Small modular reactors with outputs in the double- to triple-digit megawatt range increasingly are being eyed as a way to drive down the costs, speed deployment and give a boost to nuclear as an energy source going forward.

About a half-dozen companies are trying to commercialize early-stage ideals and models spawned primarily in academic and government labs. These efforts are being driven by U.S. Department of Energy funding, which recently has backed two of these efforts. For this work to support the development of one or two U.S. light-water reactor designs, the department allocated about $452 million to be spent over five years.

Although small reactors have been used for decades to power nuclear submarines and to produce neutrons for medical and research activities, the envisioned modern small reactors for power generation are different altogether.

The concept is simple. Develop modular reactors with a standardized, approved and certified design. And then make deployment of these reactors less expensive by reducing siting costs and by reaping economies of scale via mass production.

Basic research into such small reactors has been going on for years at DOE-funded labs. Work has now progressed from the lab to address the practical matters to get the units into operation. This is reflected in DOE's funding of the field over the last several years.

Last December, the DOE announced an award to NuScale Power to support a new project to design, certify and help commercialize innovative small modular reactors in the United States. When the award was announced, Energy Secretary Ernest Moniz noted the importance of the work in this field, saying, "Small modular reactors represent a new generation of safe, reliable, low-carbon nuclear energy technology and provide a strong opportunity for America to lead this emerging global industry."

The NuScale Power Module reactor is a small, scalable, pressurized water reactor that uses natural forces to operate and cool the plant. Each NuScale Power Module has a 160-megawatt thermal output and can generate 45 megawatts of electrical power.

Through a five-year cost-share agreement, the DOE will invest up to half of the total project cost, with the project's industry partners matching this investment. The funding for this work comes from the department's Small Modular Reactor Licensing Technical Support program.

The ultimate aim of this funded work is to help NuScale obtain Nuclear Regulatory Commission design certification and licensing, and achieve commercial operation around 2025. The DOE's cooperative agreements require that the reactors be built domestically.

Previously, in November 2012, the department awarded support to a project led by Babcock & Wilcox in partnership with the Tennessee Valley Authority and Bechtel.  This five-year cost share agreement was a first-of-a-kind engineering, design certification and licensing for small modular reactors in the United States.  The award was given to develop the company's small modular reactor system, which is a scalable, modular, advanced light-water reactor in which the nuclear core and steam generators are contained in a single vessel.  The Babcock & Wilcox Generation III++ small modular reactor mPower system is designed to generate 180 megawatts of electricity.

These funding choices have directly or indirectly caused some changes in the market. In February, Westinghouse opted to scale back work on its 225-megawatt small modular reactor, saying it was reassessing its design certification application schedule. Also in February, TerraPower, a company backed by Bill Gates and others to develop a scalable, sustainable, emission-free and cost-competitive energy source, entered into an agreement with Babcock & Wilcox. That work will support the joint development of TerraPower's Generation IV traveling wave reactor.

Outside the United States, work in this arena is accelerating. In China, Chinergy has started work on a demonstration high-temperature pebble bed modular nuclear reactor project. The system will be a gas-cooled reactor with twin reactor modules of 100 megawatts, each driving a single 200-megawatt steam turbine. The goal is to start generating commercial electricity by the end of 2017.

In Europe, Urenco, a company that enriches uranium for use in nuclear power plants, has proposed the development of 5-to-10-megawatt, plug-and-play, inherently safe reactors. It is seeking government support for a prototype uranium-fueled battery that would run for five to 10 years before requiring refueling or servicing.

In addition to these efforts, there are other small modular reactor projects in various stages of development in Russia, Canada and India.

In other parts of the world, such as throughout Africa, organizations are considering small modular reactors as a way to generate electricity. Such reactors are seen as a way to meet exploding electricity demands in regions that have until now been without generation or distribution capacity. The small modular reactors would be able to meet localized power requirements.

Clearly, there is no one design or technology that is a clear favorite to be successful. The promising designs in development through all of these efforts will need to address engineering, costs and licensing challenges before small modular reactors can go into commercial production.


Published In: EnergyBiz Magazine May/June 2014