From my reading, it seems that the USA’s reluctance to pursue the Thorium cycle had more to do with their economic confidence in their heavily researched Uranium cycle than anything else.
It’s all very well explained in this wiki article:
https://en.m.wikipedia.org/wiki/Thor..._nuclear_power
To keep on thread though, hydrogen in this respect is not a power source, it is a storage medium.
Fossil fuels, such as Jet A1, are a power source, because they are not generated, they are sucked up from the Earth’s crust, refined, and then oxidised to produce power.
Nuclear powered hydrogen electrolysis is of course different. The nuclear reactor is the power source, the hydrogen is merely the storage medium.
A very difficult storage medium, mind you, requiring either extreme pressure or extremely low temperature to store.
Other techniques have been proposed to carry the hydrogen “energy”. The hydrogen can be combined with carbon to make methane. Or carbon and oxygen to create methanol. Possibly the most promising suggestion is to combine it with nitrogen to create ammonia.
The ammonia solution seems favourable for deep sea shipping.
But the minute you combine the hydrogen with anything else like carbon, oxygen or nitrogen, you’ve immediately lost the energy-weight advantage of hydrogen! So you might as well use some form of bio-fuel.
I don’t think anyone, including Airbus, has come up with anything anywhere near viable for carrying hydrogen as a source of power on an aircraft.
To store raw hydrogen at room temp, you would need around 3000 psi. That is the pressure of aircraft hydraulic systems. Try to upscale that to tens of thousands of litres and apply safety measures.
The other option is cryogenic storage near zero Kelvin. Try to put that on an aircraft with safety measures.
The pub test says no.