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Sample records for caesium

  1. Human metabolism of caesium

    Energy Technology Data Exchange (ETDEWEB)

    Raeaef, C.L. [Lund Univ., Dept. of Radiation Physics in Malmoe (Sweden); Falk, R. [Swedish Radiation Protection Authority (Sweden); Lauridsen, Bente [Risoe National Lab. (Denmark); Rahola, T. [STUK - Radiation and Nuclear Safety Authority (Finland); Soogard-Hansen, J. [NRPA - Norwegian Radiation Protection Authority (Norway)

    2006-04-15

    A study of the human biokinetics of caesium in two forms, i.) incorporated in foodstuff (137Cs in perch and mushrooms) and ii.) in ionic state ({sup 134}Cs in aqueous solution) has been carried out at the department of Radiation Physics in Malmoe, starting in 2001. The results of the pilot study were published in 2004, and a continuation of that study has now been carried out by means of NKS funding (NKS-B Cskinetik). The aim is to, i.) investigate whether Scandinavian populations exhibit shorter biological half-time of radiocaesium than other populations; ii.) extend the biokinetic study to additional human subjects from the other Nordic countries. Results from the continued study further indicate a near complete absorption of radiocaesium in the gastro-intestinal tract, be it in ion state or contained in food matrix. So far, the literature survey of Nordic studies on biokinetics of Cs suggests that the biological half time is somewhat shorter among Scandinavian males (84 days vs. ICRP-value of 110 days), although females do not exhibit any significant difference (64 days vs ICRP value of 65 days). (au)

  2. Human metabolism of caesium

    International Nuclear Information System (INIS)

    A study of the human biokinetics of caesium in two forms, i.) incorporated in foodstuff (137Cs in perch and mushrooms) and ii.) in ionic state (134Cs in aqueous solution) has been carried out at the department of Radiation Physics in Malmoe, starting in 2001. The results of the pilot study were published in 2004, and a continuation of that study has now been carried out by means of NKS funding (NKS-B Cskinetik). The aim is to, i.) investigate whether Scandinavian populations exhibit shorter biological half-time of radiocaesium than other populations; ii.) extend the biokinetic study to additional human subjects from the other Nordic countries. Results from the continued study further indicate a near complete absorption of radiocaesium in the gastro-intestinal tract, be it in ion state or contained in food matrix. So far, the literature survey of Nordic studies on biokinetics of Cs suggests that the biological half time is somewhat shorter among Scandinavian males (84 days vs. ICRP-value of 110 days), although females do not exhibit any significant difference (64 days vs ICRP value of 65 days). (au)

  3. Radioactive caesium in British mushrooms

    International Nuclear Information System (INIS)

    Thirty-four different taxa of larger fungi have been analysed for their content of caesium 137 over a 3 year period. The majority of the material has been collected from various sites in Central Scotland; 38% of the collections were from North Wales and Merseyside. Comparison has been made between the same species from different sites and different species from the same site. It has also been possible to analyse the same species from the same plot on two consecutive years. The levels of caesium 137 in the fungal species analysed were extremely low when compared with their counterparts in Central Europe and it is concluded that the Chernobyl incident had little effect on the accumulation by these fungi of this radionuclide. There is no evidence that edible species accumulate caesium 137 at levels considered to be dangerous for consumption

  4. Caesium concentration in the Pakistani diet

    International Nuclear Information System (INIS)

    Daily dietary intakes of radioactive and non-radioactive caesium for the Pakistani population were measured. Food samples were collected on market basket method and were analysed using Instrumental Neutron Activation Analysis technique. The radioactive caesium (137Cs) in these samples was below the detectable limit, i.e. 1 mBq g-1. The geometric mean of the mass fraction of stable caesium was 9.56x1.53 ng g-1. The estimated daily dietary intake of caesium was 5.65x1.53 μg d-1 or 0.088 μg kg-1 of body weight of the reference Pakistani man weighing 64 kg. These values are 38.2% smaller than the recommended ICRP values for a 70 kg standard man. However, caesium concentration in the Pakistani diet is comparable with other reported values in the literature

  5. Leakage of caesium braquitherapy sources

    International Nuclear Information System (INIS)

    In several Venezuelan public hospitals where cervix uteri tumours are treated by intracavitary radiotherapy, that use manual after loading Fletcher method, with Caesium 137 sources, the use of improper source holders, locally manufactured from pieces of drainage plastic tubing, which deteriorated and created a corrosive environment all around the sources, omission of manufacturer's recommendations regarding corrosion information, source storage, inspection and testing, violation of International Atomic Energy Agency Radiation Protection Procedures, and lack of proper regulatory control, resulted integrity damage to about sixty special form sources (ISO2919 C 63322), leakage of Cs-137 from a supposed insoluble refractory active content (caesium silicoaluminate), and contamination of applicators, floors and bedding. When the situation was detected by means removal contamination tests, after routine inspections, the sources were removed from the hospitals, decontaminated by means of immersion in 3% EDTA solution in ultrasonic bath, subjected to leaking assessment tests, and the ones that passed were placed in low cost stainless steel source holders, designed and built by the instituto Venezolano de Investigaciones Cientificas (IVIC) returned to the hospitals. The leaking sources were removed from use and considered radioactive waste. In order to avoid the occurrence of similar situations, all the importers of such sources are now required to send them to IVIC for testing and placement in proper source holders, before they are shipped to the hospitals. (author)

  6. Maternal and Infantile Metabolism of Caesium

    International Nuclear Information System (INIS)

    Investigations concerning the caesium metabolism of three women from late pregnancy to some months after partus are reported. In two cases, biological half-times of about 30 d are found, in contrast to the half-times usually found of about 70 d. The transfer of activity from mother to child via placenta and later via breast milk has been investigated in the three cases. The specific activity of the infant was, at partus, close to that of its mother. A biological half-time for caesium in children of only 25 d was obtained in two cases. Both caesium-137 and caesium-132 were used for the investigations. The radiation doses to the subjects from these isotopes were very small and comparable with the monthly doses from body potassium. Some conclusions on the possibilities of future work are presented. (author)

  7. Contamination of pork by caesium radioisotopes

    International Nuclear Information System (INIS)

    A dynamic compartmental model for assessment of caesium transport from pigs' feed to pork has been constructed using the food chain monitoring data obtained in Czechoslovakia after the Chernobyl accident. The model is described by a set of linear first-order differential equations, the solution of which provides reliable information on the kinetics of caesium metabolism in pigs, including its retention and degree of resorption through the gastrointestinal tract wall into blood. (author)

  8. Transfer of atmospheric caesium to agricultural products

    International Nuclear Information System (INIS)

    A huge quantity of radioactive rubble was generated by the Great East Japan Earthquake. The Japanese government is considering incineration processing of such rubble in waste incinerators which have suitable equipment, and the government is urged to manage appropriately the radiation exposure of residents living in the vicinity of incinerators by inhalation and ingestion of food. In this study, we developed a model describing plant uptake of atmospheric caesium by direct deposition and root-absorption via soil. Analysis using our model has suggested that wet deposition contributes to transfer to a plant most, when caesium exists in the atmosphere. (author)

  9. Caesium incorporation and retention in illite interlayers

    OpenAIRE

    Fuller, AJ; Shaw, S.; Ward, MB; Haigh, SJ; Mosselmans, JFW; Peacock, CL; Stackhouse, S.; Dent, AJ; Trivedi, D; Burke, IT

    2015-01-01

    Radioactive caesium (chiefly 137Cs) is a major environmental pollutant. The mobility of Cs in temperate soils is primarily controlled by sorption onto clay minerals, particularly the frayed edges of illite interlayers. This paper investigates the adsorption of Cs to illite at the molecular scale, over both the short and long term. Transmission electron microscopy (TEM) images showed that after initial absorption into the frayed edges, Cs migrated into the illite interlayer becoming incorporat...

  10. Caesium-137 Chloride Retention following Accidental Ingestion

    International Nuclear Information System (INIS)

    Four men became contaminated with caesium-137 chloride due to leaks in a 100 c source. The source was believed to be completely leak proof, since the caesium chloride was contained in a welded stainless-steel capsule which was covered with an outer steel jacket of standard Oak Ridge design. Most of the contamination occurred while the men were cleaning the components of a pneumatic device used to move the source. The most heavily- contaminated individual placed his mouth over the end of a transport tube and attempted to blow some ''dust'' out of the tube. The other men handled various parts of the transport mechanism and wiped ''dust'' out of holes with their fingers. None of the men washed their hands before eating lunch. When radioactive contamination was discovered on the following day, immediate efforts were made to decontaminate the men. Arrangements for whole-body counts were also made and, on the fifth day following contamination, the men reported to the Radiation Exposure Evaluation laboratory. The body burdens on the fifth day ranged from 35 - 970 nc of caesium-137. During the next five to six days the burdens dropped rapidly and on the eleventh day ranged from 28- 780 nc. After the eleventh day the body burdens of caesium-137 changed much more slowly. Whole-body counts made between the 11th and 160th day yielded biological half-lives of 76, 95 and 126 d for the three most heavily-contaminated individuals. During the period of rapid excretion all urine and faeces were collected and counted. These counts indicated a considerable superficial contamination prior to the eleventh day since only a portion of the removed caesium-137 was found in the urine and stool specimens. The body burdens of the four men are compared with normals of the same size, build, age and diet habits. A short discussion of normal burdens is included. A brief description of the counting system, data handling techniques and calibration procedures is also included. (author)

  11. Structure of caesium disulfate at 120 and 273 K

    DEFF Research Database (Denmark)

    Ståhl, Kenny; Berg, Rolf W.; Eriksen, Kim Michael; Fehrmann, Rasmus

    2009-01-01

    The crystal structures of Cs2S2O7 at 120 and 273 K have been determined from X-ray single-crystal data. Caesium disulfate represents a new structure type with a uniquely high number of independent formula units at 120 K: In one part caesium ions form a tube surrounding the disulfate ions, [Cs8(S2...

  12. Treatment of solutions of fission products - Separation of caesium-137

    International Nuclear Information System (INIS)

    For the industrial recovery of caesium-137 from solutions of fission products, the authors utilized the analytical method for determination of caesium by dipicrylamine, adapting it to use on an industrial scale and to the high level of the activities encountered. The process recommended makes it possible both to isolate caesium as a chloride and to recover the precipitation reagent, in one and the same operation. A basic method is suggested. The authors studied the effect of radiation on dipicrylamine and its compounds, this effect proving to be practically nil for solid compounds and negligible for their solutions. The entrainment of caesium by ammonia ion was also studied. The advantages of the proposed process are : high decontamination of the caesium, simple operation and free recycling fo the reagent, high yield for caesium recovery and for dipicrylamine, considerable concentration of caesium activity, operation at room temperature and possibility of continuous operation. By this process caesium can be recovered before certain fission products are eliminated. (author)

  13. Measurement of Caesium-137 in the Normal Person

    International Nuclear Information System (INIS)

    During the period June 1959 to October 1963 the Landstuhl whole-body counter has measured the caesium-137 content of more than 15 000 normal persons. The monthly averages of these measurements indicate a steady increase In the caesium-137 content since June 1962. This increase has become more rapid during the period June 1963 to October 1963. A further evaluation of the monthly averages since June 1962 indicates a mean biologic half-life of caesium-137 of 140 d for persons older than 22 yr. A comparison of the mean caesium-137 content of persons between 8 and 17 yr of age with those older than 22 appears to indicate that the biologic half-life of caesium-137 is shorter in the younger people. This is in agreement with earlier data from this counter concerning measurements of caesium-137 content between June 1959 and December 1960: these data showed a lower caesium-137 content in children than in adults. Another evaluation of recent data from this unit concerns the standard deviation (sigma) of the caesium-137 content in a large population. From this population the sigma of measured caesium/g body potassium values is 33%. This is more than twice the sigma of the body potassium content of this same population. By comparing a group of persons who have undergone several repeat assays over an extended period of time with the monthly means of the total population measured, it has been found that the large sigma of caesium-137 content cannot be caused solely by the varying diets of the population measured. (author)

  14. Caesium dosing reduces uptake of radiocaesium by sheep

    International Nuclear Information System (INIS)

    In sheep grazing pasture contaminated by radiocaesium, administration of stable caesium was found to inhibit the uptake of radiocaesium. Eight lambs feeding on a contaminated pasture received an oral dose of 500 mg CsCl and after 6 days had a radiocaesium load 17% lower than that of a control group on the same pasture. The rate of radiocaesium excretion from 4 lambs, in metabolism cages and fed uncontaminated grass, was unaffected by CsCl dosing in comparison with controls. Thus, caesium dosing appeared to inhibit uptake but did not alter rates of caesium loss by normal processes of metabolism. Measurements of stable and radioactive caesium excretion rates were interpreted using a compartment model, based on the hypothesis of two major caesium reservoirs within the sheep, with derived biological half-lives approximately 4 and 25 days, and capacities 20 and 80% of total, respectively. Caesium dosing appeared to saturate the latter reservoir and consequently inhibit further uptake. If a practicable method of application could be achieved, caesium dosing could be useful in the management of sheep and other grazing animals on radiocaesium-contaminated pasture and could find application to radiological protection in humans. (Author)

  15. The behaviour of caesium in mountainous soils

    International Nuclear Information System (INIS)

    In the mountainous area of the Friuli-Venezia Giulia region (North-Eastern part of Italy) the Cs-137 deposition, due to Chernobyl accident, ranged from 20 to 40 kBq/m2. To study the vertical migration of radionuclides in mountainous soils, ENEA-DISP and the Regional Centre for Agricultural Experimentation (C.R.S.A.) have located four sampling stations in areas selected on vegetational basis: two in deciduous forests, one in a Abies-Fagus forest and one in a natural grassland. In these sampling stations soil chemico-physical characteristics were determined (soil texture, pH and organic matter) and the meteorological parameters daily recorded. This paper presents caesium residence half times in the superficial soil horizons evaluated on the bases of results obtained from June 1987 to December 1988. (author)

  16. Determination of caesium-137 in fast-reactor coolant systems.

    Science.gov (United States)

    Oldham, G; Ware, A R; Sykes, D J

    1969-03-01

    A method for the separation of caesium by ion-exchange involving ammonium 12-molybdophosphate has been investigated, and found to be 100% efficient for aqueous solutions with high sodium and potassium concentrations. PMID:18960518

  17. Influence of herbivory on caesium turnover in a forest ecosystem

    International Nuclear Information System (INIS)

    The effect of herbivory by bank vole (Clethrionomys glareolus) and moose (Alces alces) in relation to litterfall in a boreal forest is analysed. The main purpose is to estimate the relative importance of these processes for the transfer of caesium-137 to soil. Biomasses of litterfall and food consumption were selected from different forest biotopes. The analysis of the input and output of caesium-137 in the vole and moose populations is based on mass balance calculations for caesium-137 in steady state conditions. From this assessment, herbivory appears to be within an order of magnitude of litterfall. With due regard to the lower caesium level in litterfall than in living plant tissue, transfer of radioactive caesium by herbivory is seen to be even higher in comparison to that by litterfall, than apparent from the corresponding transfer of organic matter. In addition, the availability of caesium-137 from animal excrements is expected to be high and fast, which further emphasises the relative importance of herbivory in feed-back from vegetation to soil

  18. Project Caesium - An ion exchange model for the prediction of distribution coefficients of caesium in bentonite

    International Nuclear Information System (INIS)

    A surface chemical model is established to thermodynamically describe caesium sorption on bentonite. Caesium sorption is studied on Wyoming bentonite MX-80 in solutions of NaCl, KCl, MgCl2, CaCl2, NaNO3 and Ca(NO3)2 of concentrations varying between 0.025M and 1M, as well as in the weakly saline Allard groundwater and the strongly saline Aespoe groundwater. Based on these experiments it is shown that the sorption behaviour of caesium on bentonite can be described, within the experimental and model uncertainties, in terms of a one-site ion exchange model. The ion exchange constant for the replacement of Na+ on montmorillonite by Cs+ is logKex degrees = 1.6. The model predictions compare well with sorption data published in the open literature on both Wyoming bentonite MX-80 and other types of bentonite. For the analysis of diffusion experiments in compacted bentonite, the apparent diffusivity of tritiated water, HTO, is used as an analogue to estimate the pore diffusivity of Cs+. Since insufficient information is available at present to estimate the porosity actually available for diffusion in compacted bentonite, it is assumed that the diffusion porosity can be approximated by using the value of the bulk porosity. Under these circumstances, the cation ex change capacity (CEC) found to be available for the diffusing species in compacted bentonite corresponds to about 12% of the total CEC of bentonite. It is recognised that the errors made in the estimation of the pore diffusivity and of the diffusion porosity are contained in the reduction factor of the CEC. A discussion of the factors affecting the diffusivities of radionuclides and the problem of establishing consistent sets of diffusivity data is given in the Appendix. 33 refs, 7 figs, 12 tabs

  19. Note on Two Types of Contamination of Human Beings by Caesium-137

    International Nuclear Information System (INIS)

    The authors present an elimination curve for a case of occupational contamination by caesium-137. They also show how the caesium-137 body burden varied during 1963 in a group of persons who did not undergo occupational exposure. (author)

  20. Human metabolism of caesium[Radioecology

    Energy Technology Data Exchange (ETDEWEB)

    Raeaef, C.L. [Lund Univ., Malmoe Univ. Hospital, Dept. of Radiation Physics, Malmoe (Sweden); Falk, R. [Swedish Radiation Protection Authority, Stockholm (Sweden); Rahola, T. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland); Lauridsen, B.; Soogaard-Hansen, S. [Risoe National Lab., Roskilde (Denmark); Skuterud, L. [NRPA - Norwegian Radiation Protection Authority, Oesteraes (Norway)

    2006-04-15

    A study of the human biokinetics of caesium in two forms, i.) incorporated in foodstuff ({sup 137}Cs in perch and mushrooms) and ii.) in ionic state ({sup 134}Cs in aqueous solution) has been carried out at the department of Radiation Physics in Malmoe, starting in 2001. The results of the pilot study was published in 2004, and a continuation of that study is now undertaken by means of NKS funding (NKS-B Cskinetik). The aim is to, i.) investigate whether Scandinavian populations exhibit shorter biological half-time of radiocaesium than other populations; ii.) extend the biokinetic study to additional human subjects from the other Nordic countries. Results from the continued study further indicate a near complete absorption of radiocaesium in the gastro-intestinal tract, be it in ion state or contained in food matrix. So far, the literature survey of Nordic studies on biokinetics of Cs does not suggest that the biological half-time is shorter among Scandinavians, although there is a considerable variation between individuals. (au)

  1. Retention capacity of the calcium silicates hydrates (CSH) for caesium

    International Nuclear Information System (INIS)

    Alkalis are poorly trapped by cement and this constitutes one of the problem for the use of cement as nuclear waste matrix. Therefore we have studied the sorption of 137Cs on the CSH which are the major components of a Portland cement. CSH of different Ca/Si has been synthetised in suspension. Caesium chloride, which is highly soluble, was placed in a reactor with the CSH. To have a high precision for the caesium quantity fixed by the CSH, radioactive caesium was used as tracer. We observed that the maximum exchange capacity occurs at low Ca/Si ratio, when the structure is close to that of tobermorite. A Cs/Ca molar ratio around one could be obtained in this structure. (orig.)

  2. The utilization of caesium 137 in studying soil degradation

    International Nuclear Information System (INIS)

    The caesium 137 isotope is distributed in the atmosphere during nuclear explosions, and is absorbed in the upper horizons of the soil on reaching the ground. When it is incorporated in the fine fraction of the soil, caesium 137 measurement allows movements affecting cultivated lands (mass movements, runoff effects, wind action) and rate of soil degradation over half a century to be evaluated. Vegetal cover and techniques of soil utilization must be considered; this method has been tested on a watershed in the Parisian Basin. 5 figs., 26 refs

  3. Caesium fallout as a tracer of erosion-sedimentation

    International Nuclear Information System (INIS)

    The purpose of this paper is to set up a methodology of use of radioactive caesium fallout, to measure erosion and sedimentation in a sub-catchment and to establish the effects of geomorphological parameters, land uses and soil nature, on the losses caesium by physical process. The result obtained by this new and elegant approach, on a watershed of 4114 ha., studied before by classical and conventional techniques, gives a good evaluation of erosion, but also sedimentation rate, and permit to stand up, a model and sampling strategy, to extend the method to large catchment. 1 tab., 2 refs. (author)

  4. The mechanisms of caesium uptake by plants

    International Nuclear Information System (INIS)

    Persistent radioactive isotopes of caesium (134Cs and 137Cs) in the environment are of concern because they impact on both health and commerce. They enter the terrestrial food chain through plants. Plant roots take up Cs+ from the soil solution. To reach the shoot via the xylem, Cs+ must cross the plasma membranes of root cells at least twice. This is catalysed by transport proteins. Since Cs is an alkali metal with chemical properties similar to potassium (K), it has been suggested that the same proteins that transport K+ also transport Cs+. However, the Cs:K ratio in the shoots of different plant species grown under identical conditions varies widely. Since different transport proteins have contrasting abilities to discriminate between Cs+ and K+, this varying Cs:K ratio suggests that a different complement of transport proteins operates in different plant species. In the plasma membrane of root cells inward-rectifying K+ channels (KIRCs), outward-rectifying cation channels (KORCs and NORCs), voltage-independent cation channels (VICCs) and voltage-dependent Ca2+ channels (HACCs and DACCs) are all permeable to Cs+ and K+. In addition, the 'high-affinity' K+/H+ symporters (KUPs) and 'low affinity' transporters, such as the wheat TaLCT1 protein, may also transport Cs+ and K+. The relative abundance and selectivity of these transport proteins in the root plasma membrane will determine the relative fluxes of Cs+ and K+ to the shoot. Theoretical models describing Cs+ fluxes across the plasma membrane of root cells predict that, under natural conditions, VICCs mediate most (30 to 90%) of the Cs+ influx, with KUPs mediating the remainder, Cs+ influx through KIRCs is negligible, and stelar KORCs load Cs+ into the xylem. These predictions are consistent with the identical pharmacology of VICCs and Cs+ uptake by plants, which are both partially inhibited by La3+, Ba2+ or Ca2+ at millimolar concentrations, and the phenotypes of Arabidopsis mutants lacking the dominant root

  5. Elements of reflection on pathologies possibly induced by caesium 137

    International Nuclear Information System (INIS)

    The author discusses the content of few known publications on the possible pathological effects of caesium 137: a Belarus study on the consequences of Chernobyl, results of few autopsies performed on babies and adults, a study performed on rats, and a study performed on a set of 94 children in a sanatorium

  6. Low Level Caesium Mapping in Latvia Anno 1995

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    1999-01-01

    In Latvia the caesium-137 contamination from the Chernobyl accident and from the nuclear weapon tests in the 1960´es is very low. Conventional techniques for extracting information from the measured spectra cannot be used here. Therefore a new, sensitive technique - the pseudo concentration method...

  7. Low Level Caesium Mapping in Latvia Anno 1996

    DEFF Research Database (Denmark)

    Aage, Helle Karina

    1999-01-01

    In Latvia the caesium-137 contamination from the Chernobyl accident and from the nuclear weapon tests in the 1960´es is very low. Conventional techniques for extracting information from the measured spectra cannot be used here. Therefore a new, sensitive technique - the pseudo concentration method...

  8. The Effect of Chlorothiazide on Caesium-137 Excretion in Human Subjects

    International Nuclear Information System (INIS)

    The present study was carried out to determine factors that influence caesium metabolism in normal human subjects with particular interest in finding a therapeutic regimen for reducing the body burden of caesium. Since caesium and potassium are chemically similar, and are both localized in the intracellular compartment of the body, principally in muscle, it seemed possible that chlorothiazide, which has a marked potassium diuretic effect, might also increase caesium excretion. Four normal subjects were given a single dose of 0.1 μc of caesium-137 by mouth. Two subjects were given chlorothiazide 2.0 g/d for a total of three consecutive days starting 1 h after the caesium intake. The chlorothiazide dose was repeated at two weeks. The other two subjects were used as controls. The body burden of caesium-137 was measured by a whole-body counter at intervals up to 320 d. Daily urine collections were made for three control days and 20 d following caesium intake. The samples were analysed for electrolytes and caesium activity. Although chlorothiazide increased K excretion to 1. 5 times the control values, it had no significant effect on caesium excretion or in reducing the body burden of caesium. In all subjects a small fraction of caesium (10-20%) was excreted rapidly with a biological half-life (T),) of less than 1 d. The remainder was excreted at a constant rate with Tb of 90 to 155 d. More than 70% of the caesium eliminated from the body per day was excreted by the kidney. Tb of K was also calculated by the formula TbK = Total body K/Urine K x 0,693 x 0,8 assuming 80% of the total potassium excreted is by kidney. Tb of K was 35 to 42 d. The discrimination ratio TbCs/TbK was 2.1 to 3.8. These results demonstrate that caesium and potassium are not utilized interchangeably. Caesium is retained preferentially over potassium and changes in potassium turnover have no effect on caesium turnover. Studies are being carried out at the present time to determine the effect of

  9. Study of caesium adsorption on hydrated calcium-silicate-aluminate systems

    International Nuclear Information System (INIS)

    Immobilization of caesium in cementitious matrixes was studied in the present paper which is a key issue of handling radioactive caesium containig wastes for caesium does not form stabile compounds therefor it can not be readily immobilized. Model matrices were prepared to map up the calcium-silicate-aluminate system considering caesium immobilization, which were of different starting compositions. To caracterize Cs sorption, distribution ratios were determined. Based on the results obtained the model matrix compositions were prepared using industrial grade materials and their caesium retardation and trapping were examined by means of leaching and sorption experiments. In the light of the results obtained, it can be established that immobilization of caesium significantly depend on the starting composition of the used matrix. (orig.)

  10. Reduction of radioactive caesium in meat and fish by soaking

    Energy Technology Data Exchange (ETDEWEB)

    Petaejae, E.; Puolanne, E. (Helsinki Univ. (Finland). Dept. of Meat Technology); Rantavaara, A.; Paakkola, O. (Finnish Centre for Radiation and Nuclear Safety (STUK), Helsinki (Finland))

    1992-01-01

    The removal of radioactive caesium from meat by soaking in brine or water and the effect of injection curing, temperature, size of meat piece and cooking on this removal were studied. The availability of the brined meat for the manufacture of cured, smoked and cooked meat, oven-cooked meat and cooked sausages was also investigated. The soaking method was also tested on fish. (Author).

  11. Modelling of caesium deposition in CAGR reactor circuits

    International Nuclear Information System (INIS)

    A laboratory rig at BNL has been used to measure the deposition of radiocaesium in a CO2 gas stream onto steel surfaces in a thermal gradient furnace. The results of these measurements show that at high temperatures the deposition can be described by a model in which caesium diffuses into and out of the oxide film on the steel surface, with an evaporation boundary condition at the gas-oxide interface. A simple version of the model gives the deposition rate (dN)/dt = ngAot1/2 where ng is the concentration of caesium in the gas and Ao, the 'absorptivity', is a property of the surface. At low temperatures (below about 300 deg. C), caesium was retained by the surface. More recently, the experimental programme has been extended to cover deposition on graphite surfaces. Results show that significant retention takes place at temperatures typical of the cooler region of a CAGR circuit, although desorption is rapid at higher temperatures. A computer programme, CAESAR3, has been written to apply this model to the circuit of a CAGR. The programme handles a flexible set of parameters and can accommodate changing temperatures, pressures, flow rates, leak rates and source terms in a circuit which may have two interconnected branches. Measurements have been made of caesium distributions in the boilers of the Windscale prototype AGR and in the Hinkley Point 'B' CAGR. The results obtained are broadly in agreement with the model, although there are a number of apparent differences. Possible reasons for these are discussed. (author)

  12. Bichromatic State-insensitive Trapping of Caesium Atoms

    OpenAIRE

    Metbulut, M. M.; Renzoni, F.

    2015-01-01

    State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required w...

