[en] In order to examine a high power non-transferred type arc plasma torch used for vitrification of low and intermediate level radioactive waste (LILW) vitrification, numerical simulation and experiments verification were carried out. Temperature field was obtained based on simulation of a 3D model of the plasma torch. According to the simulation results, the highest temperature of the plasma, up to 4 1.77 10 × K, was in the channel of the first anode. The calculated values of the arc voltage were higher than the experimental ones, and the difference decreased with the increase of arc current. Tests with simulated waste established that the distance from the nozzle of the plasma torch to the waste was suitable for vitrification process. The results show the 3D numerical modelling provides valuable engineering information for plasma melter design. And the simulation results can be used as the input data for understanding and describing the temperature and velocity fields as well as the physic-chemical process in the plasma melter. (authors)