Small modular reactor

Small modular reactor
U.S. Government Accountability Office from Washington, DC, United States · Public domain · source
Name	Small modular reactor
Type	Nuclear reactor
Fuel	Uranium, Thorium, MOX
Moderators	Light water, Heavy water, Graphite, None
Coolant	Water, Molten salt, Gas, Liquid metal
Output	~1–300 MWe per module
Status	Operational, Development, Proposed

Contents

Small modular reactor Small modular reactors are compact nuclear fission power plants built from modular units intended for clustered deployment, offering alternatives to large-scale reactors for electricity, process heat, and desalination. Proponents cite potential synergies with International Atomic Energy Agency, Nuclear Energy Agency, World Nuclear Association, Electric Power Research Institute, and national agencies such as U.S. Department of Energy, UK Department for Business, Energy and Industrial Strategy, Canadian Nuclear Safety Commission, and Rosatom. Critics reference experiences from Three Mile Island accident, Chernobyl disaster, and Fukushima Daiichi nuclear disaster to evaluate risk trade-offs.

Overview

Small modular reactors (SMRs) are characterized by factory fabrication, incremental capacity addition, and standardized designs intended to reduce construction schedules and cost overruns seen in projects like Olkiluoto Nuclear Power Plant and Flamanville Nuclear Power Plant. SMR concepts overlap with microreactors championed by entities such as DARPA, X-energy, NuScale Power, Rolls-Royce (company), TerraPower, and BWXT. Deployment discussions engage stakeholders including International Energy Agency, Intergovernmental Panel on Climate Change, World Health Organization, United Nations Framework Convention on Climate Change, and finance institutions like European Investment Bank and Asian Development Bank.

Design variants include light-water reactors influenced by prototypes from Westinghouse Electric Company, pressurized and boiling water types reflecting heritage from Beznau Nuclear Power Plant and Hagley-Ferrying development lines, high-temperature gas-cooled reactors derived from HTR-10 and Pebble Bed Modular Reactor concepts, molten salt reactors tracing ideas from Oak Ridge National Laboratory and the Molten-Salt Reactor Experiment, and liquid-metal cooled fast reactors with lineage to BN-800 and Superphénix. Fuel cycles consider enriched uranium, mixed oxide fuel developed by Comurhex, and thorium cycles investigated by Indian Atomic Energy Commission and Thorium Energy Alliance. Key technology suppliers and research partners include Argonne National Laboratory, Oak Ridge National Laboratory, Idaho National Laboratory, Culham Centre for Fusion Energy, Karlsruhe Institute of Technology, China National Nuclear Corporation, Korea Atomic Energy Research Institute, and Mitsubishi Heavy Industries.

Safety features leverage passive decay heat removal similar to systems evaluated after Three Mile Island accident reforms and incorporate containment strategies building on lessons from Chernobyl disaster and Fukushima Daiichi nuclear disaster. Regulatory pathways involve bodies such as U.S. Nuclear Regulatory Commission, Office for Nuclear Regulation (UK), Nuclear Regulation Authority (Japan), Federal Service for Environmental, Technological and Nuclear Supervision (Rostechnadzor), and regional networks like European Nuclear Safety Regulators Group. Licensing frameworks draw on precedents from Nuclear Non-Proliferation Treaty, Convention on Nuclear Safety, and bilateral agreements between nations like United States–Russia HEU Agreement. Emergency preparedness references standards from International Civil Defence Organisation and coordination with agencies such as Federal Emergency Management Agency.

Economic analyses compare SMRs to conventional plants influenced by cost histories from Vogtle Electric Generating Plant, Hinkley Point C, and financing structures used by Export–Import Bank of the United States and Euler Hermes. Factors include learning curves exemplified in manufacturing sectors like Boeing and Siemens, supply chain maturity involving firms such as Cummins, Hitachi, Fluor Corporation, and workforce development tied to universities such as Massachusetts Institute of Technology, Imperial College London, Tsinghua University, and Ecole Polytechnique. Deployment scenarios appear in national strategies from Canada, United Kingdom, China, Russia, United States, India, Argentina, and regional grids including European Network of Transmission System Operators for Electricity.

Environmental assessments reference lifecycle studies by Intergovernmental Panel on Climate Change and case studies near sites like Sellafield and Hanford Site for waste management lessons. Radioactive waste pathways consider interim storage strategies used at Yucca Mountain debates and reprocessing routes pursued by La Hague and Mayak. Proliferation concerns involve safeguards from International Atomic Energy Agency inspections, safeguards technologies developed by Sandia National Laboratories, and treaty frameworks such as Nuclear Non-Proliferation Treaty and Comprehensive Nuclear-Test-Ban Treaty Organization monitoring. Decommissioning precedents include projects at Greifswald Nuclear Power Plant and Shoreham Nuclear Power Plant.

Conceptual roots trace to early civilian programs at Argonne National Laboratory, experimental reactors at Oak Ridge National Laboratory, and modular notions advanced by companies like Westinghouse Electric Company and research bodies such as Electric Power Research Institute. National programs accelerated after policy shifts following Kyoto Protocol discussions and subsequent climate policy debates at COP21. Notable milestones include milestones by NuScale Power receiving regulatory milestones from U.S. Nuclear Regulatory Commission, pilot projects by China National Nuclear Corporation at Shidao Bay, and consortium efforts led by Rolls-Royce (company) and EDF.

Active and proposed projects span multinational collaborations: NuScale Power in the United States, China National Nuclear Corporation and State Nuclear Power Technology Corporation in China, Rosatom exports to countries such as Turkey and Bangladesh with interest in SMR formats, Rolls-Royce (company) consortium in the United Kingdom, and partnerships between TerraPower and Korea Electric Power Corporation. Future trajectories depend on policy signals from European Commission, investment by development banks like Asian Infrastructure Investment Bank, research outcomes from institutions such as Lawrence Livermore National Laboratory and Paul Scherrer Institute, and public acceptance shaped by events reviewed by International Atomic Energy Agency missions. International regulatory harmonization efforts involve Multinational Design Evaluation Programme and dialogues among G7 and G20 members.