  13. Distribution of Caesium-137 in Samples Consisting of Soft Tissue, Bone and Bone Marrow

    International Nuclear Information System (INIS)

    The investigations which were performed up to now on the distribution of-caesium-137 in the human organism could not explain exactly the distribution of the radiocaesium between bone and bone marrow. That is why a reliable estimation of the radiation burden of the skeleton caused by the incorporation of atmospheric caesium-137 is not given in the literature. Therefore, the concentration of caesium-137 in compact bones as well as in bone marrow was determined. Furthermore, the concentration of caesium-137 in the soft tissue of the same individuals was measured. (author)

  14. Interdigitated electrode array based sensors for environmental monitoring of caesium

    Energy Technology Data Exchange (ETDEWEB)

    Nickson, I D [John Tyndall Nuclear Research Institute and Centre for Materials Science, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Boxall, C [Engineering Department, Lancaster University, Lancaster LA1 4YR (United Kingdom); Port, S N, E-mail: c.boxall@lancaster.ac.uk [DSTL, Salisbury, Wiltshire SP4 0JQ (United Kingdom)

    2010-03-15

    The requirement for on-line and in-situ monitoring of analytes in process and effluent streams and in ground waters has become increasingly more important in recent years. We therefore describe the development of the transduction element for a fully automated online instrument for the detection of caesium. The sensor layer for this instrument employs an Ion Selective Conductimetric Microsensor (ISCOM) as the detector. This is based upon a plasticized polymeric membrane incorporating a selective ionophore, overlaying two interdigitated microelectrode arrays. A direct relationship has been observed between the bulk conductance (as determined by the microelectrodes) of the ionophore loaded membrane and the concentration of the primary ions in solution. Caesium selective ISCOMs were prepared using an ion selective membrane containing the commercially available ionophore Calix [6]arene-hexaacetic acid hexaethyl ester, polyvinylchloride (PVC) and plasticiser Nitrophenylether (NPOE). The relative levels of membrane components have also been varied in order to further enhance the ISCOM response. We also present preliminary data concerning the caesium selectivity with respect to a range of possible interferents, including rubidium.

  15. Interdigitated electrode array based sensors for environmental monitoring of caesium

    Science.gov (United States)

    Nickson, I. D.; Boxall, C.; Port, S. N.

    2010-03-01

    The requirement for on-line and in-situ monitoring of analytes in process and effluent streams and in ground waters has become increasingly more important in recent years. We therefore describe the development of the transduction element for a fully automated online instrument for the detection of caesium. The sensor layer for this instrument employs an Ion Selective Conductimetric Microsensor (ISCOM) as the detector. This is based upon a plasticized polymeric membrane incorporating a selective ionophore, overlaying two interdigitated microelectrode arrays. A direct relationship has been observed between the bulk conductance (as determined by the microelectrodes) of the ionophore loaded membrane and the concentration of the primary ions in solution. Caesium selective ISCOMs were prepared using an ion selective membrane containing the commercially available ionophore Calix [6]arene-hexaacetic acid hexaethyl ester, polyvinylchloride (PVC) and plasticiser Nitrophenylether (NPOE). The relative levels of membrane components have also been varied in order to further enhance the ISCOM response. We also present preliminary data concerning the caesium selectivity with respect to a range of possible interferents, including rubidium.

  16. Interdigitated electrode array based sensors for environmental monitoring of caesium

    International Nuclear Information System (INIS)

    The requirement for on-line and in-situ monitoring of analytes in process and effluent streams and in ground waters has become increasingly more important in recent years. We therefore describe the development of the transduction element for a fully automated online instrument for the detection of caesium. The sensor layer for this instrument employs an Ion Selective Conductimetric Microsensor (ISCOM) as the detector. This is based upon a plasticized polymeric membrane incorporating a selective ionophore, overlaying two interdigitated microelectrode arrays. A direct relationship has been observed between the bulk conductance (as determined by the microelectrodes) of the ionophore loaded membrane and the concentration of the primary ions in solution. Caesium selective ISCOMs were prepared using an ion selective membrane containing the commercially available ionophore Calix [6]arene-hexaacetic acid hexaethyl ester, polyvinylchloride (PVC) and plasticiser Nitrophenylether (NPOE). The relative levels of membrane components have also been varied in order to further enhance the ISCOM response. We also present preliminary data concerning the caesium selectivity with respect to a range of possible interferents, including rubidium.

  17. The removal of caesium ions using supported clinoptilolite.

    Science.gov (United States)

    De Haro-Del Rio, D A; Al-Jubouri, S; Al-Joubori, S; Kontogiannis, O; Papadatos-Gigantes, D; Ajayi, O; Li, C; Holmes, S M

    2015-05-30

    In this paper, the sorptive kinetic and diffusional characteristics of caesium ion removal from aqueous solution by carbon-supported clinoptilolite composites are presented. Natural clinoptilolite was supported on carbonaceous scaffolds prepared from date stones. Thermal treatment was applied to produce voids in the carbon which was conditioned using polydiallyldimethylammonium chloride to facilitate the clinoptilolite attachment. This method allowed the formation of a consistent zeolite layer on the carbon surface. The composite was applied in the removal of non-radioactive caesium ions showing an enhanced uptake from 55 mg g(-1) to 120.9 mg g(-1) when compared to clinoptilolite. Kinetic studies using Pseudo First Order model revealed an enhanced rate constant for carbon-clinoptilolite (0.0252 min(-1)) in comparison with clinoptilolite (0.0189 min(-1)). The Pseudo-First Order model described the process for carbon-clinoptilolite, meanwhile Pseudo Second Order model adjusted better for pure clinoptilolite. Diffusivity results suggested that mass transfer resistances involved in the Cs(+) sorption are film and intraparticle diffusion for natural clinoptilolite and intraparticle diffusion as the mechanism that controls the process for carbon-clinoptilolite composite. The most significant aspect being that the vitrified volume waste can be reduced by over 60% for encapsulation of the same quantity of caesium due to the enhanced uptake of zeolite. PMID:25702634

  18. The behaviour of radioactive caesium in a boreal forest ecosystem

    International Nuclear Information System (INIS)

    The distribution of radioactive caesium (Cs-134 and Cs-137) in a boreal forest ecosystem is studied with focus in the dynamics of the turnover in, and loss from, the system. Measurements of the distribution in soil and vegetation, as well as the loss of radioactive caesium by run-off from a catchment, constitute the basis for an analysis of the caesium budget in the system. Comparisons of the distribution of 'old' Cs-137, i.e. originating from fallout due to the atmospheric nuclear weapons test, and that due to deposition after the accident in Chernobyl 1986 are used for extrapolations to future situations concerning transport of Cs-137 via the food chains over berries and moose to man. The exposure in a long term perspective due to the average intake of Cs-137 in the Swedish population by consumption of meat, milk, and milk products (i.e. of an agricultural origin) is compared to that due to ingestion of the forest products: berries (bilberry, lingonberries, and cloudberries) and moose meat. (au) (34 refs.)

  19. Caesium absorption by barley - influence of its retention by the soil - competitive action of potassium

    International Nuclear Information System (INIS)

    We have studied, in various culture media, how the absorption of caesium by barley varies with its concentration, and how this absorption can be in competition with a similar alkali cation-potassium. We have also considered the caesium distribution in the ground in particular radio-active caesium, between the soil and solution, as a function of the amount of caesium. From our work it is clear that barley behaves very differently according to whether the caesium is in a nutritive solution or is in the soil: for a nutritive solution, the fraction of caesium (radioactive and stable) absorbed by barley remains practically constant in the presence of increasing amounts (relatively small) of stable caesium; in soil, the fraction of the radio-active caesium absorbed increases as the stable caesium content (fairly low) of the soil increases, in relationship with a rapidly decreasing selectivity of the soil for Cs+. The difference between these results is thus explained by the very pronounced selectivity of the illitic soil studied for Cs+, as long as the proportion of Cs remains low, about as low as that of most natural soils. Furthermore, the K+ ion is in competition with the Cs+ ion, for absorption by barley in a culture medium in a nutritive solution or in soil, only when the potassium concentrations are relatively low, of the order of the nutritive maximum. This shows that the addition of potassium to a medium already rich in this element does not reduce the absorption of caesium by barley. The choice of experimental conditions close to natural conditions (nutritive media strong in calcium) and the examination of the distribution of radioactive caesium between the soil, the soil solution and the plant in the presence of very low doses of stable caesium make these results interesting from the 'atomic health' point of view; it should be expected that a definite contamination risk exists for plants cultivated on synthetic media and for plants such as rice and cress

  20. Development of electrokinetic remediation for caesium: A feasibility study of 2D electrode configuration system

    Science.gov (United States)

    Syah Putra, Rudy

    2016-02-01

    Agar matrix was artificially contaminated with caesium and subjected to rapid assessment of electrokinetic treatment on the basis of the 2D electrode configuration. The effect of caesium concentration on the process was investigated using different electrode configuration (i.e. rectangular, hexagonal and triangular). During treatment the in situ pH distribution, the current flow, and the potential distribution were monitored. At the end of the treatment, the caesium concentration distribution was measured. The results of these experiments showed that for caesium contamination, pH control is essential in order to create a suitable environment throughout the agar matrix to enable contaminant removal. It was found that the type of electrode configuration used to control the pH affected the rate of caesium accumulation. All of the electrode configurations tested was effective, but the highest caesium extraction was achieved when the hexagonal pattern was used to control the pH. After 72 h of treatment at 50 mA, the concentration of caesium decreased gradually from the second and first layer of agar matrix throughout the cell, suggesting that most of the caesium was concentrated on the cathode part.

  1. Uptake Evaluation Of Glass house Grown Grasses In Radio phyto remediation Of Caesium-Contaminated Soil

    International Nuclear Information System (INIS)

    A glass house experiment was performed to evaluate the uptake of grasses viz. Napier and Vetiver in radiophytoremediation of caesium-contaminated soil. The glass house radiophytoremediation experiment was designed according to the Randomized Complete Block Design (RCBD). The grasses were grown in troughs filled with soil mixed with a known specific activity of 134Cs. Initial Cs activity and activity after different cultivation time intervals of 1, 3, 6 and 9 months were analyzed using gamma spectrometer direct measurement. The results showed the uptake of caesium by Napier and Vetiver after 9 months with the transfer factors (TF) were 4.70 and 6.25, respectively. Meanwhile, the remediation of caesium from contaminated soil at the same time was 95.25 % (Napier) and 95.58 % (Vetiver). Both grasses have been found to accumulate caesium, with Vetiver accumulating higher than Napier. Thus, the present study suggests that Vetiver could be used as a potential plant for radiophytoremediation of caesium. (author)

  2. Caesium uptake by Callovian-Oxfordian clayrock under alkaline perturbation

    OpenAIRE

    Gaboreau, Stéphane; Claret, Francis; Crouzet, Catherine; Giffaut, Eric; Tournassat, Christophe

    2012-01-01

    Caesium is one of the main radionuclides present in radioactive waste. 135Cs has a very long half-life (~2.3 106 yr) and Cs is, therefore, one of the main safety relevant elements (Kissane, 2009). For these reasons, Cs is one of the most widely studied radionuclides in environmental sciences. Numerous works have been devoted to developing sorption models enabling the prediction of Cs sorption in clay-rich media. These models consider the presence of different exchange sites at clay surfaces h...

  3. Assessment of the caesium-137 flux adsorbed to suspended sediment in a reservoir in the contaminated Fukushima region in Japan

    International Nuclear Information System (INIS)

    We estimated the flux of caesium-137 adsorbed to suspended sediment in the Kusaki Dam reservoir in the Fukushima region of eastern Japan, which was contaminated by the Fukushima Nuclear Power Plant accident. The amount and rate of reservoir sedimentation and the caesium-137 concentration were validated based on the mixed-particle distribution and a sediment transport equation. The caesium-137 and sediment flux data suggested that wash load, suspended load sediment, and caesium-137 were deposited and the discharge and transport processes generated acute pollution, especially during extreme rainfall-runoff events. Additionally, we qualitatively assessed future changes in caesium-137 and sediment fluxes in the reservoir. The higher deposition and discharge at the start of the projection compared to the 2090s are most likely explained by the radioactive decay of caesium-137 and the effects of reservoir sedimentation. Predictions of the impacts of future climate on sediment and caesium-137 fluxes are crucial for environmental planning and management. - Highlights: • Sediment and caesium-137 fluxes were validated incorporating the effects of extensive reservoir operations. • The sediment and caesium-137 concentrations in a reservoir within a contaminated territory were determined. • The impacts of future projection on suspended sediment and caesium-137 fluxes were qualitatively assessed. - This study estimated the flux of caesium-137 adsorbed to suspended sediment focussing on a major reservoir in the Fukushima region of eastern Japan

  4. Caesium transfer to placenta, urine and human milk

    International Nuclear Information System (INIS)

    After the Chernobyl accident few measurements on radioactive contamination of maternal milk, placenta and urine of nursing mothers were carried out. Two previous studies on breast milk contamination were conducted in different Italian areas by the Physics Department of the National Institute of Health (Laboratorio di Fisica, Istituto Superiore di Sanita). In the first study conducted in collaboration with the Epidemiological Unit of the Lazio District, I-131, Cs-134 and Cs-137 concentrations were measured in mixed breast milk samples pooled from 5-10 women in the first week after delivery, from May 1986 to December 1987, in the Rome area. The second research was conducted, in collaboration with the Lecco Hospital, in 1989 on a group of women living in the Como Lake area (Lombardia), which was one of the areas of Northern Italy most heavily affected by Chernobyl fallout, because of intensive rainfall in the first few days after the accident. The specific diet and caesium content in maternal milk were studied recruiting pregnant women at the ''respiratory autogen training'' course. In this case, Cs-l37, Cs-134 and K-40 concentration in placenta and urine of the mothers under study had also been measured. Aim of this paper is to discuss these data and investigate the relationship between Cs-137 contamination of maternal milk, placenta and urine as a contribution to a better understanding of caesium metabolism in pregnant and nursing women

  5. Bichromatic State-insensitive Trapping of Caesium Atoms

    CERN Document Server

    Metbulut, M M

    2015-01-01

    State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required wavelength of 935.6 nm is inconvenient in terms of experimental realization. Bichromatic state-insensitive trapping is proposed to overcome the lack of suitable laser sources. We first consider pairs of laser wavelengths in the ratio 1:2 and 1:3, as obtained via second- and third- harmonic generation. We found that the wavelength combinations 931.8-1863.6 nm and 927.5-2782.5 nm are suitable for state-insensitive trapping of caesium atoms. In addition, we examine bichromatic state-insensitive trapping produced by pairs of l...

  6. Bichromatic state-insensitive trapping of caesium atoms

    Science.gov (United States)

    Metbulut, M. M.; Renzoni, F.

    2015-12-01

    State-insensitive dipole trapping of multilevel atoms can be achieved by an appropriate choice of the wavelength of the trapping laser, so that the interaction with the different transitions results in equal AC Stark shifts for the ground and excited states of interest. However this approach is severely limited by the availability of coherent sources at the required wavelength and of appropriate power. This work investigates state-insensitive trapping of caesium atoms for which the required wavelength of 935.6 nm is inconvenient in terms of experimental realization. Bichromatic state-insensitive trapping is proposed to overcome the lack of suitable laser sources. We first consider pairs of laser wavelengths in the ratio 1:2 and 1:3, as obtained via second- and third- harmonic generation. We found that the wavelength combinations 931.8-1863.6 nm and 927.5-2782.5 nm are suitable for state-insensitive trapping of caesium atoms. In addition, we examine bichromatic state-insensitive trapping produced by pairs of laser wavelengths corresponding to currently available high power lasers. These wavelength pairs were found to be in the range of 585-588 nm and 623-629 for one laser and 1064-1080 nm for the other.

  7. Behavioural Changes in Rats Internally Contaminated with Caesium-137

    International Nuclear Information System (INIS)

    Full text: The effect of low doses of 137Cs on the exercise performances, behavioural and learning processes in rats is analysed. The experiments were performed on albino male and female Wistar rats. The animals were divided as follows: two groups, M1 and F1 (males and females) internally contaminated with 490 Bq 137Cs by milk ingestion during 34 days, groups M2 and F2, internally contaminated with 283 Bq by ingestion of milk during 38 days and two control groups. The duration of forced swimming, the active avoidance reaction and the total latency time in the shuttle-box and the score of aggressive behaviour were analysed. The following results were obtained: (1) the duration of forced swimming decreased significantly in the contaminated groups as compared with controls. (2) The active avoidance reaction in the shuttle-box increased in female groups and decrease in male groups. (3) The total latency time of the same reaction was lower in animals internally contaminated with 137Cs in the first day of learning. (4) The score of aggressive behavioural rise significantly, especially in female groups. The results can be explained by neurotoxic action of the caesium on several central neural areas including monoaminergic and endocrine mechanisms and sex dependence of caesium accumulation in the organism. (author)

  8. Industrial treatment of solutions of fission products. Separation of caesium-137

    International Nuclear Information System (INIS)

    Two types of chemical treatment can be considered for the manufacture of solid sources for industrial uses from fission product solutions remaining after plutonium extraction: a) concentration of the solution and preparation of solid sources from the bulk material, without separation, b) separation of one or several fission products from which the sources are made. Examination of the radio-chemical composition of the mixture of fission products that will be available from the Marcoule reactors (G1, G2 and G3) shows that caesium-137 accounts for 30 per cent of the γ energy available immediately after the plutonium separation, 70 per cent two years after and 100 per cent after five years. There is practically no advantage in making sources from bulk fission products, since the separation of caesium-137 is no more complicated and yet it results in a material with more potential uses. The separation of caesium-137 by a method based on the standard phospho-tungstate precipitation method has been considered. Previously, the precipitated caesium phospho-tungstate was dissolved and caesium was recovered from the solution by cation-exchange or by removal of phosphate and tungstate ions by anion-exchange. A study has now been made, of the metathesis of caesium phospho-tungstate to barium phosphate and tungstate by the action of barium hydroxide, the caesium being obtained in solution as the hydroxide. The advantages of this new procedure are: - greater decontamination of caesium-137 without further purification, - possibility of direct transformation to caesium sulphate, - general simplification of the procedure and, consequently, of the equipment. (author)

  9. Caesium sorption-desorption behaviour in bottom sediments

    International Nuclear Information System (INIS)

    The objective of this study is to focus on the sorption and desorption behavior of Cs in the complex heterogeneous system of bottom sediments in order to better understand the cesium behavior during the Baltic Sea water flooding events to the Curronian Lagoon and transport of suspended particles from the Curronian Lagoon to the Baltic Sea. Three sorption and desorption experiments were carried out. A sample of bottom sediments collected in the Curronian Lagoon was used for sorption experiments. Total carbon (TC) and total organic carbon (TOC) were determined using a LECO CS-125 analyser. The stable Cs concentration was determined using ICP-MS, and clay minerals were identified by X-ray diffraction. Filtered sea water of 7.0 salinity labelled with 134Cs was used for the sorption experiment. The total concentration of Cs in solution was 0.04ppb. The solids were separated by centrifugation at 4000 rpm after different contact time between solution and sediments. Details of the experiment are described in publication. The modified Tesser sequential extraction method was used to study association of Cs in sediments. 137Cs and 134Cs activities were measured using an intrinsic germanium detector (resolution 1.9keV/1.33MeV and efficiency - 42%). The precision of 134Cs measurements by gamma spectrometry was 134Cs in sediments after different contact time indicated that more than 70% of 134Cs tracer was sorbed during the first three days. Similar results were obtained during the second experiment. The decrease in the caesium amount in the exchangeable fraction desorbed by NH4+ possibly corresponds to the decrease in the number of frayed edge sites available for Cs sorption. The decrease in the sorption rate accompanied by an increase in association of 134Cs with carbonate fraction can be attributed to the effect of coatings that are usually present in natural heterogeneous sediments. In the sediment sample used for the sorption experiment, a high content of carbonate was

  10. Prepubertal changes in the metabolism of caesium in girls?

    International Nuclear Information System (INIS)

    The results are presented of determinations from 1963 to 1967 of the 137Cs/K ratio in three children (two girls and a younger boy). In the two girls the ratio was at a maximum in late 1963. The decline by a factor of more than four during 1965-1967 was consistent with the contemporaneous reduction in dietary contamination. When adjusted to allow for the decreasing intake, the ratio shows an increase from the age of about 9.5 in each girl. It is suggested that this is a reflection of an increase in the biological half-life of caesium in the girls, associated with prepubertal hormonal changes. 5 refs.; 4 figs.; 2 tabs

  11. Caesium immobilization in hydrated calcium-silicate-aluminate systems

    International Nuclear Information System (INIS)

    A special field of application of cementitious materials in using cements for immobilization of low and medium level radioactive wastes. Clarification of mechanisms of binding is complicated by the multicomponent nature of the solidifying matrix. In the present work, interest is turned to one of the most difficult to confine, long half-life isotopes, the caesium isotope. The cement matrix for solidification of the radioactive waste can be considered, with simplification, as a CaO-SiO2-Al2O3-H2O system. The various compositions of hydrated cementitious assemblages were investigated with respect to their Cs sorption by measuring the Cs distribution ratios (Rd) therein. Trends in sorption properties were detected, and the section of the ternary phase diagram with the best performance was identified

  12. Sorption of caesium in soils from various regions of Libya

    International Nuclear Information System (INIS)

    The sorption characteristics of caesium in some common Libyan soils from various regions of Libya were studied using batch techniques. The influences of clay content, contact time and various concentrations of Cs+, K+, and NH4+ in the solution on the sorption ratio for Cs+ were determined by using tracer 134Cs. All experiments were carried out in the presence of a supporting electrolyte (0.01 N CaCl2). An apparent steady state was reached in 4 - 7 days. Important parameters influencing the sorption were clay content, pH, and the concentrations of other cations, in particular K+ and NH4+ which compete with Cs+ for the sorption sites. (orig.)

  13. Highly efficient H- ion source for cyclotrons without caesium

    International Nuclear Information System (INIS)

    Full text: An internal high current H- ion source for cyclotrons and other injectors was developed which makes use of some very effective methods of H- ion production. The source is distinguished by high gas efficiency. A surface-plasma method for H- ion production without using caesium vapor was realized. A strong current arc discharge was applied for dissociation and dissociative ionization of H2 molecules. An H+-H- recharge method using a residual gas layer adjusted by thickness and pressure was realized in this source. In a double-chamber ion source with high-current discharge in the single chamber and low-current low-volt discharge in the different chamber is used the supplementary electrode which a composite-plate cover with low electronic work function (∼1,5 eV). Anticipate of ion current of H- is 1-2 mA. (author)

  14. Observation of EIA in closed and open caesium atomic system

    Institute of Scientific and Technical Information of China (English)

    Zhao Jian-Ming; Zhao Yan-Ting; Huang Tao; Xiao Lian-Tuan; Jia Suo-Tang

    2005-01-01

    We present an experimental study on electromagnetically induced absorption (EIA) in the closed transition of a degenerate two-level Cs atomic system. The coupling and probe lasers coupled with the transition 6S1/2F=4 →6P3/2F'=5 of caesium atom. The signal of EIA was obtained and the frequency detuning and intensity effect of the pumping laser were experimentally investigated. The EIA signal in 6S1/2 F=4 → 6P3/2 F'=4 and 6S1/2 F=4 → 6P3/2F'=3 open transitions was also obtained. As the repumping laser couples with the transition of 6S1/2 F=3 → 6P3/2F'=4, the EIA signal is increased due to the hyperfine optical pumping.

  15. Crustaceous lichens sensitive monitor of caesium-137 radiation level in terrestrial environment

    Institute of Scientific and Technical Information of China (English)

    Du Chunguang; Zhao Ye; Zhang Jing; Xu Cuihua

    2005-01-01

    The activity of caesium-137 (Bq/kg) in the crustaceous lichens and other samples was determined to prove the feasibility that crustaceous lichens work as a sensitive biology monitor to record the caesium-137 (Bq/kg) radiation levels of terrestrial environment. The measurements were performed with GEM series HPGe (high-purity Germanium) coaxial detector system (ADCAM -100) made by EC & GORTEC Company in USA. It was found that the activity of caesium-137 (Bq/kg) in the crustaceous lichens was one order of magnitude higher than that found in surface soil,and was over three orders of magnitude higher than those found in the familiar biological samples. These results proved that crustaceous lichens may be one of the most sensitive biological monitors about the remote transmission and environmental radiation levels of caesium-137.

  16. Molecular and collisional processes during three photon ionisation transitions in caesium and rubidium vapours

    International Nuclear Information System (INIS)

    Interesting molecular and collisional processes are evident during three photon ionisation transitions in caesium and rubidium vapours. In particular, for caesium vapour broad hybrid resonances (molecular plus atomic transitions) have been identified. In rubidium vapour three photon ionisation s-nd, s-ns transitions as well as forbidden s-np have been observed with the s-s transitions being more prominent than theory predicts. These observations have been explained in terms of collisional ionisation. (author)

  17. The behaviour of fission product caesium in LMFBR primary circuits: experiments in a small stainless steel loop containing circulating sodium

    International Nuclear Information System (INIS)

    The available information which can be used to determine the likely behaviour of fission product caesium, released from defective fuel pins, in the primary circuit of a sodium-cooled fast reactor has been reviewed and assessed. For a relatively small number of fuel pin failures over a reactor lifetime 137Cs is potentially a predominant contributor to dose rates on out-of-core steel components if the adsorption of caesium on these components is sufficiently high. Shortcomings are identified in the existing data on caesium adsorption from liquid sodium onto austenitic steel surfaces. This has enabled the definition of those areas of work which are necessary before the behaviour of fission product caesium in the primary circuit, and the possible requirement of any alleviatory measures, can be predicted with precision and confidence. Experiments are described from which the mechanism of adsorption of caesium onto steel surfaces was elucidated, thereby enabling the prediction of the likely sorption behaviour of fission product caesium on components in the primary circuits of LMFBRs. The potential use of cold-trapping as a means of removing caesium from sodium was also investigated and found to be of no significant value; alternative methods for caesium removal are discussed. The development of methods for decontamination of steelwork which has become contaminated by caesium sorption onto chromium (III) oxides is described, although it is not clear that the levels of contamination which would arise by this mechanism under normal LMFBR operating conditions would necessitate such treatment. (author)

  18. Study of caesium sorption on Na and Ca-Mg bentonites using batch and diffusion experiments

    International Nuclear Information System (INIS)

    In most deep geological repository concepts sorption of radionuclides on bentonite represents a very important process in retarding radionuclide migration into geosphere. Despite a huge amount of studies concerning caesium sorption on bentonites, there are still some problems requiring deeper clarification. One of the most important issues is the difference between distribution coefficients (Kd) obtained using batch and diffusion experiments. The results of a comprehensive study of caesium sorption on Na bentonite (industrial sorbent Volclay KWK 20-80, Suedchemie, Germany) and Ca-Mg bentonite (raw bentonite, Rokle deposit, Czech Republic) using both of these methods suggest that the reasons of this difference can originate from different sources connected with conditions of experiments and the ways of their evaluation. The main uncertainties of caesium sorption on two different bentonites using the batch method were described and the influence on sorption has been demonstrated. Detailed mineralogical and chemical analysis of bentonite samples confirmed the differences in mineral composition and physical-chemical properties of selected bentonite types. These data are necessary for better understanding of their sorption behaviour and for sorption results evaluation. The results suggest that caesium-selective minerals present in bentonites as admixtures can govern the sorption behaviour of caesium on different bentonites at its trace concentrations. At higher concentrations, the ion exchange on non-selective sites dominates the sorption and can be well-described using sorption isotherms and ion-exchange models. It also follows from the performed experiments that the caesium sorption on studied bentonites cannot be described using the simple Kd method that is often used to evaluate distribution coefficients from diffusion experiments. The uncertainties of evaluation of sorption coefficients from diffusion experiments can also be connected with the way of diffusion

  19. DECOMMISSIONING OF A CAESIUM-137 SEALED SOURCE PRODUCTION FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Murray, A.; Abbott, H.

    2003-02-27

    Amersham owns a former Caesium-137 sealed source production facility. They commissioned RWE NUKEM to carry out an Option Study to determine a strategy for the management of this facility and then the subsequent decommissioning of it. The decommissioning was carried out in two sequential phases. Firstly robotic decommissioning followed by a phase of manual decommissioning. This paper describes the remote equipment designed built and operated, the robotic and manual decommissioning operations performed, the Safety Management arrangements and summarizes the lessons learned. Using the equipment described the facility was dismantled and decontaminated robotically. Some 2300kg of Intermediate Level Waste containing in the order of 4000Ci were removed robotically from the facility. Ambient dose rates were reduced from 100's of R per hour {gamma} to 100's of mR per hour {gamma}. The Telerobotic System was then removed to allow man access to complete the decommissioning. Manual decommissioning reduced ambient dose rates further to less than 1mR per hour {gamma} and loose contamination levels to less than 0.25Bq/cm2. This allowed access to the facility without respiratory protection.

