Mott MacDonald is to work with TerraPower on the Generic Design Assessment process for its Natrium advanced reactor. Natrium is a 345 MW sodium-cooled fast reactor with gigawatt-scale integrated molten salt energy storage, designed with safe and flexible power generation as its prime aims. Its GDA application was accepted by the UK’s Department for Energy Security and Net Zero (DESNZ) and the Office for Nuclear Regulation earlier this year and the company has started the Step 1 review process.
The objective of the GDA is to provide confidence that the proposed design is capable of being constructed, operated and decommissioned in accordance with the standards of safety, security and environmental protection required in the UK.
Mott MacDonald has worked with TerraPower providing guidance on the UK regulatory system and GDA process. The global management, engineering and development consultancy will now lead on the delivery of the core GDA documentation.
The Natrium technology is the first mover in the advanced reactor sector and is thought to be well positioned to support rapidly increasing energy demand. The patented molten salt-based energy storage system is sized to enable boosting of the system’s output to 500 MW of power when needed, as it is designed to keep base output steady, ensuring constant reliability, and can quickly ramp up when demand peaks. It is believed to be the only advanced reactor design with this feature.
The first Natrium plant is being developed through the US Department of Energy’s Advanced Reactor Demonstration Program (ARDP), a public-private partnership. That project is expected to be completed in 2030 and will then be the first utility-scale advanced nuclear power plant in the United States. TerraPower is commercialising the technology, which includes an agreement with Meta for up to eight Natrium plants in the United States by 2035.
