Half-lives of self-purification for various isotopes in soils of the Chernobyl Exclusion Zone

¹ Chornobyl Center for Nuclear Safety, Radioactive Waste and Radioecology, International Radioecology Laboratory, Slavutych 07100, Ukraine
² Texas Tech University, Lubbock, TX 79409-3131, USA
³ Institute for Nuclear Research, 03680 Kiev, Ukraine

Abstract

During 2001–2002 we investigated current contamination of soils in several places in the Chornobyl zone. We have measured the content of alpha emitting isotopes Pu, ²⁴¹Am, ^154,155Eu, ⁹⁰Sr, and ¹³⁷Cs in layers of soil up to the depth of 30 cm. By including the two mechanisms of migration: convection and diffusion in our model, we were able to estimate the ecological and effective half-lives of self-purification processes for these layers of soil. Effective half-lives vary from 20 to 400 years dependent upon the type of soil and the isotopes.