopted. For these exact reasons, nuclear is an increasingly
attractive alternative to fossil fuels. Owing to the signifi-
cantly reduced capital and operational costs, operational
flexibility and low emissions, it is believed that SMRs can
play a key role in mitigating the worst emissions associ-
ated with energy production. Of the technologies today
capable of supplying baseload power, SMRs have the
smallest environmental footprint. While unprocessed
spent fuel cells will need to be stored somewhat indefi-
nitely, the quantity of such produced per megawatt deliv-
ered compared to the emissions produced using coal- and
gas-fired plants is arguably negligible.
NuScale Power has forecast the deployment of their
FOAK SMR, the NPU, to occur during 2026.Consider-
ing the time frame between this and the receipt of a design
certification (September 2020)is6years, it is imperative
that action is soon taken by other interested parties. Global
adoption of SMRs is unlikely to be achieved with the
currently limited number of projects being developed.
Rather than merely waiting until NuScale Power and other
nuclear companies prove their success, investors and gov-
ernment need to assess the potential of SMR production
possibilities and consider placing advance orders for these.
CASE STUDY QUESTIONS
1. What is a small modular reactor and how does it
differ from large-scale nuclear reactors from an
economic, social and environmental perspective?
2. Where would SMRs be most applicable?
3. What changes can be made to make nuclear
energy more sustainable in terms of both
resource management and waste generation?
4. Can nuclear power be considered a sustainable
energy generation technique? Can it be accu-
rately compared to renewable technologies such
as wind and solar?
5. Can SMRs alone meet the energy demand of an
economy now and in the future? If so, is this
sustainable and what barriers exist?
6. Is it possible to further reduce the negative
environmental effects and externalities of
nuclear energy using SMRs?
AUTHOR CONTRIBUTIONS
Primary author: Liam Darby led the process of concep-
tualisation, analysis, original draft, review and editing.
Second author: Amanda Hansson assisted in general edit-
ing and further research as well as recalibrating the case
study.
Third author: Clement Tisdell aided in structuring, sig-
nificant editing and in refining the scope of the case study.
He undertook extra research and suggested changes to the
draft as well.
REFERENCES
1. UNFCCC. What Is the Paris Agreement. 2017. Available:
https://unfccc.int/process-and-meetings/theparis-agree
ment/what-is-the-parisagreement. Accessed 5September
2018.
2. U.S. Energy Information Administration. EIA Projects
Nearly 50%Increase in World Energy Usage by 2050,Led
by Growth in Asia. 2019. Available: https://www.eia.gov/
todayinenergy/detail.php?id¼41433. Accessed 18 October
2019.
3. Elliott D. Balancing green power: how to deal with variable
energy sources. IOP Publishing; 2016.
4. Colbert C. New Nuclear: Small Modular Reactors and
Opportunities for Kansas. Nuscale; 2017.
5. Markelj E. Small Modular Reactors—SMRs. Univerza v
Ljubljani; 2017.
6. Ernst & Young. Small Modular Reactors. Ernst & Young
LLP; 2016.
7. World Nuclear Association. Advanced Nuclear Power
Reactors. 2020. Available: https://www.world-nuclear.
org/information-library/nuclear-fuel-cycle/nuclear-power-
reactors/advanced-nuclear-power-reactors.aspx. Accessed 8
September 2018.
8. NuScale. Comprehensive Safety Features. 2019. Available:
https://www.nuscalepower.com/benefits/safety-features.
Accessed 20 October 2019.
9. World Nuclear Association. Cooling Power Plants. 2019.
Available: https://www.world-nuclear.org/information-
library/current-and-future-generation/cooling-power-
plants.aspx. Accessed 8October 2018.
Small-Scale Nuclear Energy 7
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
10. World Nuclear Association. Small Nuclear Power Reactors.
World Nuclear Association; 2018. Available: http://www.
world-nuclear.org/information-library/nuclear-fuel-cycle/
nuclear-power-reactors/small-nuclear-power-reactors.aspx.
Accessed 4September 2018.
11. The Ux Consulting Company. SMR Design Profile. The
Ux Consulting Company; 2012. Available: https://www.
uxc.com/smr/uxc_SMRDetail.aspx?key¼Indian%20220
%20MWe%20PHWR. Accessed 10 October 2018.
