In Wyoming, Bill Gates moves ahead with nuclear project aimed at revolutionizing power generation

[SarahD]

1. Sodium has a problem, reacts with water.

The US Navy tried a sodium cooled reactor, but pinhole leaks in the hear exchanger allowed sodium to come in contact with water and create tiny explosions. I'm not sure why they abandoned the concept. Modern chemistry control should be ae to overcome the difficulties. The big advantage is that the sodium coolant doesn't need to be highly pressurized. A water cooled reactor needs to be kept around two thousand pounds pressure, and that leads to problems, and loss of coolant pressure could cause catastrophic damage and meltdown, as we saw at Fukishima. Sodium would help avoid that, but I'm sure it presents its own problems.