CHAPTER 3: The role of nuclear in the
energy portfolio up to 2050 and beyond |
A "portfolio approach"
36. There are inherent uncertainties involved
in looking into the future as far as 2050. In the context of this
inquiry, these include the variable costs of raw materials and
the unpredictable rate of technology development.
For this reason, Chris Huhne MP, Secretary of State for Energy
and Climate Change, said that the Government were adopting a "portfolio
approach" to meeting the UK's future energy needs. He also
confirmed that nuclear energy would continue to play an important
part in this portfolio.
37. Many witnesses agreed with this approach
and said that nuclear energy, as a low-carbon energy source, would
be a significant and essential part of the energy portfolio in
the future, alongside renewable sources, fossil fuels with CCS
and other measures.
Professor Paul Ekins of the UK Energy Research Centre (UKERC)
told us that "we would do well to keep all the big low-carbon
options open, to develop them to the extent that we need ... to
see what will happen to their costs".
In this chapter, therefore, we explore the range of realistic
scenarios for the contribution that nuclear energy could make
to this portfolio. In Chapter 4, we go on to consider what R&D
capabilities and associated expertise would be required to keep
this range of options open.
What contribution could nuclear
make to the energy portfolio?
38. In 2010, nuclear energy contributed about
16% to the UK's electricity supply, from around 12 GW of capacity.
Gas-fired generation accounted for 47% of total supply, coal-fired
28%, wind 3%, oil 1% and 5% came from other sources.
Attempts have been made to develop scenarios which model the UK's
future energy portfolio on the basis of different levels of nuclear
capacity up to 2050 and beyond, the majority focusing on the period
up to 2050. The ERP report summarises the various scenarios.
39. We received a range of evidence about the
role that nuclear could play within the energy portfolio. All
future scenarios have consequences for the rest of the portfolio.
Professor Ekins told us, for example, that it is "quite possible
to have the amount of electricity that we both want and need,
low-carbon, by 2050 without nuclear" by pursuing other low-carbon
options, particularly energy efficiency.
Dr Douglas Parr, Chief Scientist at Greenpeace UK, shared this
view. However, as
many witnesses agreed, there would be considerable economic, structural
and social trade-offs to pursuing such a policy.
Katherine Randall, 2050 Team Leader at the Department for Energy
and Climate Change (DECC) said, for example, that "while
it is possible, technically ... to generate a pathway that does
not use nuclear", it is not desirable.
This is because various analyses of the future energy portfolio
have shown that excluding nuclear would put significantly more
pressure on supply and the use of other technologies, some of
which, such as CCS, are unproven. It would, she told us, also
require "a great deal more effort ... on the demand side"
which has so far proven to be difficult and a "significant
effort on balancing" the supply of electricity in the system.
40. As a relatively mature low-carbon technology,
nuclear is therefore, in our view, an important option which should
be retained within the energy portfolio, not least as a contingency
in the event that other, unproven, low-carbon technologies such
as CCS develop at a slower pace than anticipated. There are those
who believe, as the Secretary of State told us in oral evidence,
that shale gas could play a significant role in the future.
Uncertainties around the viability of CCS, a technology that would
be needed to make this a low-carbon energy source (not to mention
other uncertainties, for example, about the environmental impact
of such extraction or the size of the UK's reserves), suggest
that, in our view, it may not be wise to rely heavily on this
energy source to meet our future needs (see paragraph 46).
41. Witnesses also suggested that nuclear energy
was a cost-effective option. Commenting on a Climate Change Committee
(CCC) review entitled the Renewable Energy Review (May
2011) ("the CCC review"),
Adrian Gault, Chief Economist at the CCC, said that "nuclear
looks likely to be the most cost-effective low-carbon generation
option ... [and that the CCC] would see nuclear playing a very
significant role in moving towards low-carbon generation".
The Energy Technologies Institute (ETI) agreed. They calculated
that the likely additional system costs to the UK of not building
Generation III reactors would be £9 billion
a year to 2050.
42. The ERP report suggests that, realistically,
"between 12-38 GW of installed [nuclear] capacity will be
required" to achieve a secure, reliable and low-carbon energy
system in 2050, with 12 GW likely to be the minimum amount of
nuclear generating capacity needed (see Box 2 for an overview
of some of the scenarios presented in the report).
Given however that the UK's nuclear capacity is currently around
12 GW it is not clear to us how adopting the minimum 12 GW pathway
would enable the UK to meet the target of reducing greenhouse
gas emissions by 80% (from 1990 levels) by 2050, without a dramatic
increase in the contribution of renewable sources and CCS (particularly
since the Government intend to electrify the transport sector
over this period, which currently accounts for 37% of primary
energy consumption in the UK).
We were not surprised therefore that the ETI and others took the
view that a higher contribution from nuclear would be inevitable.
