Unfortunately I'm very dubious about this approach; hope I'm...

Unfortunately I'm very dubious about this approach; hope I'm wrong.
The process described involves long exposure to concentrated sulphuric acid: no small matter or cost. Applied to about a million ton of residue.
Then there's the question; if the Th from the WLP has been extracted and concentrated then you have (a smaller amount of) genuine radioactive residue. What's the gain?
Finally there's the suggestion the process will produce "a resource suitable for nuclear fuel". This suggests the author isn't across his brief as, currently Th isn't a nuclear fuel. (It might be down the line as new reactor tech is adopted but in any case there are much better Th resources.)
I really doubt Th removal from the WLP is viable or particularly useful.