A simple and innovative small light water reactor built on decades of proven BWR technology and operating experience.
As the world advances toward carbon neutrality, demand for reliable, affordable, carbon-free power continues to grow. The BWRX-300 being developed jointly by Hitachi GE Vernova Nuclear Energy and its U.S.-based sister company, GE Vernova Hitachi Nuclear Energy, is a small light water reactor that combines enhanced economic performance and high-level safety. Through innovative technologies and a simplified design, the BWRX-300 delivers enhanced safety and low-cost operation in a smarter and simpler way. Its name, BWRX-300, reflects its heritage as the tenth generation evolution of the boiling water reactor (BWR) technology, as it includes X, the Roman numeral for ten and 300, which is its approximate electrical output in megawatts. Drawing on proven technologies and expertise developed over many years, the BWRX-300 is designed to be a next-generation reactor offering enhanced simplicity, safety, reliability and economic performance.
Construction of the first BWRX-300 unit is underway in Darlington, Ontario in Canada, and a total of four units are planned. Deployment planning is also progressing in Saskatchewan, Canada, and the construction permit application process is moving forward for the Clinch River site in the United States. Efforts to deploy BWRX-300 reactors across North America are moving forward from planning toward implementation.
The small BWRX-300 light water reactor is designed to deliver enhanced safety and economic performance, be efficient, have a predictable construction process and facilitate operational flexibility through its innovative safety systems and simplified design.
Designed to mitigate Loss-of-Coolant Accidents (LOCAs)
Provides up to seven days of cooling without AC power or operator action
Innovative safety systems make it possible to simplify the reactor’s systems.
Use of proven modular construction technology
Operational flexibility
Siting flexibility
EPZ (Emergency Planning Zone)
Preparations and planning for the construction and deployment of BWRX-300 reactors are progressing across North America and Europe, accelerating the development of projects around the world. Leveraging its proven BWR technologies and experience, Hitachi is working to support the deployment of BWRX-300 reactors.
Selected by SaskPower in 2022 to be the first small modular reactor (SMR) in Saskatchewan.
Ontario Power Generation (OPG) selected the BWRX-300 as the first SMR project in Canada. Four units are planned, and work is underway to begin the commercial operation of the first reactor by the end of 2030.
The Tennessee Valley Authority (TVA) is considering the deployment of a reactor near Oak Ridge, and it submitted a construction permit application in 2025.
In July 2026, Synthos Green Energy (SGE), a Poland-based SMR development and investment company, announced plans to deploy 14 BWRX-300 units at three sites in the United Kingdom. Commercial operation of the first unit is targeted to begin in 2034.
Through a partnership with ORLEN Synthos Green Energy (OSGE), plans to build 26 reactors at six sites are advancing. Poland’s Ministry of Climate and Environment published decisions-in-principle (DIPs) for the plans in 2023.
Fermi Energia, an Estonia-based company founded by nuclear industry professionals, selected the BWRX-300 small modular reactor from GE Vernova Hitachi Nuclear Energy. The companies have worked together since 2019 and they signed a comprehensive cooperation agreement in 2021 covering licensing support, supply chain development and other activities.
GE Vernova Hitachi Nuclear Energy, TVA (U.S.), OPG (Canada) and SGE (Poland) are jointly investing in the development of the BWRX-300 standard design. This agreement was signed in Washington, D.C. in 2023.
In line with the U.S.-Japan strategic investment framework, Hitachi signed a Memorandum of Understanding with the U.S. Department of Commerce in 2025. The agreement supports efforts to strengthen U.S. electrical infrastructure, including cooperation on SMRs.
In March 2026, Hitachi, Ltd. and GE Vernova signed a Memorandum of Understanding to jointly explore opportunities to deploy BWRX-300 reactors in Southeast Asia. The companies are also considering enhanced collaboration with Japan's nuclear supply chain as they explore deployment throughout Asia.
SGE, GE Vernova, Hitachi and Samsung C&T have signed a Memorandum of Understanding establishing a framework for cooperation on market development and commercial opportunities for the deployment of the BWRX-300 in Central and Eastern Europe and the United Kingdom.
Download the BWRX-300 Fact Sheet (PDF, 0.89 MB) from the link below.
