Targets of ThC_x and UC_x have been used for production of Fr, Ra(Ac) nuclides of astrophysical interest at the IRIS mass separator on line with the 1 GeV proton synchrocyclotron at LNPI. A fine-grained powder of a target has been prepared using a special technology based on high temperature destruction of the thermostable organometallic compounds of U, Th or Cm (diphtalocyanine). New neutron-rich nuclides have been identified: ²³²Fr (5 ± 1 s), ²³³Ra (30 ± 5 s), ²³⁴Ra (30 ± 10 s). The yields of some nuclides from a CmC_x target have been also determined.