Phytoremediation is used at a number of DOE sites but I have not heard about any use of hemp yet.
Cannabis Cleans Up Nuclear Radiation and Toxic Chemical Waste
http://realfarmacy.com/cannabis-nuclear-radiation/
mite bee gist an expensive weigh to remove n ship the contaminated four burial...
"All parts of hemp plants contain heavy metals and this is why their use as a commercially utilisable plant material is limited. "
https://www.sciencedirect.com/science/article/pii/S0926669002000055 (https://www.sciencedirect.com/science/article/pii/S0926669002000055)
This article can be considered part of the pro cannabis campaign. Many other species have been used successfully and have a lesser chance of contaminating humans in the final phases of each growth cycle.
http://www.resilience.org/stories/2014-08-11/using-plants-to-clean-contaminated-soil/ (http://www.resilience.org/stories/2014-08-11/using-plants-to-clean-contaminated-soil/)
http://magicalchildhood.com/life/2017/07/17/seven-plants-weeds-and-flowers-that-naturally-remove-lead-from-your-property/ (http://magicalchildhood.com/life/2017/07/17/seven-plants-weeds-and-flowers-that-naturally-remove-lead-from-your-property/)
A link for those interested in the hows and whys of remediation via plants planting.
https://www.sciencedirect.com/science/article/pii/S1878535213002712 (https://www.sciencedirect.com/science/article/pii/S1878535213002712)