Small Modular Reactors (SMRs)

Extracted Attributes

• Type

  Nuclear Fission Reactor

• Benefits

  Reduced on-site construction time, improved containment efficiency, enhanced safety, lower staffing costs, lower initial capital investment, greater scalability, siting flexibility, carbon-free electricity, reduced installation costs

• Historical Origin

  Military purposes (submarines, ships)

• Common Reactor Type

  Pressurized Water Reactor (PWR)

• Construction Method

  Factory-built, shipped, and installed on-site

• Key Design Features

  Modular system for scalability, passive safety features, compact, simplified designs, lower core power, larger fractions of coolant

• Primary Applications

  Powering buildings, commercial operations, desalination, facility heating, data centers, industrial applications, remote areas

• Newer Reactor Designs

  Generation IV, thermal-neutron, fast-neutron, molten salt, gas-cooled

• Thermal Power Output Unit

  Megawatts thermal (MWt)

• Electrical Power Output Range

  5 MWe to 300 MWe per module

• Safety Record (US Naval Reactors)

  No disclosed incidents of radioactive material release

• Developer of First Full-Scale Prototype

  NuScale Power

• Inventor of First Commercially Viable SMR

  José N. Reyes Jr.

Timeline

• Small reactors were first designed mostly for military purposes to power submarines and ships with nuclear propulsion. (Source: Summary, Wikipedia)

  1950-XX-XX

• Researchers at Oregon State University (OSU), headed by José N. Reyes Jr., invented the first commercially viable SMR. (Source: Summary, Wikipedia)

  2007-XX-XX

• NuScale Power developed the first full-scale prototype of their SMR design, working with OSU. (Source: Summary, Wikipedia)

  2013-XX-XX

• NuScale Power received the first U.S. Nuclear Regulatory Commission approval for a commercial SMR in the United States. (Source: Summary, Wikipedia)

  2022-XX-XX

Small modular reactor

The small modular reactor (SMR) is a class of small nuclear fission reactor, designed to be built in a factory, shipped to operational sites for installation, and then used to power buildings or other commercial operations. The term SMR refers to the size, capacity and modular construction. Reactor type and the nuclear processes may vary. Of the many SMR designs, the pressurized water reactor (PWR) is the most common. However, recently proposed SMR designs include generation IV, thermal-neutron reactors, fast-neutron reactors, molten salt, and gas-cooled reactor models. Commercial SMRs have been designed to deliver an electrical power output as low as 5 MWe (electric) and up to 300 MWe per module. SMRs may also be designed purely for desalinization or facility heating rather than electricity. These SMRs are measured in megawatts thermal MWt. Many SMR designs rely on a modular system, allowing customers to simply add modules to achieve a desired electrical output. Small reactors were first designed mostly for military purposes in the 1950s to power submarines and ships with nuclear propulsion. The thermal output of the largest naval reactor as of 2025 is estimated at 700 MWt (the A1B reactor). No naval reactor meltdown or event resulting in the release of radioactive material has ever been disclosed in the United States, and in 2003 Admiral Frank Bowman testified that no such accident has ever occurred. There has been strong interest from technology corporations in using SMRs to power data centers. Modular reactors are expected to reduce on-site construction and increase containment efficiency. These reactors are also expected to enhance safety by using passive safety features that do not require human intervention, although this is not specific to SMRs but rather a characteristic of most modern reactor designs. SMRs are also claimed to have lower power plant staffing costs, as their operation is fairly simple, and are claimed to have the ability to bypass financial and safety barriers that inhibit the construction of conventional reactors. Researchers at Oregon State University (OSU), headed by José N. Reyes Jr., are credited with inventing the first commercially viable SMR in 2007. Working with OSU, NuScale Power developed the first full-scale prototype in 2013 and, in 2022, received the first Nuclear Regulatory Commission approval for a commercial SMR in the United States. OSU and the research team are the original patent holders of their design.

