Austenitic steel was the reference cladding material in sodium cooled fast neutron nuclear reactors. These alloys exhibit good high temperature mechanical properties and they can withstand very high irradiation doses. To further increase the performance of these alloys, two distinct ways of improvement are possible: oxides dispersion strengthening or ultra fine grain microstructure. In order to achieve the desired enhanced material, powder metallurgy and in particular mechanical alloying route is promising. However, the high ductility of austenitic steel significantly reduces the powder production yield and worsens the supersaturation of oxides during mechanical alloying. To overcome this issue, multiple batches were produced using high-energy horizontal attritor at times ranging from 5 to 40 hours and consolidated by Spark Plasma Sintering (SPS). This paper tackles the characterization of powders after mechanical alloying and SPS compacts.