  20. Determination of erosion and accretion rates using caesium-137

    International Nuclear Information System (INIS)

    Within drainage basins, soil erosion status may be indicated by levels of absorbed 137Cs within the soil. Further refinements of the relationship between soil loss and 137Cs loss for various soil types, geographic locations for soils experiencing severe erosion will enable more accurate predictions of net soil loss rates to be made. For a long time quantification of sediment sources within catchments has been a difficulty for hydrogeomorphologists interpreting sediment outputs, and the 137Cs technique holds much promise for its resolution. Storage, another major component of the sediment budget, may also be quantified by 137Cs, provided careful sampling and interpretation are practised. Caesium-137 as a dating-tool is less useful at sites with low rates of sediment accumulation, ostensibly those unaffected by human activity in the catchment. The tracer 137Cs has become a well-established tool in sediment research in several countries. The provision of adequate detector facilities will ensure the further development of the technique in Australia, thus helping hydrogeomorphologists achieve the goal of predicting sediment delivery ratios and drainage basin sediment budgets with some certainty

  1. The effect of caesium and xenon addition on negative hydrogen ion production

    International Nuclear Information System (INIS)

    The presence of caesium in hydrogen discharges is known to increase the extracted negative hydrogen ion current by up to sixteen fold. The mechanism for this phenomenon is not understood. Here Langmuir probe and photodetachment techniques have been used to measure the effects on plasma parameters, including the negative ion density, of adding caesium and xenon to a multicusp ion source. The addition of xenon, also a heavy element but unreactive, allows possible negative ion confinement effects to be explored. No significant change in the negative ion density was observed when up to 20% xenon was introduced, although other plasma parameter changes were observed. Caesium addition increased the negative ion concentration. This increase was found to depend on the wall temperature. copyright 1996 American Institute of Physics

  2. Recent studies on the interception and the retention of caesium by grass, barley and peas

    International Nuclear Information System (INIS)

    Experiments with artificial depositions of radio caesium during the growth period have been carried out. The studies are complementary to experiences after the Chernobyl fallout and aimed at a description of the relative transfer to the harvest products of grass, barley and peas after initial interception during growth. It was found that the apparent residence half-time of caesium in grass on old established leys producing winter feed was about one month and that the reduction in nuclide content up to the harvest time for this reason mainly depended on dilution by growth. Also the grain crops were found to be sensitive to depositions during almost the whole season. It should be due to translocation of caesium within the plant. The data obtained can make the basis for prediction of the consequences of fallouts. (au)

  3. Caesium dynamics in the peats and associated vegetation of northern Greece and northern Scotland

    International Nuclear Information System (INIS)

    Sequential analyses have shown that Chernobyl-derived caesium has been largely retained in Greek basin peats (highly cultivated, base-rich, sedge peats) and retained/cycled in Scottish upland peats (uncultivated, base-poor, blanket peats). To investigate the mechanisms of retention and cycling in the Scottish peat/vegetation system, a laboratory experiment was carried out involving 'microcosms' intact peat cores. Festuca ovina was grown from seed in the cores prior to nebuliser-application of simulated rain containing caesium-134. The major factors investigated were competitive ion exchange from ammonium (designed to simulate animal waste inputs), freeze-thaw activity, and cropping (designed to simulate upland grazing). The effects of these factors are discussed in relation to the physio-cochemical and biological properties of the peat and vegetation and to our observations of the movement of caesium in the field. (author)

  4. A simple method with imaging plates for examination of soil contaminated with radioactive caesium

    International Nuclear Information System (INIS)

    A simple and convenient system with imaging plates (IPs) was well constructed for the radioactivity examination of soil contaminated with radioactive caesium. A set of two IP strips was vacuum-sealed with thin polyethylene film to prevent the IP strips from direct contacting soil and from being moisturized. In the examination of radioactive soil, a stainless steel pipe including this IP strip monitor was put into the ground and then it was kept in a lead container after being pulled out of the ground for the reduction of the surrounding gamma-ray background. In addition, a sensitive reader was well made for the measurement of the photostimulated luminescence through the scanning of a laser beam on the IP strip. It was confirmed from experiments on actual radioactive-caesium-contaminated soil that the IP strip monitor with the reader effectively detected beta-rays from radioactive caesium and could be satisfactorily used for the examination of radioactive soil. (author)

  5. Uptake and retention of radio-caesium in earthworms cultured in soil contaminated by the Fukushima nuclear power plant accident

    International Nuclear Information System (INIS)

    To understand the effects of radionuclides on non-human biota and the environment, it is essential to study the intake and metabolism of radio-isotopes in earthworms which are among the most important soil organisms, and Eisenia fetida, which were used in this study, are known to be sufficiently sensitive to chemicals and representative of common earthworms. In this study, we assessed the concentration ratios, uptake and retention, absorbed dose rate, and distribution of radio-caesium in earthworms. The concentration ratios of 137Cs (i.e., the concentrations of radio-caesium in earthworms relative to those in dry soil) were higher early in the culturing period and decreased gradually over the experimental period. 137Cs taken up by E. fetida was cleared rapidly after the worms were cultured in radio-caesium-free soil, suggesting that the metabolism of radio-caesium in earthworms is very rapid. Autoradiography demonstrated that the concentration of radio-caesium within the digestive tract was as high as that in the soil, while radio-caesium in the body tissue was lower than radio-caesium in the soil and was almost uniformly distributed among earthworm tissues. The highest absorbed dose rate of total exposure to radio-caesium (137Cs + 134Cs) was calculated to be 1.9 × 103 (μGy/day) in the earthworms. - Highlights: • We assessed the concentration ratios of 137Cs in earthworms/dry soil. • The distribution of radio-caesium was relatively uniform throughout the earthworm body without any distinguishable accumulation in specific organs or tissues. • We estimated the absorbed dose rate of radio-caesium for earthworms

  6. The Body Burden of Caesium-137 in People of Southern Finland 1961-1963

    International Nuclear Information System (INIS)

    In connection with the investigations of the caesium-137, body burden of Finnish Lapps several measurements of smaller groups of people living in Southern Finland were carried out. In November 1961 eleven Helsinki inhabitants, five men and six women, 15 to 54 yr. old, were counted for caesium-137 and potassium in Stockholm. None of these persons were laboratory workers, two were schoolboys. They were apparently healthy. Their diet was studied by the interview method. Ten of these people were counted again in the mobile whole-body counter of the Radiochemical Department of the University of Helsinki one year later. The average body burden of caesium-137 in men (5, average age 29) had increased from 8.4 nc in November 1961 to 18.4 nc in November 1962, in women (5, average age 34) from 2.9 nc to 8.7 nc. Potassium contents were the same within 2% (men 140 g, women, 100 g) For more detailed studies larger control groups were selected at the beginning of 1963 and counted four times, in February, May, August and October. For the group of men 25 privates of an infantry battalion (age 19, average weight 65 kg), for women 24 girl students of a household school (age 22, average weight 60 kg), were selected. In both cases the diet could be checked in detail and could be considered to be an average Finnish diet. In addition, the individual food consumption of each subject was studied by interview with the aid of weighed samples. Caesium-137 contents of both diets were determined for the time periods between the measurements. In both groups the caesium-137 content remained about constant (men, 17,5 nc; women, 11 nc) until the end of June, when the caesium-137 content of milk and meat was approximately doubled within about one week. At the end of August the body burden of caesium-137 had increased in, both groups to about 40% above the spring level in the middle of October the men's values had increased by 22%, the women's values by 14% of the August level. The determination of

  7. Radiometric detection of non-radioactive caesium flux using displaced naturally abundant potassium

    International Nuclear Information System (INIS)

    We report on a method that allows for the radiometric detection of non-radioactive caesium by the measurement of potassium ions displaced from an ion exchange barrier. Electrokinetic transport of K+ and Cs+ through concrete samples was measured using a bespoke scintillation detector to monitor electrolyte concentrations. Results show experimental ionic flux and diffusion parameters of non-active caesium (∼1 x 10-5 mol m-3) were consistent with those recorded for potassium and also with values reported in relevant literature. This work demonstrates a novel concept that can be applied to proof-of-concept studies that help develop the next generation of nuclear decommissioning technologies. (author)

  8. Investigations on caesium 134 and 137 contamination of game hunted for food in Hessia

    International Nuclear Information System (INIS)

    The amount of caesium 134 and 137 in Hessian game hunted for food (556 animals) after the reactor accident at Chernobyl was investigated. Comparisons have been made before and after the accident. Although there was only a very low level of contamination, the contamination rate of different species varied; on average, the Red Deer showed the highest activity (130 Bq/kg). The level of caesium contamination was mostly influenced by the permanent habitat of the animals. The main influence was due to regional, geographical and meteorological conditions. The influence of age or sex could not be determined. The contamination rate was shown to decrease with time

  9. Kinetics of caesium and potassium absorption by roots of three grass pastures and competitive effects of potassium on caesium uptake in Cynodon sp

    International Nuclear Information System (INIS)

    Caesium uptake by plant roots has been normally associated with the uptake of potassium as the potassium transport systems present in plants have also the capacity to transport caesium. Three grass species (Eragrostis curvula, Cynodon sp and Distichlis spicata) growing in seminatural grassland of central Argentina were selected to study their capability to incorporate Cs+ (and K+) using electrophysiological techniques. Although the 137Cs soil inventory ranged between 328-730 Bq m-2 in this region, no 137Cs activity was detected in these plants. However, all the species, submitted previously to K+ starvation, showed the uptake of both Cs+ and K+ when micromolar concentrations of these cations were present in the medium. The uptake showed saturation kinetics for both cations that could be fitted to the Michelis-Menten model. KM values were smaller for K+ than for Cs+, indicating a higher affinity for the first cation. The presence of increasing K+ concentrations in the assay medium inhibited Cs+ uptake in Cynodon sp., as expected if both cations are transported by the same transport systems. This effect is due to the competition of both ions for the union sites of the high affinity potassium transporters. In field situation, where soil concentration of Cs+ is smaller than K+ concentration, is then expectable that caesium activity in plants is not detectable. Nevertheless, the studied plants would have the capacity to incorporate caesium if its availability in soil solution increases. In addition, studies of Cs/K interaction can help us to understand the variability in transfer factors

  10. Kinetics of caesium and potassium absorption by roots of three grass pastures and competitive effects of potassium on caesium uptake in Cynodon sp.

    Science.gov (United States)

    Ayub, J. Juri; Valverde, L. Rubio; Garcia-Sanchez, M. J.; Fernandez, J. A.; Velasco, R. H.

    2008-08-01

    Caesium uptake by plant roots has been normally associated with the uptake of potassium as the potassium transport systems present in plants have also the capacity to transport caesium. Three grass species (Eragrostis curvula, Cynodon sp and Distichlis spicata) growing in seminatural grassland of central Argentina were selected to study their capability to incorporate Cs+ (and K+) using electrophysiological techniques. Although the 137Cs soil inventory ranged between 328-730 Bq m-2 in this region, no 137Cs activity was detected in these plants. However, all the species, submitted previously to K+ starvation, showed the uptake of both Cs+ and K+ when micromolar concentrations of these cations were present in the medium. The uptake showed saturation kinetics for both cations that could be fitted to the Michelis-Menten model. KM values were smaller for K+ than for Cs+, indicating a higher affinity for the first cation. The presence of increasing K+ concentrations in the assay medium inhibited Cs+ uptake in Cynodon sp., as expected if both cations are transported by the same transport systems. This effect is due to the competition of both ions for the union sites of the high affinity potassium transporters. In field situation, where soil concentration of Cs+ is smaller than K+ concentration, is then expectable that caesium activity in plants is not detectable. Nevertheless, the studied plants would have the capacity to incorporate caesium if its availability in soil solution increases. In addition, studies of Cs/K interaction can help us to understand the variability in transfer factors.

  11. Caesium activity in nursing mothers and in the mother's milk one year after Chernobyl accident

    International Nuclear Information System (INIS)

    Linear correlation between Cs-137 concentration in mother's milk and the mother's Cs-137 whole body activity was obtained. A simple metabolic model is proposed to interpret measured data. Caesium activity in mother's milk was five times lower than in dairy products. (orig./HP)

  12. The selectivity of zirconium phosphate for caesium in electrochemical ion exchange

    International Nuclear Information System (INIS)

    The properties of amorphous zirconium phosphate are investigated as an inorganic ion exchanger for use in liquid waste treatment by electrochemical ion exchange. Experiments to determine and increase the selectivity for caesium exchange over sodium are discussed, including various pulsed waveforms and studies with rotating membranes. Automation of a sampling system with pH and atomic absorption measurements is described. (author)

  13. In vivo experiments on the accumulation of caesium-134 in heart and skeletal muscle of pigs

    International Nuclear Information System (INIS)

    The accumulation of 134Cs in muscle tissue of pigs after intravenous application of the isotope was studied. Calculated on the basis of plasma concentration the accumulation of the caesium isotope in muscle tissue was quantitatively affected by the following factors: mode and duration of application (single dose or continuous application), condition of the muscle (healthy or damaged muscle), proportion of red fibres in the muscle, and time elapsed between end of infusion and assay. The excretion of 134Cs from plasma of pigs by the kidney and intestine was faster than the removal of the caesium isotope from skeletal muscles. Two weeks after a l6-day period of continuous infusion of 134Cs, the radioisotope concentrations in skeletal muscles were 150 to 400 times those found in plasma. Compared with potassium ions in muscles, accumulation of the heavier and slightly larger caesium ions was 1.7 to 2.5 times higher. Caesium accumulation in muscles with a relatively high proportion of red fibres was higher than in white muscles. When the muscles were damaged by feeding a selenium- and vitamin-E-deficient diet for six weeks, accumulation of 134Cs was greatly reduced. (author)

  14. Theoretical calculations of primary particle condensation for cadmium and caesium iodide vapours

    International Nuclear Information System (INIS)

    This report considers a model of aerosol nucleation from the vapour phase which has been developed by Buckle. The applicability of the model has been tested by considering the condensation of caesium iodide and cadmium vapours under a wide variety of pre-mixed flow conditions of interest to PWR severe accident studies. (U.K.)

  15. Rhenium volatilisation as caesium perrhenate from simulated vitrified high level waste from a melter crucible

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, T.A.; Short, R.J.; Gribble, N.R.; Roe, J.I. [National Nuclear Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom); Steele, C.J. [Sellafield Ltd, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom)

    2013-07-01

    The Waste Vitrification Plant (WVP) converts Highly Active Liquor (HAL) from spent nuclear fuel reprocessing into a stable vitrified product. Recently WVP have been experiencing accumulation of solids in their primary off gas (POG) system leading to potential blockages. Chemical analysis of the blockage material via Laser Induced Breakdown Spectroscopy (LIBS) has shown it to exclusively consist of caesium, technetium and oxygen. The solids are understood to be caesium pertechnetate (CsTcO{sub 4}), resulting from the volatilisation of caesium and technetium from the high level waste glass melt. Using rhenium as a chemical surrogate for technetium, a series of full scale experiments have been performed in order to understand the mechanism of rhenium volatilisation as caesium perrhenate (CsReO{sub 4}), and therefore technetium volatilisation as CsTcO{sub 4}. These experiments explored the factors governing volatilisation rates from the melt, potential methods of minimising the amount of volatilisation, and various strategies for mitigating the deleterious effects of the volatile material on the POG. This paper presents the results from those experiments, and discusses potential methods to minimise blockages that can be implemented on WVP, so that the frequency of the CsTcO{sub 4} blockages can be reduced or even eradicated altogether. (authors)

  16. Caesium inhibits the colonization of Medicago truncatula by arbuscular mycorrhizal fungi

    International Nuclear Information System (INIS)

    Contamination of soils with radioisotopes of caesium (Cs) is of concern because of their emissions of harmful β and γ radiation. Radiocaesium enters the food chain through vegetation and the intake of Cs can affect the health of organisms. Arbuscular mycorrhizal (AM) fungi form mutualistic symbioses with plants through colonization of the roots and previous studies on the influence of AM on Cs concentrations in plants have given inconsistent results. These studies did not investigate the influence of Cs on AM fungi and it is therefore not known if Cs has a direct effect on AM colonization. Here, we investigated whether Cs influences AM colonization and if this effect impacts on the influence of Rhizophagus intraradices on Cs accumulation by Medicago truncatula. M. truncatula was grown with or without R. intraradices in pots containing different concentrations of Cs. Here, we present the first evidence that colonization of plants by AM fungi can be negatively affected by increasing Cs concentrations in the soil. Mycorrhizal colonization had little effect on root or shoot Cs concentrations. In conclusion, the colonization by AM fungi is impaired by high Cs concentrations and this direct effect of soil Cs on AM colonization might explain the inconsistent results reported in literature that have shown increased, decreased or unaffected Cs concentrations in AM plants. - Highlights: • Colonization of plants by arbuscular mycorrhizal fungi is negatively affected by increasing soil caesium concentrations. • Shoot caesium concentrations are not influenced by AM fungi at soil caesium concentrations above about 3 μg Cs kg−1. • The direct effect of caesium on AM fungi might impact on the influence of AM fungi on Cs accumulation in plants. • This might explain the inconsistent results reported in literature on Cs accumulation in AM plants

  17. The use of bentonite and zeolite as caesium-binders in feed to reindeer - experiences from Sweden

    Directory of Open Access Journals (Sweden)

    Birgitta Åhman

    1990-09-01

    Full Text Available Feeding is used in Sweden to lower radiocaesium levels in reindeer before slaughter. In feeds used for this purpose, bentonite is added as a caesium-binder to prevent absorption of radiocaesium, since the animals usually have som access to contaminated pasture in their corrals. Bentonite is efficient as a caesium-binder but increases water consumption and excretion of urine. Zeolite has been used as a caesium-binder to reindeer in a few experiments. The effect, however, has been inferior to that of bentonite. It seems that zeolite, mixed in feeds, loose some of its effect as the feed is stored. The need of a caesium-binder is demonstrated by results from practical feeding of reindeer where radiocaesium levels have not decreased as expected when feed without bentonite has been used.

  18. Deposition of caesium and strontium substances on growing crops: Effects and countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Bengtsson, S. (Swedish Univ. of Agricultural Sciences, Dept. of Soil and Environment (Sweden))

    2010-03-15

    Full text: To investigate how the two radionuclides caesium (134Cs) and strontium (85Sr) are taken up and transported to the harvested parts (the seeds) by fallout in a growing crop. Further on how this is related to the size and time of the fallout. From the information collected recommendation of suitable countermeasures at different scenarios to prevent further spreading to food stuff can be suggested. In the project a number of field trials where artificial deposited by the two radionuclides 134Cs and 85Sr in a contaminated rainfall, on the two agricultural crops Brassica napus L. (spring rape) and Triticum aestivum L. (spring wheat). The trial contained different treatments where the radionuclides where deposited by a rainfall simulator at different growing stages of the crops. The field trial continues for two more years and the reason for that is due to the variation of the climate for the different years. The radionuclides were applied in the form of a wet deposition and the rainfall was about 1 mm m-1 with a concentration of 20 kBq m-1 for each radionuclide. Samples were taken from the plots at the day(s) after the treatment of contaminated rainfall, both from the latest treated plots and from the earlier treated plots. The hypotheses are: 1. That the size of the deposition and the time in relation to the development stages of the crop will steer how much caesium and strontium that are coughed, detained and transferred to the harvested parts. 2. That the levels of caesium and strontium in the harvested parts of the crops are related to the insensitivity of the rainfall after a deposition and also how long time the first intensive rain will occur. 3. That the size of caesium and strontium in harvested plant parts are related to the size of uptake throw the leaves. 4. If the deposition of caesium and strontium will be the same, the levels of caesium will be much higher than strontium in the harvested parts. (author)

  19. Caesium and plutonium migration in forest soils of the Chernobyl 30 km zone

    International Nuclear Information System (INIS)

    Vertical distributions of radiocaesium and plutonium inventories and uranium ratios (238U:235U) are presented for forest soils at three sites within the Chernobyl 30 km exclusion zone. The uranium ratios indicate the presence of reactor fuel fragments ('hot particles') at all sites, but with declining significance with distance from the ChNPP. Caesium and plutonium distributions in soil profiles were evaluated using a compartmental model to derive migration half times for each horizon. Migration rates at each site were lowest for the AoH horizon. The AoH horizon at the site with the largest apparent population of 'hot particles' exibited the longest caesium and plutonium migration half times, which generally decreased with distance from the ChNPP (i.e. with decreasing 'hot particle' densities). Plutonium appears to be more mobile than radiocaesium, possibly due to the movement of soluble Pu humic complexes formed within the surface organic soil horizons. (author)

  20. Caesium-137 as an indicator of geomorphic processes in a drainage basin system

    International Nuclear Information System (INIS)

    Caesium-137 from fallout from nuclear weapons tests is adsorbed on fine sediments and becomes an effective tracer. It is hypothesised that within a drainage basin, sites undergoing little or no erosion accumulate Cs-137 in their upper layers; cultivated soils will have Cs-137 uniformly distributed within the cultivated layer; eroded soils, cultivated or not, will have relatively less Cs-137, depending on the severity of erosion. Accumulated sediments will have characteristic Cs-137 profiles reflecting temporal fallout variations and sedimentation history. This hypothetical model is largely confirmed by results from Maluna Creek basin, where erosion and accumulation of sediments has taken place. Soils under viticulture have about one third the Cs-137 content of soils with grass cover, indicating more severe erosion under cultivation. Caesium-137 profiles in alluvial fan and flood plain deposits correlate with sediment layers and known cultivation history

  1. New ion selective materials. Application to the selective extraction of caesium

    International Nuclear Information System (INIS)

    This research thesis addresses the synthesis and assessment of ion selective materials. The first part reports the development of a general method of assessment of ion selective materials. In the second part, the author describes different methods used to insolubilize macro-cycles on hydrophilic polymers. The obtained polyurethanes are synthesised. These hydrophilic polymers display interesting complexing properties and selectivities with respect to cations of alkali metals. Then the author addresses the improvement of selectivity with respect to caesium of ion exchange resorcinol-formaldehyde resins. Different factors affecting selectivity are identified, and the concept of molecular print is used to study the improvement of selectivity. The effect of macro-cyclic structures on phenolic resins with respect to caesium is highlighted

  2. Experimental investigations of caesium and iodine release from irradiated UO2

    International Nuclear Information System (INIS)

    The modelling of the behaviour of fuel rods whose temperature is rising requires a knowledge of fission product release under such conditions. For this purpose an experimental apparatus has been developed and built for the determination of vapour pressures by the Knudsen method. The results obtained on UO2 samples of light-water reactor fuel with a burnup of 32 MWd tU-1 shows that a noticeable release of iodine and caesium occurs only at fuel temperature above 1400-15000C. Thus the influence of iodine on the mechanical behaviour of fuel rods under loss-of-coolant-accident conditions can be neglected. The onset temperature for iodine release matches excellently the pellet-clad-interaction (PCI) threshold identified in ramping experiments. The relative release is nearly equal for iodine and caesium, and increases rapidly with temperature and burnup. (author)

  3. Psychosocial aspects of the victims of the accident with caesium-137 in Goiania (1987-1994)

    International Nuclear Information System (INIS)

    In September of 1987 two men took possession of and violated a source containing Caesium-137, which caused the Radiological Accident of Goiania. Besides the direct victims, a significant part of the community of Goiania was directly involved with this accident. The psychosocial impact in the social groups involved in this radiological accident - the population as a whole, immediate neighbours of contaminated sites, professionals and the victims themselves - gave rise to specific behaviour and attitudes which will be discussed in this paper. (author)

  4. Caesium-137 in a boreal forest ecosystem. Aspects on the long-term behaviour

    International Nuclear Information System (INIS)

    Cycling of radioactive caesium, particularly the isotope Cs-137, is studied in boreal forest biotopes mainly located at the Vindeln experimental forest, 60 km NW of Umeaa, Sweden, (64 degrees 16'N, 19 degrees 48'E). The distribution of radioactive caesium in this forest ecosystem, prior to and in different periods after the Chernobyl accident, reflects the existence of fast changes particularly at an early stage after the deposition, superimposed on slow redistribution over long time periods. The definite causes to this complex dynamic behaviour are not yet unambiguously established. In this work we use the specific results from local field studies as a basis to describe the general pattern and time dependence of Cs-137 redistribution in a boreal forest. We raise the hypothesis that: 'Cs-137 present in a boreal forest tends towards a homogenous distribution among the living cells of that system'. This hypothesis is based on physiological characteristics concerning transport over cell membranes and intracellular distribution in comparison to potassium, and the apparently conservative conditions prevailing for caesium in boreal ecosystems - e.g. the facts that very little of the radioactive caesium deposited over the forest area is lost from the system by run off, more than 90% of the total deposition of Cs-137 resides in the upper organic horizon in podzol areas, and that the availability in the ecosystem, as can be seen from the Cs-137 concentration in moose meat, is not significantly different in 1985 (i.e. prior to the Chernobyl accident) in comparison to the period 1986-1990. The aim of this work is to elucidate how predictions, based on our hypothesis about redistribution processes in the boreal forest, corroborates with the main features in the time-dependent change of Cs-137 activity, according to measurements on perennial vegetation from the local sites. In particular the implicit dependence of the dynamics of the redistribution processes on primary

  5. Investigations on frequency distribution of whole-body retention parameters of caesium in humans

    International Nuclear Information System (INIS)

    The fission product caesium radionuclides, 137Cs and 134Cs, play an important role in internal dose received by members of the population as the consequence of reactor accidents or nuclear weapon tests. Better knowledge on the biokinetic parameters of these radionuclides leads to more realistic dose estimate. Since these parameters, apart from their age and sex dependence have also individual variability, it is worth to investigate quantitatively and characterize statistically these variations. (author)

  6. Environmental study of radioactive caesium in Greek lake fish after the Chernobyl accident

    International Nuclear Information System (INIS)

    The radiological status of radiocaesium in the Greek environment until 1986 has been characterized by the impact of world-wide fallout. During 1986, the Chernobyl nuclear accident resulted in an average deposition of total caesium(134Cs + 137Cs) of ∼ 9 kBq m-2 in Greece, while regional averages ranged within 3-45 kBq m-2. The radioactive contamination of the lake ecosystems is potentially a radiologically important consequence of the accident. The effects of 137Cs and 134Cs introduced into a number of major Greek lake ecosystems has been evaluated in the present work by determination of their concentrations in various lake fish species during the years 1986, 1988 and 1989. Although the representative and predominant species typically differ from lake to lake, while the local deposition of caesium varies significantly, the bioaccumulation of caesium by the examined species seems to depend rather on the fish species than on the local environmental parameters. The time-dependence of the fish contamination has been used to evaluate the contribution of lake fish consumption to the total ingestion dose of the population. (author)

  7. The use of the tracer caesium-137 for studying sediment movement in a drainage basin

    International Nuclear Information System (INIS)

    The environmental isotope caesium-137 (137Cs), a product of atmospheric nuclear weapons tests, was used as a tracer to assess sediment sources and sediment redistribution in the drainage of Maluna Creek, Hunter Valley, New South Wales. Caesium-137 levels were found to be significantly different between the three main land-use groups of forest, grassland and vines. Caesium-137 amounts per unit area were greatest in the forest and least in cultivated vineyards, and were attributed to accelerated soil erosion from cultivated areas. Soil losses from four runoff plots correlated positively with the loss of 137Cs (in relation to estimated input) in soils adjacent to the plots. Relative amounts of 137Cs in soil profiles in a northern tributary basin of Maluna Creek were used to trace eroded soils from vineyards to sedimentation sites in adjacent alluvial fans and a downstream farm dam reservoir. The redistribution of 137Cs in the sedimentary deposits was related to particle size, the greatest amounts of the isotope being found on finer sediments in the reservoir

  8. The Time Analysis and Frequency Distribution of Caesium-137 Fall-Out in Muscle Samples

    International Nuclear Information System (INIS)

    For low concentrations of artificial radioactivity in the body, detrimental effect will be most likely in that fraction of the population having many times the average amount. A meaningful evaluation of the nuclear fall-out hazard can only be made if the frequency distribution of radioactivity in the population is known. Attempts to determine the shape of the distribution curve from Kulp's data on strontium-90 concentration in children's bones have met limited success because of the small sample size and lack of strontium-90-calcium equilibrium in bone. To overcome these limitations, we have measured the caesium-137 content in approximately 900 muscle samples. These tissue samples were removed during post-mortem operations from January 1959 to August 1963. The use of caesium-137 as a fission product monitor assures that all members of the group, regardless of their age, were essentially in equilibrium with the radioactive environment at the time of death. The period of investigation coincides with the first weapon test moratorium and the resumption of large- scale testing in the fall of 1961. Average caesium-137 in the samples was relatively constant throughout 1959, decreased a factor of two during 1960, and remained relatively stable until the early summer of 1962. Since mid-1962 the average level of caesium-137 radioactivity in the sample population has steadily increased and was four times greater than the 1962 minimum by the summer of 1963. Time-independent histograms of the data have been assembled by fitting a polynomial to the raw data (sample radioactivity as a function of data of death). This pooled data has been tested statistically against normal, log-normal, and gamma frequency distributions. Results indicate that the experimental distribution is definitely not Gaussian and is best fitted by a gamma distribution. By using the empirically derived gamma distribution it is possible to predict the fraction of the population having N times the average

  9. The determination of caesium and silver in soil and fungal fruiting bodies by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Methods have been developed for the determination of caesium and silver in soil and fungal samples by microwave-assisted aqua regia digestion, followed by electrothermal atomic absorption spectrometry. The procedure was found to be repeatable (for soil, RSD -1, respectively, and for fungi, RSD -1, respectively) and reasonably efficient. Silver was recovered quantitatively from reference soils, but only about 80-85% of the caesium present could be extracted. Poorer caesium recoveries (< 70%) were obtained if, as part of the sample preparation procedure, solutions were taken to dryness in glass beakers prior to analysis. The detection limits were 0.02 mg Ag and 0.09 mg Cs per gram of dry soil, which are adequate for the determination of the analytes at typical environmental levels. The methods were applied in the analysis of three types of soil, a peaty podzol, a clay loam and a sandy loam and no significant matrix interferences were observed except in the determination of caesium in the sandy loam. For caesium, non-linear response curves, thought to be due to ionisation interference, were encountered using one atomic absorption spectrometer, but were not observed with the other instrument

  10. An experimental study on the possibilities of direct transfer of caesium 137 from sediment to the carps (Cyprinus carpio L.)

