Weekly, consecutive primary coolant samples from a boiling water reactor have been analyzed for239, 240Pu,238Pu+241Am,242Cm and244Cm for about two years, and for238Pu,241Pu and241Am for one year. Concentration ranges are reported. Samples were prepared for counting either directly by evaporation or by
chemical separation on BioRad AG 1×4 resin and subsequent electrolysis, and were counted in 20 cm dia Frish grid ionization
chambers. Procedures are described. For most actinide nuclides, activity ratios in primary coolant were found to be different
from those in worldwide fallout, thus allowing an identification of origin in the case, that actinides should be detected
in the vicinity of a nuclear power station.