31 May 2024

The hype surrounding SMRs is way overblown

By Jan van Evert, editor Nuclear Monitor

Small Modular Reactors or SMRs are increasingly popular for a couple of years. Some politicians see them as an alternative for the current reactors that can be build quicker,  simpler, and cheaper. This month, the Polish ministry of Climate and Environment approved a plan for a Rolls-Royce SMR of 470 MW.

SMRs are nuclear reactors that are ‘small’ (defined as 300 megawatts of electrical power or less), can be largely assembled in a centralized facility, and would be installed in a modular fashion at power generation sites. The only SMR currently under construction is in China. In the United States, only one company has applied to the Nuclear Regulatory Commission (NRC) for a permit to build a reactor of 345 megawatts. This example and the one in Poland show that in practice SMRs are not always small. The reactor in the Polish plan is of the same size as for instance the Borssele nuclear power plant in The Netherlands.

There are however, several problems surrounding SMRs that make them a lot less attractive than they seem. First of all, small reactors are less economical than large ones. In other words, they produce more expensive electricity than larger nuclear power plants. SMR developers try to reduce capital cost by reducing or eliminating many of the safety features required for operating reactors. But these changes so far haven’t had much of an impact on the total cost. On top of that, SMRs still have a long way to go to compete with wind and solar power.

Secondly, Small Modular Reactors can’t solve the radioactive waste problem. The industry makes highly misleading claims that certain SMRs will reduce the problem of radioactive waste management by generating less waste, or even by “recycling” their own wastes.

In reality, small reactors will produce just as much nuclear waste as large reactors per unit of heat generated.

Thirdly, SMRs do not use fuel more efficiently than large reactors. The amount of uranium fuel that must undergo nuclear fission to produce a certain amount of heat, is the same whether a reactor is large or small. Although reactors that use coolants other than water  operate at higher temperatures, which can increase the efficiency of energy conversion, this is not a big enough effect to outweigh other factors that decrease fuel efficiency.

Finally, any nuclear reactor needs several permits such as a construction permit, an environmental license etc. This administrative process usually takes several years and constitutes a large part of the total time needed to build a nuclear power plant. Building smaller units won’t gain any time.

Read the full article here.