It might be a good idea to add thorium and protactinium. Thorium could generate among uranium, be used as a source of energy, and a way to produce higher actinides. Protactinium would part of the process chain between thorium and uranium, and decay chain of higher actinides.

Why, though?

Why not?

Thorium could generate among uranium, be used as a source of energy, and a way to produce higher actinides. Protactinium would be part of the process chain between thorium and uranium, and decay chain of higher actinides.

Actinium, radium, and polonium are also part of the decay chain of actinides. They are highly radioactive and unstable. But it's also the case for berkelium and californium. So I suppose they might be used as a source of energy like others.

There is also the radon, the last noble gaz, which is also radioactive and unstable. It might be used like other noble gazes.

There is also the francium and astatine which are part of the decay chain, but they are so radioactive and unstable (few minutes for francium, few hours for astatine), that they be used for anything.

The decay chain ends with bismuth, lead, and thallium, which are stable.

This sounds like a great idea for a totally different mod, as is seems totally out of scope for this one.

It's not so out of scope since it's one of main aspect of this mod to produce of higher actinides for being used as bigger source of energy.

"This mod suffers from problem X. This could be resolved by adding something with effect Y. One such example would be to add Z, which would have effect Y to fix problem X."

I don't see this suggestion really fixing any problem with the mod. You're just proposing totally separate/new content, which makes it out of scope, even if it is on topic.

Thorium is already in. It is made by combining Promethium Ore and Hydrogen Gas in an isotope cloche.

Oh yeah you're right, although it has currently reduced use compared to other actinides. Anyway it could generate like uranium, since it's more stable and more common than uranium. Also it would be coherent to add protactinium as part of the process and decay chain between thorium and uranium. For the others (actinium, radium, radon, polonium), it's up to you to choose.

There is only the one uranium ore node on the Shattered Planet and no others.