    International Nuclear Information System (INIS)

    The exchanges of caesium 137 with the Rhone river water and deposits and its direct transfer from water and deposits to the carp are studied. The sediments have a high retention capacity for radiocaesium associated with fine particles and certain clays (illite). Caesium desorption from sediment to water is always very weak (less than 5% of the initial activity of the sediments); it varies with the agitation and salinity of the water. The transfer of caesium from the water to the carps is characterized by a regular increase of activity in the fish. After 63 days of experimentation, equilibrium has not been reached, the carp have retained only 1% of the water activity, and their concentration factor is about 4. The transfer of caesium from sediment to the fish is weak but regular. After 79 days of experimentation, equilibrium has not been reached. Less than 1% of the sediments activity is found in the fish; the transfer factor is about 10-3. Because of the high content of caesium 137 in sediments, the activity of the carp is increased and the concentration factor, calculated in relation to the surface water, is greater than 60

  11. Studies on an araldite-based membrane of copper hexacyanoferrate (III) as a caesium ion-sensitive electrode

    International Nuclear Information System (INIS)

    Solid membranes of copper hexacyanoferrate (III) in araldite are evaluated as a caesium ion-sensitive electrode. The electrode can be used for caesium determination in the concentration range of 10-1 to 10-4M. The potentials generated across the membrane are reproducible and steady potentials are attained in about 1 to 2 min. The same electrode can be used over a period of 6 months without significant change in potential. The electrode can be used in the pH ranges 2.5 to 6.0 at 10-2M Cs+ and 3.0 to 6.0 at 10-3M Cs+, and in presence of a number of interfering ions. Potentiometric titration of caesium nitrate with 12-molybdophosphoric acid was also carried out using the membrane as an end point indicator. (author)

  12. Caesium 137: Properties and biological effects resulting of an internal contamination

    International Nuclear Information System (INIS)

    Caesium-137 (137Cs) is a radionuclide present in the environment mainly as the result of the atmospheric nuclear weapons testing and accidents arising in nuclear power plants like the Chernobyl accident in 1986. Nowadays, the health consequences resulting from a chronic exposure to this radionuclide remain unknown. After absorption, the caesium is distributed relatively homogeneously within the body, with a more important load in children than in adults. The toxicity of 137Cs is mainly due to its radiological properties. A high dose of 137Cs is responsible for a medullar dystrophy, disorders of the reproductive function, and effects on liver and renal functions. Disorders of bone mineralization and brain damages were also described in human beings. At lowest dose, 137Cs induces disturbances of wakefulness-sleep cycle, but not accompanied with behavioural disorders. The cardiovascular system was also perturbed. Biological effects of 137Cs on the metabolisms of the vitamin D, cholesterol and steroid hormones were described, but do not lead to clinical symptoms. In human beings, 137Cs leads to an immune deficiency, congenital and foetal deformations, an increased of thyroid cancer, as well as neurological disorders. It seems that children are more sensitive to the toxic effects of caesium than the adults. At present, the only effective treatment for the decorporation of the ingested 137Cs is the Prussian Blue (Radiogardase). The use of pectin to de-corporate the ingested 137Cs, in children notably, is sometimes proposed, but its administration still remains an open question. To conclude, the available scientific data suggest that 137Cs could affect a number of physiological and metabolic functions and consequently, could participate in the health risks associated to the presence of other contaminants in the environment. (authors)

  13. Absorption spectroscopy of cold caesium atoms confined in a magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Yan Shu-Bin; Liu Tao; Geng Tao; Zhang Tian-Cai; Peng Kun-Chi; Wang Jun-Min

    2004-01-01

    Absorption spectra of cold caesium atoms confined in a magneto-optical trap are measured around D2 line at 852nm with a weak probe beam. Absorption reduction dip due to electromagnetically induced transparency (EIT)effect induced by the cooling/trapping field in a V-type three-level system and a gain peak near the cycling transition are clearly observed. Several mechanisms mixed with EIT effect in a normal V-type three-level system are briefly discussed. A simple theoretical analysis based on a dressed-state model is presented for interpretation of the absorption spectra.

  14. Isolation and identification of cobalt and caesium resistant bacteria from a nuclear fuel storage pond.

    OpenAIRE

    Dekker, L.; Osborne, T. H.; Santini, J. M.

    2014-01-01

    One of the issues facing the nuclear power industry is how to store spent nuclear fuel which is contaminated with radionuclides produced during nuclear fission, including caesium ((134) Cs(+) , (135) Cs(+) and (137) Cs(+) ) and cobalt ((60) Co(2+) ). In this study we have isolated Co(2+) and Cs(+) resistant bacteria from water collected from a nuclear fuel storage pond. The most resistant Cs(+) and Co(2+) isolates grew in the presence of 500 mM CsCl and 3 mM CoCl2 . Strain Cs67-2 is resistant...

  15. Alteration in caesium behavior in rice caused by the potassium, phosphorous, and nitrogen deficiency

    International Nuclear Information System (INIS)

    The physiological effects of critical nutrient deficiencies (K, P, N) on the uptake of caesium (Cs) and impact on plant growth has been investigated in rice plants. Growth defects were observed after 2 weeks of a state of nutrient starvation (K, P, or N). However, only K starvation produced increased Cs content in the shoot and the intensive transport to young leaves. These observations support that modification of Cs uptake and transport in rice plants was achieved based on the distinctive physiological effect of K. (author)

  16. A possible role of caesium radiations in the control of propagation of hookworm

    International Nuclear Information System (INIS)

    Faeces charcoal mixtures containing eggs of sheep hookworm, Haemonelus ocatorus were exposed to caesium radiation (23 r to 1656 r) from 1st to 7th day incubation. Each plate was exposed only once. A dose related inhibition of transformation of eggs to infective larvae was observed. The maximum effect was observed on 2nd day of incubation. The radiation has maximum effect on the 1st stage larvae followed by 2nd stage. The 3rd stage or infective larvae are relatively resistant to the effect of radiation. (author). 14 refs

  17. Sorption of caesium and strontium onto calcium silicate hydrate in saline groundwater

    International Nuclear Information System (INIS)

    Full text of publication follows: In the concept for radioactive waste disposal in Japan, cement is a potential waste packaging and backfilling material and is expected to provide chemical containment. The sorption of radionuclides onto cement materials, which controls the aqueous concentrations of elements in the pore-water, is a very important parameter when considering the release of radionuclides from the near field of a cementitious radioactive waste repository. Many safety assessment calculations currently assume radionuclide retardation as linear sorption equilibrium and describe it with a distribution ratio (Rd value). In this study, the sorption mechanism is discussed by measuring the sorption isotherm of caesium, strontium (10-5 ∼ 10-2 mol dm-3) and sodium (10-4 ∼ 10-1 mol dm-3) onto Calcium Silicate Hydrate (C-S-H gel, Ca/Si 0.65 ∼ 1.2) at a liquid:solid ratio of 100:1, to support the assumption. In addition, the competitive sorption between caesium or strontium, and sodium is studied by sorption measurements using a range of sodium chloride concentration to simulate different ionic strengths in saline groundwater. The initial and equilibrated aqueous compositions were measured in the sorption experiments and it was found that caesium, strontium and sodium were sorbed by substitution for Ca in C-S-H phases by examining the mass balance. Based on the experimental results, we propose a modelling approach in which the ion-exchange model is employed and the presence of some calcium sites with different ion-exchange log K values in C-S-H is assumed by considering the composition and the structure of C-S-H. The modelling calculation results predict the measured Rd values well and also describe the competition of sorption of caesium or strontium, and sodium in the experiments. The log K values for sorption of each cation element decreased as Ca/Si ratio of C-S-H gel increased. This agrees with the trend that C-S-H gel is negatively charged at low Ca

  18. Sorption/desorption processes of caesium and strontium in soil: is the Kd-concept adequate?

    International Nuclear Information System (INIS)

    Interaction with the soil matrix is one of the key processes for the migration of radionuclides in the terrestrial environment. Usually it is modeled by a simple distribution coefficient Kd of trace concentrations between solid and liquid phases. Laboratory experiments using a modified diffusion technique have been performed to study the interaction of caesium with a Eutric Cambisol soil pellet. Of the sorption models tested, assuming first order kinetics incorporating a Freundlich isotherm resulted in the best fit to the experimental data. The Kd model completely failed to describe the experimental data. Desorption showed a marked hysteresis. (author)

  19. Poly[μ3-aqua-aqua-μ5-(4-nitro­benzoato)-caesium

    OpenAIRE

    Graham Smith

    2013-01-01

    In the structure of the title complex, [Cs(C7H4NO2)(H2O)2]n, the caesium salt of 4-nitrobenzoic acid, the irregular CsO9 coordination sphere comprises three bridging nitro O-atom donors, a bidentate carboxylate O,O′-chelate interaction, a triple-bridging water molecule and a monodentate water molecule. A three-dimensional framework polymer is generated, within which there are water–carboxylate O—H...O and water–water O—H...O hydrogen-bonding interactions.

  20. Patients blood serum ferritin concentrations changes associated with Caesium-137 incorporation

    International Nuclear Information System (INIS)

    The results of radioimmune study of ferritin and carcinoembryonic antigen in 60 persons: 35 those who took part in liquidation of the Chernobyl accident and incorporated 25.9-70.4 MBq of Cesium-137,25 residents of Rivno Region with 7.4-203.5 MBq of the radionuclide in the organism are reported. The increased concentration of ferritin and carcinoembryonic antigen in blood serum was noted to be determined more often in the residents of the areas polluted with Caesium-137 than in liquidators. The tumor markers levels depended to some extent on bad habits (smoking, alcohol) and existing chronic diseases of the alimentary system

  1. A facility for the production of 123I by spallation of caesium

    International Nuclear Information System (INIS)

    An on-line facility for the production of 123I by spallation of elemental caesium by 482 MeV protons has been in operation at a TRIUMF beam dump for about two years. Radioxenon from the target is efficiently trapped on alumina which is subsequently used to remove the 121Te decay product. The yield is 100 mCi/h from a 20 g/cm2 target at 10 μA. Impurities are 125I 121Te 123I consists mainly of iodide along with significant iodate impurity. The product is used extensively in Canadian clinics for thyroid analyses and labelling radiopharmaceuticals. (auth)

  2. Distribution coefficients of caesium, chlorine, iodine, niobium, selenium and technetium on Olkiluoto soils

    International Nuclear Information System (INIS)

    Retention of caesium, chlorine, iodine, niobium, selenium and technetium was investigated on soil samples from Olkiluoto using laboratory batch sorption experiments. Distribution coefficients were measured for both dried and sieved and untreated (wet, not sieved) mineral soil and humus in aerobic and anaerobic conditions. Mineralogical composition of the samples was determined by XRD-analysis. Caesium was sorbed efficiently on mineral soil samples and less efficiently on humus. Sorption decreased with decreasing cation exchange capacity and clay fraction content. The effect of competing cations decreased in the order Cs+>NH4+>K+>Ca2+>Na+. Chlorine was not retained by mineral soil samples, and the sorption was weak on humus. The sorption of iodine was the strongest on humus and the weakest on the untreated mineral soil samples in the anaerobic conditions. In the mineral soil samples, the sorption decreased with decreasing organic matter content and increasing pH. The retention of niobium on soil samples was the most efficient among the studied elements. The retention was high regardless of the aeration conditions. Sorption on humus was smaller. Selenium was retained efficiently on humus. Sorption on mineral soil samples was stronger in aerobic conditions. Sorption increased with time. Technetium was sorbed well on humus and anaerobic, untreated mineral soil samples. Sorption increased with increasing organic matter content and decreasing redox potential. The results from the sorption experiments are used in the site specific radionuclide migration modelling. (orig.)

  3. Caesium-137 and sediment budgeting within a partially closed drainage basin

    International Nuclear Information System (INIS)

    Caesium-137 (137Cs) when combined with landform element analysis and sediment budgeting provides a powerful geomorphological tool in studies of erosion. Application of the 137Cs technique to a partially closed cultivated drainage basin in Saskatchewan, Canada, allowed for the identification of eroded areas, zones of stability, and depositional areas. Sediment redistribution was calculated for a 30 year period and indicated that 68% of the sites had experienced accelerated erosion rates in excess of soil formation rates (1.0 t ha-1 yr-1) 47% of the sites had rates in excess of 5.0 t ha-1 yr-1, and 14% of the sites had erosion rates greater than the upper tolerable soil loss boundary of 11.0 ha-1 yr-1. A digital elevation model indicated that eroded sites primarily had convex (divergent) shapes. These areas were also characterized by thin A-horizons, decreased total nitrogen percent, and thin zones of CaCO3 depletion. Caesium-137 and sediment budgeting indicated that there was a minor net loss of 137Cs and sediment from the partially closed basin and this was attributed to aeolian transport, which is generally ignored in 'closed' basin studies. (orig./BBR)

  4. The deposition of Chernobyl caesium-137 in heavy rain and its persistent uptake by grazing sheep

    International Nuclear Information System (INIS)

    Activity escaped from the wrecked reactor at Chernobyl for 10 days and spread over most of Europe. Part of the debris crossed Britain a week after it was emitted. Heavy thunderstorms and a northward-moving cold front washed out much of the radioactive iodine and caesium it carried, especially on to the upland areas of North Wales, northern England, SW Scotland and Ulster. Several lessons have been learnt, including information on the dry and wet removal rates. The deposition of Chernobyl debris was of transient importance to agriculture in lowland areas which are rich in clay minerals. There, levels of iodine-131 in milk in the 2 weeks following the debris' passage over the country were readily detected, even though the levels were well below Government limits, but fell to insignificance thereafter. In contrast, in upland sheep-rearing areas, the caesium has remained mobile in the acidic soils and levels in sheep have often exceeded Government limits, and have been decreasing only slowly since 1986

  5. Factors influencing caesium-137 levels in moose (Alces alces) and small game in Northern Sweden

    International Nuclear Information System (INIS)

    In the third annual hunting season after the Chernobyl accident the concentration of Cs-137 in meat of northern Swedish moose was significantly higher than in the first one (1986). In September 1986 the mean Cs concentration was 500 Bq/kg in calves but in September 1988 it has risen 1300 Bq/kg. This increase was only temporary and a rapid decline occured after September and by December 1988 the concentration of Cs was the same as in late 1986. Adult moose showed the same increase during the hunt 1988 but to a lower magnitude. Typical food plants of moose such as bilberry (Vaccinum myrtillus) and birch (Betula pubescens) showed, contradictory to expected by the level in moose, a decline of concentration caesium from 1986 to 1988. A probable explanation to the dramatically increased concentration of Cs in moose is a change in diet selection during 1988. Small mammals such as voles and lemmings showed a variation in concentration of caesium-137 which was more dependent on other factors than on their body size. This emphasize the necessity to study diet selection by herbivores in detail in order to predict uptake and changes in environmental contaminants. (orig.)

  6. Hydroxyapatite supported caesium carbonate as a new recyclable solid base catalyst for the Knoevenagel condensation in water

    OpenAIRE

    Monika Gupta; Rajive Gupta; Medha Anand

    2009-01-01

    The Knoevenagel condensation between aromatic aldehydes and malononitrile, ethyl cyanoacetate or malonic acid with hydroxyapatite supported caesium carbonate in water is described. HAP–Cs2CO3 was found to be a highly active, stable and recyclable catalyst under the reaction conditions.

  7. Use of caesium-137 as a tracer of erosion and sedimentation: Handbook for the application of the caesium-137 technique. UK Overseas Development Administration research scheme R4579

    International Nuclear Information System (INIS)

    The caesium 137 technique has become an important tool for investigating soil erosion. It permits retrospective assessment of medium-term erosion rates. The application of the technique requires only one field visit, and the results can be provided within a relatively short time. The soil redistribution rates estimated represent an average for the last 30-35 years, and are therefore less influenced by extreme events. The rates estimated represent the sum of all erosive processes. Both rates and patterns of soil redistribution may be quantitatively assessed. A range of erosion estimates may be obtained, including mean rates of erosion and deposition and net rates of soil export from the field. The whole field may be studied without disturbance to the slope environment. The spatial resolution of the data obtained is defined by the sampling strategy. Chapters of part 1 discuss the basis of the 137Cs technique, the potential for its further development, and define a protocol for its application. Part 2 includes descriptions of case studies from China, Zimbabwe and Lesotho, which illustrate the value of the 137Cs technique in the assessment of soil erosion

  8. Can inter-cultivar variation in caesium and strontium uptake reduce contamination of forage grasses? - Can inter-cultivar variation in caesium and strontium accumulation by forage grasses be used to reduce contamination of cows' milk in radiologically contaminated areas?

    International Nuclear Information System (INIS)

    Radiocaesium and radiostrontium primarily enter the food chain via plant root uptake, including indirectly via animal fodders. Inter-species variation in caesium and strontium accumulation in plants has previously been reported to be over two orders of magnitude. This variation could be exploited to select crops with relatively low uptake to reduce transfer of these radionuclides to consumers in contaminated areas. Exploiting intra-species (i.e. inter-cultivar) variation in caesium and strontium uptake has not yet been evaluated as a remediation strategy as sufficient data have not been available. As cows' milk has been one of the main contributors to human dose following the Chernobyl and Mayak accidents, we have chosen to focus on elucidating the extent and nature of inter-cultivar variation in caesium and strontium uptake in forage grasses. A total of 412 cultivars from four species of forage grass; perennial ryegrass (Lolium perenne; 284 cultivars), Italian ryegrass (Lolium multiflorum; 17 cultivars), hybrid ryegrass (Lolium hybridum; 101 cultivars) and tall fescue (Festuca arundinacea; 10 cultivars) were sampled from 20 sets of experimental plots in Aberystwyth (Wales, UK) and Edinburgh (Scotland, UK). Fifty-nine cultivars were grown in both locations. At least three replicates of the same cultivar were grown in each set of plots. Vegetation samples from 2208 plots were collected both in spring 2013 (May-June) and summer 2013 (August-September). The samples were oven-dried and milled then analysed for elemental composition using inductively coupled plasma mass spectrometry (ICP-MS). Stable caesium and strontium were measured as a proxy measurement for radiocaesium and radiostrontium concentrations. Concentrations of chemical analogues of caesium and strontium (potassium and calcium) and a number of other elements were measured. Soil samples from the experimental plots were also collected, dried, milled and analysed using ICP-MS. This paper will present the

  9. Caesium carbonate as a highly efficient catalyst for the synthesis of macrocyclicdiamides

    Directory of Open Access Journals (Sweden)

    Esmael Rostami

    2014-07-01

    Full Text Available In this research work, we report the synthesis of macrocyclicdiamides from the reaction of diesters and aliphatic diamines in the presence of caesium carbonate. It has been demonstrated that among the carbonate of alkali metals (Li2CO3, Na2CO3, K2CO3 and CS2CO3, CS2CO3 appears to be the best catalyst for macrocyclization. Diesters with different substitution patterns on the aromatic ring reacted smoothly with diamines under optimal conditions, affording the corresponding macrocycles in high yields. Introducing a rigid group (e.g., sulfone on the substrate led to somewhat decreased yield. Various substrates proved to be suitable for this macrocyclization reaction, especially, the flexible ones.

  10. Caesium Radionuclide Uptake from Wet Soil to Kangkung Plant (Ipomoea sp)

    International Nuclear Information System (INIS)

    Caesium radionuclide transfer from soil to kangkung plant (Ipomoea sp) generally consumed by people had been examined to obtain transfer factor value for internal radiation dose assessment via soil-plant-human pathway. The kangkung plants were cultivated on watered soil medium containing 134Cs with concentration of about 80 Bq/g, and the 134Cs uptake by plants, i.e root, stem, and leaves, were measured using gamma spectrometer. The 134Cs plant uptake was expressed as transfer factor, i.e. ratio of plant 134Cs concentration to 134Cs concentration on soil medium. From this research it was obtained transfer factor value of 134C from soil to plant is 0.07, and the transfer factor for root, stem, and leaves are 0.34 ; 0.05 ; 0,03 respectively, after 45 days cultivation. The transfer factor values are less than one, indicate that kangkung plant do not accumulate Cs radionuclide from soil. (author)

  11. Synthetic crystalline calcium silicate hydrate (I): cation exchange and caesium selectivity

    International Nuclear Information System (INIS)

    Solid crystalline calcium silicate hydrate (I) synthesized from equimolar amounts of Ca and Si under hydrothermal conditions at 120 oC shows cation exchange properties towards divalent metal cations such as Ni, Cu, Cd, or Hg. It also exhibits caesium selectivity in the presence of Na+. The exchange capacity and selectivity of the solid can be increased by 10 and 28 %, respectively, upon substitution of 0.01 mol of the Ca2+ in its structure by Na+. The ability of metal cation uptake by the solid was found to obey the order Ni2+ > Hg2+ > Cu2+ > Cd2+. The different affinities of calcium silicate hydrate (I) towards these ions can be used for their separation from solutions and also in nuclear waste treatment. The mechanism of the exchange reaction is discussed. (author)

  12. Promoting the conversion of caesium phospho-molybdate to zirconium molybdate

    International Nuclear Information System (INIS)

    During the management of Highly Active Liquors precipitation of caesium phospho-molybdate occurs. It was recently discovered that this solid can convert to another solid, zirconium molybdate. under certain process conditions This contribution focuses on the background chemistry to molybdates in high acid media, various chemical factors that have been considered for effecting the conversion rate, along with some experimental results. It has been observed that high temperature and low acidity are favourable to conversion. Other factors such as phosphate levels and concentration lead to an increase in the conversion time. A two-stage mechanism for the conversion has been proposed based on the experimental data and knowledge of molybdate chemistry. (authors)

  13. Redistribution of caesium-137 by erosion and deposition on an australian soil

    International Nuclear Information System (INIS)

    Caesium-137, a nuclear fallout product which is carried down to the ground by rainfall and becomes tightly adsorbed to soil particles, is being used to study soil erosion and accumulation. The measurement of 137Cs activity in soil cores in an upland catchment on the Darling Downs has revealed a vertical and areal distribution of this isotope which is in general agreement with expectations based on the topography, the observed erosion and deposition sites, the variation in 137Cs fallout through time, and hypotheses of 137Cs redistribution. Such information may allow the development of a practical technique for estimating soil erosion and accumulation rates using this isotope; it also allows testing of mathematical models of erosion/deposition processes

  14. Enhanced Raman sideband cooling of caesium atoms in a vapour-loaded magneto-optical trap

    CERN Document Server

    Li, Y; Feng, G; Nute, J; Piano, S; Hackermuller, L; Ma, J; Xiao, L; Jia, S

    2015-01-01

    We report enhanced three-dimensional degenerated Raman sideband cooling (3D DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loading magneto-optical trap. Our improved scheme involves using a separate repumping laser and optimized lattice detuning. We load $1.5 \\times 10^7$ atoms into the Raman lattice with a detuning of -15.5 GHz (to the ground F = 3 state). Enhanced 3D DRSC is used to cool them from 60 $\\mu$K to 1.7 $\\mu$K within 12 ms and the number of obtained atoms is about $1.2 \\times 10^7$. A theoretical model is proposed to simulate the measured number of trapped atoms. The result shows good agreement with the experimental data. The technique paves the way for loading a large number of ultracold Cs atoms into a crossed dipole trap and efficient evaporative cooling in a single-cell system.

  15. Experimental observation of pump-probe spectra of caesium D2 line with a vapour cell

    Institute of Scientific and Technical Information of China (English)

    Wang Yan-Hua; Yang Hai-Jing; Zhang Tian-Cai; Wang Jun-Min

    2005-01-01

    Pump-probe spectra of caesium D2 line are experimentally investigated in a Cs atomic vapour cell with copropagating orthogonal linearly-polarized pump and probe laser beams. Absorption-reduction dips duo to electromagnetically induced transparency (EIT) in multi-A-type Zeeman sublevels of 6 S1/2 F=3-6 P3/2 F'=2 hyperfine transition and absorption-enhanced peaks due to electromagnetically induced absorption (EIA) in 6 S1/2 F=4-6 P3/2 F'=5 hyperfine transition are demonstrated. With detuned pump beam abnormal sign-reversed signals inside the EIT dip and the EIA peak are clearly observed.

  16. Observation of four-wave mixing in caesium atoms using a noncycling transition

    Institute of Scientific and Technical Information of China (English)

    Wang Li-Rong; Ma Jie; Zhao Jian-Ming; Xiao Lian-Tuan; Jia Suo-Tang

    2006-01-01

    In this paper the generation of four-wave mixing (FWM) signal using a noncycling transition of caesium atoms is investigated when the pumping laser is locked to the transition 6S1/2F = 4 → 6P3/2F' = 4, and meanwhile the probe frequency is scanned across the 6S1/2F = 4 → 6P3/2 transition. The efficiency of the four-wave mixing signal as a function of the intensity of the pumping beams and the detuning of the pumping beams is also studied. In order to increase the detection efficiency, a repumping laser which is resonant with 6S1/2F = 3 → 6P3/2F' = 4 transition is used. A theoretical model is also introduced, and the theoretical results are in qualitative agreement with experimental ones.

