Structure steel material suitable for fusion reactor

A structural steel material is suitable to fusion reactor, it is a martensite steel with low activation and is composed of element Fe, and it also contains the alloys Cr, W, V, Ta, Mn and C. It is suitable to use in the fusion reactor which has the resistance against the irradiation. The recipe of this steel replaces the elements Mo, Nb and Ni which are contained in the normal steels with W, Ta, V and Mn, so it assures the characteristic of low activation. Through optimization of the ingredients, the main nature of the steel increases. At the same time we strictly control the lever of long nuclear lifetime radioactive impurity which is created by irradiation with neutron. The half-life of the radioactive species which activated by irradiation with neutron is short, and the lever can be decreased to lower than the operational lever 10mSv/h in 100 years.