Investigation of spatial distribution of <Superscript>137</Superscript>Cs in soil in area of location of the Armenian NPP

Problem of evaluation of spatial distribution of ¹³⁷Cs in soil and of direct radiation impact of the Armenian NPP on population dwelling in the region of its location, on the background of global radioactive fallouts and aftermaths of the Chernobyl accident is solved. Content of radiationdangerous radionuclide ¹³⁷Cs in soil on the territory with radius 50 km including the NPP area has been investigated. Points of monitoring have been chosen on the basis of analysis of meteorological data and calculation of the distance where emissions from NPP have maximal concentration in air. The obtained results agree well with the data of UN Scientific Committee of Radiation Action.     

Cesium, americium and plutonium isotopes in ground level air of vilnius

Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. Increases in activity concentration of radionuclides in the atmosphere were observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. The activity concentrations of ¹³⁷Cs were measured in two to three days samples while plutonium and americium in monthly samples. The extremely high activity concentrations of ²³⁸Pu, ^239,240Pu, ²⁴¹Am determined in the atmosphere during the Chernobyl accident can be explained by transport of “hot particles” of different composition. Activity concentration in 1995–2003 of ²⁴¹Am and ^239,240Pu isotopes ranged from 0.3 to 500 and from 1 to 500 nBq/m³, respectively. ²³⁸Pu/^239,240Pu activity ratio in measured samples differs from 0.03 to 0.45. A decrease in ²⁴⁰Pu/²³⁹Pu atomic ratio from 0.30 to 0.19 was observed in 1995–2003.     

Measurements of134Cs and137Cs by gamma spectrometry in some Italian soils following the nuclear reactor accident of chernobyl

Summary The concentration as well as the vertical distribution of¹³⁴Cs and¹³⁷Cs were determined in several soil samples subsequently to the Chernobyl accident. The soil samples were selected in some representative geomorphological situation in Apulia that is a region of Italy. Both undisturbed and cultivated soils were considered. The total deposition of¹³⁷Cs as due to the Chernobyl accident was estimated and the obtained results were also controlled by measurements of the radioactive fall-out in rain and snow during 1986 and 1987. Also the deposition of^239,240Pu during 1986 and 1987 was measured.

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Riassunto è stata determinata la concentrazione e la distribuzione verticale, di¹³⁴Cs e¹³⁷Cs in alcuni campioni di terreno successivamente all'incidente di Chernobyl. I campioni sono stati selezionati in alcune situazioni geomorfologiche rappresentative della Puglia. Sono stati presi in considerazione sia terreni indisturbati che coltivati. è stata determinata la deposizione totale di¹³⁷Cs dovuta all'incidente di Chernobyl. Questo risultato è stato valutato anche in relazione alle misure di ricaduta di¹³⁷Cs nella pioggia e nella neve durante l'ultimo quadrimestre 1986 e il 1987. Per la medesima ricaduta è stato anche misurato il^239,249Pu.

     

<Emphasis Type="Italic">In situ</Emphasis> study of the <Superscript>41</Superscript>Ar plume released from the Ignalina NPP

The ⁴¹Ar gamma ray radiation was registered using the in situ method in the vicinity of the Ignalina nuclear power plant (NPP). The sum of gamma rays, that are reaching the HPGe detector, situated along the wind direction, from a number of plume segments and which are registered in the energy range of about 1.29 MeV, is calculated. An independent technological regime of the operating reactor method of the determination of the ⁴¹Ar emission rate from NPP stack is introduced.      