  17. Monitoring of caesium-137 in food plants and muscle from moose, red deer and wild reindeer in 2010

    International Nuclear Information System (INIS)

    The monitoring of Cs-137 fall-out from the Chernobyl accident in 1986, started the same year. Several plants and wild reindeer in natural ecosystems in Nord-Rondane have been followed annually ever since. Four more wild reindeer ranges were included in 2001: Setesdal-Ryfylkeheiene, Hardangervidda, Nord-Ottadalen, Snoehetta and Nord-Rondane. From 2007 Forollhogna was also included. On fixed plots in Nord-Rondane and Snoehetta some of the reindeer forage plants, including both higher plants and fruticose lichens, have been sampled and analyzed annually since 1986. This was also done in 2010. In addition plants and lichens were sampled at five locations along an altitudinal gradient at Soendre Knutshoe, and at 7-8 locations along an east-west gradient from Kollaflata to Skarhoe in the Jora valley continuing along the Aursjoe to Torbudalen. All these locations were sampled annually between 1987-1990, but they have not been sampled since. In 2010 samples from red deer and moose was also collected from eight different regions located within the following counties: Oppland, Telemark, Vest-Agder, Rogaland, Sogn and Fjordane, Nord-Troendelag, Nordland and Troms. Red deer were sampled in four regions and moose in six. Both species were sampled in Oppland. In 2010 76, 49 and 61 samples were collected from wild reindeer, red deer and moose respectively. All measures of caesium levels were performed on dried samples. For the 596 samples of plants and lichen the results refer to caesium-levels in dried samples. For the meat samples, results refer to caesium-137 levels in raw meat. Due to large variation in measured levels of caesium within species and sampling area, we give median values instead of mean values.The highest caesium levels in wild reindeer were found in Snoehetta (1010 Bq/kg) and Nord-Rondane (2686 Bq/kg). The levels found in the other areas were considerably lower. The highest caesium levels in both red deer (Sel, 677 Bq/kg) and moose (Vaaga, 365 Bq/kg) were found

  18. Effects of potassium fertilization on caesium transfer to grass, barley and vegetables after Chernobyl

    International Nuclear Information System (INIS)

    The fallout in 1986 caused considerable problems on grassland in several Swedish districts. For all agricultural crops in these districts a higher level of potassium fertilization was recommended in 1987. The situation was also under observation on many field sampling and field experimental sites. The latter, which have given data for 1987-1989, were selected in different environments, on organic and on sandy soils, on permanent and temporary grassland and on land used for arable crops as well as for vegetables. Some of them were permanent pastures in the mountain district. The experimental treatments were 0, 50, 100, and 200 kg K per ha. It was found that the highest annual transfer to grass, 4-10% of the total deposition per unit area, occurred on permanent grasslands from one pasture on peat soil and from one pasture in the mountain district. The total transfer to arable crops from peat soil in control treatments was about 0.5% of the total deposition. From the mineral soils the corresponding transfers were about 0.05%. The potassium treatments were effective already on the 50-100 kg level, although 200 kg K per ha gave the highest reduction in total caesium transfer with 60-80% on grassland. The effect was observed already in the 1st cut. In the barley crops the potassium applications caused a relative reduction in caesium transfer to the same extent as on the grassland but on a lower absolute level. Among the vegetables, the order in cesium transfer to the crop took place in the order: Lettuce>Potatoes>Carrots>Leek. (au)

  19. Caesium concentration factors in wild herbivores and the fox (Vulpes vulpes L.)

    International Nuclear Information System (INIS)

    A selection of wild animals was sampled in the winter of 1986/87. The sites chosen for sampling were based on information obtained from surveys carried out by The Institute of Terrestrial Ecology in the spring and autumn of 1986. Animals included deer, grouse, hares and rabbits, and foxes which were collected as a top carnivore in the food chain. Variation in concentration of caesium between species from the same area was unpredictable; rabbits never exceeded 200 Bq kg-1 (fresh wt) of 137Cs in their flesh, even when adjacent to deer forests with over 1000 Bq kg-1 in the venison. The greatest complication arose from areas of peaty uplands where the pre-Chernobyl 137Cs from weapons-testing was much higher than expected. This pre-Chernobyl contribution amounted to 630 Bq kg-1 in a red grouse from the Pennines, and 650 Bq kg-1 in a roe deer from near the Borders, being c. 60% of the total. Significant differences in concentration factors were found depending on species, food, sex, breeding condition and age. Contrasting the decrease of the two caesium isotopes in roe deer from forestry on peat with those from woodlands on mineral soils, it appeared that after an initial fall in concentration, the only decrease thereafter occurred on the mineral soils. Nowhere were radiocaesium concentrations high enough to cause concern amongst consumers of game and other wild animals, even when levels exceed 3000 Bq kg-1 (fresh wt) as they did in red deer, red grouse and the blue hare. (author)

  20. The importance of feeding rate for the accumulation of radioactive caesium in fish after the Chernobyl accident

    International Nuclear Information System (INIS)

    The accumulation of radioactive caesium in roach (Rutilus rutilus) and perch (Perca fluviatilis) was studied in a Swedish forest lake which was heavily contaminated in spring 1986 with fallout from the reactor accident in Chernobyl. During the whole growing season of 1986, the diet, feeding rate and Cs-137 activity in the food (zooplankton) were monitored simultaneously. The activities in small perch were about twice as high as in small roach, although their diet was very similar. This can be explained solely by differences in feeding rates and metabolic activity. By accounting for these factors, the accumulation rate of radioactive caesium in fish during the first growing season after contamination of the lake could be predicted with a simple box model, with feeding rate as one of the most important regulating factors. (au) (23 refs.)

  1. Radioactive caesium in Boreal forest landscapes - Dynamics and transport in food webs. Summary of research 1986-1996

    International Nuclear Information System (INIS)

    The need for - but also the paucity of - radioecological knowledge concerning the boreal forest became particularly apparent after the nuclear power plant accident in Chernobyl in April 1986. As a consequence several new projects were initiated in the Nordic countries with particular focus on the behaviour of radioactive caesium in terrestrial and aquatic systems characteristic for the Fenno-Scandinavian landscapes. Among these new projects a multi-disciplinary co-operation in Umeaa between scientists at the Swedish University of Agricultural Sciences, and the Defence Research Establishment emerged. Initially this joint work focused mainly on descriptions of the dynamic changes of the content of radioactive caesium in soil-plant and animal communities in the county of Vaesterbotten. Most of the studies have been performed at the Vindeln experimental forest, 60 km NW of Umeaa. Plants of key interest were: bilberry (Vaccinium myrtillus), birch (Betula spp.), and pine (Pinus sylvestris), and among the animals: the moose (Alces alces) and a small rodent, the forest vole (Clethrionomus glareolus). Gradually over the past ten years the research has entered the stage where the specific causes of the caesium behaviour have been addressed - partly by the help of models developed for simulating forest ecosystems, partly by complementary field experiments. This paper reviews our main findings on this theme concerning the behaviour of radioactive caesium in boreal landscapes and significant pathways to man, as has become apparent from the radioecological co-operation dating from about ten years back. A list of the publications arising from these studies since 1986 is also presented in this report

  2. Internal dosimetry for continuous chronic intake of caesium-137 in cedar pollen after the Fukushima Daiichi nuclear power plant accident

    International Nuclear Information System (INIS)

    Internal exposures of members of the public were assessed for chronic intake of caesium-137 in cedar pollen after the Fukushima Daiichi nuclear power plant accident. Committed effective doses were evaluated using the DSYS-chronic code, which was developed at the Japan Atomic Energy Agency (JAEA). The Activity Median Aerodynamic Diameter (AMAD) and particle density for cedar pollen were assumed to be 32 μm and 0.7 g·cm-3, respectively. The observation period was from early February to the end of May, 2012. It was found that the committed effective doses for adults in Fukushima, Ibaraki, and Tokyo were 1.6-1.8×10-3 μSv, 4.5×10-4 μSv, and 3.0×10-4 μSv, respectively. Hence, it can be stated that internal doses from chronic intake of caesium-137 in cedar pollen were insignificant in 2012. In addition, retention and excretion functions for caesium-137 in the whole body were found to be dependent on the times of intake and the fractional activity related to chronic intake. (author)

  3. Long-term loss rates of radioisotopes of cobalt, zinc, ruthenium, caesium and silver by Mytilus edulis under field conditions

    International Nuclear Information System (INIS)

    Long-term loss rates of cobalt, zinc, ruthenium, caesium and silver by Mytilus edulis soft parts as well as shells were measured under field conditions in the Mediterranean Sea at Monaco during a period of 13 months after experimental contamination. For all 5 elements, the loss could be described by two exponential functions for the soft parts and one for the shells. Biological half lives for the long-lived compartment ranged from ∼20 days for caesium to 100 - 200 days for cobalt, zinc, ruthenium and silver for soft parts as well as for shells. A comparison with results from similar experiments performed under very different environmental conditions in the Baltic Sea indicated that caesium and maybe silver had a faster turnover in the warm and saline Mediterranean, whereas loss rates for cobalt and zinc were comparable. It is argued, that reliable deduction of loss rates require experiments running over several months to a year, and it is pointed out that shorter term experiments - even up to 3 months - may give biased results. (author)

  4. Experimental investigations on the caesium dynamics in H2/D2 low temperature plasmas

    International Nuclear Information System (INIS)

    The fusion experiment ITER requires powerful neutral beam injection (NBI) systems for heating and current drive. The neutral beam with a power of 16.5 MW at an energy of 1 MeV is generated via accelerating negative hydrogen ions and subsequent neutralization in a gas target. A key component of the NBI system is the ion source which has to provide accelerated current densities of 200 A/m2 D- and 300 A/m2 H-. Such ion sources are currently under development and are based on the surface conversion mechanism: atoms and positive ions from a low temperature hydrogen plasma are converted into negative ions at a low work function surface, which is therefore coated with the alkali metal caesium. For that purpose Cs is introduced into the ion source via evaporation from a reservoir. Due to its high chemical reactivity, the adsorbed Cs layer is susceptible to impurities from the residual gas, which degrades the work function of the converter surface. Consequently, the stability and reliability of a high negative ion current density significantly depends on the Cs dynamics in the hydrogen plasma and in the vacuum phases between the pulses. In order to investigate the Cs dynamics on a fundamental level including plasma and surface chemistry, dedicated studies are performed in a flexible laboratory experiment under ion source relevant conditions. The inductively coupled plasma (ICP) setup is equipped with a comprehensive set of diagnostics to measure Cs fluxes, the Cs density, local and global plasma parameters, the work function of a sample surface as well as the impurity content. Owing to the strong Cs dynamics the diagnostics can moreover be applied simultaneously to relate parameters from different diagnostics to the same experimental condition. Furthermore, a reliable Cs source is developed, capable of stable Cs evaporation with well adjustable evaporation rates. The fundamental investigations have emphasized that the Cs dynamics in vacuum as well as in hydrogen and

  5. Caesium-137 distribution, inventories and accumulation history in the Baltic Sea sediments

    International Nuclear Information System (INIS)

    The Baltic Sea is susceptible to pollution by hazardous substances due to limited water exchange, shallowness, and the large catchment area. Radionuclides, particularly 137Cs, are one of the most hazardous anthropogenic substances present in the Baltic environment. This study was conducted to present 137Cs present contamination that should further be a subject of reliable monitoring when the new Nuclear Power Plant is put into operation in the northern Poland. The sea-wide, up to date distribution of 137Cs activities and inventories in the Baltic Sea bottom sediments are presented. The 137Cs activity concentrations were measured in 30 cm long sediment cores collected at 22 sampling stations. Sediment accumulation rates were quantified by 210Pb geochronology to follow the history of 137Cs accumulation. The 137Cs inventories and fluxes were calculated. Most of the Baltic Sea sediments accumulated 137Cs in the range from 750 to 2675 Bq m−2. The Bothnian Bay is severely contaminated by 137Cs with inventories up to 95,191 Bq m−2. This region is moreover characterized by extremely large patchiness of 137Cs inventories. The 137Cs annual fluxes are highest at the two stations located at the Bothnian Bay (342 Bq m−2 and 527 Bq m−2) due to large Chernobyl 137Cs contamination of that region and high sediment accumulation rates. When these stations are excluded, the recent, annual mean value of 137Cs load to the Baltic Sea deposits is 38 ± 22 Bq m−2. The distribution of radio-caesium inventories over the Baltic Sea nowadays reflects the pattern of Chernobyl contamination. The radio-caesium deposited in surface sediments is not permanently buried, but may be resuspended and redeposited by currents, bioturbation or anthropogenic activities. -- Highlights: • 137Cs contamination in the Baltic Sea was studied before the new NPP is put into operation. • Bothnian Sea sediments are severely contaminated by 137Cs (inventories up to 95,191 Bq m−2). • Most of the

  6. Soil erosion of agricultural land in Western Australia estimated by caesium - 137

    International Nuclear Information System (INIS)

    The caesium-137 technique was used to estimate net soil loss from 10 hill slopes in the agricultural area of Western Australia. The gravel fraction of the soil was found to have approximately 56% of the total 137Cs activity found on the 137Cs appeared not to have uniformly labelled the soils in uncleared areas, possibly due to the redistribution of rainfall in the canopy and above the soil surface, and the water repellence of some soils. A previously established calibration curve was used to calculate net soil losses from the 10 hill slopes. Potato-growing land and slopes below rock outcrops in the Wheat Belt appear to have experienced the most severe erosion since the soils were first labelled with 137Cs in the mid 1950s (19-27 t ha-1 yr-1). Hill slopes below rock outcrops had appreciably less 137Cs than those below lateritic breakaways, indicating the presence of sheet erosion. 15 refs., 2 tabs., 7 figs

  7. A dynamic model of caesium transport in lakes and their catchments

    International Nuclear Information System (INIS)

    A mathematical model has been developed to predict radiocaesium concentrations over time within individual compartments of the lake and its catchment. The lake has been divided into five compartments; catchment, lake water (epilimnion and hypolimnion during stratification), lake sediment and fish. Radiocaesium enters the lake via contaminated rainfall and catchment runoff. A proportion of this radiocaesium absorbs onto suspended solids in the lake. This proportion is represented by a distribution coefficient. Sedimentation of the suspended solids occurs at a rate defined by the areal removal coefficient and results in increased caesium concentrations in the sediment. The ingestion of radiocaesium by either water column or benthic feeding fish is described by transfer functions. The model has been tested against data collected from Esthwaite water and Windermere shortly after the Chernobyl reactor accident from May 1986 to December 1987. The model simulates observed radiocaesium concentrations in Esthwaite lake water and sediment and also in lake water, sediment and fish in Windermere. The model could form the basis of a valuable management tool for the water industry should a major airborne pollution event occur again. (author)

  8. The use of caesium-137 measurements to establish a sediment budget for the Start catchment, Devon

    International Nuclear Information System (INIS)

    Caesium-137 (137Cs) measurements have been used to investigate the delivery of sediment from the hillslopes to a lake which marks the downstream limit of the small agricultural Start basin in Devon, UK. Total 137Cs inventories and 137Cs depth distributions in sediment cores were used to estimate that the eroded sediment stored within the fields and on the flood plain of the main river was equivalent to sediment yields of ca. 21 and 30 t km-2 year-1. Based on published information on sediment accumulation in the lake, the minerogenic sediment yield from the basin was estimated to be ca 29 t km-2 year-1. The erosion rate on the hillslopes in the basin, calculated as the sum of the sediment yield to the lake and the two storage components, is ca. 80 t KM-2 year-1. Of the soil eroded from the slopes more than 60% is stored at intermediate locations and the sediment delivery to the lake is less than 40%. The calculated soil erosion rate for the Start basin is consistent with an estimate of the erosion rate for the basin of the nearby Old Mill Reservoir of ca. 63 t km-2 year-1. (Author)

  9. Mapping of caesium fallout from the Chernobyl accident in the Jotunheimen area

    Energy Technology Data Exchange (ETDEWEB)

    Baranwal, Vikas C.; Ofstad, Frode; Roenning, Jan S.; Watson, Robin J.

    2011-07-01

    As a consequence of the Chernobyl accident, several areas in Norway received radioactive fallout. One of these areas is the eastern part of Jotunheimen in central Norway. Immediately after the accident in 1986, the Geological Survey of Norway (NGU) performed airborne gamma-ray spectroscopy in central Norway. At that time, it was not possible to calculate reliable radionuclide concentrations, and the data were presented as total counts per second. Several man-made radionuclides were present in the initial fallout, but due to short half-lives, most of these have now disintegrated into stable isotopes. 137Cs, with a half-life of 11.000 days ({approx} 30 years) is still present in the environment in significant quantities, leading to high radioactivity levels in meat from reindeer and sheep. To obtain a detailed map of the caesium fallout concentration in Jotunheimen, an airborne gamma-ray spectrometry (AGRS) survey was carried out, focussing on reindeer grazing areas. This project was a cooperation between Reindeer Husbandry Administration, Norwegian Radiation Protection Authority and the Geological Survey of Norway. (auth)

  10. Radiative heat transfer in plasma of pulsed high pressure caesium discharge

    Science.gov (United States)

    Lapshin, V. F.

    2016-01-01

    Two-temperature many component gas dynamic model is used for the analysis of features of radiative heat transfer in pulsed high pressure caesium discharge plasma. It is shown that at a sufficiently high pressure the radial optical thickness of arc column is close to unit (τR (λ) ∼ 1) in most part of spectrum. In this case radiative heat transfer has not local character. In these conditions the photons which are emitted in any point of plasma volume are absorbed in other point remote from an emission point on considerable distance. As a result, the most part of the electric energy put in the discharge mainly near its axis is almost instantly redistributed on all volume of discharge column. In such discharge radial profiles of temperature are smooth. In case of low pressure, when discharge plasma is optically transparent for own radiation in the most part of a spectrum (τR(λ) << 1), the emission of radiation without reabsorption takes place. Radiative heat transfer in plasma has local character and profiles of temperature have considerable gradient.

  11. Caesium and tungsten behaviour in the filamented arc driven Kamaboko-III negative ion source

    International Nuclear Information System (INIS)

    The ITER neutral beam injection is based on the acceleration and neutralization of negative deuterium ions. The target performance for the ITER beam source is to accelerate to 1 MeV a 40 A D- beam, with a current density of 200 A m-2, with pulse lengths of ≥1000 s. It was found that in long pulse operation the negative ion yield from the filamented Kamaboko III ion source (a model of ITER ion source) degrades in comparison with short pulse operation, <5 s. This could be linked to the behaviour of caesium (Cs), which is added to the source to increase its negative ion yield and tungsten (W) evaporated from filaments. Cs and W are co-adsorbed on the source walls and the plasma grid and the composition of this coating can vary during long pulse operation. The possible consequences of this changing surface on the negative ion production will be discussed. Tungsten filaments have a limited lifetime in the ion source and changing filaments and refilling of the Cs oven are the only scheduled maintenance events for the ITER injectors. These are complicated operations as the ITER injectors will be highly activated and all maintenance has to be carried out remotely. Therefore, increasing the filament lifetime and decreasing the Cs consumption are highly desirable. This paper presents results of relative measurements (including spectroscopic and chemical) of the W content of the Kamaboko-III source and reports relevant calculations on Cs consumption and W evaporation

  12. Enhancement of the work function of indium tin oxide by surface modification using caesium fluoride

    International Nuclear Information System (INIS)

    The work function of indium tin oxide (ITO) was modified using caesium fluoride (CsF). Various concentrations of CsF was spin-coated on top of ITO and baked while the residual CsF was washed away with DI water. The work function of all the ITO samples was measured using ultraviolet photoelectron spectroscopy and it was found that the work function of ITO reaches as high as 5.75 eV. The work function rapidly increases with small concentrations of CsF solution and then decreases for higher concentrations. Using atomic force microscopy and x-ray photoelectron spectroscopy, the cause was determined to be the change in surface roughness and the oxygen concentration, with the former having a much greater influence on the work function than the latter. The current density of ITO/poly(vinylcarbazole)/Al hole-only devices using the modified ITO increases by more than seven orders of magnitude compared with the control device. (paper)

  13. Effect of soil potassium and calcium on caesium and strontium uptake by plant roots

    International Nuclear Information System (INIS)

    Caesium-134 and 85Sr root uptake was studied in lettuce plants growing in two contaminated soils with contrasting properties: sandy-loam versus sandy texture, each with 1.5 and 0.1 cmol kg-1 of K exchangeable forms, and 9.1 and 1.6 cmol/ kg-1 of Ca exchangeable forms, respectively. The soil was contaminated by aerosols representative of a nuclear power plant accidental release at far-field conditions. The percentage of the total deposition absorbed by mature plants was always very low: 0.04% and 0.28% for 134Cs and, 1.33% and 5.17% for 85Sr in sandy-loam and sandy soil, respectively. In plants, 134Cs and 85Sr radionuclide activity concentrations decreased over time. The transfer factors were higher in the sandy soil. Greater K selectivity than 134Cs was always observed, although the selectivity of K was higher in the sandy soil which had a lower K concentration. In the sandy-loam soil which had a higher Ca concentration, selectivity of 85Sr was higher than that of Ca. These results suggest that radionuclide uptake by roots depended on the availability in the soil of the radionuclides and root uptake selectivity, which were both related to the nutrient concentration in the soil solution. (Author)

  14. Strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions

    International Nuclear Information System (INIS)

    This work is devoted to the quantification and the identification of the predominant processes involved in strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions. The transport and fate of radionuclides in the subsurface is affected by various physical and chemical processes including advective and diffusive transport as well as chemical and biological transformations. Laboratory experiments and the use of a multiple tracer approach allow to isolate the contributions of each elementary process and to control the physico-chemical conditions in the system. To be more representative of the field conditions, we decided to perform column miscible displacement experiments. We perform batch and flow-through reactor experiments to characterize the radionuclides sorption mechanisms. Miscible displacement experiments within homogeneous columns and modeling allow to characterize the hydrodynamic properties of the soil and to describe the radionuclides behaviour under dynamic conditions at different water contents. We show that the water content of porous media affect the transport behaviour of inert and strongly sorbing radionuclides. Our results demonstrate that a parametrized transport model that was calibrated under completely saturated conditions was not able to describe the advective-dispersive transport of reactive solutes under unsaturated steady state conditions. Under our experimental conditions, there is no effect of a decrease of the mean water content on the sorption model parameters, but the transport parameters are modified. We established for the studied soil the relation between hydrodynamic dispersion and water content and the relation between pore water velocity and water content. (author)

  15. The kinetics of caesium absorption by roots of winter wheat and the possible consequences for the derivation of soil-to-plant transfer factors for radiocaesium

    International Nuclear Information System (INIS)

    Caesium (Cs) uptake in roots of winter wheat followed a dual pattern similar to that established for potassium uptake in barley roots. This suggests the operation of two discrete uptake systems for Cs. The 'System 1' (low concentration) uptake mechanism for caesium, however, can be resolved into two hyperbolic components which both obey Michaelis-Menten kinetics. The Michaelis-Menten equation was used to derive a function which describes the variation in solution-to-root transfer factor for any element for which the appropriate root uptake constants (Km and Vmax) can be determined. This function successfully described available data for root uptake of caesium and potassium, predicting that the solution-to-root transfer factor decreases in relation to an increase in the substrate concentration of each respective element. At substrate concentrations equivalent to carrier-free radiocaesium concentrations, however, the solution-to-root transfer factor predicted by the function and by empirical data suggests that the relationship between root uptake and solution concentration of caesium is linear. These findings are discussed in relation to the comparative physiology of caesium and potassium uptake by plant roots and with respect to radioecological studies. (author)

  16. In-vivo estimates for the uptake of caesium-137 by cattle grazing contaminated pasture around the Esk and Irt estuaries, Cumbria, U.K

    International Nuclear Information System (INIS)

    Sea water contaminated with diluted radioactive effluent from the Windscale nuclear complex in Cumbria periodically floods low-lying grazing pasture around the estuaries of the rivers Esk, Irt and Mite near Ravenglass. During 1979, an experiment was carried out to measure the transfer of caesium-137 from grass to muscle in cows grazing these pastures. Grass samples were taken and in vivo external gamma-ray measurements were made on cattle. A very low transfer coefficient was found, less than 9 x 10-4 days kg-1 with a best estimate of 4 x 10-4 days kg-1, compared with a more usual value of around 3 x 10-2 days kg-1. The low transfer seems to occur because the bulk of the caesium-137 on the grass is bound to resuspended estuarine surface sediment deposited during flooding. In this form, the caesium-137 is only poorly adsorbed across the gut of the grazing cattle. (orig.)

  17. In-vivo estimates for the uptake of caesium-137 by cattle grazing contaminated pasture around the ESK and IRT estuaries, Cumbria, U.K.

    Science.gov (United States)

    Sumerling, T J

    1981-12-01

    Sea water contaminated with diluted radioactive effluent from the Windscale nuclear complex in Cumbria periodically floods low-lying grazing pasture around the estuaries of the rivers Esk, Irt and Mite near Ravenglass. During 1979, an experiment was carried out to measure the transfer of caesium-137 from grass to muscle in cows grazing these pastures. Grass samples were taken in a vivo external gamma-ray measurements were made on cattle. A very low transfer coefficient was found, less than 9 X 10-4 days kg-1 with a best estimate of 4 X 10-4 days kg-1, compared with a more usual value of around 3 X 10-2 days kg-1. The low transfer seems to occur because the bulk of the caesium-137 on the grass is bound to resuspended estuarine surface sediment deposited during flooding. In this form, the caesium-137 is only poorly absorbed across the gut of the grazing cattle. PMID:7336201

  18. The influence of caesium-137 distribution in Poland's north-eastern ecosystem on effective dose 10 years after the Chernobyl disaster

    International Nuclear Information System (INIS)

    A comparison is presented of particular methods of exposure in the first year after the Chernobyl disaster and ten years later. This comparison shows that the population exposure due to the presence of radiocaesium in the environment results from the presence of caesium contained in the soil, which provides 68% of the dose (as compared to 32% in 1987) while the influence of diet has been reduced to 32% (from 68%). The exposure from caesium-137 contained in the air has dropped from 14% to 0. The effective dose from caesium has been 50 times smaller than that from environmental sources of the natural radiation estimated for the region under study to be 1.61 mSv.y-1. (author)

  19. Measurements of Caesium-137 in Finnish Lapps in 1962-1964 by a Mobile Whole-Body Counter

    International Nuclear Information System (INIS)

    The construction, calibration and use in-field investigations of a mobile whole-body counter of the type developed by K. Lidén et al, in Sweden are described. The lead shield of the present system (2 t) is located)in-the middle of a covered heavy truck. The subject is surrounded by a 4-cm thick lead coffin, the Nal(Tl) crystal (5 an-diam. x 3 in) being protected from the other directions than the coffin by 8 cm of lead. The instrumentation consists of a 512-channel analyser, printer, x, y-recorder, and stabilizer, which are kept in shock- and dust-proof boxes during transport. The truck is provided with a thermostated heating system and contains two dressing cubicles. The system was calibrated for caesium-137 by two methods: (1) By administering per os a precisely known amount (200 to 300 nc) caesium-137 to several subjects and determining the counting efficiency after 3 to 6 d. The excreted portion of caesium-137 was determined by collecting and analysing the faeces and urine. (2) By counting a plastic phantom filled with 70.kg of a solution containing 1552 nc caesium-137. The first method gave a 4,6% higher efficiency than the second. The efficiency obtained by the first method was adopted as, the true calibration. This was also checked by three inter-calibration measurements with two other whole-body counting laboratories. The agreement was good (within 1 to 4%). For potassium a preliminary calibration was made by the use of the phantom. The efficiency is 2.51 cpm/nc caesium-137 (0.60- 0.72 MeV, 20 channels), and 0.145 cpm/g K (1.38- 1.55 MeV, 30 channels). When the truck is parked on rock, the corresponding background counts with a 70 kg sugar phantom-are 77 cpm and, 58 cpm, respectively. On sandy soil the background is about half of that on rock. With this mobile counter three field investigations were carried out in Finnish Lapland. In May 1962 218 Lapps statistically representative groups from the three Finnish Lapp countries, Inari, Karesuanto and Utsjoki

  20. Radioactive caesium in Boreal forest landscapes - Dynamics and transport in food webs. Summary of research 1986-1996

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, R.; Nylen, T.; Palo, T

    1998-12-01

    The need for - but also the paucity of - radioecological knowledge concerning the boreal forest became particularly apparent after the nuclear power plant accident in Chernobyl in April 1986. As a consequence several new projects were initiated in the Nordic countries with particular focus on the behaviour of radioactivecaesium in terrestrial and aquatic systems characteristic for the Fenno-Scandinavian landscapes. Among these new projects a multi-disciplinary co-operation in Umeaa between scientists at the Swedish University of Agricultural Sciences, and the Defence Research Establishment emerged. Initially this joint work focused mainly on descriptions of the dynamic changes of the content of radioactive caesium in soil-plant and animal communities in the county of Vaesterbotten. Most of the studies have been performed at the Vindeln experimental forest, 60 km NW of Umeaa. Plants of key interest were: bilberry (Vaccinium myrtillus), birch (Betula spp.), and pine (Pinus sylvestris), and among the animals: the moose (Alces alces) and a small rodent, the forest vole (Clethrionomus glareolus). Gradually over the past ten years the research has entered the stage where the specific causes of the caesium behaviour have been addressed - partly by the help of models developed for simulating forest ecosystems, partly by complementary field experiments. This paper reviews our main findings on this theme concerning the behaviour of radioactive caesium in boreal landscapes and significant pathways to man, as has become apparent from the radioecological co-operation dating from about ten years back. A list of the publications arising from these studies since 1986 is also presented in this report.

