FIELD: NPPs. SUBSTANCE: invention relates to a device for freezing liquid sodium in NPP pipelines. The device contains a housing with a thermal screen, inlet and outlet pipes, a nitrogen tank, control valves, an evaporator and a heater. The heat shield is located between the device and the pipeline. Moreover, gaseous nitrogen is used to remove heat, which intensively freezes sodium. EFFECT: increasing the safety of the device for freezing liquid sodium in NPP pipelines in case of its depressurization. 1 cl, 1 dwg.