Written evidence submitted by Dr Jonathan Dean


  1. The Committee is inviting written evidence responding to the following questions. The deadline for submissions is 5pm Friday 12 August.

1.        What role can, or should, nuclear power play in achieving net zero and UK energy security?

  1. The latest version of National Grid Electricity System Operator (ESO) Future Energy Scenarios report puts the likely need for nuclear power stations at between 5-15 GW capacity by 2050.  This is perhaps the most detailed, and credible estimate of likely future requirements, designed to satisfy both net zero and energy security requirements.
  2. The ESO sees nuclear as providing both baseload power and using waste heat to provide decarbonised space heating.
  3. The ESO does not specify where, or what size, the nuclear stations should be built, but the role of them suggests the best locations would be:
  1. In Wales such locations would be the industrial areas around Deeside and Port Talbot.



2.        What are the main challenges to delivering the UK Government’s commitment to bring at least one large-scale nuclear project to final investment decision by the end of this Parliament?

  1. Very few challenges if Sizewell C is selected.
  2. If Sizewell C is not selected, immense, as there are no other projects suitably developed.

3.        How important is the finance model to ensuring a successful nuclear project, and is the regulated asset base (RAB) model the best one to deliver this?

  1. The finance model really should be a non-issue if nuclear power is economically viable to the developer.  This can enhanced if:

4.        What practical steps can the UK Government take to support the nuclear industry in developing a range of nuclear technologies, including small modular reactors?

  1. Select and designate sites for nuclear development that are most likely to enable and economic and efficient project to be developed:
  1. Coastal locations or estuaries such as the Thames, Humber, Mersey, Dee, Severn would most likely satisfy these requirements.

5.        What would the likely cost be to the taxpayer of the UK Government supporting the development of a new nuclear power station at Wylfa?

  1. Wylfa is a bad location for a thermal power station of any scale:
  1. If, for political reasons, it is deemed appropriate to designate a site on Anglesey, then:
  1. Due to the issues with Wylfa, whatever support is offered, it will be greater that selecting and supporting a site in a more optimal location.

6.        What is the potential economic impact for Wales of a new nuclear power station at Wylfa?

  1. There is undoubtably an economic benefit to Wales of siting new economic activity at Wylfa.  However, it would be no greater, if not less, that siting a nuclear station in a more optimal location.
  2. Economic impact for Anglesey would be no greater than the economic impact from developing offshore wind in the Irish Sea, an activity that cannot be located elsewhere and is already assessed as being essential for net zero and energy security.

Welsh Affairs Committee – Nuclear Energy in Wales Annex

Wales only needs offshore wind to power net zero

  1. Electricity consumption in Wales in 2018 was 14.9 TWh of which 7.4 TWh came from renewable sources (50%)
  2. National Grid Electricity System Operator (ESO) estimate that to achieve net zero by 2050, electricity consumption will increase by 2.3 - 3.0 times, mainly depending on the route taken to decarbonise the majority of building heating and industry (electricity or hydrogen), and the source of hydrogen (electrolysis of water or steam reforming of methane/natural gas with carbon capture)
  3. Sources of power include onshore wind, offshore wind, solar, nuclear, biomass, gas with carbon capture, hydro and other smaller sources
  4. This will mean Wales needs to generate from 34.3 - 44.7 TWh of power, of which 26.9 - 37.3 TWh will need to be new, carbon free, generation
  5. The amount of GB offshore wind capacity will be just over 80 GW installed capacity to almost 120 GW, with an estimated capacity factor of 50%. Of this, at least 15.4 GW will be in North Wales/Irish Sea (over 18% of entire GB capacity)
  6. Given the area of the Welsh part of the Irish Sea currently undeveloped, it is reasonable to assume that at least 6 GW capacity (possibly more) can be installed. This would generate roughly 26 TWh, almost enough to get the whole of Wales to net zero. Currently there is one wind farm licensed in this region of 1.5 GW (the BP/EnBW Mona development) which should be operational by 2028 and existing small wind farms of no more than 1 GW in total
  7. In order to reach the higher estimate of generation to achieve net zero a further 12 TWh of power are required. If this were to be supplied by additional offshore wind this would require a further 2.7 GW installed capacity
  8. The Crown Estate has already announced plans for an initial development of floating offshore wind in the Celtic Sea of 4 GW, with leasing scheduled for 2023. There is significantly more potential above this. While the Celtic Sea is shared between Ireland, Wales and England, much of the potential in the U.K. Celtic Sea are in the Welsh part. Achieving an additional 2.7 GW capacity in the Welsh Celtic Sea should be entirely feasible
  9. The recent leasing round by Crown Estate Scotland has granted 25 GW of leases, of which 14 GW are floating wind, indicating the industry is showing significant confidence in the technology
  10. Based on this, Wales only needs offshore wind to power net zero (obviously much action is required to decarbonise heating and transport to create the demand). All necessary generation can be achieved using the ample resources at sea. Other technologies such as tidal lagoons, tidal flow, solar and biomass can all be utilised as well. Balancing and storage will be required, and these services can be either at local/distribution level or in the GB transmission system as a whole
  11. Sources of data


August 2022