It seems to me that they do a drilling down to 2m; they then do a further drilling down to 4.7m and they can't find any radioactive material. If they go even deeper, they're not going to find any material that wasn't already detectable at 4.7m. It's just completely ridiculous that they're going to go down further, because it's only on the surface that you're most likely to find any material, and they couldn't find any.