  1. Caesium removal from fuel pond water using a composite ion exchanger containing nickel hexacyanoferrate

    International Nuclear Information System (INIS)

    Spent fuel elements from the Bohunice A1 reactor were stored in a pond. To limit corrosion of the cladding, they were held within thimbles which contained a corrosion inhibiting solution of potassium chromate (Chrompik). This proved to be not effective enough, fuel pins did fail, releasing significant amounts of radioactive caesium and also, due to hydrogen gas pressurisation, significant amounts of contaminated Chrompik were released into the pond together with approximately 100 TBq of Cs-137. This paper presents the work undertaken to remove this Cs-137 as part of the first phase of decommissioning the pond. The design is based on a skid mounted unit, comprising a shielded mechanical filter unit and a shielded ion exchange (IX) column unit, with interconnecting pipework and valves. The IX column is housed within a lead shielded overpack and connections to it are made by self-sealing quick release couplings. The IX column is of upward flow design and filled with a composite ion exchanger containing Nickel Hexacyanoferrate (II). The IX column packages may be stored within their own shielding once spent. Two operational runs have been completed, removing 25 TBq of Cs137 in each run. With a fresh column, the Decontamination Factor (DF) for Cs-137 uptake was initially over 5000. The DF then fell slowly over the first 1000 bed volumes to 3500, where it remained for most of the run. The run was terminated when calculations indicated that the column packing had absorbed the specified maximum loading of 25 TBq of Cs137. At this point the DF was 1500

  2. Promotion of radiation peroxidation in models of lipid membranes by caesium and rubidium counter-ions: micellar linolenic acids

    International Nuclear Information System (INIS)

    Caesium and rubidium counter-ions increase peroxidation in irradiated micelles of linoleic (18 : 2) and linolenic (18 :3) acids. The effect was specific to Cs+ and Rb+ in the alkali metal series. The effect was independent of the salts used (Cl-, NO3-, Cl04-) and, therefore, independent of the chaotropic nature, and reactivity with hydroxyl radicals of Cl-, NO3- and ClO4-. The promotion of peroxidation by Cs+ and Rb+ is interpreted in terms of their effect on fatty acid micelle structure. The dependence of radiation peroxidation on lipid structure in the micelles may be significant for studies of peroxidation in highly structured cell membranes. (author)

  3. Results of several years experiments on the absorption of radioactive strontium and caesium by cultivated plants (1962)

    International Nuclear Information System (INIS)

    This report follows on to the report number CEA 1860 and uses results obtained in 1960 to give more precise details concerning the data presented in the preceding report. First results obtained on the vine are given. The Sr absorption coefficient has varied very little from one year to the next and that of caesium has slightly diminished. The values obtained suggest that the concentrations of 90Sr and 137Cs in irrigation water should not exceed 1/5 of the maximum permissible concentration in drinking water. (authors)

  4. Poly[μ-aqua-μ5-[2-(2,3,6-tri­chloro­phenyl)acetato]-caesium

    OpenAIRE

    Graham Smith

    2013-01-01

    In the structure of the title complex, [Cs(C8H4Cl3O2)(H2O)]n, the caesium salt of the commercial herbicide fenac [(2,3,6-trichlorophenyl)acetic acid], the irregular eight-coordination about Cs+ comprises a bidentate O:Cl-chelate interaction involving a carboxylate-O atom and an ortho-related ring-substituted Cl atom, which is also bridging, a triple-bridging carboxylate-O atom and a bridging water molecule. A two-dimensional polymer is generated, lying parallel to (100), within which there ar...

  5. The Use of Caesium-137 Measurements for Assessing Soil Erosion and Sedimentation in the Riva Basin (Istanbul, NW Turkey)

    International Nuclear Information System (INIS)

    The paper summarizes the findings of an assessment of soil redistribution in the Riva basin, upstream of the Omerli reservoir, based on use of the fallout radionuclide Caesium-137. This reservoir is located at the eastern side of Istanbul, Turkey, and is the main provider for water to Istanbul. In the Riva basin, soil erosion and associated sediment deposition and potential mass movements are natural landscape forming processes. However, these processes are being accelerated by human intervention, creating a serious threat for sustainable intensification of the agricultural production, watershed management and the conservation of the local natural resources. To determine soil redistribution rates and patterns using the fallout radionuclide approach, samples were collected from an uncultivated flat reference sites and the cultivated sloping farmland (two transects). According to the results of gamma spectroscopy measurements of Caesium-137 and the outputs from the proportional model and simplified mass balance model for both transects, erosion rates varied between -2.4 t ha-1 a-1 and -36.0 t ha-1 a-1 and deposition rates between +1.7 t ha-1 a-1 and +10.5 t ha-1 a-1. (author)

  6. Sediment Budgets and Source Determinations Using Fallout Caesium-137 in a Semiarid Rangeland Watershed, Arizona, USA

    International Nuclear Information System (INIS)

    Analysis of soil redistribution patterns and sediment sources in semiarid and arid watersheds provides information for understanding watershed sediment budgets and for implementing management practices to improve rangeland conditions and reduce sediment loads in streams. The purpose of this research was to develop sediment budgets and to identify potential sediment sources using 137Caesium (137Cs) and other soil properties in a series of small semiarid subwatersheds on the USDA ARS Walnut Gulch Experimental Watershed near Tombstone, Arizona, USA. Soils were sampled in a grid pattern on two small subwatersheds and along transects associated with soils and geomorphology on six larger subwatersheds. Soil samples were analyzed for 137Cs and selected physical and chemical properties (i.e. bulk density, rocks, particle size, soil organic carbon). Suspended sediment samples collected at flume sites on the Walnut Gulch Experimental Watershed were also analyzed for the same properties. Sediment budgets measured using 137Cs inventories for a small shrub and a small grass subwatersheds found eroding areas in these watersheds were losing 5.6 and 3.2 t ha-1 a-1, respectively; however, a sediment budget for each of the small subwatersheds, including depositional areas, found net soil loss to be 4.3 t ha-1 a-1 from the shrub watershed and near zero t ha-1 a-1 from the grass subwatershed. The suspended sediments collected at the flumes of the larger subwatersheds were enriched in silt, clay, and 40K, but not for 137Cs. Using multivariate mixing models to determine sediment source indicated that the shrub dominated subwatersheds were contributing most of the suspended sediments measured at the outlet flume of the Walnut Gulch Experimental Watershed. Both methodologies (sediment budgets and sediment source analyses) indicate that shrub dominated systems provide more suspended sediments to the stream systems. These studies also suggest that sediment yields measured at the outlet of a

  7. 137 Caesium distribution in the eastern Mediterranean Sea. Recent changes and future trends

    International Nuclear Information System (INIS)

    A series of sampling campaigns were carried out in the eastern Mediterranean in the period 1995-1997, to examine the relationship between the distribution of 137Cs in the water column and water mass circulation. 137Cs concentration in the surface water ranges between 3.3 and 4.0 mBq/l all over the area, indicating that the input due to the Chernobyl accident has been transferred to deep water layers by convection processes. In fact, in the vertical profiles, relative maxima are observed in the intermediate (4 mBq/l) and deep waters (∼2.5 mBq/l) formed after the Chernobyl accident. A clear Chernobyl signal also traces the new deep waters formed in the Aegean Sea that, exiting from the Cretan Arc Straits, since 1991 are spreading in the bottom layer of the eastern Mediterranean. The changes in 137Cs vertical profiles related to the new thermohaline circulation of the intermediate and deep waters of the eastern Mediterranean are being monitored at a deep station in the western Ionian Sea. The 1997 profile shows a decrease in 137Cs concentration both in the Levantine intermediate water and in the eastern Mediterranean deep water with respect to 1996. The decrease in Levantine intermediate water is likely due to seasonal/interannual variability, while the changes in the deep layer are related to the spreading westward into the Ionian of the new Aegean dense water. Along the path towards the western Mediterranean, 137Cs content in the Levantine intermediate water decreases from ∼4 mBq/l in the W-Ionian Sea to ∼2 mBq/l at the western sill of the Sicily Straits, due to mixing with underlying water, with lower caesium content, near the Malta Sill. Time-series measurements at the western sill of the Sicily Straits show that, while 137Cs concentration in the surface water entering the eastern Mediterranean remained constant (∼3.5 mBq/l) in the period 1993-1997, its level in the Levantine intermediate water leaving the basin decreased from 3.5 to 2.0 mBq/l

  8. {sup 137} Caesium distribution in the eastern Mediterranean Sea. Recent changes and future trends

    Energy Technology Data Exchange (ETDEWEB)

    Papucci, C.; Delfanti, R. [ENEA, Marine Environment Research Centre, P.O. Box 316, 19100 La Spezia (Italy)

    1999-09-30

    A series of sampling campaigns were carried out in the eastern Mediterranean in the period 1995-1997, to examine the relationship between the distribution of 137Cs in the water column and water mass circulation. 137Cs concentration in the surface water ranges between 3.3 and 4.0 mBq/l all over the area, indicating that the input due to the Chernobyl accident has been transferred to deep water layers by convection processes. In fact, in the vertical profiles, relative maxima are observed in the intermediate (4 mBq/l) and deep waters ({approx}2.5 mBq/l) formed after the Chernobyl accident. A clear Chernobyl signal also traces the new deep waters formed in the Aegean Sea that, exiting from the Cretan Arc Straits, since 1991 are spreading in the bottom layer of the eastern Mediterranean. The changes in 137Cs vertical profiles related to the new thermohaline circulation of the intermediate and deep waters of the eastern Mediterranean are being monitored at a deep station in the western Ionian Sea. The 1997 profile shows a decrease in 137Cs concentration both in the Levantine intermediate water and in the eastern Mediterranean deep water with respect to 1996. The decrease in Levantine intermediate water is likely due to seasonal/interannual variability, while the changes in the deep layer are related to the spreading westward into the Ionian of the new Aegean dense water. Along the path towards the western Mediterranean, 137Cs content in the Levantine intermediate water decreases from {approx}4 mBq/l in the W-Ionian Sea to {approx}2 mBq/l at the western sill of the Sicily Straits, due to mixing with underlying water, with lower caesium content, near the Malta Sill. Time-series measurements at the western sill of the Sicily Straits show that, while 137Cs concentration in the surface water entering the eastern Mediterranean remained constant ({approx}3.5 mBq/l) in the period 1993-1997, its level in the Levantine intermediate water leaving the basin decreased from 3.5 to 2

  9. Combined Use of Caesium-137 Methodology and Conventional Erosion Measurements in the Mistelbach Watershed (Austria)

    International Nuclear Information System (INIS)

    Over the past thirty years, many studies identified water erosion worldwide as one of the major causes of soil degradation on arable land. However, in order to develop appropriate soil conservation strategies more quantitative long term assessments of the soil erosion process are still needed. Therefore, in the present study, the magnitude of erosion and sedimentation was quantified using Fallout RadioNuclides (FRN) in combination with conventional runoff plots measurements in a small agricultural watershed under conventional and conservation cropping practices at Mistelbach located in Austria. A preliminary test of the use of the FRN Caesium-137 (137Cs) was successfully implemented in the Mistelbach watershed. A valid reference site - a small forest within the watershed - was identified and characterized (texture and physicochemical parameters). In this undisturbed area, a classical exponential depth distribution of 137Cs activity was found with 90% of the 137Cs in the first 15 cm; no 137Cs was detected below 20 cm. Seventy six (76) samples were collected on integrated grids basis. The reference value was 1954±91 Bq m-2 (mean ± 95% confidence interval) with a coefficient of variation of 20.4%. Two one meter soil profiles were also collected in the sedimentation area and analysed using the 137Cs method combined with the conversion model Mass Balance Model 2 (MBM 2). Using the 137Cs data, the sedimentation rates down slope of the field containing the runoff plots were estimated to be 26 t-1 ha-1 a-1 using the 137Cs depth distribution profile and at 20 t-1 ha-1 a-1 using the MBM 2. In the lowest part of the watershed sedimentation rates of up to 51 t-1 ha-1 a-1 were estimated through the 137Cs depth distribution profile. These results were linked to long term erosion measurements (1994-2006) from runoff plots just up-slope from the sedimentation area. The average soil erosion reached 29 t ha-1 a-1 from the conventional tilled plot, 4 t ha-1 a-1 from the

  10. Analysis of the kinetic behaviour of iodine and caesium isotopes in the primary circuit of LWR's during severe fuel damage accidents

    International Nuclear Information System (INIS)

    This State of the Art report deals with the chemical behaviour of caesium and iodine in the primary system, focusing particularly on kinetic chemical aspects. In case of a postulated severe accident in a nuclear reactor, cesium and iodine fission products are among the major contributors to health harm because of their high volatility and radiotoxicity. The extent of the release of such fission products to the environment depends on the effectiveness of transport through different structures in the reactor coolant system and within the reactor building. The release from fuel has been briefly studied; only those aspects concerning to iodine and caesium chemical forms when released have been reviewed; nevertheless the emphasis has been put on the transport of such elements and their species through the primary system. Some thermochemical equilibrium studies, applied to primary circuit conditions in LWR's, have been analyzed. The revision of the few kinetic studies existing on this matter has shown that kinetic behaviour of iodine and caesium isotopes in the primary circuit is an aspect poorly studied, despite the fact that kinetic aspects could have great importance on the chemical species formed under certain conditions. Other phenomena affecting iodine and caesium transport, besides chemical reactions, such as interactions with surfaces, aerosols or other chemical species have also been examined from available information on diverse experiments

  11. Density functional theory metadynamics of silver, caesium and palladium diffusion at β-SiC grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Rabone, Jeremy, E-mail: jeremy.rabone@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, D-76125 Karlsruhe (Germany); López-Honorato, Eddie [Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV), Unidad Saltillo, Industria Metalúrgica 1062, Parque Industrial, Ramos Arizpe 25900, Coahuila (Mexico)

    2015-03-15

    Highlights: • DFT metadynamics of diffusion of Pd, Ag and Cs on grain boundaries in β-SiC. • The calculated diffusion rates for Pd and Ag tally with experimental release rates. • A mechanism of release other than grain boundary diffusion seems likely for Cs. - Abstract: The use of silicon carbide in coated nuclear fuel particles relies on this materials impermeability towards fission products under normal operating conditions. Determining the underlying factors that control the rate at which radionuclides such as Silver-110m and Caesium-137 can cross the silicon carbide barrier layers, and at which fission products such as palladium could compromise or otherwise alter the nature of this layer, are of paramount importance for the safety of this fuel. To this end, DFT-based metadynamics simulations are applied to the atomic diffusion of silver, caesium and palladium along a Σ5 grain boundary and to palladium along a carbon-rich Σ3 grain boundary in cubic silicon carbide at 1500 K. For silver, the calculated diffusion coefficients lie in a similar range (7.04 × 10{sup −19}–3.69 × 10{sup −17} m{sup 2} s{sup −1}) as determined experimentally. For caesium, the calculated diffusion rates are very much slower (3.91 × 10{sup −23}–2.15 × 10{sup −21} m{sup 2} s{sup −1}) than found experimentally, suggesting a different mechanism to the simulation. Conversely, the calculated atomic diffusion of palladium is very much faster (7.96 × 10{sup −11}–7.26 × 10{sup −9} m{sup 2} s{sup −1}) than the observed penetration rate of palladium nodules. This points to the slow dissolution and rapid regrowth of palladium nodules as a possible ingress mechanism in addition to the previously suggested migration of entire nodules along grain boundaries. The diffusion rate of palladium along the Σ3 grain boundary was calculated to be slightly slower (2.38 × 10{sup −11}–8.24 × 10{sup −10} m{sup 2} s{sup −1}) than along the Σ5 grain boundary. Rather

  12. The effect of organics on the sorption of strontium, caesium, iodine, neptunium, uranium and europium by glacial sand

    International Nuclear Information System (INIS)

    This study has been undertaken within the Commission of the European Communities MIRAGE II program on the determination of radionuclides in the geosphere. Preliminary batch sorption experiments have been carried out to study the behaviour of strontium, caesium, iodine, europium and uranium in a glacial sand-groundwater system. The effect of (i) the presence or absence of natural organic material and (ii) the addition of increasing quantities of EDTA or acetate on the distribution ratios was determined. In some cases speciation modelling was used as an aid to designing the experiments and interpreting the results. The aim of this work was to select suitable tracers for use in field experiments at Drigg. Cumbria and the results are intended to aid the design of future experiments rather than to provide a complete analysis of the radionuclide-organic interactions. 11 tabs., 49 refs

  13. Ultra-high and persistent optical depths of caesium in Kagom\\'e-type hollow-core photonic crystal fibres

    CERN Document Server

    Kaczmarek, Krzysztof T; Sprague, Michael R; Kolthammer, W Steven; Feizpour, Amir; Ledingham, Patrick M; Brecht, Benjamin; Poem, Eilon; Abdolvand, Amir; Russell, Philip St J; Walmsley, Ian A; Nunn, Joshua

    2015-01-01

    Alkali-filled hollow-core fibres are a promising medium for investigating light-matter interactions, especially at the single-photon level, due to the tight confinement of light and high optical depths achievable by light-induced atomic desorption. However, until now these large alkali vapour densities could only be generated for seconds at most once per day, severely limiting the practicality of the technology. Here we report the generation of highest observed transient ($>10^5$ for minutes) and highest observed persistent (>2000 for hours) optical depths of alkali vapours in hollow-core fibres to date, using a caesium-filled Kagom\\'e-type hollow-core photonic crystal fibre. Our results pave the way to light-matter interaction experiments in confined geometries requiring long operation times and large atomic number densities, such as single-photon-level light-matter interaction experiments and fundamental investigations of hot dense atomic gases.

  14. Solvothermal Synthesis of Caesium Tungsten Bronze in the Presence of Various Organic Acids and Its NIR Absorption Properties

    International Nuclear Information System (INIS)

    Nanoparticles of caesium tungsten bronze were successfully synthesized by solvothermal reactions in ethanol with the introduction of different organic fatty acids with various carbon numbers of 1 to 5. Compared to the sample prepared in pure ethanol, the samples obtained by mixed solvent of ethanol and fatty acids showed higher production yield, smaller particle size, more uniform particles size distribution and higher Cs/W atomic ratio. In addition, all of samples obtained using acids-ethanol mixed solvent exhibited higher visible light transmittance and greater NIR absorption performance, indicating the potential application for smart window and heat-ray shielding materials. The addition of acetic acid showed the best performance to facilitate the formation of well dispersed CsxWO3 regular nanorods, leading to its excellent optical properties.

  15. Determining the hyperfine structure constants of caesium 8S1/2 state aided by atomic coherence

    International Nuclear Information System (INIS)

    High-sensitivity spectroscopy of caesium's higher excited 8S1/2 state is obtained by a coherent two-photon transition via an intermediate resonance state. The ladder-type atomic system is driven by two counter-propagating low-power diode lasers, the probe laser being tuned to the transition from the ground state to the intermediate state (6S1/2–6P1/2), and the coupling laser to that between the intermediate and the final state (6P1/2–8S1/2). By locking the probe laser and scanning the coupling laser, the electromagnetically induced transparency (EIT) peaks appear in the probe transmission when the coupling laser resonates with each of the hyperfine levels. Compared with conventional EIT, where the signal-to-noise ratio is limited by the absorptive Doppler background, here these narrow-linewidth peaks have no Doppler background. The peak centres are well determined from theoretical fits to the experimental data. To accurately measure the 8S1/2 hyperfine structure splitting, we developed a simple method to eliminate error arising from the nonlinear frequency scanning by employing an optical waveguide phase modulator and a confocal Fabry–Perot cavity. The hyperfine structure constants of the caesium 8S1/2 state are obtained from hyperfine structure splitting measurements. Systematic effects from the ac-Stark and Zeeman shifts are studied. The measured hyperfine magnetic dipole constant A = (219.08 ± 0.12) MHz is consistent with previous results. (paper)

  16. Radioactive caesium in fish in Swedish lakes 1986-1988 -general pattern related to fallout and lake characteristics

    International Nuclear Information System (INIS)

    This study investigates how the concentration of 137Cs varied geographically in Sweden during 1986, 1987 and 1988 in different fish species to study how different lake properties influence the 137Cs uptake in fish, to try to develop a load diagram for lakes when 137Cs in fish is used as an effect parameter, and to study how the caesium concentration varies seasonally and with fish size. A register was compiled, containing a broad set of data from 644 Swedish lakes. The median 137Cs concentration in fish increased between 1986 and 1987 by between 13% (trout) and 240% (pike). The increase between 1987 and 1988 has stagnated for most species, but not for pike where the concentration increased 82% in the 'the median lake'. The in-lake, between-lake and temporal variations are large and differ from species to species. About 14 000 lakes in Sweden had fish ('100 g perch') with 137Cs concentrations above 1500 Bq/kg (w/w) during the autumn of 1987. Apart from the radioactive fallout, the water retention time is the individual factors of greatest importance for the variability of 137Cs concentration in fish between these lakes. Lake water hardness and/or conductivity also influence the uptake of 137Cs in fish. (author)

  17. Determining soil redistribution in Dian Lake catchment by combined use of caesium-137 and selected chemical properties

    Institute of Scientific and Technical Information of China (English)

    Zhang Mingli; Yang Hao; Xu Congan; Wang Yihong

    2009-01-01

    Recent development in the use of the environmental radionuclide caesium-137 for documenting rates and patterns of soil redistribution on the cultivated or uncultivated land and estimating rates of sediment deposition on floodplains represents an important advance that overcomes many of the limitations' of the conventional techniques commonly applied in such investigations.A study on soil redistribution (including soil erosion and deposition) was carried out in the Dian Lake catchment,Yunnan Province,using 137Cs and selected chemical properties.The average soil erosion rate was 1,280.2 t km-2yr-1.Soil erosion rate occurring on different parts of the slope was significantly different on different parts of the slope,increasing from the top,the bottom to the middle slope.The average soil erosion rate is also different with the land use type and that of the cultivated land (1,672.8 t km-2 yr-1) is higher than of the uncultivated land (1,161.2 t km-2yr-1).The result shows that landform,slope gradient and land use type are key factors that influence the size of soil erosion.In addition,we also find the SOC and TN contents and amount of the soil erosion to be correlated in the soil.With the soil erosion occurring,there are land degradation and the local eco-environmental problems,such as water eutrophication in Dian Lake

  18. Long range transport of caesium isotopes from temperate latitudes to the equatorial zone during the winter monsoon period

    International Nuclear Information System (INIS)

    An air radioactivity monitoring study carried out in Dalat, Vietnam since 1986 has revealed distinct peaks of caesium isotope concentrations in air and fallout during December-January, when the monthly average air temperature was lowest and dry fallout dominated. These peaks provide evidence of the intrusion of more radioactive cold air masses from temperate northern latitudes during the development of large-scale anti cyclones, frequently observed in the most active winter monsoon period. High dry fallout velocity (about 10 cm/s) determined from the measured concentrations, clearly demonstrates one of the most relevant features of cold air masses: behind the cold front, vertical air motion is descending. The role of other processes, such as injection of radioactive air from stratosphere and local resuspension of soil dust, has been shown to be insignificant. The interpretation of the experimental results was based on the analysis of environmental -meteorological factors as well as the behaviour of other naturally-occurring radionuclides. (author). 7 refs, 2 figs

  19. Spatial variability of caesium-137 inventories at reference sites: an example from two contrasting sites in England and Zimbabwe

    International Nuclear Information System (INIS)

    Bomb-derived caesium-137 (137Cs) fallout has been widely used to investigate rates and patterns of soil erosion and sediment deposition. Within this approach considerable importance is placed on establishing the local total 137Cs fallout or inventory at a reference site. However, relatively little information currently exists concerning the variability of 137Cs inventories at reference sites. This paper reports an investigation of the spatial variability of 137Cs inventories at two contrasting reference sites at Yendacott, England and Msana, Zimbabwe. Replicate bulk soil cores were collected at the intersections of a grid, yielding 60 and 27 samples from Yendacott and Msana, respectively. Although the total variability may be derived from four sources (random spatial, systematic spatial, sampling and measurement), the observed variability was in both cases primarily due to random spatial variations in 137Cs inventories. The reference inventory range (at the 95% confidence level) was 205-230 and 17.0-33.4 mBq cm-2 for the Yendacott and Msana sites, respectively. (Author)

  20. Change of the radionuclide content of landscapes contamination in the small catchment at the Bryansk-Belarus caesium spot

    International Nuclear Information System (INIS)

    The results of the joint Russian-Belarus RFBR-BelRFBR project no. 02-05-81011 will be shown. Information on the spatial redistribution of 137Cs within small catchment and through the connected landscapes is an important background for estimating consequences of the Chernobyl contamination. 137Cs can be used as a tracer for study the direction and intensity of geo-chemical processes in landscapes of small catchment. The experimental data on the modern radionuclide content of soil and plant contamination have been received at the expeditions of 2000-2004 in the regions situated on distances 50, 150 and 250 km from the Chernobyl NPP on territories of Belarus and Russia. Some small catchment in the Dnieper basin have been studied (Braginka, Sozh and Moskovka rivers). The content of 137Cs, 90Sr, 239+240Pu and 241Am in soils will be presented. The modern variability of contamination levels in each of connected landscapes will be compared with the variability estimated immediately after the Chernobyl accident. The high spatial fixation of Caesium spots by the Polessye landscapes will be shown. (author)

  1. Can inter-cultivar variation in caesium and strontium uptake reduce contamination of forage grasses? - Can inter-cultivar variation in caesium and strontium accumulation by forage grasses be used to reduce contamination of cows' milk in radiologically contaminated areas?

