01 Introduction

This episode is the seventh in an 8 part series on nuclear reactor technology. 

In this episode we will describe a topic which has been in the news in recent years, which is "small modular reactors", or SMRs for short.

03 What is an SMR?

Basic Definition

A small modular reactor is a nuclear reactor that is designed to be largely built in a factory and subject to as little on-site assembly as possible.

The main goal is to lower costs by reducing construction times and allowing a more rapid start of return on investment.

04 Sized Based Definition

Some people put a numerical size limit on SMRs, saying that they must be no larger than 300 MW to qualify as an SMR.

However this limit is not universally accepted, and not all SMR designs fall within this arbitrary limit.

I will ignore this numerical limit and just consider anything to be an SMR if it meets the criteria of being largely built in a factory with minimal on-site assembly.

05 The Actual Goal of the SMR Idea

The actual goal of the SMR idea is to build reactors rapidly and efficiently on more or less an assembly line basis rather than hand crafting each one.

One engineer in the nuclear industry has compared building reactors to building ships.

Traditional shipbuilding techniques involved assembling each ship from the keel up on the slipways from individual components.

06

Newer shipbuilding techniques assemble ships as separate "blocks" inside factory-like buildings and then join completed blocks together in a final assembly stage.

This requires careful planning and tight quality control, but it results in building ships much more rapidly and economically.

This engineer said that SMRs are attempting to bring this newer way of doing things to the nuclear reactor industry as well. 

07 SMR Categories - Small Versus Micro

08 Small SMRs

09 Small SMRs and Small Grids

10 Micro SMRs for Micro Loads

13 Micro SMRs for Large Industry

14 SMRs to Power Data Centres

15 What's This Nonsense About "Micro Small Modular Reactor" You Ask?

17 Small Reactors and Modular Reactors That Are Not SMRs

20 Standard Versus Proprietary Fuel

23 Where SMRs are Currently Being Built

24 HTR-PM in China

28 Repurposed Ship Reactors in Russia

31 300 MW BWR in Canada

33 470 MW PWR in UK

35 25 MW PWR in Argentina

37 Various Experimental SMRs

38 Modular Large Reactors

40 Conclusion

SMRs are a new trend in nuclear reactor design.

However, they are really two different things which fill two different needs.

One style is intended to adopt designs which allow for more rapid construction with more of the work being done in the factory and less on the construction site, with the overall goal of reducing costs.

The other style is to provide very small reactors to power remote communities and mines, or to provide process heat to large industries.

The first SMRs are in operation or under construction.

The most promising grid scale designs at present are simply scaled down and simplified conventional designs that use standard commercial fuel.

Larger reactors will incorporate modular construction techniques, blurring the lines between them and SMRs.

In the next episode we will talk about future reactor technologies, particularly what are referred to as "Generation IV" reactors.