12. U.S. Nuclear Regulatory Commission. Application Review
Schedule for the NuScale Design. U.S. Nuclear Regulatory
Commission; 2020. Available: https://www.nrc.gov/
reactors/new-reactors/design-cert/nuscale/review-schedule.
html. Accessed 20 September 2019.
13. World Nuclear News. NuScale Makes First Canadian SMR
Review Submission. World Nuclear News; 2020. Available:
https://world-nuclear-news.org/Articles/NuScale-makes-
first-Canadian-SMR-review-submission. Accessed 17 Octo-
ber 2018.
14. Morgan MG, Abdulla A, Ford MJ et al. US nuclear
power: the vanishing low-carbon wedge. PNAS. 2018;
115(28):71847189.
15. Brick S, Thernstrom S. Renewables and decarbonization:
studies of California, Wisconsin and Germany. Electr J.
2016;29(3):612.
16. Nian V, Chou SK, Su B et al. Life cycle analysis on carbon
emissions from power generation—The nuclear energy
example. Appl Energy. 2014;118:6882.
17. Wang Y, Sun T. Life cycle assessment of CO2emissions
from wind power plants: methodology and case studies.
Renew Energy. 2012;43:3036.
18. Gerbinet S, Belboom S, Le
´onard A. Life Cycle Analysis
(LCA) of photovoltaic panels: a review. Renew Sust Energy
Rev. 2014;38:747753.
19. Liang X, Wang Z, Zhou Z et al. Up-to-date life cycle
assessment and comparison study of clean coal power
generation technologies in China. J Clean Prod. 2013;
39:2431.
20. U.S. Energy Information Administration. How Much
Carbon Dioxide is Produced Per Kilowatt-Hour of U.S.
Electricity Generation? U.S. Energy Information Admin-
istration; 2018.
21. Talati S, Zhai H, Morgan M. Viability of carbon capture
and sequestration retrofits for existing coal-fired power
plants under an emission trading scheme. Environ Sci
Technol. 2016;50(23):1256712574.
22. World Nuclear Association. World Nuclear Performance
Report. 2019. Available: https://www.world-nuclear.org/
getmedia/d77ef8a1-b720-44aa-9b87-abf09f474b43/
performance-report-2019.pdf.aspx. Accessed 17 October
2018.
23. Strezov V, Evans A, Evans T. Comparing the Sustainability
Parameters of Renewable, Nuclear and Fossil Fuel Electric-
ity Generation Technologies. World Energy Council for
Sustainable Energy; 2015.
24. Modern Power Systems. NuScale Joins B&W on the SMR
Bench. Modern Power Systems; 2014. Available: http://
www.modernpowersystems.com/features/featurenuscale-
joins-bw-on-the-smrbench-4264827. Accessed 3October
2018.
25. Mundy T. NuScale SMR Technology. NuScale Power;
2014.
26. Entergy. A Comparison: Land Use by Energy Source—
Nuclear, Wind and Solar. Entergy; 2015.
27. Rooney M. Small Modular Reactors: The Next Big Thing
in Energy? American Security Project; 2012,10.
28.IngersollD.Integrating Nuclear in Renewables.Nuclear
Engineering International; 2016.
29. Montgomery S. The Nuclear Industry Is Making a Big Bet
on Small Power Plant. The Conversation Company; 2018.
Available: https://theconversation.com/thenuclear-
industry-is-making-a-big-bet-onsmall-power-plants-94795.
Accessed 3October 2018.
30. World Nuclear Association. Electricity and Energy Storage.
World Nuclear Association; 2020. Available: https://
www.world-nuclear.org/information-library/current-and-
future-generation/electricity-and-energy-storage.aspx.
Accessed 17 October 2018.
31. World Nuclear Association. Small Nuclear Power Reactors.
World Nuclear Association; 2020. Available: https://www.
world-nuclear.org/information-library/nuclear-fuel-cycle/
nuclear-power-reactors/small-nuclear-power-reactors.aspx.
Accessed 17 October 2018.