137Cs and 40K activity concentration measurements and elemental analysis in lichen samples collected from the Giresun province of northeastern Turkey

About 21 years after the Chernobyl accident, ¹³⁷Cs and ⁴⁰K activity concentration measurements using gamma-ray spectroscopy and elemental analysis using energy dispersive X-ray spectroscopy were performed in five different lichen species collected from the Giresun province of northeastern Turkey. Being a symbiosis of algae and fungi, lichens are mostly used for environmental measurements since the fungal partner is responsible for the uptake of necessary nutrients or harmful substances, such as heavy metals of radionuclides. The gamma activity results showed that ¹³⁷Cs, an artificial radionuclide released from the Chernobyl power plant accident, is still eminent in the environment of the province. The mean activity concentrations of ¹³⁷Cs and ⁴⁰K ranged from 24 to 254 with the mean value of 102 Bq kg^?1 and from 345 to 2103 with the mean value of 1143 Bq kg^?1 in dry weight. The results of the elemental analyses showed potassium, calcium, titanium, iron, tin, and barium in different concentrations.     

Cesium,americium and plutonium isotopes in ground level air of Vilnius

Systematic observations of radionuclide composition and concentration in the atmosphere have been carried out at the Institute of Physics in Vilnius since 1963. Increases in activity concentration of radionuclides in the atmosphere were observed after nuclear weapon tests and the Chernobyl NPP accident. At present the radiation situation in Lithuania is determined by two main sources of radionuclides, forest fire and resuspension products transferred from highly polluted region of the Ukraine and Belarus. The activity concentrations of ¹³⁷Cs were measured in two to three days samples while plutonium and americium in monthly samples. The extremely high activity concentrations of ²³⁸Pu, ^239,240Pu, ²⁴¹Am determined in the atmosphere during the Chernobyl accident can be explained by transport of “hot particles” of different composition. Activity concentration in 1995–2003 of ²⁴¹Am and ^239,240Pu isotopes ranged from 0.3 to 500 and from 1 to 500 nBq/m³, respectively. ²³⁸Pu/^239,240Pu activity ratio in measured samples differs from 0.03 to 0.45. A decrease in ²⁴⁰Pu/²³⁹Pu atomic ratio from 0.30 to 0.19 was observed in 1995–2003.     

Fission products from the damaged Fukushima reactor observed in Hungary

Fission products, especially ¹³¹I, ¹³⁴Cs and ¹³⁷Cs, from the damaged Fukushima Dai-ichi nuclear power plant (NPP) were detected in many places worldwide shortly after the accident caused by natural disaster. To observe the spatial and temporal variation of these isotopes in Hungary, aerosol samples were collected at five locations from late March to early May 2011: Institute of Nuclear Research, Hungarian Academy of Sciences (ATOMKI, Debrecen, East Hungary), Paks NPP (Paks, South-Central Hungary) as well as at the vicinity of Aggtelek (Northeast Hungary), Tapolca (West Hungary) and Bátaapáti (Southwest Hungary) settlements. In addition to the aerosol samples, dry/wet fallout samples were collected at ATOMKI, and airborne elemental iodine and organic iodide samples were collected at Paks NPP. The peak in the activity concentration of airborne ¹³¹I was observed around 30 March (1–3 mBq m^?3 both in aerosol samples and gaseous iodine traps) with a slow decline afterwards. Aerosol samples of several hundred cubic metres of air showed ¹³⁴Cs and ¹³⁷Cs in detectable amounts along with ¹³¹I. The decay-corrected inventory of ¹³¹I fallout at ATOMKI was 2.1±0.1 Bq m^?2 at maximum in the observation period. Dose-rate contribution calculations show that the radiological impact of this event at Hungarian locations was of no considerable concern.     

Speciation of radionuclides of the Chernobyl origin in aerosol and soil samples

Speciation of^134,137Cs,⁹⁰Sr,²³⁴U,²³⁸U,²³⁸Pu,^239,240Pu and²⁴¹Am was investigated in aerosol samples collected after the Chernobyl accident and in the Chernobyl soil. Sequential extraction experiments have shown a wide range of association of radionuclides, depending on sources, transformation perculiarities and radionuclide nature. Changes in speciation of¹³⁷Cs and⁹⁰Sr at various temperatures in the Chernobyl soil were analyzed. It was found that at 200°C–700°C a transformation of speciation of¹³⁷Cs took place and more available physico-chemical forms of Cs were formed. After heating at 900°C, up to 94% of¹³⁷Cs was found in the residual form and was not extractable even with 7 M HNO₃. Heating of the soil to 450°C and 900° C resulted in the formation of less available forms of⁹⁰Sr.     