    Energy Technology Data Exchange (ETDEWEB)

    Penrose, B. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Lancaster, LA1 4AP (United Kingdom); School of Biosciences, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD (United Kingdom); Beresford, N. [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Lancaster, LA1 4AP (United Kingdom); Broadley, M.; Crout, N.M.J.; King, J.; Young, S. [School of Biosciences, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD (United Kingdom); Lovatt, A. [Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Gogerddan, Aberystwyth, Ceredigion, SY23 3E E (United Kingdom); Thomson, R. [Science and Advice for Scottish Agriculture (SASA), Roddinglaw Road, Edinburgh, EH12 9FJ (United Kingdom)

    2014-07-01

    Radiocaesium and radiostrontium primarily enter the food chain via plant root uptake, including indirectly via animal fodders. Inter-species variation in caesium and strontium accumulation in plants has previously been reported to be over two orders of magnitude. This variation could be exploited to select crops with relatively low uptake to reduce transfer of these radionuclides to consumers in contaminated areas. Exploiting intra-species (i.e. inter-cultivar) variation in caesium and strontium uptake has not yet been evaluated as a remediation strategy as sufficient data have not been available. As cows' milk has been one of the main contributors to human dose following the Chernobyl and Mayak accidents, we have chosen to focus on elucidating the extent and nature of inter-cultivar variation in caesium and strontium uptake in forage grasses. A total of 412 cultivars from four species of forage grass; perennial ryegrass (Lolium perenne; 284 cultivars), Italian ryegrass (Lolium multiflorum; 17 cultivars), hybrid ryegrass (Lolium hybridum; 101 cultivars) and tall fescue (Festuca arundinacea; 10 cultivars) were sampled from 20 sets of experimental plots in Aberystwyth (Wales, UK) and Edinburgh (Scotland, UK). Fifty-nine cultivars were grown in both locations. At least three replicates of the same cultivar were grown in each set of plots. Vegetation samples from 2208 plots were collected both in spring 2013 (May-June) and summer 2013 (August-September). The samples were oven-dried and milled then analysed for elemental composition using inductively coupled plasma mass spectrometry (ICP-MS). Stable caesium and strontium were measured as a proxy measurement for radiocaesium and radiostrontium concentrations. Concentrations of chemical analogues of caesium and strontium (potassium and calcium) and a number of other elements were measured. Soil samples from the experimental plots were also collected, dried, milled and analysed using ICP-MS. This paper will present

  2. Caesium 137: Properties and biological effects resulting of an internal contamination;Cesium 137: proprietes et effets biologiques apres contamination interne

    Energy Technology Data Exchange (ETDEWEB)

    Lestaevel, P.; Racine, R.; Bensoussan, H.; Rouas, C.; Gueguen, Y.; Dublineau, I.; Bertho, J.M.; Gourmelon, P.; Jourdain, J.R.; Souidi, M. [Institut de Radioprotection et de Surete Nucleaire, IRSN, laboratoire de radiotoxicologie experimentale, direction de la radioprotection de l' homme, 92 - Fontenay-aux-Roses (France)

    2010-02-15

    Caesium-137 ({sup 137}Cs) is a radionuclide present in the environment mainly as the result of the atmospheric nuclear weapons testing and accidents arising in nuclear power plants like the Chernobyl accident in 1986. Nowadays, the health consequences resulting from a chronic exposure to this radionuclide remain unknown. After absorption, the caesium is distributed relatively homogeneously within the body, with a more important load in children than in adults. The toxicity of {sup 137}Cs is mainly due to its radiological properties. A high dose of {sup 137}Cs is responsible for a medullar dystrophy, disorders of the reproductive function, and effects on liver and renal functions. Disorders of bone mineralization and brain damages were also described in human beings. At lowest dose, {sup 137}Cs induces disturbances of wakefulness-sleep cycle, but not accompanied with behavioural disorders. The cardiovascular system was also perturbed. Biological effects of {sup 137}Cs on the metabolisms of the vitamin D, cholesterol and steroid hormones were described, but do not lead to clinical symptoms. In human beings, {sup 137}Cs leads to an immune deficiency, congenital and foetal deformations, an increased of thyroid cancer, as well as neurological disorders. It seems that children are more sensitive to the toxic effects of caesium than the adults. At present, the only effective treatment for the decorporation of the ingested {sup 137}Cs is the Prussian Blue (Radiogardase). The use of pectin to de-corporate the ingested {sup 137}Cs, in children notably, is sometimes proposed, but its administration still remains an open question. To conclude, the available scientific data suggest that {sup 137}Cs could affect a number of physiological and metabolic functions and consequently, could participate in the health risks associated to the presence of other contaminants in the environment. (authors)

  3. A new approach to predicting environmental transfer of radionuclides to wildlife: A demonstration for freshwater fish and caesium

    International Nuclear Information System (INIS)

    The application of the concentration ratio (CR) to predict radionuclide activity concentrations in wildlife from those in soil or water has become the widely accepted approach for environmental assessments. Recently both the ICRP and IAEA have produced compilations of CR values for application in environmental assessment. However, the CR approach has many limitations, most notably, that the transfer of most radionuclides is largely determined by site-specific factors (e.g. water or soil chemistry). Furthermore, there are few, if any, CR values for many radionuclide-organism combinations. In this paper, we propose an alternative approach and, as an example, demonstrate and test this for caesium and freshwater fish. Using a Residual Maximum Likelihood (REML) mixed-model regression we analysed a dataset comprising 597 entries for 53 freshwater fish species from 67 sites. The REML analysis generated a mean value for each species on a common scale after REML adjustment taking account of the effect of the inter-site variation. Using an independent dataset, we subsequently test the hypothesis that the REML model outputs can be used to predict radionuclide, in this case radiocaesium, activity concentrations in unknown species from the results of a species which has been sampled at a specific site. The outputs of the REML analysis accurately predicted 137Cs activity concentrations in different species of fish from 27 Finnish lakes; these data had not been used in our initial analyses. We recommend that this alternative approach be further investigated for other radionuclides and ecosystems. - Highlights: • An alternative approach to estimating radionuclide transfer to wildlife is presented. • Analysed a dataset comprising 53 freshwater fish species collected from 67 sites. • Residual Maximum Likelihood mixed model regression is used. • Model output takes account of the effect of inter-site variation. • Successfully predicted 137Cs concentrations in different fish

  4. Desorption behaviour of artificial radionuclides sorbed on to estuarine silt: (1) Caesium-137 and ruthenium-106, (2) Zirconium-95 and niobium-95

    International Nuclear Information System (INIS)

    A series of desorption tests was carried out on silt contaminated with radioactive waste from the Sellafield (formerly Windscale) fuel reprocessing plant. The aim of the desorptions was to attempt to elucidate the chemical form in which certain radionuclides were held by the sediments. The first part of the study indicated that caesium was held, in the main, on inaccessible ion-exchange sites and that ruthenium appeared to be partially adsorbed and partially held by anion-exchange sites. The second part of the study indicated that zirconium and niobium were sorbed chemically or physically in the form of complex hydrous oxides. (author)

  5. Spectral anomalies of the effect of light-induced drift of caesium atoms caused by the velocity dependence of transport collision frequencies

    International Nuclear Information System (INIS)

    The spectral features of the light-induced drift (LID) velocity of caesium atoms in inert buffer gases are studied theoretically. A strong temperature dependence of the spectral LID line shape of Cs atoms in Ar or Kr atmosphere in the vicinity of T ∼ 1000 K is predicted. It is shown that the anomalous LID of Cs atoms in binary buffer mixtures of two different inert gases can be observed at virtually any (including ambient) temperature, depending on the content of the components in these mixtures. The results obtained make it possible to precisely test the interatomic interaction potentials in the experiments on the anomalous LID. (quantum optics)

  6. Poly[(μ6-4-amino-3,5,6-trichloro­pyridine-2-carboxyl­ato)aqua­caesium

    OpenAIRE

    Smith, Graham

    2012-01-01

    In the structure of the title complex, [Cs(C6H2Cl3N2O2)(H2O)] n , the caesium salt of the commercial herbicide picloram, the Cs+ cation lies on a crystallographic mirror plane, which also contains the coordinating water mol­ecule and all non-H atoms of the 4-amino-3,5,6-trichloro­picolinate anion except the carboxyl­ate O-atom donors. The irregular CsCl4O5 coordination polyhedron comprises chlorine donors from the ortho-related ring substituents of the picloramate ligand in a bidentate chelat...

  7. EFFICIENCY OF PROTECTIVE MEASURES TO REDUCE INTERNAL DOSE FROM CAESIUM RADIONUCLIDES FOR THE INHABITANTS OF RADIOACTIVE CONTAMINATION AREA IN THE FIRST YEARS AFTER THE CHERNOBYL ACCIDENT

    Directory of Open Access Journals (Sweden)

    I. G. Travnikova

    2012-01-01

    Full Text Available In the paper, we use the data on the content of caesium radionuclides in foodstuffs and in Bryansk region adult inhabitant’s body, on their food ration and its changes during the first years after the Chernobyl accident, and on the measures to protect the population from internal exposure. We calculate dynamics of 137Cs intake in the body and its contents therein, while maintaining a traditional diet and while replacing food products for radiationfree ones. The results show that the actual 137Cs content in the body is usually below the one calculated on the basis of the food ration. It was found out that individual 137Cs contents in the body correlate with the rate of meat, dairy and natural food products consumption and with factors of protection from internal exposure. The efficiency of the protective measures to reduce the intake and the content of caesium radionuclides in the body of inhabitants, as well as the average effective dose in the first years after the accident has been quantitatively assessed.

  8. A modified version of the combined in-diffusion/abrasive peeling technique for measuring diffusion of strongly sorbing radionuclides in argillaceous rocks: A test study on the diffusion of caesium in Opalinus Clay

    International Nuclear Information System (INIS)

    A filter free diffusion set-up was developed for measuring the diffusion of strongly sorbing radionuclides in indurated argillaceous rocks such as Opalinus Clay (OPA) that normally disintegrate when contacted with a solution. Small bore cores drilled parallel to the bedding plane and embedded in epoxy resin were found to be stable and could be used for performing in-diffusion measurements. The method was tested with the diffusion of caesium, spiked with caesium-134, in Opalinus Clay. The profile of Cs in the clay sample was determined with a modified version of the abrasive peeling technique. The diffusion parameters obtained for caesium were in fair agreement with those determined earlier using the classical through-diffusion technique where stainless steel filters were used to confine the samples. - Highlights: • We developed a simple method to study diffusion of radionuclides in clay rocks. • We tested the method with diffusion of caesium in Opalinus Clay. • The obtained diffusion parameters are in agreement with previous studies. • The proposed technique forms a step forward for migration studies in clay rock

  9. The granulometrical fractions of soil, distributions of caesium-137 on its and the fastening of soil surface contaminated by radionuclides at locations of the 'Azgir test site'

    International Nuclear Information System (INIS)

    products of chain reaction in the moment of UGNE; radioactive ejections from spaces after explosions; contamination of locations during the break-down of spaces and a fulfilment of technological operations of different purposes; a burial of radioactive wastes in trenches in the limits of locations; local traces of atmospherical falls - out from radioactive clouds, formed as a result of the Chernobyl Catastrophe (traces were discovered during aero-gamma-spectro metrical surveys, carried out in the beginning of 1990). Accordingly to a change of granulometric composition there was taken place and a redistribution of caesium-137, the main part of which was concentrated in the fraction of 0.063 mm and was in limits of from 79.5% up to 92.2%. An efficiency of an action of polymeric composition, introduced into soil for fastening and binding of radionuclides in surface soil layer, can be estimated by data of measurements of caesium-137 distribution in granulometric fractions of soil samples, sieved and divided into 6 dimension components: 1.25 mm; 0.7 mm; 0.4 mm; 0.1 mm; 0.063 mm and <0.063 mm. Further, in indicated probes, by the method of wet sieving, there was also determined the granulometric composition by 6 above-mentioned fraction and the additional seventh fraction ('clay'), extracted during the wet sieving of soil samples. Then, in each obtained fraction there was measured the specific activity of caesium-137. In order to study the real distribution of caesium-137 on granulometric fractions there were measured specific activities of caesium-137 in all fractions, extracted after wet sieving and analogous to those, which were obtained during dry sieving, and in the fraction 'clay', formed during the process of wash-out of soil probes by water. The use of wet sieving had led to the redistribution of caesium-137 content in fractions, which was fixed by the method of dry sieving, where caesium-137 was mainly in fractions : 0.1 mm; 0.4 mm; 0.7 mm and 1.25 mm. In the same

  10. Caesium absorption by barley - influence of its retention by the soil - competitive action of potassium; Absorption du cesium par l'orge - influence de sa retention dans le sol - action competitive du potassium

    Energy Technology Data Exchange (ETDEWEB)

    Ferron-Trosseau, F. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-06-01

    We have studied, in various culture media, how the absorption of caesium by barley varies with its concentration, and how this absorption can be in competition with a similar alkali cation-potassium. We have also considered the caesium distribution in the ground in particular radio-active caesium, between the soil and solution, as a function of the amount of caesium. From our work it is clear that barley behaves very differently according to whether the caesium is in a nutritive solution or is in the soil: for a nutritive solution, the fraction of caesium (radioactive and stable) absorbed by barley remains practically constant in the presence of increasing amounts (relatively small) of stable caesium; in soil, the fraction of the radio-active caesium absorbed increases as the stable caesium content (fairly low) of the soil increases, in relationship with a rapidly decreasing selectivity of the soil for Cs{sup +}. The difference between these results is thus explained by the very pronounced selectivity of the illitic soil studied for Cs{sup +}, as long as the proportion of Cs remains low, about as low as that of most natural soils. Furthermore, the K{sup +} ion is in competition with the Cs{sup +} ion, for absorption by barley in a culture medium in a nutritive solution or in soil, only when the potassium concentrations are relatively low, of the order of the nutritive maximum. This shows that the addition of potassium to a medium already rich in this element does not reduce the absorption of caesium by barley. The choice of experimental conditions close to natural conditions (nutritive media strong in calcium) and the examination of the distribution of radioactive caesium between the soil, the soil solution and the plant in the presence of very low doses of stable caesium make these results interesting from the 'atomic health' point of view; it should be expected that a definite contamination risk exists for plants cultivated on synthetic media and for

  11. Irradiation of members of the general public from radioactive caesium following the Chernobyl reactor accident: Field studies in a highly contaminated area in the Bryansk region, Russia

    Science.gov (United States)

    Thornberg, Charlotte

    From 1990 to 1998, estimations of the effective dose due to irradiation from 137Cs and 134Cs were carried out for inhabitants in rural villages in the Bryansk region, Russia. The villages, situated about 180 km from the Chernobyl power plant received deposition of 137Cs in the range 0.9-2.7 MBq m-2 due to the accident in 1986. The body burden of 137,134Cs was estimated from measurements of the urinary concentration of caesium radionuclides, together with in vivo measurements using a portable detector. The external effective dose was estimated from measurements with thermoluminescent (TL)-dosemeters worn by the participants during one month each year. In a case study, the changes in biokinetics of 137Cs during pregnancy was investigated in a woman with an unintended intake of 137Cs via mushrooms grown in the area. During pregnancy the biological half-time of caesium was 54% of that before pregnancy. The ratio of the 137Cs concentration in breast milk (Bq L-1) to that in the mother's body (Bq kg-1) was 15% one month after the child was born. The body burden of 137Cs in the Russian individuals calculated from urine samples showed a good agreement with the body burden estimated from in vivo measurements in the same individuals. Normalisation of the caesium concentration in the urine samples by the use of potassium or creatinine excretion introduced systematic differences and a larger spread in the calculated values of the 137Cs body burden as compared with calculations without normalisation. The yearly effective dose to inhabitants in the Russian villages varied between 1.2 and 2.5 mSv as a mean for all villages between 1991 and 1998 and the internal effective dose was 30-50% of the total effective dose. The external effective dose decreased on average 15% per year, while the internal effective dose varied, depending to a great extent on the availability of mushrooms. The cumulated effective dose for a 70-year period after the accident was calculated to be 100 m

  12. Computer modelling of the chemical speciation of caesium, uranium(VI) and neptunium(V) in human duodenal fluids under fasting conditions

    International Nuclear Information System (INIS)

    A model simulating the human duodenal contents under physiologically realistic, fasting conditions was developed using the joint expert speciation system (JESS) computer program and database and used to investigate the chemical speciation of caesium, uranium(VI) and neptunium(V). Over the pH range 5.0-9.0, and the concentration range 5x10-15-5x10-5 mol dm-3, caesium was predicted to occur predominantly as the absorbable free monovalent cation Cs+ (∼95%) with species such as CsHPO4- and CsCl representing the remainder. The presence or absence of sulphate at 2.1x10-3 mol dm-3 did not influence the predicted speciation. Uranium was predicted to be present entirely as a soluble, highly charged species, both in the absence and in the presence of sulphate. Between pH 5.0 and ∼6.5 the UO2H2(PO4)22- predominated, above this pH carbonate species, either UO2(CO3)46- or, possibly, UO2(CO3)58-. At pH 8.0, and in the presence of sulphate, neptunium(V) was predicted to exist solely as the tetrasulphate species, whilst in the absence of sulphate, an array of negatively charged soluble carbonate species predominated. Studies over the pH range 5.0-9.0 predicted the formation of a spectrum of negatively charged carbonate and phosphate species, ∼40% of the total neptunium was predicted to be present as the electrically net-neutral species NpO2HCO3 at pH6.0, ∼20% at pH 7.0, ∼10% at pH 7.5 and ∼1% at pH 8.0. The observed speciation patterns of uranium and neptunium did not change over the concentration range 5x10-15-5x10-5 mol dm-3 and no solid species were predicted to occur under the conditions simulated. Whether the predicted electrically net-neutral neptunium species or the uranium pentacarbonate species do actually occur under true physiological conditions remains to be established. The observed speciation patterns for caesium and uranium are consistent with the observed absorption of these elements by humans; however, the observations for neptunium appear to be

  13. The behaviour of transport from the fission products caesium and strontium in coated particles for high temperature reactors under irradiation conditions

    International Nuclear Information System (INIS)

    At first survey is given about existing knowledge of the behaviour of caesium and strontium fission product transport in coated particles. In order to describe the complicated fission product transport mechanisms under irradiation conditions a suitable calculating model (SLIPPER) is taken over and modified to the special problems of an irradiation experiment. Fundamentally, the fission product transport is represented by the two contributions of diffusion and recoil, at which the diffusion is described by effective diffusion coefficients. In difference of that the possibility of a two-phase-diffusion is examined for the Cs diffusion in the fuel kernel. The model application on measuring results from irradiation experiments of KFA-Juelich and Mol-Belgien allowed the explanation from the characteristic of fission product transport in coated particles under irradiation conditions and produced effective diffusion coefficients for the fission products Cs and Sr. (orig.)

  14. Monitoring of caesium-137 in food plants and muscle from moose, red deer and wild reindeer in 2010.; Overvaaking av cesium-137 i beitevekster og kjoett av elg, hjort og villrein i 2010.

    Energy Technology Data Exchange (ETDEWEB)

    Veiberg, Vebjoern; Gaare, Eldar; Stokke, Sigbjoern; Solberg, Erling J.; Skuterud, Lavrans

    2011-07-01

    The monitoring of Cs-137 fall-out from the Chernobyl accident in 1986, started the same year. Several plants and wild reindeer in natural ecosystems in Nord-Rondane have been followed annually ever since. Four more wild reindeer ranges were included in 2001: Setesdal-Ryfylkeheiene, Hardangervidda, Nord-Ottadalen, Snoehetta and Nord-Rondane. From 2007 Forollhogna was also included. On fixed plots in Nord-Rondane and Snoehetta some of the reindeer forage plants, including both higher plants and fruticose lichens, have been sampled and analyzed annually since 1986. This was also done in 2010. In addition plants and lichens were sampled at five locations along an altitudinal gradient at Soendre Knutshoe, and at 7-8 locations along an east-west gradient from Kollaflata to Skarhoe in the Jora valley continuing along the Aursjoe to Torbudalen. All these locations were sampled annually between 1987-1990, but they have not been sampled since. In 2010 samples from red deer and moose was also collected from eight different regions located within the following counties: Oppland, Telemark, Vest-Agder, Rogaland, Sogn and Fjordane, Nord-Troendelag, Nordland and Troms. Red deer were sampled in four regions and moose in six. Both species were sampled in Oppland. In 2010 76, 49 and 61 samples were collected from wild reindeer, red deer and moose respectively. All measures of caesium levels were performed on dried samples. For the 596 samples of plants and lichen the results refer to caesium-levels in dried samples. For the meat samples, results refer to caesium-137 levels in raw meat. Due to large variation in measured levels of caesium within species and sampling area, we give median values instead of mean values.The highest caesium levels in wild reindeer were found in Snoehetta (1010 Bq/kg) and Nord-Rondane (2686 Bq/kg). The levels found in the other areas were considerably lower. The highest caesium levels in both red deer (Sel, 677 Bq/kg) and moose (Vaaga, 365 Bq/kg) were found

  15. Radioactive caesium contamination due to Fukushima Daiichi Nuclear Power Plants accident in Osaka city. Evaluation of accumulation and decontamination of radioactive materials via reverse logistics function of a city

    International Nuclear Information System (INIS)

    We surveyed background level of radioactive contamination in city area of Osaka before combusting the wide area disposal of disastrous debris at a municipal waste incineration plant of Osaka city. The debris was caused by Tohoku district great earthquake disaster and suspected to be contaminated with radionuclides released from the Fukushima Daiichi Nuclear Power Plants. We also investigated radioactivity in incineration ash of municipal waste incineration plants and of sewage treatment plants, as well as in water clarifier sludge of potable water treatment plants, and evaluated the accumulation and cleansing of radioactive materials via the reverse logistic function of the city. Radioactive caesium deposited in Osaka city area was estimated to be approximately 4.3 GBq from the concentrations observed in the monthly fallout, whereas that collected as municipal wastes and sewage was estimated to be approximately 0.9 GBq a year in 2011. Even two years after the accident, 134Cs, which is the evidence of the Fukushima Daiichi Nuclear Power Plant accident, had been detected in the municipal wastes at a level comparable to the activities found just after the accident, however, the radioactive caesium concentration in fallout measured in the Osaka city area had decreased below a detection limit after May 2012. Introduction of materials contaminated with radioactive caesium from outside the city area was suspected because the observed contamination level was inexplicable by that of observed in the environmental wastes such as pruned branches which are contaminated by with the fallout in city area of Osaka. (author)

  16. Effects of fluvial processes in different order river valleys on redistribution and storage of particle-bound radioactive caesium-137 in area of significant Chernobyl fallout and impact on linked rivers with lower contamination levels

    Science.gov (United States)

    Belyaev, Vladimir; Golosov, Valentin; Shamshurina, Evgeniya; Ivanov, Maxim; Ivanova, Nadezhda; Bezukhov, Dmitry; Onda, Yuichi; Wakiyama, Yoshifumi; Evrard, Olivier

    2015-04-01

    Detailed investigations of the post-fallout fate of radionuclide contamination represent an important task in terms of environmental quality assessment. In addition, particle-bound radionuclides such as the most widespread anthropogenic isotope caesium-137 can be used as tracers for quantitative assessment of different sediment redistribution processes. In landscapes of humid plains with agriculture-dominated land use the post-fallout redistribution of caesium-137 is primarily associated with fluvial activity of various scales in cascade systems starting from soil erosion on cultivated hillslopes through gully and small dry valley network into different order perennial streams and rivers. Our investigations in the so-called Plavsk hotspot (area of very high Chernobyl caesium-137 contamination within the Plava River basin, Tula Region, Central European Russia) has been continuing for more than 15 years by now, while the time passed since the Chernobyl disaster and associated radioactive fallout (1986) is almost 29 years. Detailed information on the fluvial sediment and associated caesium-137 redistribution has been obtained for case study sites of different size from individual cultivated slopes and small catchments of different size (2-180 km2) to the entire Plava River basin scale (1856 km2). It has been shown that most of the contaminated sediment over the time passed since the fallout has remained stored within the small dry valleys of the 1-4 Hortonian order and local reservoirs (>70%), while only about 5% reached the 5-6 order valleys (main tributaries of the Plava River) and storage of the Plava floodplain itself represents as low as 0.3% of the basin-scale total sediment production from eroded cultivated hillslopes. Nevertheless, it has been shown that contaminated sediment yield from the Plava River basin exerts significant influence on less polluted downstream-linked river system. Recent progress of the investigations involved sampling of 7 detailed depth

  17. Progress report on a filed study of soil-to-plant transfer of radioactive caesium, strontium and zinc in tropical Northern Australia

    International Nuclear Information System (INIS)

    This report covers: background, study location, design and rationale, farming practice and application, climate monitoring, summaries of the results of chemical analyses, gamma spectrometry and other analyses performed on plants and soil samples and calculation of transfer factors. Comparison with data from the literature, and a brief discussion of the results and implications for the on-going study are also presented. A detailed evaluation of the results has not been performed at this stage as the study is in progress.The main general observations to date are as follows. Transfer factors for caesium (Cs) and strontium (Sr) are not substantially different from the expected values based on the earlier studies mainly within temperate climates. In contrast, the values for zinc (Zn) are more than an order of magnitude greater than anticipated. Most of the radioactivity added to the soils has been retained in the top 5 cm of both soils. There has been a general decline in decay-corrected radioactivity in soils but also an indication of increased heterogeneity in surface distribution. Additional sampling will be undertaken to address this issue

  18. Sensitivity of the modelled deposition of Caesium-137 from the Fukushima Dai-ichi nuclear power plant to the wet deposition parameterisation in NAME

    International Nuclear Information System (INIS)

    This paper describes an investigation into the impact of different meteorological data sets and different wet scavenging coefficients on the model predictions of radionuclide deposits following the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. Three separate operational meteorological data sets, the UK Met Office global meteorology, the ECMWF global meteorology and the Japan Meteorological Agency (JMA) mesoscale meteorology as well as radar rainfall analyses from JMA were all used as inputs to the UK Met Office's dispersion model NAME (the Numerical Atmospheric-dispersion Modelling Environment). The model predictions of Caesium-137 deposits based on these meteorological models all showed good agreement with observations of deposits made in eastern Japan with correlation coefficients ranging from 0.44 to 0.80. Unexpectedly the NAME run using radar rainfall data had a lower correlation coefficient (R = 0.66), when compared to observations, than the run using the JMA mesoscale model rainfall (R = 0.76) or the run using ECMWF met data (R = 0.80). Additionally the impact of modifying the wet scavenging coefficients used in the parameterisation of wet deposition was investigated. The results showed that modifying the scavenging parameters had a similar impact to modifying the driving meteorology on the rank calculated from comparing the modelled and observed deposition

  19. Accumulation of potassium, rubidium and caesium (133Cs and 137Cs) in various fractions of soil and fungi in a Swedish forest

    International Nuclear Information System (INIS)

    Radiocaesium (137Cs) was widely deposited over large areas of forest in Sweden as a result of the Chernobyl accident in 1986 and many people in Sweden eat wild fungi and game obtained from these contaminated forests. In terms of radioisotope accumulation in the food chain, it is well known that fungal sporocarps efficiently accumulate radiocaesium (137Cs), as well as the alkali metals potassium (K), rubidium (Rb) and caesium (Cs). The fungi then enhance uptake of these elements into host plants. This study compared the accumulation of these three alkali metals in bulk soil, rhizosphere, soil-root interface, fungal mycelium and sporocarps of mycorrhizal fungi in a Swedish forest. The soil-root interface was found to be distinctly enriched in K and Rb compared with the bulk soil. Potassium concentrations increased in the order: bulk soil 137Cs could be prevented by providing additional Rb or K at contaminated sites. The levels of K, Rb, and Cs found in sporocarps were at least one order of magnitude higher than those in fungal mycelium. These results provide new insights into the use of transfer factors or concentration ratios. The final step, the transfer of alkali metals from fungal mycelium to sporocarps, raised some specific questions about possible mechanisms.

  20. Tracing sediment sources in the Williams River catchment using caesium-137 and heavy metals: towards an assessment of the relative importance of surface erosion and gully erosion

    International Nuclear Information System (INIS)

    Recent sediment sourcing in the 1175km2 Williams River catchment near Newcastle, NSW, has involved the use of caesium-137 (137Cs) and heavy metals to identify zones of erosion and estimate erosion rates. Sediment sources to the Williams River include sheet erosion from forested and grazed lands, stream channels (especially banks), gullies and roads. The fallout environmental radioisotope 137Cs was used to assess the erosion status of five vegetated slopes using soil sampling along transects. The net loss or gain of 137Cs at each sampling point was compared with the 137Cs level at a reference site at the slope crest. Net soil loss at each point was calculated from an Australian regression model relating net soil loss from runoff-erosion plots to 137Cs deficit in soils (n=34; r=0.84). Net soil gain was calculated using the regression model in reverse mode. A weighted net soil loss (or gain) was then calculated for each slope transect. Results showed low net soil loss, ranging from zero to 0.64 t ha-1 yr1, suggesting that slopes were not major contributors of sediment to the Williams River. A small sub-catchment south of Wirragulla Hill, typical of the lower Williams region, was selected for more detailed tracing of sediment sources. The catchment contains gullies, sheet-erosion exposed sub-soil, grassland and one unsealed road. Heavy metals and 137Cs have been used to fingerprint the sources, and these measurements will be compared with suspended sediment collected from drainage water in the creek. Only preliminary results have been obtained for this component of the study. The paper will assess these two approaches for the identification of sediment sources and discuss practical applications in water resources management

  1. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    Science.gov (United States)

    Stohl, A.; Seibert, P.; Wotawa, G.; Arnold, D.; Burkhart, J. F.; Eckhardt, S.; Tapia, C.; Vargas, A.; Yasunari, T. J.