32. Kim G. SMR Cost Estimates, and Costs of SMRs Under
Construction. 2019. Available: https://wiseinternational.
org/nuclear-monitor/872-873/smr-cost-estimates-and-
costs-smrs-under-construction. Accessed 18 October 2019.
33. Lovering JR, Yip A, Nordhaus T. Historical construction
costs of global nuclear power reactors. Energy Policy 2016;
91:371382.
34. U.S. Energy Information Administration. Cost and Per-
formance Characteristics of New Generating Technolo-
gies, Annual Energy Outlook 2020.2020.Available:
https://www.eia.gov/outlooks/aeo/assumptions/pdf/
table_8.2.pdf. Accessed 20 January 2020.
35. Cooper M. Small modular reactors and the future of
nuclear power in the United States. Energy Res Soc Sci.
2014;3(C):161177.
36. NuScale. Water Efficient Technology. NuScale; 2019.
Available: https://www.nuscalepower.com/benefits/
reduced-water-consumption. Accessed 23 September 2018.
37. Yi J. Water Use of Electricity Technologies: A Global
Meta-Analysis. Elsevier; 2019.
38. World Nuclear Association. Decommissioning Nuclear
Facilities. World Nuclear Association; 2018.Available:
http://www.world-nuclear.org/informationlibrary/nuclear-
fuel-cycle/nuclearwastes/decommissioning-nuclearfacilities.
aspx. Accessed 18 October 2019.
39. OECD. Decommissioning Nuclear Power Plants. Nuclear
Energy Agency; 2003,77.
8CASE STUDIES IN THE ENVIRONMENT 2020
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
40. Jenkins S. Chemical Engineering Plant Cost Index: 2018
Annual Value—Chemical Engineering. 2018.Available:
https://www.chemengonline.com/2019-cepci-updates-
january-prelim-and-december-2018-final/. Accessed 10
October 2018.
41. OECD. Costs of Decommissioning Nuclear Power Plants.
Nuclear Energy Agency; 2016,77.
42. Raimi D. Decommissioning US Power Plants. Resources
for the Future; 2017. Available: https://www.rff.org/
publications/reports/decommissioning-us-power-plants-
decisions-costs-and-key-issues/. Accessed 18 October 2019.
43. World Nuclear Association. The Nuclear Fuel Cycle.
World Nuclear Association; 2017. Available: http://
www.world-nuclear.org/information-library/nuclearfuel-
cycle/introduction/nuclear-fuel-cycleoverview.aspx.
Accessed 5September 2018.
44. Zhang J. Nuclear Fuel Reprocessing and Waste Manage-
ment. Virginia Tech; 2018.
45. Levenson M. Research Reactor Aluminium Spent Fuel:
Treatment Options for Disposal Chapter: 3.Waste-Package
Performance Criteria, The National Academies Press; 1998.
46. NuScale. Cost-competitive Energy. NuScale Power; 2019.
Available: https://www.nuscalepower.com/newsletter/
nucleus-spring-2019/cost-competitive-energy. Accessed
20 January 2020.
47. Centrus. High Assay Low Enriched Uranium. 2020.
Available: https://www.centrusenergy.com/what-we-do/
nuclear-fuel/high-assay-low-enriched-uranium/. Accessed
20 January 2020.
48. NuScale. FAQ: Regulatory Implications. NuScale Power;
2020. Available: https://www.nuscalepower.com/about-us/
faq#RI5. Accessed 20 January 2020.
49. Bedford D. Peak Uranium and the Sustainability of
Nuclear Energy. Stanford University; 2018.
50. Dittmar M. The end of cheap uranium. Sci Total Environ.
2013;461462,792798.
51. Nuclear Energy Agency and OECD. Small Modular Reac-
tors: Nuclear Energy Market Potential For Near-Term
Deployment. 2016. Available: https://www.oecd-nea.org/
ndd/pubs/2016/7213-smrs.pdf. Accessed 22 September
2018.
52. Bhattacharyya SC, Palit D. Mini-Grids for Rural Electrifi-
cation of Developing Countries Analysis and Case Studies
from South Asia. 1st ed. Springer; 2014.
53. BBC. Russia Floating Nuclear Power Station Sets Sail
Across Arctic. BBC; 2019. Available: https://www.bbc
.com/news/world-europe-49446235. Accessed 28 January
2020.
