Methods of measuring radioactivity in the environment

摘要

A variety of sampling methods have been utilized to assess the amount of deposited activity, mainly from (sup 137)Cs, from the Chernobyl accident and from nuclear weapons tests. Starting with the Chernobyl accident in 1986 sampling of air and rain was used to determine the composition and amount of radioactive debris from this accident. The resulting deposition and its removal from urban areas was then studied through measurements on sewage sludge and water. The main part of the thesis considers methods of determining the amount of radiocesium in the ground through soil sampling. In connection with soil sampling a method of optimizing the sampling procedure has been developed and tested in the areas of Sweden with high amounts of (sup 137)Cs from the Chernobyl accident. This method was then used in a survey of the activity in soil in Scania (south Sweden) with fallout activity from nuclear weapons and Chernobyl. By comparing the results from this survey with deposition calculated from precipitation measurements it was found possible to predict the deposition pattern over Scania for both nuclear weapons and Chernobyl fallout. In addition, the vertical distribution of (sup 137)Cs has been modelled and the temporal variation of the depth distribution has been described. 65 refs. (Atomindex citation 28:049454)