Sorption of 137Cs^{137}Cs and Pb on sediment samples from a drinking water reservoir

This study focused on 137Cs and Pb accumulation in sediments from the Dobczyce Reservoir in southern Poland. Elements’ spatial distribution as well as their distribution in sediment core samples were analyzed. The conditions of cesium and lead desorption were also investigated. The distribution coefficient for 137Cs (KCs) was obtained using a radiometric determination in combination with static ion-exchange chromatography. Determination of the distribution coefficient for Pb (KPb) was performed by means of atomic absorption spectrometry (electrothermal technique). The experiments were carried out considering various concentrations of potassium and calcium ions (from 5·10-3 to 10-5 mol·dm-3 by addition of KNO3 and Ca(NO3)2, respectively). It was found that: a) spatial distribution of anthropogenic 137Cs and Pb in the sediments of the Dobczyce Reservoir results mainly from hydrological conditions of the sedimentation process and, on the other hand, from the sorptive properties of the deposited material b) in the case of 137Cs sorption, a pronounced competitive effect was noted for K ions; much less effect was found for Ca. On the contrary, in the case of lead such a competitive effect was visible for Ca, much less for K. The conditions of 137Cs desorption from the sediments caused by K and Ca ions present in water were estimated

Concentrations of ^{137}Cs and ^{40}K radionuclides and some heavy metals in soil samples from the eastern part of the Main Ridge of the Flysch Carpathians

The aim of the study is to present the results of determination of radioactivity of artificial ^{137}Cs and natural ^{40}K and certain heavy metals in soil samples collected from the eastern part of the Main Ridge of Carpathians, including the Beskid Niski Mts and the Bieszczady Mts. The evaluation of level of radionuclides was based on the bulk density analysis of the soil. A valuable finding of the study was a good linear correlation between the level of ^{137}Cs concentration and bulk density of the soil as well as an inverse correlation between radioactivity of natural ^{40}K and tested soil density. This might indicate though a high competitiveness of these elements between each other. Moreover, a good correlation between the concentrations of artificial element ^{137}Cs and Pb has been also observed in soil samples collected from the Beskid Niski Mts. In most cases, the level of artificial ^{137}Cs was lower comparing to an average ^{137}Cs concentration established for soils in Poland

A Geological Context in Radiation Risk Assessment to the Public

The work aimed to show the applicability of geological studies to the investigation of radiation risk assessment due to the presence of naturally occurring radionuclides of terrestrial origin in the soil. Soil samples were taken from a Tatra Mountains area for which geological maps were available. The concentration of selected radionuclides incl. 40K, 238U and 232Th was determined by gamma-ray spectrometry with a HPGe-detector. Radioactivities and calculated absorbed dose rates were co-related to complex bedrock matrices based on an original methodology. The correlations were proved by performing a Principal Component Analysis (PCA). The rocks that had a significant impact on the rate of absorbed dose from the soil were strongly related to the radioactivity of the uranium series. The share of the following fractions was the most significant: granite with pegmatite, gneiss, granitoid and gneiss, coquina, marl and glauconite, hard limestone, dolomite and limestone. The rock types additionally showed good correlation with radioisotopes from the thorium series. Granitoids with potassium feldspar, on the other hand, contributed the largest share of 40K radioisotope content

Wstępna ocena zawartości radionuklidów w osadzie dennym pobranym z Jamskiego Stawu (Słowacja)

Jamske Pleso lake is one of almost 200 lakes located in the Tatra Mountains. This post glacial water reservoir is set on a strictly protected area. In this work, sediment samples taken from Jamske Pleso Lake were analysed for radioactivity of natural 226Ra, 210Po, 210Pb and artificial 137Cs. The sediment core was taken by use of Limnos corer. After preparation of the physical sample, gamma measurements were executed in hermetically closed vessels. A preliminary study showed that concentration of natural radionuclides is in typical values for lakes located in this area. An elevated concentration of 226Ra (mean 57 ± 29 Bq ∙ kg–1) is an effect of uranium rich bedrock of the lake. Radioactivity of 137Cs is close to that reported in other Tatras lakes. Using 137Cs as an indicator allowed a preliminary estimate of the depth of the sediments deposited in 1960s.Jamski Staw (słow. Jamské Pleso) to jeden spośród niemal 200 tatrzańskich stawów. Ten zbiornik o charakterze polodowcowym położony jest na terenie objętym ochroną ścisłą. Celem niniejszej pracy było wyznaczenie poziomu radioaktywności naturalnych 226Ra, 210Po i 210Pb oraz sztucznego 137Cs w profilach osadów dennych pobranych z Jamskiego Stawu. Profile rdzeniowe osadów pobrano przy pomocy czerpaka firmy Limnos. Po wstępnej obróbce próbek i umieszczeniu ich w szczelnych naczyniach pomiarowych poddano je analizie z wykorzystaniem spektrometru promieniowania gamma. Wstępne wyniki pokazały, że radioaktywność naturalnych izotopów jest na zbliżonym poziomie, do notowanej w innych stawach tego regionu. Podniesiony poziom radioaktywności 226Ra (średnia 57 ± 29 Bq ∙ kg–1) jest związany z zawierającym uran, granitowym trzonem podłożem skalnym jeziora. Radioaktywność 137Cs jest na podobnym poziomie co w innych stawach tatrzańskich. Wykorzystanie 137Cs jako znacznika czasu pozwoliło na wstępną identyfikację warstw osadów nagromadzonych w latach 60. XX wieku

Self-absorption correction and efficiency calibration for radioactivity measurement of environmental samples by gamma-ray spectrometry

In this work empirical functions which relate the full-energy peak efficiency with sample height, energy, matrix composition and bulk density for voluminal samples in a cylindrical counting geometry were found. Accurate determination of the radioactivity of gamma-emitting radionuclides in environmental samples requires taking into account self-absorption. For the obtained self-absorption correction factor, a direct transmission method was chosen. Finally, this paper proposes a simple correlation between the self-absorption correction factor and the bulk density and height of the measured sample for a given energy

The activity of selected gamma radionuclides in the Tatra National Park

Cesium is naturally occurring active metal, represented by one stable isotope 133Cs, and number of artificial, unstable, isotopes. The most common artificial isotope of cesium is 137Cs, present in the environment of the Tatra Mountains due to nuclear weapon testing in late `50, and nuclear reactor accident in Chernobyl in 1986. However in recent years the growth in biofuels use for power generation can be the next source of 137Cs emission. Burning wood cultivated on grounds contaminated by 137Cs can introduce secondary emission of this isotope to the atmosphere.This paper presents the results of determination of gamma emitting radionuclides artificial 137Cs and natural 40K in soil samples from the Tatra Mountains. Results show some differences in the vertical distribution of examined radionuclides. It was found that the change of activity of 137Cs in the soil samples depends mostly on the soil density and on the concentration of organic material. The state of “zero” 137Cs activity was developed in the form of maps