Residual power is of concern for the safety of all kinds of nuclear reactors and the environmental consequences of an accident caused by it. In the case of the NET (Next European Torus) fusion reactor, residual power is due to decay heat of activated structural materials. Preliminary temperature transients after plasma shut-down have been assessed assuming one year of nominal running and 100% of load factor.Loss of flow accidents (LOFA) were studied and the results show that no major hazard will arise from a LOFA on a single circuit, while reactor melting could happen in the case of a LOFA in the whole reactor. Additional calculations show that one of the main cooling circuits remaining operational could be enough to avoid major hazards, so that thermohydraulic analysis is underway to arrange the circuit of the inboard first walls for natural cooling so as to guarantee that the reactor is inherently safe.