Applicability of alleviated limits of non-metallic impurities in lithium for advanced fusion neutron source

•Alleviation of impurities levels in Li for IFMIF-type neutron source are suggested.•No fatal problems are found by applying the alleviation of impurities levels.•Level of Be-7 in Li under process can be diminished by the alleviation. The alleviated limits of impurities of nitrogen and hydrogen isotopes in lithium are suggested to be 400wppm and 550appm, respectively for early realization of Advanced Fusion Neutron Source planned in Japan. The applicability of the suggestion is discussed by comparing to that of IFMIF. As the results, not less than 4-year buffer for R&D of nitrogen trap are brought in, which is thought as one of bottle neck. Additionally, the application of this suggestion would diminish the beryllium (a radioactive isotope will generate in A-FNS process) concentration in processing lithium, as well. On the other hand, it is indicated that there would be no fatal problems by application of the present suggestion.