[en] The influence of fast neutron irradiation at 600 K on some of the properties of Zr₃Al-based alloys is summarized. The Zr₃Al intermetallic grows under the influence of fast neutron irradiation. The growth exceeds 0.6 percent after a fluence of 2.3 x 10²⁵n.m.^-2, appears to increase linearly with fluence and shows no sign of saturation. The irradiation growth is recoverable by annealing at 773-973 K. Neutron irradiation influences the mechanical properties. In the 0 to 10²⁵ n.m^-2 fluence range there is a significant yield stress increase, a smaller increase in the ultimate tensile strngth and a reduction in the plastic elongation. At fluences above 10²⁵n.m^-2 there is a complete loss of ductility. The plane strain fracture toughness decreases to as low as 0.44 MPa.msup(1/2) at a fluence of 2.3 n.m^-2