AbstractOne current concept in fusion blanket module design is to utilize water as the coolant and liquid lithium-lead as the breeding/neutron-multiplier material. Considering the possibility of certain off-normal events, it is possible that water leakage into the liquid metal may occur due to a tube rupture and provoke a pressure increase in the blanket module.For realistic simulation of such in-blanket events, the BLAnket Safety Test facility (BLAST) has been built. It simulates the transient event by injecting subcooled water under high pressure into a stagnant pool of liquid Li17Pb83. The reaction kinetics data required for the quantification of the chemical reaction have been measured in a separate facility. These results are more general since measurements have been performed with various LiPb-alloys.Among other results, the experiments indicate that an upper static pressure limit, which corresponds to the actual water injection pressure, was not exceeded. Current results are presented.