|Fig. 1: Sample diagram of a light water small modular nuclear reactor.  (Courtesy of the GAO. Source: Wikimedia Commons)|
All around the world the push to decarbonize power supplies has led to significant challenges. The United Kingdom understands this better than anyone. The UKs government has already decided to phase out unabated coal firing plants.  This provides a significant increase in energy demand that will need to be filled by clean energy. When this is coupled with the fact that the UK will be closing many old, large nuclear power plants in the coming years, approximately half of the country's electricity capacity is expected to go offline by 2030.  This forces Britain to look for innovative ways to meet its energy demands. One idea that has gained significant traction and support is the development of small modular nuclear reactors (SMR) (see Fig. 1).  Sources say that the UK government is expected to provide up to 56 million pounds of funding for the research and development of SMR technology. 
The concept of a mini nuclear reactor is nothing new.  As other reports have stated, countries, such as France and Finland, have already explored the idea of large-scale SMR utilization.  However, in Britain they gained traction when they became commonplace in nuclear submarines in the 1950s.  SMRs can provide around 300 MWe, a significantly lower amount of power than a large reactor project.  The interest in SMRs is completely understandable. SMRs provide an abundance of advantages. They are small compared to large reactors, compact, and factory built.  This allows SMRs to be more mobile.  They can be moved for decommissioning and placed underground or in water.  Additionally, SMRs have the ability to be moved between high consumption locations, and they can tap into existing electricity transmission cables.  A final advantage is relative cost. A joint venture led by Rolls-Royce, a key producer of SMRs for the Royal Navy, has an estimated cost of £1.25 billion.  This estimate comes in significantly lower than other nuclear projects being constructed in the UK. For comparison, the British Hinkley Point Nuclear Plant is estimated to cost £19.6 billion. 
One of the biggest challenges to SMR implementation is the lack of research and development. At the end of 2017, the UK committed £100 million to the research of SMRs.  Despite this large amount of funding, there appears to still be doubt regarding the feasibility of SMRs. Government officials have repeatedly made it clear that developers will only get financial help if they can prove their SMR will be affordable and competitive with rival energy sources.  Energy experts say that more still needs to be learned about the implementation of SMRs.  Paul Dorfman, a research fellow at University College London, said: The real question the government must ask is this: given the ongoing steep reduction in all renewable energy costs, and since SMR research and development is still very much ongoing, by the time SMRs comes to market, can they ever be cost competitive with renewable energy?  The issue is most likely economies of scale.  SMRs have a lower cost per unit, but they have longer running costs than large nuclear plants.  To get a perspective of cost per unit of a large plant, another major nuclear project in the UK, the Hinkley Point power station, is expected to produce 3.2 billion watts of power.  When taking into account the projected cost of 19.6 billion pounds, the average cost is 6.12 pounds per watt of power. It is hard to imagine SMRs as being more expensive. In an ideal setting, the implementation of series of SMRs can be beneficial, but more research needs to be undertaken before a fully informed decision and large financial backing can be considered reasonable.
© Patrick Perrier. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 N. Chestney, "UK Government to Fund Research into Mini-Nuclear Plants," Independent, 7 Dec 17.
 M. Gibson, "Britain's on the Brink of a Small-Scale Nuclear Reactor Revolution," The Register, 24 May 17.
 S. Harber, "Small Nuclear Reactors: Background, Potential Applications, and Challenges," Physics 241, Stanford University, Winter 2016.
 A. Vaughan, "UK Government to Release Funding for Mini Nuclear Power Stations," The Guardian, 3 Dec 17.
 "Hinkley Point: EDF Adds £1.5bn to Nuclear Plant Cost," BBC News, 3 Jul 17.
 "Nuclear Reactors: Status and Challenges in Development and Deployment of New Commercial Concepts," U.S. General Accountability Office, GAO-15-652, July 2015.