Nuclear Research and Development Capabilities - Science and Technology Committee Contents

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.[52] 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.[53]

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.[54] 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".[55] 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.[56] 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.[57]

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.[58] Dr Douglas Parr, Chief Scientist at Greenpeace UK, shared this view.[59] However, as many witnesses agreed, there would be considerable economic, structural and social trade-offs to pursuing such a policy.[60] 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.[61] 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.[62]

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.[63] 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")[64], 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".[65] 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[66] a year to 2050.[67]

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).[68] 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).[69] We were not surprised therefore that the ETI and others took the view that a higher contribution from nuclear would be inevitable.[70] The ETI suggested that 35-55 GW would be the "optimum" level.[71] 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%".[72]

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.[73] 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%[74] 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[75] (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 portfolio—from low to high—to 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.

UKERC scenarios

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"),[76] it is estimated that around 12 GW of nuclear energy capacity would constitute 15% of the total electricity supply in 2050.[77] 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.[78] 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,[79] 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[80] included a range of pathways (or scenarios), from 0 GW capacity up to 146 GW (between 0 and 98% of total electricity supply—the 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[81]

To be on course to meet the 80% target by 2050, the CCC's central scenario[82] 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).[83] 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.[84] 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 2100—based 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".[85] 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.[86] (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 products—that 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 risks—if 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

53   Q 444 Back

54   NRD 08, 14, 21; QQ 2-3, 79, 231, 445  Back

55   Q 3 Back

56   UK Energy in Brief 2011, DECC, 2011. Back

57   Nuclear Fission, op.cit. Back

58   Q 3 Back

59   QQ 3, 8 Back

60   QQ 3, 5, NRD 08, 29 Back

61   QQ 3, 5 Back

62   Q 5 Back

63   Q 442 Back

64   Renewable Energy Review, the Climate Change Committee, May 2011 ("the CCC review"). Back

65   Q 2 Back

66   At today's rates. Back

67   NRD 08 Back

68   Nuclear Fission, op. cit Back

69   UK Energy in Brief 2011, DECC, 2011. Back

70   NRD 08, 16 Back

71   NRD 08 Back

72   Q 58 Back

73   Q 2 Back

74   Renewable Energy Review op. cit. Back

75   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

76   Making the transition to a secure and low-carbon energy system, UKERC, 2010. Back

77   From the 50-CCSP scenario, see page 39 of the UKERC report for a description of the scenario assumptions. Back

78   From the 50-CCP and 50-CSAM scenarios, Ibid. Back

79   From the 50-CAM scenario, Ibid. Back

80   2050 Pathways Analysis, HM The Government, July 2010, p21 Pathway Gamma. Back

81   The Renewable Energy Review op. cit. Back

82   For the central scenario, see page 156 of the Renewable Energy Review op. cit.  Back

83   NRD 08, 21; Q 19 Back

84   NRD 31 Back

85   NRD 41 Back

86   NRD 31 Back

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