54. Locatelli G. Cogeneration: An Option to Facilitate Load
Following in Small Modular Reactors. Elsevier; 2016.
Small-Scale Nuclear Energy 9
Downloaded from http://online.ucpress.edu/cse/article-pdf/doi/10.1525/cse.2020.1112327/404637/cse.2020.1112327.pdf by guest on 22 July 2020
ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
Understanding the water use of power production is an important step to both a sustainable energy transition and an improved understanding of water conservation measures. However, there are large differences across the literature that currently present barriers to decision making. Here, the compiled inventory of the blue water use of power production from existing studies allowed to uncover the characteristics of water use and to investigate current uncertainties. The results show that photovoltaics, wind power, and run-of-the-river hydropower consume relatively little water, whereas reservoir hydropower and woody and herbaceous biomass can have an extremely large water footprint. The water consumption of power production can differ greatly across countries due to different geographic conditions. Only a few studies provided the values for the influencing factors of water use, such as the capacity factor. Values that are reported came mainly from assumptions and other literature rather than direct measurement. Omitting a life cycle stage may lead to significant underestimations. Water scarcity is attracting more attention, but the few existing results are not useable for a regional comparison due to data gaps and inconsistent measurements. In the future, a clear and detailed definition of the water footprint and system boundary of power production is essential to improving comparisons and energy systems modelling.
Article
Full-text available
An analysis of electricity systems in Germany, California and Wisconsin finds that balanced portfolios made up of zero- and low-carbon baseload resources, as well as wind and solar, are the most cost-effective means of producing electricity and reducing carbon.
Article
Full-text available
The increasing penetration of renewables, especially wind generation, have dramatically changed the economics and realities of grid management in ways that now encourage some level of load-following capabilities for historically baseload plants, including nuclear. The NuScale small modular reactor design currently under development in the United States is well suited for integration with renewables because of several design features related to the nuclear steam supply system, the power conversion system, and the overall plant architecture. The multi-module nature of a NuScale plant allows the plant output to be varied in three ways spanning a wide range of different time frames: (1) taking one or more modules offline for extended periods of sustained wind output, (2) adjusting reactor power for one or more modules for intermediate periods to compensate for hourly changes in wind generation, or (3) bypassing the steam turbine for rapid responses to wind generation variations. Results are presented from a recent analysis of nuclear-wind integration that utilized historical wind generation data from the Horse Butte wind farm in Idaho. Also discussed is the experience of Energy Northwest in their implementation of limited load-shaping at the Columbia Generating Station.
Article
Full-text available
The existing literature on the construction costs of nuclear power reactors has focused almost exclusively on trends in construction costs in only two countries, the United States and France, and during two decades, the 1970s and 1980s. These analyses, Koomey and Hultman (2007); Grubler (2010), and Escobar-Rangel and Lévêque (2015), study only 26% of reactors built globally between 1960 and 2010, providing an incomplete picture of the economic evolution of nuclear power construction. This study curates historical reactor-specific overnight construction cost (OCC) data that broaden the scope of study substantially, covering the full cost history for 349 reactors in the US, France, Canada, West Germany, Japan, India, and South Korea, encompassing 58% of all reactors built globally. We find that trends in costs have varied significantly in magnitude and in structure by era, country, and experience. In contrast to the rapid cost escalation that characterized nuclear construction in the United States, we find evidence of much milder cost escalation in many countries, including absolute cost declines in some countries and specific eras. Our new findings suggest that there is no inherent cost escalation trend associated with nuclear technology.
Conference Paper
Full-text available
The sustainability parameters of electricity generation have been evaluated by the application of eight key indicators. Photovoltaics, wind, hydro, geothermal, biomass, natural gas, coal and nuclear power have been assessed according to their price, greenhouse gas emissions, efficiency, land use, water use, availability, limitations and social impacts on a per kilowatt hour basis. The relevance of this information to the Australian context is discussed. Also included are the results of a survey on Australian opinions regarding electricity generation, which found that Australian prefer solar electricity above any other method and also support wind power, with over 90% support, however coal, biomass and nuclear power have low acceptance rates at 30% or less. Most Australians, greater than 90%, believe that the government is not doing enough to support renewable electricity.
