The photofission process has been recently considered for the production of neutron rich isotopes and the development of radioactive beams. The radioprotection hazard should be studied accordingly. A survey of the radiative electron energy loss theory is reported in order to estimate numerically the bremsstrahlung production of thick targets. The resulted bremsstrahlung angular and energy theoretical distributions delivered from W and UCx thick converters are presented and compared with previous results. This study is focused on initial kinetic energies of the electron beam included in the range 30-60 MeV, suitable for the production of large photon yields able to induce the 238U fission. The source term for 50 MeV incident electrons is reported for radioprotection purposes.