> Making hydrogen from water and solar light is certainly better than using nuclear energy for that.

Using heat is the most efficient and if you use nuclear heat directly, and you don't have to go to the step of converting to electricity, you get huge efficiency.

> There is no reason for consuming valuable nuclear fuel

Nuclear fuel is not valuable once you have a closed cycle. Fuel cost are already only a few % of total nuclear cost and in a closed cycle would be almost nothing. As soon as you breed fuel from fertile material the cost is basically 0.

> The efficiency of converting solar energy into hydrogen is already acceptable.

It requires a very large plant to do in many small batches and cost 20x what hydrogen costs from natural gas. Its not efficient and will not be for the next 20+ years at least.