Small Modular Reactors

Josh Sharma
March 27, 2018

Submitted as coursework for PH241, Stanford University, Winter 2018


Fig. 1: An example of a small modular plant. [5,6] (Courtesy of the GAO)

With renewable energy becoming more popular and cheaper by the day, nuclear energy seems to be dying out, especially after the most recent disaster in Fukushima. But it is unknown whether small modular reactors be enough to jumpstart the nuclear energy field back to what it once was. First off, what defines a small modular reactor. A small modular reactor is a nuclear reactor that produces less than 300 megawatts. This is a fraction of what nuclear power plants we see today produce. A full sized plant can produce over a 1,000 megawatts. [1] Currently they are not any cheaper than our current nuclear options but they do come with several other benefits as well as the potential to become cheaper if usage increases.

Benefits of Small Modular Reactors

Small modular reactors come with many benefits that larger nuclear power plants dont have. The main one of course being their size. Their small size allows them to be more secure and potentially cheaper. Theyre so small that they can be made in a factory setting and them shipped to their intended location, and as they grow in popularity, with enough being made like this, the price of them will only decrease. [2] The decreased size comes with a lower initial cost which may end up being their biggest advantage. This may be their biggest advantage because the lower initial cost for one small modular reactor compared to a traditional plant, could be the difference between being built in the first place. [3] Communities that may not have been able to afford a full sized nuclear power plant may be able to afford a small modular reactor. Their smaller size allows them to be placed underground where they can take advantage of cooling techniques that can function without power or human assistance. For example, NuScale is planning to construct a plant in Idaho using small modular reactors, where the reactor cores will sit underground in a super seismic-resistant heat sink. [4] This means that the reactors can use natural processes in order to stay cool for indefinite periods.


Small nuclear reactors seem to be a viable option especially in the near future to help support the nuclear energy industry. Although the price per megawatt is not any lower than conventional plants, because of their smaller sizes, they are cheaper per reactor than larger ones, thus the funds to build them can be easier to obtain. [2] This being the biggest advantage in the short run, as well as all the other previously said benefits make small modular reactors more viable than traditional plants if nuclear power wants to stay relevant. They may be the hero that the nuclear energy industry needed, but I think that renewable energy will become too cheap and too accessible to ever make nuclear energy viable in the long run.

© Josh Sharma. 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.


[1] K. Stacey, "Small Modular Reactors Are Nuclear Energy's Future," Financial Times, 25 July 16.

[2] "Small Modular Reactors: A Window on Nuclear Energy," Andlinger Center, Princeton University, June 2015.

[3] J. Temple, "Small Reactors Could Kick-Start the Stalled Nuclear Sector," Technology Review, 17 July 17.

[4] J. Conca, "NuScale's Small Modular Nuclear Reactor Keeps Moving Forward," Forbes, 16 Mar 17.

[5] S. Harber, "Small Nuclear Reactors: Background, Potential Applications, and Challenges," Physics 241, Stanford University, Winter 2017.

[6] "Nuclear Reactors: Status and Challenges in Development of New Commercial Concepts," U.S. Government Accountability Office, GAO-15-652, July 2015.