Bill Gates’s Next-gen Nuclear Plant Packs in Grid-scale Energy Storage

Wind, solar, geothermal, hydro, wave power… Sustainable resources are an essential pillar of any strategy to decarbonize the planet’s power generation sectors and eradicate fossil fuel usage. However, for several factors – intermittency, location dependence, land needs, and others – they can not accomplish it independently.

A scalable form of zero-emissions energy that can reliably produce power all year round uninterrupted is needed to remove greenhouse gases from the world’s energy sectors thoroughly. It would be significantly better if it rapidly ramps its output up and down to help the power grid cope with load spikes and interruptions in renewable energy supplies. Currently, advanced nuclear power is the best candidate to fill this role.

Although nobody wants their backyard to be associated with disasters such as Chernobyl and Fukushima, nuclear is verifiably one of the safest forms of energy generation. Nuclear power has caused only 0.07 fatalities per terawatt of energy supplied, including the high-profile disasters that have led to its poor reputation, while coal and oil-derived energy cause 24.6 and 18.4.

With a projected death toll of a 2°C temperature rise – between 300 million and 3 billion premature deaths over one to two centuries – the fourth generation of nuclear power is being reconsidered. Given the many decades of development, advanced modeling, and materials technology on its side, its excellent safety is likely to improve.

The collaboration between Bill Gates’s Terrapower and GE Hitachi Nuclear Energy is a promising initiative backed by heavy private investment and the US Department of Energy. Thanks, in part, to a US$80 million DoE grant announced in October, Natrium (Latin for sodium) has the chance to demonstrate its “cost-competitive, sodium fast reactor with a molten salt energy storage system” at an adequate commercial scale.

By the mid to late 2020s, the Natrium’s demonstration plant will be completely operational and linked to the power grid in its future location. Instead of using water as its reactor coolant, the plant’s fast-neutron reactor will use high-temperature liquid sodium.

The wide 785-degree temperature range between its solid and gaseous states is one of sodium’s key advantages; water, offering only a 100-Kelvin range, needs to be pressurized to handle higher amounts of heat energy. The high levels of pressure immensely increase the cost of the plant, as nuclear-grade high-pressure components are not affordable and can have explosive consequences.

At normal atmospheric pressures, liquid sodium will transfer an impressive amount of heat away from the reactor. Additionally, it will not dissociate into hydrogen and oxygen, nullifying the risk of Fukushima-style hydrogen explosions. Being non-corrosive sidesteps the issue that puts a question mark over molten salt reactors.

The Natrium design, like many of the next-generation nuclear reactors under development, will use High-Assay, Low Enriched Uranium (HALEU) as its nuclear fuel. The U-235 isotope represents around 0.7 percent of the natural uranium coming out of the ground, which later splits to generate nuclear energy. Furthermore, using centrifugal processes or gas diffusion, the traditional Low Enriched Uranium (LEU) nuclear reactor fuel is enriched to contain 3-5 percent U-235, being further enriched, between 5 and 20 percent. Comparatively, nuclear weapons need uranium enriched to more than 90 percent.

By reprocessing fuel from traditional nuclear power plants, HALEU fuel can be produced. Its higher grade betters reactor performance and efficiency, allowing advanced reactors to be much smaller than LEU plants. According to Natrium, it should be four times more fuel-efficient than light water reactors. 

Regarding safety, the natural circulation of the air will function as emergency cooling. In the event of a power outage, the control rods will drop by themselves due to gravity. Unlike light water reactors, the plant does not need an extensive containment shield thanks to the liquid sodium design, and to boost the safety factor while cutting costs, the design places the reactor underground.

Outputting a constant 345 MWe in the form of heat, the Natrium plant is designed to run at 100 percent output, 24/7. The heat is conveyed through the liquid sodium cooling system and carried to a separate molten salt thermal energy storage system similar to what has been proven in many direct solar plants worlwide. On another end of this storage system, a set of steam turbines can use that constant power and generate enough electricity to supply approximately 225,000 homes.

The Natrium design has an extraordinary benefit; its storage system means the Natrium plant can respond to demand raises or intermittent renewable energy supply drops by harnessing that stored heat and increasing its turbines up to 150 percent of the nominal reactor power, sending out 500 MWe for around 5.5 or more hours.

That stands for virtually a gigawatt-hour of extra on-demand energy storage, significantly more than even the greatest grid-scale battery projects under development. This is a huge advantage, specifically in decarbonization, where load-reactive systems like this certainly play a crucial part in supporting renewable energy sources through the optimals and troughs in their less foreseeable generation cycles.

The DoE demo plant funding is undoubtedly superb information for Natrium, which currently can develop and prove its abilities prior to moving to roll comparable plants out at scale, which will be considerably bigger and much more efficient. It is likewise somewhat of a payback for Terrrapower, which was preparing to construct an experimental nuclear reactor outside Beijing to test and show its distinct Travelling Wave Generator technology when United States Government assents on technology deals with China compelled it to discard the project in 2019.

If everything turns out, the Natrium design promises to be quick to build and commission and to make use of much less nuclear-grade concrete than conventional designs – a significant factor in keeping the cost low and minimizing the “eco-friendly premium” on the emissions-free energy. Will designs like this help place some light back on nuclear power? Opportunities for these businesses will undoubtedly be tremendous as fossil fuels are reduced. Time will tell.

Originally published on Newatlas.com