Nuclear goes modular

Utilities Unbundled - Issue 15

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After major setbacks following the 2011 Fukushima disaster, the nuclear industry is making a comeback. Will the smaller, cheaper and safer design of small modular reactors (SMRs) win over critics?

Building standardized units in a factory that can be shipped to site fully assembled – including containment – reduces project construction risks.

As governments and utilities search for low-carbon generation, the benefits of SMRs look compelling:

  1. Cheaper: SMRs require less up-front capital than large-scale plants. The modular design allows units to be deployed incrementally, so cash generated from the electricity sales of the first operational units can offset the negative cash flows of subsequent unit construction.
  2. Less construction risk: Building standardized units in a factory that can be shipped to site fully assembled reduces project construction risks, a key consideration as delays and cost overruns have damaged the credibility of larger projects.
  3. Safe: Smaller means less fuel and fewer radiation hazards, and some designs can be placed below ground level, providing additional radiation shielding and security benefits.
  4. Clean and reliable: As more renewable energy is added to the grid, inherent problems with intermittency create real challenges for reliable dispatch. SMRs provide a reliable base load supply, free of carbon emissions.

Multiple designs but LWRs lead the pack

SMRs include a diverse range of technologies and reactor designs with unit capacities below 300 megawatt electric (MWe), including:

  • Light water reactors (LWRs)
  • Heavy water reactors (HWRs)
  • Breeder reactors
  • Gas-cooled or pebble-bed fast reactors

LWR designs are the most commercially promising in the near term, given their low technological risk. “Ninety percent of the design is well proven,” says Ian Hore-Lacy, Senior Research Analyst with the World Nuclear Association (WNA). “The main change is the integral reactors: on many, the steam generators actually sit inside the pressure vessel.”

NuScale, established in 2000, was one of the first companies to focus exclusively on SMR development. “In 2009, a lot of people still thought we were nuts,” says Mike McGough, Chief Commercial Officer for NuScale. “Now there are other suppliers, and we see a real market for smaller, safe, incrementally scalable nuclear power plants.”

Challenges in commercializing SMRs

In the US, the top challenges are:

  • Regulatory process
  • Financing
  • Supply chain
  • Public acceptance

“With a design certification application running to nearly 10,000 pages, and 39 months for the Nuclear Regulatory Commission to review a new design, regulatory uncertainty can be a key challenge,” says McGough. “We still have components that have to be built, including the turbine and a purpose-built factory to manufacture the power modules. These take time and investment.”

Although public acceptance remains a challenge, perceptions of nuclear energy are becoming more positive globally. Getting the message out regarding safety is central to NuScale’s approach.

“Our design is immune to a Fukushima-like station blackout, as in these circumstances our plant would safely shut itself down and cool itself off indefinitely with no operator action, no additional water other than what we have in the plant and, most importantly, no power,” says McGough.


This is an abridged version of the full article in Utilities Unbundled.

For more information on this topic, please contact Bradley Hartnett.