Potre-H: A Dynamic Model for Rationuclide Transport in Agricultural Ecosystems

Abstract

This paper presents a dynamic compartment model that simulates the transfer of radionuclides through components of agricultural systems following deposition to ground, and predicts the resulting concentrations in food products. The system of linear differential equations corresponding to this model was solved analytically for release in the dormant season, before or after sowing, and for release in the growing season as a single or time dependent deposition. Model predictions have also been compared with levels ¹³¹I and ¹³⁷Cs in grass and milk resulting from the Chernobyl accident.     

Observation of high spin levels in131Cs from131Ba decay

The γ- and conversion electron spectra following¹³¹Ba ε-decay are investigated, using HPGe detector and mini-orange electron spectrometer. Attention is particularly focussed on identifying weak transitions associated with low energy high spin levels in¹³¹Cs level scheme earlier inferred in reaction studies but not yet observed in¹³¹Ba decay. Our experiment identifies 15 new gammas and 6 new conversion lines in this decay. Internal conversion coefficients and multipolarities of several transitions are determined. Five new levels (3 with I^π = 7/2⁺ and one each with I^π 9/2⁺ and 11/2⁻) are introduced in the¹³¹Cs level scheme based on our observations taken together with the results from reaction studies. Spin-parity assignments to a few other levels are also suggested     

Study of removal processes of <Superscript>7</Superscript>Be and <Superscript>137</Superscript>Cs from the atmosphere

In order to understand better the way in which radioactive contamination may be transferred from the atmosphere to other ecological compartments it is necessary to obtain information of the deposition mechanisms of radionuclides. Concentration and speciation of ¹³⁷Cs and ⁷Be in the atmospheric aerosol and deposition were studied. The mixed deposition velocities of water-soluble and insoluble ¹³⁷Cs and ⁷Be were determined. The relation between activity concentrations of insoluble ⁷Be in the atmosphere and its amount in deposition was observed. It is supposed that in the deposition process of radiocesium the precipitation plays an important role in scavenging of water-soluble radiocesium by falling raindrops, in contrast to insoluble ¹³⁷Cs where the dry deposition becomes predominant.     

Observation of fallout deposition in an outdoor swimming pool 50 km away from the Fukushima Daiichi nuclear power plant

After the accident at the Fukushima Daiichi nuclear power plant (NPP), outdoor school swimming pools at Fukushima were decontaminated to curb the redistribution of radioactivity into downstream farmlands. In the process, the radioactivity concentrations of the pool water and sediment substances (residue) were measured to estimate the deposition density of the fallout. At a pool situated 50 km away from the NPP, the average concentrations of radiocesium (^134+137Cs) for the water and residue were quantified as 170 Bq L⁻¹ and 3.6 × 10⁵ Bq kg⁻¹, respectively. Taking account of the radioactivity concentrations and of the water balance in and around the pool, the deposition density of radiocesium, as of August 2011, was precisely determined to be 0.32 ± 0.03 MBq m⁻² (k = 1). The density corroborated the previous results obtained by other methods, i.e., airborne surveys, in-situ Ge surveys and soil samplings at neighboring locations. Other than radiocesium, the only gamma-emitting nuclide detected was ^110mAg, with a concentration of 560 Bq kg⁻¹ in the residue. The radioactivity concentrations of ⁸⁹Sr, ⁹⁰Sr, ²³⁸Pu and ^239+240Pu in the water were all less than the minimum detectable activities – 2, 0.1, 0.002 and 0.002 Bq L⁻¹, respectively.     

