Vertical profiles of Pu-239,Pu-240 and Am-241 in two sphagnum mosses of Italian peat

During the last two years the Urbino University and the Padua ICTIMA CNR co llaborated on a special radioecological program having the aim to study the Pu and Am retention behaviour in Sphagnum peat in the Alps region (norther n Italy). Pu-239,Pu-240, Pu-238 and Am-241 were separated and determined by extraction chromatography, electroplating and alpha spectrometry; Pu-242 a nd Am-243 were used as the yield tracers. The paper summarizes the results dealing with the vertical profiles of the radionuclides in Sphagnum compact um and S. nemoreum. Several 1-2 cm high sections were obtained and dated by Pb-210 determination. Typical concentration peaks for Pu and Am were found at a depth corresponding to the early 1960s which is the period characteri zed by the maximum nuclear weapon tests. (C) 1999 Elsevier Science B.V. All rights reserved.