APPENDIX 57
Supplementary memorandum by Professor
Jim Skea, UKERC
The complete nuclear life-cycle needs to be
considered when assessing greenhouse gas emissions from nuclear
power. Even though nuclear electricity generation produces virtually
no greenhouse gas emissions at the point of generation (see Figure
1 below), greenhouse gases are released at all the stages of the
fuel cycle, including fuel preparation and transportation, and
during plant construction and decommissioning, (IAEA, 2000).
The main contributors to greenhouse gas emissions
from nuclear power are fuel extraction, conversion, enrichment,
plant construction and decommissioning and materials. Fuel enrichment
by gas diffusion is an energy intensive process that can increase
greenhouse gas releases by an order of magnitude when compared
to enrichment by centrifuge. Fuel reprocessing accounts for 10-15%
of the total greenhouse gas emissions from nuclear power. These
emissions are highly country-specific as they depend on national
fuel mixes, (IAEA, 2000).
According to the OECD Nuclear Energy Agency
(NEA) and International Atomic Energy Authority (IAEA), and although
this varies according to reactor characteristics and location,
nuclear power emits between 2.5-5.7 tCeq/GWh (see Figure 1). By
contrast, coal emits around 245 tCeq/GWh, gas emits around 100
tCeq/GWh while emissions from electricity generation per unit
of electricity supplied from fossil fuels are estimated to have
been around 165 tCeq/GWh in 2004 in the UK. The overall emissions
from electricity generated from all sources (including nuclear
and renewables) amounted to 125 tCeq/GWh, (DTI, 2005). According
to the IAEA in 2000, greenhouse gas emissions from nuclear power
are in a similar range to onshore wind power and small-scale hydropower.
The large scale implementation of nuclear power
has been questioned as an appropriate response to climate change,
especially regarding the adequacy of nuclear fuel supplies. The
argument put forward by critics like Mortimer, Storm van Leeuwen
and Smith rests on the assumption that if the use of nuclear energy
were to increase significantly then known uranium resources would
be quickly consumed. This would lead to the use of lower grade
uranium ores resulting in increased energy consumption and CO2
emissions. However, the World Nuclear Association disputes the
assumption that no further low cost reserves of uranium remain
to be found, as new nuclear build and higher uranium demand would
lead to increased exploration and the discovery of additional
resources.
Figure 1
Range of total greenhouse gas emissions
(in g Ceq/kWh) from electricity production
chains, (IAEA, 2000)
GHG emissions at the point of electricity generation
are shown in the dark bar segments. Shown in the light bar segments
are emissions from all other stages of the electricity chain,
ie fuel mining, preparation, and transport, plant construction
and decommissioning and the manufacture of equipment.
Professor Jim Skea
Research Director
UK Energy Research Centre
REFERENCES
DTI (2005) Energy Trends—March 2005. Available
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IAEA—Spadaro, J, Langlois, L, Hamilton,
B (2000) Assessing the Difference: Greenhouse Gas Emissions of
Electricity Generation Chains. The IAEA Bulletin 42:2 Available
from: http://www.iaea.org/Publications/Magazines/Bulletin/Bull422/article4.pdf
Mortimer, N (1989) Aspects of the greenhouse effect,
Friends of the Earth evidence to Hinkley Point C public enquiry
(FOE9).
NEA (2002) Nuclear Energy and the Kyoto Protocol.
Available from: http://www.nea.fr/html/ndd/reports/2002/nea3808-kyoto.pdf
Storm van Leeuwen, J, Smith, P (2005) Nuclear Power,
the Energy Balance—Chapter 1: The CO2 emissions of the nuclear
life-cycle. Available from: http://www.stormsmith.nl/Chap-1-CO-2-emission-of-the-nuclear-fuel-cycle.PDF
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Emissions from the Nuclear Fuel Cycle—A paper by the Uranium
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