Thanks for that, but the Plexus page was my original reference. When I discovered the citation of 818 pCi/g elsewhere doing other research, it quickly became a conundrum. My frustration was at its height when I posted here.
With no reference, the only 2 official sources I could find are ANL and NRC (National Research Council), both having published very different numbers. Hence my request also for source(s) I may not be privy to or unsuccessfully-sourced despite all my time on this very stupid problem...that just so happens to have a corresponding impact that’s not so stupid...