Bill Gates and the fast sodium reactor

The network is increasingly reported that Bill Gates is actively advocating the idea of ​​developing nuclear energy to reduce greenhouse gas emissions and, as a result, to combat global warming.

According to the Washington Post , Microsoft’s co-founder spends a lot of time communicating with politicians to convince Congress to spend billions of dollars over the next decade on pilot projects to test new designs of nuclear power reactors. In addition, Gates promises to invest his own funds in the amount of $ 1 billion.

At the end of last year, in his pre-New Year address, he also noted the need for the development of nuclear energy, pointing out the absence of greenhouse gases in the operation of nuclear power units and safety with an adequate level of R & D.

Such activity in the information space is associated with problems arising from American sanctions. Because of them, the construction of TerraPower's reactors in China is now in question.

Gates TerraPower company defines itself as an incubator of ideas and technologies that can solve problems related to energy independence, environmental sustainability, and the development of medicine through the use of nuclear technologies.

At the moment, the company is developing projects for two nuclear power plants: fast sodium TWR and liquid-salt MCFR.



Principal view of MCFR and TWR reactors

Of the two samples presented, the company is still banking on TWR.

The fast sodium reactor TWR is a system with a standard layout for a sodium-cooled reactor, namely the primary coolant pipelines, where sodium cools the core of the second circuit, where the first circuit sodium gives off heat to the second circuit sodium, and the second circuit’s sodium The circuit heats the water to produce superheated steam.

There are TWR projects with an electrical capacity of 300 and 600 MW. For an installation with a capacity of 600 MW, the planned efficiency will be 41%. The sodium coolant temperature at the entrance to the core is 360, at the output is 510.

And yes, I do not specifically mention the "traveling wave", since only a name remains from this idea.


TWR conceptual diagram

The developers themselves note that this arrangement was used for all known realized sodium-cooled fast neutron reactors, including the experimental reactor (EBR-II) in the USA, in Phenix and SuperPhenix in France, BN-600, BN-800 in Russia , in the Chinese Experimental Fast Reactor (CEFR) in China.

The active zone (diameter - 4 m, height - 5.5 m) is recruited from 511 fuel assemblies of the hexagonal profile. The fuel will be metallic uranium with the addition of zirconium U-10% Zr, enclosed in shells of ferritic-martensitic stainless steel.

Several types of cassettes are used: ignition fuel assemblies (driver assembly), presumably with high enrichment characteristic of fast neutron reactors, fuel assemblies of the feed assembly with depleted uranium, and test assemblies.


Areva test build


It is assumed that as a result of the accumulation of fissile nuclides in the fuel fuel, there will be a shift of fuel fuel in the active zone instead of the previously burned ignition fuel assemblies using a reloading machine. Chain reaction management will occur using 15 mobile assemblies.


TWR core map and calculated linear energy release over cassettes

TerraPower cooperates with more than 50 scientific and industrial organizations and enterprises around the world. For example, test irradiations of the fuel cell cladding material were carried out at the research reactor BOR-60 (NIAR). In total, more than 1500 samples were used. Neutron doses amounted to about 155 sleep.

The developers note the high safety of the facility, the low amount of radioactive waste generated during operation.

The company offers this technology for solving global warming problems, providing energy to countries and areas with low electrification.

For an understanding of the possible problems associated with this type of reactor installations, the example is the Japanese NPP Monju - the power unit with a fast sodium reactor of which was launched in 1994. After the fire and leakage of sodium in 1995, the unit did not actually start up until 2010, when it was decided to decommission it.

This type of reactor is characterized by a large number of technical issues related to sodium problems as a coolant, the creation of unique equipment and materials capable of operating with large neutron fluxes, with more energy than thermal neutrons. Additionally for the TWR reactor there is a question of the possibility of using fuel assemblies to feed without prior processing.

Despite all the difficult issues, there is a development of these technologies. China and Russia at the moment, of course, lead in research on the subject of fast reactors. An annual conference is held under the auspices of the IAEA in Yekaterinburg, where the best experts on fast reactors gather.

However, in my subjective opinion, at the moment, fast neutron reactors are of weak commercial interest and are not well suited to combat climate change and electrification issues. But perhaps it is the company Gates will be the pioneer.