I once used DU bricks for a shielding application, and the amount of 235 was given in ppm, and that was not a large number (150?). These may have been special, or the assay was wrong (which I doubt because the assay was important). It was something to work with blocks the size of Wonder Bread sandwiches that weighed ~25 pounds! They read out at 5 mREM/hour at contact with a standard 25 mm Geiger probe on a Ludlum, which in the ambient I was in, was quite low enough.
Thanks for the link, I have it and it’s useful.