Internal radiocesium contamination of adults and children in Fukushima 7 to 20 months after the Fukushima NPP accident as measured by extensive whole-body-counter surveys

The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima.Extensive whole-body-counter surveys (n = 32,811) carried out at the Hirata Central Hospital between October, 2011 and November, 2012, however show that the internal exposure levels of residents are much lower than estimated. In particular, the first sampling-bias-free assessment of the internal exposure of children in the town of Miharu, Fukushima, shows that the ¹³⁷Cs body burdens of all children (n = 1,383, ages 6–15, covering 95% of children enrolled in town-operated schools) were below the detection limit of 300 Bq/body in the fall of 2012. These results are not conclusive for the prefecture as a whole, but are consistent with results obtained from other municipalities in the prefecture, and with prefectural data.     

Measurement of radionuclides and absorbed dose rates in soil samples of Peshawar,Pakistan, using gamma ray spectrometry

The analysis of gamma-emitting radionuclides in nature, i.e. ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs, has been carried out in soil samples collected from Peshawar University Campus and surrounding areas using a high purity germanium detector coupled with a computer-based high-resolution multichannel analyser. The activity concentrations in soil ranged from 30.20±0.65 to 61.90±0.95, 50.10±0.54 to 102.80±1.04, 373.60±4.56 to 1082±11.38 and 9.50±0.11 to 46.60±0.42 Bq kg^?1 for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs, with a mean value of 45±7.70, 67±12.50, 878±180 and 19±9.20 Bq kg^?1, respectively. The radium equivalent activity, internal and external hazard indices have mean values of 203.40±29.40 Bq kg^?1, 0.56 and 0.68, respectively. The mean values of outdoor and indoor absorbed dose rates in air and the annual effective dose equivalents were found to be 106.50 and 128 nGy h^?1 and 0.19 and 0.54 mSv y^?1, respectively. In the present study, ⁴⁰K was the major radionuclide present in soil samples. The presence of ¹³⁷Cs indicates that this area also received some fallout from the nuclear accident of the Chernobyl power plant in 1986. The activity concentrations of radionuclides found in soil samples during the current investigation were nominal. Therefore, they are not associated with any potential source of health hazard to the public.     

Soil depth profile of 137Cs, 210Pb and 40K in Algeria

ABSTRACT

Three soil depth profiles of ²¹⁰Pb, ¹³⁷Cs and ⁴⁰K at different areas of Algeria were studied. The soil sampling areas are near the location where the French nuclear tests took place at 1960–1966. The two depth soil profiles were collected at Ghardaia region and the third one at Reggane region. The vertical distributions of radionuclides at the two soil depth profiles from Ghardaia region are different, probably due to the different soil composition. The soil depth profile from sandy soil show uniformity in the distribution of radionuclides without a clear maximum (peak). The soil depth profile that characterised by silty sand show a clear peak at 20–50?cm depth for all studied radioactive nuclides, while the observed activities are two times higher than the corresponding values in sandy soil samples. More specifically in Ghardaia region the ²¹⁰Pb, ¹³⁷Cs, ⁴⁰K activity concentrations ranged between 27 and 50?Bq?kg^?1, 0.2 and 3?Bq?kg^?1 and 75 and 90?Bq?kg^?1 respectively in sandy soil type and between 37 and 75?Bq?kg^?1, 4 and 6?Bq?kg^?1 and 140 and 180?Bq?kg^?1 respectively in silty sand soil type. Finally, the third depth soil profile collected from Reggane site presents a completely different distribution of the studied radionuclides. The activity concentrations of ²¹⁰Pb, ¹³⁷Cs, ⁴⁰K ranged between 37 and 51?Bq?kg^?1, 0.16 and 0.39?Bq?kg^?1 and 120 and 309?Bq?kg^?1 respectively. Three peaks in the ¹³⁷Cs distribution revealed, were most probably, Chernobyl related ¹³⁷Cs accounts for the surface peak, while the deeper peaks are connected to the weapons fallout.     

