[en] The US Fusion Materials program recently adopted a requirement that structural alloys qualify for shallow land burial at end of life. In the absence of a directly applicable regulation, the activation limits currently being used are taken from a US Nuclear Regulatory Commission regulation, 10CFR61, developed to handle existing waste streams from the commercial nuclear industry. Activation calculations are characterized by many uncertainties, e.g., in nuclear data, in handling of multi-step reactions, in appropriate neutron flux-spectra, in component lifetimes, and in the viability of isotopic tailoring. These uncertainties, coupled with uncertain regulatory criteria, mean that calculated concentration limits should be viewed only as a qualitative guide in developing reduced activation materials