The ETI suggested that 35-55 GW would be the "optimum"
level. Dame Sue Ion,
Chair of the Euratom Science and Technology Committee for the
European Commission, agreed. She told us that:
"various studies that have been done ... have
said that the mathematics and the engineering do not add up [for
12 GW of nuclear energy]; ... you need closer to 40 GW in order
to stand even a fighting chance [of meeting the UK's greenhouse
gas reduction targets], even then with a very significant reduction
in demand of the order of 26% to 30%".
43. More recent scenarios also indicate the need
for more nuclear capacity and suggest that a greater dependency
may be likely before 2030. Mr Gault of the CCC told us that "various
modelling analyses" find that "early decarbonisation
of the power generation sector" will be necessary to achieve
an 80% reduction in carbon emissions by 2050, with significant
reductions necessary through the period to 2030.
The CCC has calculated that achieving the necessary energy supply
by 2030, and reductions in carbon emissions from 500 grams per
kilowatt hour (g/(kW.h)) to a level of 50 g/(kW.h) in 2030, will
require 30-40 GW of low-carbon investment between 2020-30, on
top of approximately 16 GW of capacity that will be required before
this period. In a scenario where renewables contribute 40%
to the UK's electricity supply, which is considered to be an achievable
but technically very challenging target, they estimate that, in
total, 22 GW of nuclear capacity will be required before 2030,
significantly higher than the commitments to date from the energy
sector under the new build programme of approximately 16 GW of
capacity by 2025
(see Box 2).
44. Some experts suggest that 12 GW of energy
generation is the minimum contribution that nuclear could make
to the energy portfolio up to 2050. However, the weight of evidence
indicates that a significantly higher contribution of around 22-38
GW is likely to be required to enable early decarbonisation of
the sector before 2030 and to meet the UK's long-term greenhouse
gas emission targets up to 2050 and beyond.
45. The Government should now put in place
plans which provide for a range of contributions from nuclear
energy to the overall energy portfoliofrom low to highto
meet the UK's future energy needs up to 2050 and beyond. These
plans should ensure that the UK has adequate R&D capabilities
and associated expertise to keep the option of a higher nuclear
energy contribution to the energy portfolio open and recognise
that maintaining sufficient capabilities and suitably trained
people will require a long lead time.
46. Given the weight of evidence we received
and that CCS is still an unproven technology, we do not believe
that the Government can base the UK's energy future on the assumption
that fossil fuels, including shale gas, with CCS will enable the
UK to meet its greenhouse gas reduction targets safely and securely.
(We discuss this issue further in paragraphs 81 to 86 below.)
The contribution that nuclear energy could
make to the energy mix: future energy scenarios
|There is considerable variation between the different
energy scenarios that have been produced due to differences in
the assumptions that underpin them, such as the demand for energy
in 2050, the cost of different technologies or the market incentives
selected within the scenario. These can be found in the relevant
publications. For this reason, the scenario results should be
taken only as an indication of the range of contributions that
nuclear could make to the overall energy portfolio.
At the lower end of the future scenarios which UKERC
set out in its report Making a transition to a secure and low-carbon
energy system ("the UKERC report"),
it is estimated that around 12 GW of nuclear energy capacity would
constitute 15% of the total electricity supply in 2050.
At the high end of the scenario range, around 38 GW of nuclear
energy by 2050 would equal to about 45-49% of total electricity
supply. Neither of
the scenarios specifically looked at the ability to meet the 80%
reduction target. The higher scenario represents a 90% reduction
or a "least cost" scenario and the lower scenario represents
a pathway that favours earlier decarbonisation and more rapid
action than is possible from nuclear technologies, reaching a
70% reduction by 2050.
For UKERC's "low-carbon core" scenario,
which assumes that the 80% target will be met, it is estimated
that 29 GW of nuclear energy will be needed by 2050, and will
generate 38% of the UK's total electricity supply.
DECC 2050 Pathways Analysis
The DECC pathways analysis
included a range of pathways (or scenarios), from 0 GW capacity
up to 146 GW (between 0 and 98% of total electricity supplythe
highest technically feasible contribution) but did not consider
the cost implications of each technology. The Alpha pathway looked
at contributions from various technologies within the energy portfolio,
where nuclear supplied about 39 GW or 30% of total electricity
supply. DECC will be producing a pathway in late 2011 which includes
consideration of the costs of different technologies.
The CCC Review
To be on course to meet the 80% target by 2050, the
CCC's central scenario
estimates that, by 2030, 40% of electricity will come from renewables
and 22 GW of electricity supply will come from nuclear, equal
to 38% of total electricity supply.
The role of different nuclear
technologies and fuel cycles
47. Nuclear energy generation, to a greater or
lesser extent, will be an important part of the UK's energy portfolio
up to 2050 and beyond. That much is clear. Less certain is which
of the different nuclear technologies will be most effective in
providing this capacity. This will depend, in part, on the point
at which the supply of uranium begins to operate as a cost driver
or constraint on the sector.
