CHP and High Temperature
Reactors
Presentation to NC2I Conference
14th September 2015
Gas cooled and high temperature
reactors in the UK
CHP and High Temperature Reactors
GCR & HTRs – a UK history
The UK has a substantial history of gas cooled, graphite moderated reactors of
increasing core temperature
Magnox (Gen I):
• Commercial operation 1956 – 2010s
• CO2 coolant, unenriched U metal fuelled
• Core temperature 400°C
Source : Nuclear Decommissioning Authority
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CHP and High Temperature Reactors
GCR & HTRs – a UK history
Advanced Gas-cooled Reactors (Gen II):
• Commercial operation 1976 - present
• CO2 coolant, UO2 fuelled
• Core temperature ~640°C
Source : Office of Nuclear Regulation
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CHP and High Temperature Reactors
GCR & HTRs – a UK history
Winfrith “Dragon” research reactor (materials and fuels test reactor)
• Helium cooled,
• Variety of TRISO fuels
(UO2, ThO2, Pu carbide)
• Operated 1965-1976
• Core temperature 750°C
Source : Research Sites Ltd.
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CHP and High Temperature Reactors
HTRs – UK activity in 2015
HTR development activity in the UK has shifted to the private sector. 2
companies currently known to be active in developing designs:
• U-Battery (a consortium of Urenco, Amec Foster Wheeler and Atkins)
– Gas cooled – helium in primary circuit, nitrogen in secondary circuit.
– TRISO prismatic fuel
– Designed for heat as much as power : outlet temperature 800°C
– 4 MW electric / 10 MW thermal
• HTMR Ltd (a sister company of Steenskampskraal Thorium Ltd.)
– Helium cooled HTMR100 reactor
– TRISO pebble bed fuel
– Designed for heat or power
– 35 MW electric / 100 MW thermal
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CHP and High Temperature Reactors
The potential for nuclear heat and
cogeneration in the UK
CHP and High Temperature Reactors
Decarbonising the UK – cogeneration in context
• Current heat demand in UK varies between ~30GW to >200GW, whilst
electricity supply varies between ~30GW to ~50 GW.
• Decarbonising UK energy system through electrification of heat production
is a challenge (even with heat pumps for low grade heat).
• Economically competitive cogeneration from thermal electrical power plant
has long been an area of interest… especially if it is from low carbon
generation!
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CHP and High Temperature Reactors
Nuclear heat and cogeneration: UK potential
Current UK Government policy is that thermal power stations, including nuclear
ones, should be combined with CHP where this is possible.
– “…development consent applications for nuclear power stations should
demonstrate that the applicant has fully considered the opportunities for CHP.”
Nuclear National Planning Statement, 2011
On should be technically feasible to transport heat to settlements at least up to
50km away from a power station.
Assumes mid to low grade heat, taken off the lower end of the steam turbines
of current plant. Applicable to all nuclear plant HTRs.
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CHP and High Temperature Reactors
Nuclear heat and cogeneration : UK potential
However…
– “…the economic viability of CHP opportunities…may be more limited for new
nuclear power stations because the application of a demographic criterion for
new nuclear power stations can result in stations being located away from
major population centres and industrial heat demand..”
Nuclear National Planning Statement, 2011
• Nuclear sites tend to be a long way from population and industry centres.
• Magnox were required to be remote from population centres.
• More recent (and proposed) designs have been assessed as being safer. A
reactor is not obliged to be remote.
• Office for Nuclear Regulation’s siting criteria combine safety assessment
and demographic analysis, which defines limits to sites’ proximity to
population centres.
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CHP and High Temperature Reactors
Nuclear heat and cogeneration :
UK potential
2 current sites are shown with heat demands from the
UK heat map.
Sizewell
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CHP and High Temperature Reactors
Hinkley Point
Nuclear heat and cogeneration : UK potential
Barriers to uptake of nuclear CHP from current plant
Domestic heat demand:
• Demand density is very low near current nuclear power stations.
• Heat networks in the UK are currently too small to utilise a significant
proportion of the heat available from current designs of nuclear power
stations (largest is 60 MW thermal).
• Cost of heat network development.
• Result is that nuclear CHP for domestic heating cannot compete with gas
(domestic heating falls outside the EU Emissions Trading System)
Industrial heat demand:
• Lack of industrial customers close enough to nuclear plant.
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CHP and High Temperature Reactors
Nuclear CHP in the UK
Assessing potential for small modular reactors
There might be greater potential for the use of CHP in the future if Small
Modular Reactors (SMRs) are taken forward. (SMR ≤ 300 MW electrical)
•
In principle SMRs may have greater flexibility of siting.
•
Heat production volume and flexibility may be more compatible with heat networks.
•
Economics may be more favourable (e.g. build cost, time to deployment).
•
Some designs offer higher grade heat than current large nuclear power stations,
making industrial process heat supply.
Late 2014 – Completed overview of global market
Spring 2015 – DECC commissioned a programme of work to assess
implications of SMR deployment for UK. Aims to engage with developers of all
SMR types, including HTR SMRs. Due for completion in March 2016.
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CHP and High Temperature Reactors
Thank you for your attention!
CHP and High Temperature Reactors