SMR-300
The SMR-300 stands at the forefront of modern energy innovation, embodying safety, security, and sustainability.
Holtec Britain’s SMR-300 will produce a steady source of low carbon electricity, safely bringing 320 MWe (net plant output) of green power to UK homes and businesses over the next 80 years.
The SMR-300 has been engineered using proven Pressurised Water Reactor (PWR) technology, using fuel similar to that already used at Sizewell B, and other new UK reactors under development including Hinkley Point C.
We have drawn upon decades of proven PWR operating experience and Holtec’s manufacturing pedigree, as well as existing UK nuclear presence at Sizewell B. We have the ability to manufacture large reactor components in our own facilities which gives us quality control and value for money.
The result? A sustainable and reliable contribution to UK energy independence for generations to come.
Site Layout
The SMR-300 is a compact plant arrangement, with two 300 MWe reactors combined into a single power station. The design ensures that site boundaries such as the Exclusion Area Boundary (EAB), Low-Population Zone (LPZ), and Emergency Planning Zone (EPZ) can be as close to the site boundary as possible.
The site layout is designed to ensure that nuclear assets, including the reactor core, are protected and unauthorised access is prevented.
How does a Holtec SMR-300 work?
SMR-300 is a safe and secure two-loop Pressurised Water Reactor (PWR), that provides a steady source of clean energy from the fission heat from low-enriched uranium fuel.
Nuclear fission occurs when atoms are split apart, which releases energy and heats pressurised water which is carried through the coolant loops to the steam generator. Once inside the steam generator, the heat boils the water in a secondary loop, creating steam. This steam is then used to run the turbine, powering the generator.
The steam then enters the condenser, where it undergoes condensation and transforms back into water. This resulting water is then pumped out of the condenser and returns to the steam generator to be heated again.
The use of reactor coolant, or primary system booster pumps during normal operation is necessary to produce the 300MWe of power from each reactor for homes and industry. Importantly, the design employs gravity driven safety systems to ensure crucial safety functions for maintaining cooled and contained nuclear fuel are assured, noting those safety systems do not rely on pumps, external water, external power, or operator action. The plant design provides multiple and diverse pathways to reject heat from the core. The annular reservoir, a large body of water situated outside the primary containment, serves as an ultimate heat sink.
Spent fuel from the SMR-300 will be safely dry stored in our HI-STORM UMAX system, held in an underground vertical ventilated module. This proven system was designed by Holtec and is already in use at multiple reactor sites.
It has been licensed by the nuclear regulators in the United States for up to 100 years, with an expected long-term storage period possible of over 300 years, as supported by industry studies. A similar Holtec system has been licensed by the ONR in the UK for the safe storage of spent fuel for up to 100 years.
The materials and construction of the SMR-300 ensure a long service life by reducing life-limiting factors such as types of cracking and erosion. The plant is designed and engineered to reduce maintenance costs and provide ease of onsite inspections.
Supply Chain Partners
Hyundai E&C is a leading South Korean EPC construction company, boasts a rich portfolio including over twenty nuclear plants combined in Korea and in UAE, and is responsible for performing the SMR-300 BOP design and overall installation and testing of the SMR-300 plant in the United Kingdom. The cooperation leverages Hyundai E&C’s expertise in design, procurement, and construction management capabilities for major projects. Hyundai E&C, located in Seoul, South Korea, was established in 1947 and is a part of Hyundai Motor Group. HDEC utilises the resources of the group as effectively as possible to provide added value to the stakeholders, partners, and environment.
Mitsubishi Electric Corporation (MELCO) is a leading electrical, instrumentation and control supplier. The Mitsubishi Electric Total Advanced Control (MELTAC®) Digital I&C distributed control and protection system has been fully integrated into the SMR-300 design. MELTAC® has been applied in over 900 applications at 24 nuclear power plants in Japan and 14 overseas nuclear power plants and has over 50 million hours of operating experience with zero plant trips due to software or hardware failures. Holtec has formed a collaborative agreement with MELCO, and signed a joint development agreement in 2016, under which MELCO have developed the digital I&C systems and the associated human-system interface infrastructure.
Framatome masters the design, development and fabrication of safe, ever more high-performance, advanced fuels for all types of light water reactors. Framatome has research units, fuel manufacturing facilities, and a fully integrated supply chain spread throughout France, Germany and the US. Holtec has a contract with Framatome Inc. for the fuel qualification and licensing support. The SMR-300 fuel specification ensures that the fuel can be supplied from existing Framatome fuel fabrication facilities.
Mott MacDonald is a global engineering, management and development consultancy which undertakes nuclear projects for major clients in the United Kingdom and Europe, with expertise in the UK regulatory review process and UK codes and standards. Mott MacDonald is supporting Holtec Britain on the UK regulators Generic Design Assessment and will continue to support Holtec on future UK projects.