An array of hyperpure germanium detectors has recently been employed at ORNL for the identification and quantification of internally deposited actinides. Its advantages over the phoswich detector-the current state-of the-art for detection of the actinides-were found to be improved background reduction and superior energy resolution. The germanium system and the currently operating phoswich system are discussed and compared. The improvement in performance of the germanium system over the phoswich system (a factor of 2.5 for 239Pu and 15.3 for 241Am) appears to justify the financial investment, particularly when 241Am is used as an indirect means of detection and measurement of 239Pu.
(C)1981Health Physics Society