Article
Nuclear power holds the potential to make a significant contribution to decarbonizing the US energy system. Whether it could do so in its current form is a critical question: Existing large light water reactors in the United States are under economic pressure from low natural gas prices, and some have already closed. Moreover, because of their great cost and complexity, it appears most unlikely that any new large plants will be built over the next several decades. While advanced reactor designs are sometimes held up as a potential solution to nuclear power's challenges, our assessment of the advanced fission enterprise suggests that no US design will be commercialized before midcentury. That leaves factory-manufactured, light water small modular reactors (SMRs) as the only option that might be deployed at significant scale in the climate-critical period of the next several decades. We have systematically investigated how a domestic market could develop to support that industry over the next several decades and, in the absence of a dramatic change in the policy environment, have been unable to make a convincing case. Achieving deep decarbonization of the energy system will require a portfolio of every available technology and strategy we can muster. It should be a source of profound concern for all who care about climate change that, for entirely predictable and resolvable reasons, the United States appears set to virtually lose nuclear power, and thus a wedge of reliable and low-carbon energy, over the next few decades.
Book
Renewable energy sources are large but some are variable and intermittent. The wide-scale use of renewable energy sources for energy supply will require the adoption of ways to compensate for their variability. This book reviews the technical options looking at their pros and cons and how they might work together to support a reliable and sustainable energy system. This is a rapidly advancing area of research and practice and Balancing Green Power offers an ideal introduction to the field.
Article
Nuclear Power Plants (NPPs) have been historically deployed to cover the base-load of the electricity demand. Nowadays some NPPs might perform daily load cycling operation (i.e. load following) between 50% and 100% of their rated power. With respect to the insertion of control rods or comparable action to reduce the nuclear power generation, a more efficient alternative might be the “Load Following by Cogeneration”, i.e. diverting the excess of power, respect to the electricity demand, to an auxiliary system. A suitable cogeneration system needs: 1. To have a demand of electricity and/or heat in the region of 500 MWt – 1 GWt; 2. To meet a significant market demand; 3. To have access to adequate input to process; 4. To be flexible: cogeneration might operate at full load during the night when the request (of) for electricity is low, and be turned off during the daytime. From the economic standpoint, it is essential that the investment in the auxiliary system is profitable. This paper provides a techno-economic assessment of systems suitable for coupling with a NPP for load following. The results show that district heating, desalination and hydrogen might be technically and economically feasible.
Article
Using data on the coal-fired electric generating units (EGUs) in Texas we assess the economic feasibility of retrofitting existing units with carbon capture and sequestration (CCS) in order to comply with the Clean Power Plan's rate-based emission standards under an emission trading scheme. CCS with 90% capture is shown to be more economically attractive for a range of existing units than purchasing emission rate credits (ERCs) from a trading market at an average credit price above $28 per MWh under the final state standard and $35 per MWh under the final national standard. The breakeven ERC trading prices would decrease significantly if the captured CO2 were sold for use in enhanced oil recovery, making CCS retrofits viable at lower trading prices. The combination of ERC trading and CO2 use can greatly reinforce economic incentives and market demands for CCS and hence accelerate large-scale deployment, even under scenarios with high retrofit costs. Comparing the levelized costs of electricity generation between CCS retrofits and new renewable plants under the ERC trading scheme, retrofitting coal-fired EGUs with CCS may be significantly cheaper than new solar plants under some market conditions.
Article
Small modular reactor designs with power levels of less than 300 MWe are being developed in several countries. While there are several potential advantages with these reactors, they are also confronted with multiple challenges. Important among these challenges is to have these new reactor designs licensed by national regulatory bodies. Because of the many novel features incorporated in different SMR (small modular reactor) designs, careful and thorough licensing procedures are critical to maintaining safety of the nuclear fleet. This paper examines how different countries have engaged in the process of licensing new reactor designs, and demonstrates both similarities and differences between countries. In many cases, designers have emphasized the safer design and deployment features of SMRs and attempted to use those features as reasons to get existing licensing requirements diluted. This raises the concern that the promised safety enhancements in SMR designs could be offset by a simultaneous relaxation of licensing requirements.