Web Search Results

• Advanced Small Modular Reactors - Idaho National Laboratory

  A small modular reactor (SMR) is a nuclear fission reactor that features factory-built-and-assembled modules in a variety of configurations and electricity outputs. About 1/10 to 1/4 the size of a traditional nuclear energy plant, SMRs feature compact, simplified designs with advanced safety features. Small modular reactors are envisioned to vary in size according to configuration. [...] Nuclear energy generates more than half of the nation’s carbon-free electricity. Advanced small modular reactors offer advantages such as relatively small size, reduced capital investment, ability to be sited in locations not possible for larger nuclear plants, and provisions for incremental power additions. SMRs also offer distinct safeguards, security and nonproliferation advantages. Specific benefits include: Configurability [...] Like any fission reactor, a small modular reactor uses energy from a controlled nuclear chain reaction to create steam that powers a turbine to produce electricity. Advanced SMR designs span a range of sizes and technology options. Some use light water as a coolant while others rely on coolants such as a gas, liquid metal or molten salt. Some SMRs would use fuel akin to what runs today’s nuclear reactors, while others would use new types of fuels.

• Small Nuclear Power Reactors - World Nuclear Association

  Small modular reactors (SMRs) are defined as nuclear reactors generally 300 MWe equivalent or less, designed with modular technology using module factory fabrication, pursuing economies of series production and short construction times. This definition, from the World Nuclear Association, is closely based on those from the IAEA and the US Nuclear Energy Institute. Some of the already-operating small reactors mentioned or tabulated below do not fit this definition, but most of those described do

• What are Small Modular Reactors (SMRs)? | IAEA

  Small modular reactors (SMRs) are advanced nuclear reactors that have a power capacity of up to 300 MW(e) per unit, which is about one-third of the generating capacity of traditional nuclear power reactors. SMRs, which can produce a large amount of low-carbon electricity, are: Learn more about nuclear fission and energy. ## Advantages of SMRs [...] Small modular reactors (SMRs) have a power capacity of up to 300 MW(e) per unit. Many SMRs, which can be factory-assembled and transported to a location for installation, are envisioned for markets such as industrial applications or remote areas with limited grid capacity. (Image: A. Vargas/IAEA) [...] Many of the benefits of SMRs are inherently linked to the nature of their design – small and modular. Given their smaller footprint, SMRs can be sited on locations not suitable for larger nuclear power plants. Prefabricated units of SMRs can be manufactured and then shipped and installed on site, making them more affordable to build than large power reactors, which are often custom designed for a particular location, sometimes leading to construction delays. SMRs offer savings in cost and

• Benefits of Small Modular Reactors (SMRs) - Department of Energy

  Small modular reactors offer a lower initial capital investment, greater scalability, and siting flexibility for locations unable to accommodate more traditional larger reactors. They also have the potential for enhanced safety and security compared to earlier designs. Deployment of advanced SMRs can help drive economic growth. [...] SMRs can reduce a nuclear plant owner’s capital investment due to the lower plant capital cost. Modular components and factory fabrication can reduce construction costs and duration. [...] The term “modular” in the context of SMRs refers to the ability to fabricate major components of the nuclear steam supply system in a factory environment and ship to the point of use. Even though current large nuclear power plants incorporate factory-fabricated components (or modules) into their designs, a substantial amount of field work is still required to assemble components into an operational power plant. SMRs are envisioned to require limited on-site preparation and substantially reduce

• Small Modular Reactors explained - Energy - European Commission

  SMRs are defined as small nuclear reactors with a maximum output of 300 Megawatt electric (MWe) and can produce 7.2 million kWh per day. By comparison, large-size nuclear power plants have an output of over 1,000 MWe and can produce 24 million kWh per day. SMRs can vary in size from around 20 megawatts electric (MWe) up to 300 MWe and can use a range of possible coolants including light water, liquid metal or molten salt, depending on the technology. [...] SMRs are harnessing the operating experience from traditional large reactors, as well as the use of small-scale reactors in nuclear submarines and other nuclear-powered vessels, such as icebreakers. SMRs have passive (inherent) safety systems, with a simpler design, a reactor core with lower core power and larger fractions of coolant. These altogether increase significantly the time allowed for operators to react in case of incidents or accidents. [...] As they aresmallerin size, power output and capacity,they need less space and less cooling water, but offer greater flexibilityfor site selection than large nuclear plants. They are modular and can be produced in series, which allows for production cost efficiency through economies of scale. As their systems and components can be factory-assembled,they can be transported as modulesor even whole units to a location, reducing installation costs.