PLUTONIUM IN SOILS, BOTTOM SEDIMENTS AND LICHEN NEAR PEACEFUL NUCLEAR-EXPLOSION SITES IN THE REPUBLIC-OF-SAKHA (YAKUTIA)

During the 1974-1987 period 12 paceful nuclear explosions were conduct ed in the Republic of Sakha (Yakutia). For the first time Pu-239,Pu-24 0 and Pu-238 concentrations were determined in samples of sails, botto m sediments and lichen taken at the ''Craton-3'' and ''Crystal'' nucle ar explosion sites. At the ''Craton-3'' Pu-239,Pu-240 concentrations i n the range 6.2 mBq/g to 5.9 Bq/g samples of soil and Pu-239,Pu-240, c oncentrations up to 7.4 Bq/g in samples of lichen were observed Pu-239 ,Pu-240 concentration measurements in bottom sediments of a stream was hing out the banking around the borehole of ''Craton-3'' show that plu tonium migrates in the direction of the Markha river. At the ''Crystal '' site local plutonium concentrations up to 35 Bq/g in soil and 1.8 B q/g in lichen were observed.