Beeinflussung der Flüchtigkeit von trägerfreiem 137Cs-Chlorid bei erhöhter Temperatur durch Zusatz von Alkali- und Erdalkalisalzen

Zur Ermittlung des Einflusses von Fremdsalzen auf die Flüchtigkeit des ¹³⁷Cs beim Veraschen von biologischen Untersuchungsproben wurde trägerfreies ¹³⁷Cs-Chlorid in Platinschälchen in Gegenwart verschiedener Alkali-und Erdalkalisalze bei Temperaturen von 350…600 °C erhitzt und die aufgetretenen Verluste bestimmt. Es ziegte sich, daβ Natrium-, Kalium-, Nitrat,- Chlorid- und Carbonationen erheblich zur Erhöhung der Verluste beitragen, während die Phosphat. und Sulfationen eine starke Reduzierung der Flüchtigkeit des trägerfreien ¹³⁷Cs bewirken. Über Schluβfolgerungen für die Veraschung von biologischen Untersuchungsproben wird berichtet.     

Optoacoustic gas analyzer based on a13C16O2 laser for multicomponent pollution of air

A computer-aided optoacoustic gas analyzer based on a continuous¹³C¹⁶C₂ laser for multicomponent pollution of atmospheric air is described. The analyzer has the ability to detect absorption of radiation by detected substances at the level of ∼1·10⁻⁹ cm⁻¹ at a time resolution of 30 sec. Results of an experiment on simultaneous detection of H₂O, CO₂, NO₂, NH₃, HNO₃, OCS, and C₂H₄ in the atmospheric air using 40 laser lines are presented. B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 345–350, May–June, 1999.     

Statistical relationship between activity concentrations of radionuclides 226Ra, 232Th, 40K,and 137Cs and geological formations in surface soil of Jordan

An extensive study was conducted to determine the activity concentrations of natural and artificial radionuclides ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs in soil samples of each governate of Jordan. A total of 370 samples have been measured using a high-purity germanium detector. The activity concentration for ²²⁶Ra, ²³²Th, ⁴⁰K, and ¹³⁷Cs has mean values of 42?±?3, 23?±?3, 309?±?21, and 3.7?±?0.9 Bq kg^–1, respectively. The highest mean activity concentration for ²²⁶Ra was found to be 138?±?4 Bq kg^–1 in the Alkarak governate. In the Ajloun and Jarash governates, the highest mean activity concentration was 35?±?3 Bq kg^–1 for ²³²Th, and 14.2?±?1.9 Bq kg^–1 for ¹³⁷Cs, respectively. Geological influence on the activity concentrations was investigated using the one-way analysis of variance (ANOVA) and independent samples. The ANOVA results indicate that there are strong significant differences between the activity concentrations of ²³²Th, ⁴⁰K, and ¹³⁷Cs based on geological formations the radionuclides occur. The main contribution to gamma dose rate was due to ²²⁶Ra activity concentration. Radium equivalent and external hazard index are associated with a mean value of 98 Bq kg^–1, and 0.266, respectively.     

Statistical Method for Determination of the Photopeak Area of Scintillation γ-Spectra

A comparatively unsophisticated analytical statistical method is developed for determination of the parameters of the peak of full absorption processing scintillation γ-spectra. The generasl beckground under the photopeak is linearly approximated and an accuracy estimation was done. The method is illustrated with several applciaitons of non-destructive γspectroscopic analysis of ¹³⁷Cs in soil samples. Concentrations of the order of severals pCi¹³⁷Cs are determined accurately enough at disturbing influence of the peak of full absorption of RaC(²¹¹Bi) and 610 KeV. The control data was processed by means of a “Minsk-22” computer under a convenient programme. The results correspond to those obtained according to the described method at a reliable estimation of accuracy.     

Rotational analysis of the 0–9, 0–10 and 0–11 bands of theA 2II u -X 2II g band system of (16O18O)+

High-resolution spectra of the 0–9, 0–10 and 0–11 bands of theA ²II _u —X ²II _g system of (¹⁶O¹⁸O)⁺ ion have been studied for their rotational structure. This study enables a direct determination of the Λ-doubling parameters of theA ²II _u andX ²II _g states. The model of ‘pure precession’ explains, though not entirely, the Λ-doubling of theX ²II _a state as arising out of its interaction with theB ² Σ _g ⁻ state. The Λ-doubling in theA ²II _u state was found insignificant.