48. The Government, the CCC and the ETI each
stated that, even for scenarios involving a higher contribution
from nuclear, demand for new nuclear plant could be met through
Generation III technologies and a once-through fuel cycle (see
Box 3). This is because,
in their view, uranium will not be a cost driver in the period
up to 2050. The Cambridge Nuclear Energy Centre supported this
view and noted that a recent study by the Massachusetts Institute
of Technology on fuel cycles suggested that nuclear fuels were
more abundant than previously thought and could be extracted at
a cost below that of re-cycled fuel.
This would mean that light water reactors (LWRs) and the once-through
fuel cycle option would be the most cost-effective option for
this century. AMEC however took a different view: "It is
predicted that uranium demand would exceed identified reserves
in about 2060 and exceed estimated (as yet undiscovered) reserves
by 2100based on the projected growth of LWRs. Commercial
deployment of fast reactors with a closed fuel cycle by 2050 would
maintain the uranium demand within the estimated reserves indefinitely".
They stated that "a decade delay in implementing fast reactors could
result in uranium shortages towards the end of the century".
Due to the risk of such constraints, many countries, such as France,
are currently investing in research to close the fuel cycle. France
plans to ensure that the country has a sustainable supply of fuel
by 2100 (see Appendix 5).
49. There are also uncertainties about the rate
of development of advanced nuclear reactor technologies, many
of which have yet to be demonstrated.
(We consider the implications of this uncertain picture for the
assessment of our future nuclear R&D needs and associated
expertise in Chapter 5 below.)
The nuclear fuel cycle
|There are three categories of fuel cycle, which differ
depending on the number of times and manner in which the uranium
and plutonium in the spent fuel is recycled.
Open fuel cycle
This is also referred to as "once-through"
because the fuel passes through a reactor only once, after which
it is disposed of without chemical processing. Currently, with
uranium being relatively abundant, most countries rely exclusively
on a once-through fuel cycle. However, only 3-5% of the original
uranium is consumed if the fuel is used in this way.
Closed fuel cycles
In this case the used nuclear fuel is recycled multiple
times to improve fuel utilization and reduce the long-term waste
burden. After fuel has been in a reactor, the remaining uranium,
plutonium and other transuranic elements are chemically separated
from the fission productsthat is, the fuel is reprocessed.
A closed cycle will generally involve the use of a fast reactor.
In this case a very high proportion of the uranium can be utilized
(70-90%). France, Japan and Russia employ a closed fuel cycle
in certain nuclear facilities.
Modified open fuel cycle
This involves a limited number of separation steps,
conventional reactors and ideally the uranium, plutonium and transuranic
elements remain together in order to lower proliferation risksif
the plutonium is not separated it cannot be weaponised. While
not all the uranium is used, substantially more (6-12%) is used
than in the open fuel cycle.
52 The ERP report identifies the main uncertainties
affecting the future of nuclear energy as the timing, availability
and costs of CCS, the cost of natural gas, the overall carbon
reduction target for the sector, the scale of demand and the cost
of new nuclear. Back
Q 444 Back
NRD 08, 14, 21; QQ 2-3, 79, 231, 445 Back
Q 3 Back
UK Energy in Brief 2011, DECC, 2011. Back
Nuclear Fission, op.cit. Back
Q 3 Back
QQ 3, 8 Back
QQ 3, 5, NRD 08, 29 Back
QQ 3, 5 Back
Q 5 Back
Q 442 Back
Renewable Energy Review, the Climate Change Committee,
May 2011 ("the CCC review"). Back
Q 2 Back
At today's rates. Back
NRD 08 Back
Nuclear Fission, op. cit Back
UK Energy in Brief 2011, DECC, 2011. Back
NRD 08, 16 Back
NRD 08 Back
Q 58 Back
Q 2 Back
Renewable Energy Review op. cit. Back
Under this scenario 10 GW of supply will come from fossil fuels
with CCS and 42 GW from wind (equal to 19 GW supply due to intermittent
supply around a 40% load factor). Back
Making the transition to a secure and low-carbon energy system,
UKERC, 2010. Back
From the 50-CCSP scenario, see page 39 of the UKERC report for
a description of the scenario assumptions. Back
From the 50-CCP and 50-CSAM scenarios, Ibid. Back
From the 50-CAM scenario, Ibid. Back
2050 Pathways Analysis, HM The Government, July 2010, p21
Pathway Gamma. Back
The Renewable Energy Review op. cit. Back
For the central scenario, see page 156 of the Renewable
Energy Review op. cit. Back
NRD 08, 21; Q 19 Back
NRD 31 Back
NRD 41 Back
NRD 31 Back