“…The paper deals with the 9% Cr F/M steel T91, which used to be one of the best candidates for LFR internal structures, owing to its very good strength, toughness, resistance to the radiation, and oxidation/dissolution in HLM. However, suitability of the T91 was questioned due to its indicated sensitivity to cracking in HLM, namely, LBE and Pb, based on data from laboratory testing (Nicaise et al, 2001;Auger et al, 2004;Van den Bosch et al, 2006;Di Gabriele et al, 2008;Long & Dai, 2008;Vogt et al, 2008;Coen et al, 2010;Auger et al, 2011;Gorse et al, 2011;Hojná & Di Gabriele, 2011;Gong et al, 2015;Hojná et al, 2015;Stergar et al, 2016;Di Gabriele et al, 2017). (Martín et al, 2004;Heinzel et al, 2014;Schroer et al, 2014b), 304L (Martín et al, 2004), 1.4970 (Heinzel et al, 2014)], F/M (T91, E911 (Aiello et al, 2004a;Schroer et al, 2014a;Tsisar et al, 2017;Yurechko et al, 2018)], and martensitic steels (F82H (Martín et al, 2004), 56T5 (Deloffre et al, 2002)) exposed to LBE as a function of temperature (A) and time (B).…”