    2012-04-01

    This presentation will show the results of a paper currently under review in ACPD and some additional new results, including more data and with an independent box modeling approach to support some of the findings of the ACPD paper. On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant (FD-NPP) developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions of two isotopes, the noble gas xenon-133 (133Xe) and the aerosol-bound caesium-137 (137Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined the first guess with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 16.7 (uncertainty range 13.4-20.0) EBq, which is the largest radioactive noble gas release in history not associated with nuclear bomb testing. There is strong evidence that the first strong 133Xe release started early, before active venting was performed. The entire noble gas inventory of reactor units 1-3 was set free into the atmosphere between 11 and 15 March 2011. For 137Cs, the inversion results give a total emission of 35.8 (23.3-50.1) PBq, or about 42% of the estimated Chernobyl emission. Our results indicate that 137Cs emissions peaked on 14-15 March but were generally high from 12 until 19 March, when they

  2. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2011-10-01

    Full Text Available On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant (FD-NPP developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions of two isotopes, the noble gas xenon-133 (133Xe and the aerosol-bound caesium-137 (137Cs, which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined the first guess with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 16.7 (uncertainty range 13.4–20.0 EBq, which is the largest radioactive noble gas release in history not associated with nuclear bomb testing. There is strong evidence that the first strong 133Xe release started very early, possibly immediately after the earthquake and the emergency shutdown on 11 March at 06:00 UTC. The entire noble gas inventory of reactor units 1–3 was set free into the atmosphere between 11 and 15 March 2011. For 137Cs, the inversion results give a total emission of 35.8 (23.3–50.1 PBq, or about 42% of the estimated Chernobyl emission. Our results indicate that 137Cs emissions peaked on 14–15 March but were generally high from 12 until 19 March, when they suddenly dropped by orders of magnitude exactly when spraying of

  3. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2012-03-01

    Full Text Available On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions into the atmosphere of two isotopes, the noble gas xenon-133 (133Xe and the aerosol-bound caesium-137 (137Cs, which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined it with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 15.3 (uncertainty range 12.2–18.3 EBq, which is more than twice as high as the total release from Chernobyl and likely the largest radioactive noble gas release in history. The entire noble gas inventory of reactor units 1–3 was set free into the atmosphere between 11 and 15 March 2011. In fact, our release estimate is higher than the entire estimated 133Xe inventory of the Fukushima Dai-ichi nuclear power plant, which we explain with the decay of iodine-133 (half-life of 20.8 h into 133Xe. There is strong evidence that the 133Xe release started before the first active venting was made, possibly indicating structural damage to reactor components and/or leaks due to overpressure which would have allowed early release of noble gases. For 137

  4. Strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions; Transfert de radioelements en zone non saturee. Etude experimentale et modelisation appliquees au Site Pilote de Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Szenknect, St

    2003-10-15

    This work is devoted to the quantification and the identification of the predominant processes involved in strontium and caesium transport in unsaturated soil from Chernobyl Pilot Site under steady flow conditions. The transport and fate of radionuclides in the subsurface is affected by various physical and chemical processes including advective and diffusive transport as well as chemical and biological transformations. Laboratory experiments and the use of a multiple tracer approach allow to isolate the contributions of each elementary process and to control the physico-chemical conditions in the system. To be more representative of the field conditions, we decided to perform column miscible displacement experiments. We perform batch and flow-through reactor experiments to characterize the radionuclides sorption mechanisms. Miscible displacement experiments within homogeneous columns and modeling allow to characterize the hydrodynamic properties of the soil and to describe the radionuclides behaviour under dynamic conditions at different water contents. We show that the water content of porous media affect the transport behaviour of inert and strongly sorbing radionuclides. Our results demonstrate that a parametrized transport model that was calibrated under completely saturated conditions was not able to describe the advective-dispersive transport of reactive solutes under unsaturated steady state conditions. Under our experimental conditions, there is no effect of a decrease of the mean water content on the sorption model parameters, but the transport parameters are modified. We established for the studied soil the relation between hydrodynamic dispersion and water content and the relation between pore water velocity and water content. (author)

  5. Uptake of radionuclides caesium and cobalt

    International Nuclear Information System (INIS)

    By means of chemical treatment ammonium, potassium, sodium and H-form of zeolite were prepared. The chemical modifications of zeolite were carried out with: 2M solution of NaNO3, NH4NO3, KNO3; 0,1M solution of HCl; NaOH solution of different concentration. The method of model radioactive solution was used to find the sorption ability for cesium and cobalt every modified zeolite. The model solution were 0.05M solution of cobalt labelled by 60Co or cesium labelled by 137Cs. The highest sorption ability was observed for zeolite modified by NaOH. The influence of pH on uptake of cesium and cobalt by modified zeolite was searched as well. The experimental data (leaching tests, compressive strength measurement and porosity) were measured for the case the Cs and Cs from model water solution and radioactive waste water were up taken on chemically modified zeolite and were subsequently incorporated into cement casts on blast furnace cement slags basis. The leachability was tested in water, in basis solution and in acid solution. The leachability in water and basic solution was negligible, in acid solution it was less than 4% which is inside of value of applied measure method. The compressive strength, porosity and leaching experiment are hopefully and show good mechanical stability and good retention of observed radionuclides in samples exposed in leaching solutions. (J.K.)

  6. Radioactive caesium in hunters and their families

    International Nuclear Information System (INIS)

    We have measured the whole-body content of radiocesium in men and women in households, where at least one member is a hunter. Hunter families live to a great extent on forest products, such as mushrooms, berries and meat from game. Measurements were performed in two areas in northern Sweden and in three areas in the middle part of Sweden with deposition levels between 7 to 80 kBq/m2. The average whole body content of 137Cs varied between 0.3 to 1.9 kBq for women and 0.6 to 4.7 kBq for men, depending on the deposition level. Each individual in the measured group was also asked to fill in questionnaire and a food diary to provide complementary information of, e.g., food intake and other life conditions. The single dietary factor most clearly related to whole-body content in these groups is the intake of meat from moose. The best regression model with variables from the questionnaire explained 60% of the variance in the whole-body content of 137Cs in the measurement group. Some of the variables in this model were deposition level, sex, rate of intake and estimated consumption of moose meat and estimated amount of bilberries in the fridge. 6 refs, 5 figs, 14 tabs

  7. Inorganic caesium lead iodide perovskite solar cells

    OpenAIRE

    Eperon, GE; Paterno', GM; Sutton, RJ; Zampetti, A.; Haghighirad, A; Cacialli, F.; Snaith, H.

    2015-01-01

    The vast majority of perovskite solar cell research has focused on organic-inorganic lead trihalide perovskites. Herein, we present working inorganic CsPbI3 perovskite solar cells for the first time. CsPbI3 normally resides in a yellow non-perovskite phase at room temperature, but by careful processing control and development of a low-temperature phase transition route we have stabilised the material in the black perovskite phase at room temperature. As such, we have fabricated solar cell dev...

  8. Chernobyl caesium distribution in two forest soils

    International Nuclear Information System (INIS)

    The Chernobyl nuclear accident on April 26, 1986 affected a considerable part of Europe, including the Romanian territory too. The soil acts as an integrator and the main part of the received radionuclides remains here. However, due to diffusion, leaching and runoff, activity of living organisms in soil, human activity and different other factors, the deposited radionuclides on the soil surface can be removed from the original deposition areas. Mainly, the transport of Cs-137 from soil to other environmental factors is intensively studied having in view the natural resource exploitation in radioactive contaminated areas, this radionuclide being one of the most important radioisotopes released by earlier nuclear weapon tests and nuclear accidents. Generally, migration rates of radionuclides in soil are evaluated by column and percolation experiments, in controlled conditions and using well-defined concentrations of the radionuclide. As part of the environment, the forests have been contaminated up to a depth of 30 cm by the radionuclides resulting from Chernobyl nuclear accident. As the forest is a source of radionuclides for intake and habitat for some critical groups and also a secondary source of contamination (resuspension, erosion), its radioecology became an increasing research topic. The depth distribution of radiocaesium was analysed in the brown-reddish forest type soil of two forests. The depth profile and the specific activity of each layer permit the assessment of total deposition, migration rate and diffusion coefficient for Cs-137 and Cs-134. The total deposition of Cs-137 is about 47 kBq/m2 for Magurele area and about 14 kBq/m2 for Naipu forest. The migration rate is more than 10 times higher in Naipu forest as compared to Magurele forest. The diffusion coefficients are similar, namely about 0.2 cm2/year. (authors)

  9. Chernobyl caesium distribution in two forest soils

    International Nuclear Information System (INIS)

    The Chernobyl nuclear accident on April 26, 1986, affected a considerable part of Europe, including the Romanian territory too. As part of the environment, the forests, covering up to 30 % area of Romania, were contaminated by the radionuclides resulting from Chernobyl nuclear accident. Being a source of radionuclides for intake and habitat for some critical groups and also a secondary source of contamination (resuspension, erosion), forest radioecology is an increasing research topic. The distribution of radiocaesium with depth was analysed in the brown-reddish forest type soil of two forests. The profile with depth and the specific activity of each layer permit the assessment of: total deposition, migration rate and diffusion coefficient for Cs-137 and also Cs-134. The total deposition of Cs-137 is about 47 kBq/m2 for Magurele area and about 14 kBq/m2 for Naipu forest. The migration rate is more than 10 times greater in Naipu forest as in Magurele forest. The diffusion coefficients are similar, about 0.2 cm2/an. (author)

  10. Deposition of caesium to surfaces of buildings

    International Nuclear Information System (INIS)

    Outdoor surfaces of several different types of building material have been analysed for 134Cs and 137Cs and the results used to estimate deposition velocities using integrated air doses. The Chernobyl reactor accident would have been the only significant source of 134Cs and, for materials unlikely to have intercepted precipitation during the passage of the main plume, dry deposition velocities have been inferred. Substantial amounts of 137Cs on the older building materials would have been due to nuclear weapons fall-out. For brick walls, 134Cs levels were below the limits of analytical detection and upper limits of dry deposition velocity have been estimated. Values have also been inferred for roofing felt and flat clay and corrugated concrete roof tiles. 137Cs levels on older roofing materials indicate significant weathering of weapons fall-out. (author)

  11. Sorption studies of caesium by complex hexacyanoferrates

    International Nuclear Information System (INIS)

    A comprehensive literature review was carried out on the preparation of complex hexacyanoferrates in a granular form suitable for use in a packed column. The preparation of sodium nickel hexacyanoferrate using a freeze-thaw method was studied in detail and a method developed to produce a consistent and reproducible granular product. The equilibrium and sorption kinetics were studied using batch and column tests, and the process modelled to predict performance under various conditions. (author)

  12. Structural study of caesium-based britholites Sr{sub 7}La{sub 2}Cs(PO{sub 4}){sub 5}(SiO{sub 4})F{sub 2}; Etude structurale de britholite au cesium Sr{sub 7}La{sub 2}Cs(PO{sub 4}){sub 5}(SiO{sub 4})F{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Boughzala, K.; Gmati, N.; Bouzouita, K. [U.R. materiaux inorganiques, departement de chimie, faculte des sciences, Monastir (Tunisia); Ben Cherifa, A. [Laboratoire de thermodynamique appliquee, departement de chimie, faculte des sciences de Tunis (Tunisia); Gravereau, P. [Institut de chimie de la matiere condensee, universite de Bordeaux, CNRS - UPR9048, 33 - Pessac (France)

    2010-11-15

    Several studies demonstrated the ability of britholites to retain radionuclides such as the caesium and actinides. Therefore, three compounds with formulas Sr{sub 8}LaCs(PO{sub 4}){sub 6}F{sub 2}, Sr{sub 7}La{sub 2}Cs(PO{sub 4}){sub 5}(SiO{sub 4})F{sub 2} and Sr{sub 2}La{sub 7}Cs(SiO{sub 4}){sub 6}F{sub 2}, were prepared by solid state reaction. However, it seems that only the mono-silicated composition was obtained in a pure state. In this present work, the X-ray diffraction and magnetic nuclear resonance have been used to investigate the structure for this composition. The results showed that in fact this phase was not pure, but it was mixed with a secondary phase, SrLaCs(PO{sub 4}){sub 2}. The refinement by the Rietveld method allowed also to precise the distribution of La{sup 3+} and Cs{sup +} ions between the two cationic sites of the apatite. (authors)

  13. Sorption behaviour of caesium on a bentonite sample

    International Nuclear Information System (INIS)

    Sorption of elements like Cs on clay is one of the principal processes delaying their release from deep repositories of nuclear wastes into the environment. The sorption processes taking place between non-purified natural clay material (bentonite) and synthetic groundwater (containing Ca, Mg, Na, K and carbonates) were therefore studied experimentally and modelled for Cs to determine whether thermodynamic computer codes capable of predicting the behaviour of this element in natural systems might be developed. The model used, based on the properties of a pure montmorillonite phase, incorporates the surface reactions for natural major ions and sorbing cations but does not have any adjustable parameters. The weight of each parameters used in the model is assessed. Surface reactions are classified as either major or minor, and a simplified model of Cs sorption that considers only the major processes is proposed. This simplified model might correspond to the less sophisticated thermodynamic model included in coupled geochemistry-transport models. (orig.)

  14. Sorption behaviour of caesium on a bentonite sample

    Energy Technology Data Exchange (ETDEWEB)

    Hurel, C. [Lab. de Chimie Analytique Bio-Inorganique et Environnement, UMR CNRS 5034, Univ. de Pau et des Pays de l' Adour, Helioparc Pau Pyrenees, Pau (France); GRECI, Univ. de Reims Champagne-Ardenne, Moulin de la Housse, Reims (France); Marmier, N.; Fromage, F. [GRECI, Univ. de Reims Champagne-Ardenne, Moulin de la Housse, Reims (France); Seby, F.; Bourg, A.C.M. [Lab. de Chimie Analytique Bio-Inorganique et Environnement, UMR CNRS 5034, Univ. de Pau et des Pays de l' Adour, Helioparc Pau Pyrenees, Pau (France); Giffaut, E. [ANDRA, Agence Nationale pour la Gestion des Dechets Radioactifs, Chatenay-Malabry (France)

    2002-07-01

    Sorption of elements like Cs on clay is one of the principal processes delaying their release from deep repositories of nuclear wastes into the environment. The sorption processes taking place between non-purified natural clay material (bentonite) and synthetic groundwater (containing Ca, Mg, Na, K and carbonates) were therefore studied experimentally and modelled for Cs to determine whether thermodynamic computer codes capable of predicting the behaviour of this element in natural systems might be developed. The model used, based on the properties of a pure montmorillonite phase, incorporates the surface reactions for natural major ions and sorbing cations but does not have any adjustable parameters. The weight of each parameters used in the model is assessed. Surface reactions are classified as either major or minor, and a simplified model of Cs sorption that considers only the major processes is proposed. This simplified model might correspond to the less sophisticated thermodynamic model included in coupled geochemistry-transport models. (orig.)

  15. Animated molecular dynamics simulations of hydrated caesium-smectite interlayers

    Directory of Open Access Journals (Sweden)

    Sposito Garrison

    2002-09-01

    Full Text Available Computer animation of center of mass coordinates obtained from 800 ps molecular dynamics simulations of Cs-smectite hydrates (1/3 and 2/3 water monolayers provided information concerning the structure and dynamics of the interlayer region that could not be obtained through traditional simulation analysis methods. Cs+ formed inner sphere complexes with the mineral surface, and could be seen to jump from one attracting location near a layer charge site to the next, while water molecules were observed to migrate from the hydration shell of one ion to that of another. Neighboring ions maintained a partial hydration shell by sharing water molecules, such that a single water molecule hydrated two ions simultaneously for hundreds of picoseconds. Cs-montmorillonite hydrates featured the largest extent of this sharing interaction, because interlayer ions were able to inhabit positions near surface cavities as well as at their edges, close to oxygen triads. The greater positional freedom of Cs+ within the montmorillonite interlayer, a result of structural hydroxyl orientation and low tetrahedral charge, promoted the optimization of distances between cations and water molecules required for water sharing. Preference of Cs+ for locations near oxygen triads was observed within interlayer beidellite and hectorite. Water molecules also could be seen to interact directly with the mineral surface, entering its surface cavities to approach attracting charge sites and structural hydroxyls. With increasing water content, water molecules exhibited increased frequency and duration of both cavity habitation and water sharing interactions. Competition between Cs+ and water molecules for surface sites was evident. These important cooperative and competitive features of interlayer molecular behavior were uniquely revealed by animation of an otherwise highly complex simulation output.

  16. Caesium teletherapy revised: a collimation system for an antique

    International Nuclear Information System (INIS)

    A description is given on how, at the Newcastle Mater Misericordiae Hospital, it has been possible to utilise an old Telecaesium 137 unit to deliver radiation at a low dose rate. These rates are those normally used in conventional brachytherapy. This was achieved by using an extended point source and divergent beam collimation to produce a uniform beam with reduced penumbra. Attenuating filters of lead were then added to reduce the dose rate from greater than 1 Gy/min to between 0.6 and 4.8 Gy/hr. Patient stabilization and comfort has also been discussed. 3 refs., 7 figs., 2 tabs

  17. Societal representations on the accident with caesium-137

    International Nuclear Information System (INIS)

    The influence of societal representations on the theme of nuclear energy are reviewed in the light of the public's reactions to the accident with the capsule of 137Cs in Goiania. As a starting point, it is accepted that the panic caused by the accident can be properly understood only if human subjectivity is taken into consideration. This perspective is required whenever events unfold which put human life and the environment at risk. Faced with the accident, the public internalized radioactivity - an element unknown to them - as a certainty of contracting cancer and ultimately death, despite the fact that such outcomes can only be the result of excessive exposure to radioactivity. (author)

  18. Correlation of erosion measurements and soil caesium-137 content

    International Nuclear Information System (INIS)

    This paper reports a calibration between measured soil loss from small plots and measured soil 137Cs content (expressed as a percentage loss relative to the 137Cs content of a local stable reference soil). The regression represents a simple and rapid tool for the estimation of net soil loss from sites which have a uniform and continuous history of land-use. (author)

  19. Adsorption of Radioactive Strontium and Caesium from Mixtures of Solutions

    International Nuclear Information System (INIS)

    In this thesis, the adsorption of the radioactive Cs and Sr on two different types of cement, Sulfate Resistant Cement and Portland Composed Cement, was investigated. The gamma-active Cs-137 and Sr-85 were used as tracers. Four different mixtures of solutions of Cs and Sr were used in experiments; a) The solution containing trace amount of Sr-85 and Cs-137 b) 1.10-5 - 1.10-1 M *SrCl2 solutions containing trace amount of Cs-137 c) 1.10-5 - 1.10-1 M *CsCl solutions containing trace amount of Sr-85 d) The equal amount of mixtures of 1.10-5 - 1.10-1 M SrCl2 and 1.10-5 - 1.10-1 M CsCl solutions. It was shown that the convenient ph values for the comparison of Cs and Sr adsorption on both cement were 2.5 and 11.0. It was observed that the adsorption capacity of Sr on Sulfate Resistant Cement was twice that for the Portland Composed Cement in the solutions containing trace amount of Cs-137 and 1.10-5 - 1.10-1 *SrCl2. The in cease in adsorption capacity is related to the Ca to Sr ion exchange in Sulfate Resistant Cement containing appreciable amount of C3S. The adsorption of Cs and Sr on both types of cement in solutions containing equal amount of CsCl and SrCl2 was greater than that of individual solutions of CsCl and SrCl2. This latter behavior is related to the ion charge, the hydration of ions and the interaction of the Cs with the Sr on the surface of adsorbent. It was observed that although Portland Composed Cement adsorbs Cs selectively, Sulfate Resistant Cement has a greater affinity for Sr. Cs adsorption is not affected by ph changes whilst Sr adsorption is highly dependent on ph

  20. Parameters for Cold Collisions of Lithium and Caesium Atoms

    CERN Document Server

    Ouerdane, H

    2015-01-01

    We calculate the s-wave scattering length and effective range and the p-wave scattering volume for $^7$Li atoms interacting with $^{133}$Cs atoms via the X$^1\\Sigma^+_g$ molecular potential. The length and volume are found by fitting the log-derivative of the zero energy wave function evaluated at short range to a long range expression that accounts for the leading van der Waals dispersion potential and then incorporating the remaining long range dispersion contributions to first order. The effective range is evaluated from a quadrature formula. The calculated parameters are checked from the zero energy limits of the scattering phase shifts. We comment on ill-conditioning in the calculated s-wave scattering length.

  1. Modelling soil transport and plant uptake of radio-caesium

    International Nuclear Information System (INIS)

    A mechanistic model was developed to simulate the transport of radio-Cs in soils and its subsequent uptake by vegetation. The soil parameters in the model have been 'calibrated' by a process of parameter estimation by fitting model results to experimental data on the radio-Cs distribution in the soil profile. The experiment was used was not originally designed for this purpose and the data was non-ideal. Nevertheless it proved a useful initial test of the model. The experiment carried out at ITE Merlewood was intended to study the recycling of radio-Cs deposited by contaminated sheep faeces. Separate experiments were conducted to measure the rate at which radio-Cs is removed from faeces and it was therefore possible to determine source terms for the model. The cumulative rate of uptake by the vegetation was measured and at the end of the experiment the distribution of radio-Cs within the soil profile determined. (author)

  2. Concentration of caesium isotopes in foodstuffs in Poland

    International Nuclear Information System (INIS)

    One of the sources of the radioactive doses obtained by people resulting from the radiological contamination of the environment, is the transfer of radionuclides to the organism via ingestion. Radioactive isotopes in foodstuffs appear as a result of nuclear activities on the globe, mainly because of nuclear explosion and, recently, after the Chernobyl accident. Since the early sixties the network of Service for Measurement of Radioactive Contamination in Poland systematically controlled all kinds of important food products. Radiochemical methods and gamma spectrometry has been used to determination the activity of radioactive isotopes. This contribution reports of the determination of 134Cs and 137Cs concentration in milk, meat, vegetables, fruits, cereals and 'forest products' during period 1985-1999. In 1985 the average 137Cs level was below 1 Bq/kg (except forest products). Moreover, no regional differences were observed the whole territory of Poland. After the Chernobyl accident situation changed completely. Average activity of 137Cs in milk was 25 Bq/l in May 1986, 20-25 Bq/kg in beef and 10-15 Bq/kg in pork (summer months). Also fruit picked up in June and July was contaminated, mainly currents. The contamination of vegetables was less important. The activity of cesium isotopes in forest mushrooms and wild game were much higher than in other tested foodstuffs. From the 1987 level of radioactive contamination was decreasing gradually. In 1999 the activity of 137Cs of vegetables, cereals, fruit was on level as it has been in 1985 as for meat and milk it is higher. Level of radiocesium in 'forest products' is still high. The average annual effective dose from ingestion of radiocesium was on level 0.088 mSv in 1986 and 0.006 mSv in 1999. (author)

  3. Surface erosion assessment in New Zealand using caesium-137

    International Nuclear Information System (INIS)

    The 137Cs technique has provided the first quantitative, medium-term data on rates of soil redistribution by surface erosion on both cropland and rangeland in New Zealand. Research has also provided data on natural short-range variability of 137Cs in uneroded soils, and a technique for independently estimating 137Cs input values from rainfall. The greatest research need remains the development of robust, accurate calibration procedures for converting 137Cs measurements to rates of erosion. Emphasis has been on application of the technique to provide field-based data on erosion rates, with limited research to further develop the technique. This paper summarises recent research in these two areas

  4. Uptake of caesium-137 from peat and compost mould by vegetables in a greenhouse experiment

    Energy Technology Data Exchange (ETDEWEB)

    Malm, J.; Uusi-Rauva, A.; Paakkola, O. (Helsinki Univ. (Finland). Faculty of Agriculture and Forestry); Rantavaara, A. (Finnish Centre for Radiation and Nuclear Safety (STUK), Helsinki (Finland))

    1991-01-01

    A pot experiment was conducted to study the root uptake of {sup 137} Cs by vegetables grown in peat and composite mould in a greenhouse. The {sup 137}Cs in the growing media originated from Chernobyl fallout. The vegetables were cucumber (Cucumis sativus L. var. Farbio VDP SF 76), tomato (Lycopersicon esculentum L. Var. Virosa), parsley (Petroselinum crispum A.W. Hill var. Non plus ultra), radish (Raphanus Sativus L. var. Nondan) and lettuce (Lactuca sativa L. var Atraktion). The effect of adding potassium to the peat was also studied. The transfer factors (activity in plant dry weight/activity in soil dry weight) varied from 0.66 to 1.8 for peat and from 0.060 to 0.19 for compost mould. Addition of potassium did not have any clear effect on the transfer factors. (Author).

  5. Non cancerous diseases following a chronic intern contamination by caesium 137: cataracts and cardiac arrhythmias

    International Nuclear Information System (INIS)

    This work of thesis joins within the framework of an analysis of the sanitary consequences of the nuclear accident of Chernobylsk. Since 2005, the I.R.S.N. is interested in the not cancerous pathologies (cataracts, and cardiac arrhythmias) observed among the children living on the contaminated territories after the fallout of Chernobylsk and has in this aim implemented a research programme called E.P.I.C.E. (Evaluation of the pathologies induced by a chronicle contamination by cesium) whom objective is to show an eventual link between the chronicle ingestion of contaminated food and these pathologies emergence. An exploitation of the results of the pilot study,first phase of the E.P.I.C.E. program was realized. The analysis was completed by two bibliographical reviews relative to the knowledge available on these diseases. The results of this pilot study suggest: on one hand, an absence of link between the activity in cesium 137 at the level of the heart, of the whole body and the emergence of disorder of the heart rhythm; on the other hand, for the cases of cataract, a link between the load in cesium 137 at the neck level and the emergence of the disease in 40 % of the cases. However, these results must be considered with caution because several limits and, in particular, a way of selection affect this study. concerning the scientific literature, this one stays rather poor because only thee articles make reference to a relationship between cesium 137 and the emergence of these non cancerous pathologies. After having exposed the context, this thesis draws up the situation of knowledge relative to cataracts and to cardiac arrhythmias and their possible relationship with ionizing radiations, collect the results stemming from the analysis of the pilot study and envisages future epidemiological studies. (N.C.)

  6. Does the Fukushima NPP disaster affect the caesium activity of North Atlantic Ocean fish?

    Science.gov (United States)

    Kanisch, G.; Aust, M.-O.

    2013-08-01

    Fillet samples of marine fish collected from the East/West Greenland currents (GC) and from the Baltic Sea (BS) have been investigated by gamma-ray spectrometry within the regular German monitoring programme. In samples of the second half of 2011, 134Cs traces have been detected that are suggested to originate from the Fukushima fallout that was deposited in March/April 2011 over the northern North Atlantic and accumulated by fish. The radionuclide 134Cs (half-life 2 yr) was indeed detected with quite small activities at about 0.0036 Bq kg-1 w.w. Existing box models describing the transport of Cs within seawater boxes of the northeast Atlantic allowed for estimation of 134Cs contributions from other sources, i.e. from the Chernobyl fallout and from discharges by the two major European nuclear reprocessing plants; both were negligible around Greenland, while for the Chernobyl fallout a small 134Cs background contribution to BS fish was estimated. Model results confirmed the level of 134C measured in BS fish and showed its maximum to have occurred in winter 2011/2012 followed by a continuous decrease. It was also determined that 134Cs activity, but not that of 134Cs, showed a significant negative correlation with sampling depth (150-400 m) of GC fish; this strengthens our Fukushima fallout assumption. As a result, the Fukushima fallout in these sea areas only marginally enhanced (GC: 4%; BS: 0.1%) pre-Fukushima levels of individual dose rates received by human fish consumers; the addition was around 0.001 μSv following the consumption of 10 kg of fish per year, which is not expected to cause concern according to present guidelines for radiation protection.

  7. Does the Fukushima NPP disaster affect the caesium activity of North Atlantic Ocean fish?

    Directory of Open Access Journals (Sweden)

    G. Kanisch

    2013-08-01

    Full Text Available Fillet samples of marine fish collected from the East/West Greenland currents (GC and from the Baltic Sea (BS have been investigated by gamma-ray spectrometry within the regular German monitoring programme. In samples of the second half of 2011, 134Cs traces have been detected that are suggested to originate from the Fukushima fallout that was deposited in March/April 2011 over the northern North Atlantic and accumulated by fish. The radionuclide 134Cs (half-life 2 yr was indeed detected with quite small activities at about 0.0036 Bq kg−1 w.w. Existing box models describing the transport of Cs within seawater boxes of the northeast Atlantic allowed for estimation of 134Cs contributions from other sources, i.e. from the Chernobyl fallout and from discharges by the two major European nuclear reprocessing plants; both were negligible around Greenland, while for the Chernobyl fallout a small 134Cs background contribution to BS fish was estimated. Model results confirmed the level of 134C measured in BS fish and showed its maximum to have occurred in winter 2011/2012 followed by a continuous decrease. It was also determined that 134Cs activity, but not that of 134Cs, showed a significant negative correlation with sampling depth (150–400 m of GC fish; this strengthens our Fukushima fallout assumption. As a result, the Fukushima fallout in these sea areas only marginally enhanced (GC: 4%; BS: 0.1% pre-Fukushima levels of individual dose rates received by human fish consumers; the addition was around 0.001 μSv following the consumption of 10 kg of fish per year, which is not expected to cause concern according to present guidelines for radiation protection.

  8. Does the Fukushima NPP disaster affect the caesium activity of North Atlantic Ocean fish?

    Directory of Open Access Journals (Sweden)

    G. Kanisch

    2013-03-01

    Full Text Available Fillet samples of marine fish collected from the East/West Greenland current (GC and from the Baltic Sea (BS, have been investigated by gamma-ray spectrometry within the regular German monitoring program. In samples of the second half of 2011 134Cs traces have been detected, suggested to originate from the Fukushima fallout being deposited in March/April 2011 over the northern North Atlantic and accumulated by fish. The radionuclide 134Cs (half-live 2 yr was indeed detected with quite small activities at about 0.0036 Bq kg−1 w.w. Existing box-models describing the transport of Cs within seawater boxes of the NE Atlantic allowed estimating that 134Cs contributions from other sources, i.e. from the Chernobyl fallout and from discharges by the two major European nuclear reprocessing plants, both were negligible around Greenland, while for the Chernobyl fallout a small 134Cs background contribution to BS fish was estimated. Model results confirmed the level of 134Cs measured in BS fish and showed its maximum to have occurred in winter 2011/2012 followed by a continuous decrease. It was also determined that 134Cs activity, but not that of 134Cs, showed a significant negative correlation with sampling depth (150–400 m of GC fish; this strengthens our Fukushima fallout assumption. As a result, the Fukushima fallout in these sea areas only marginally enhanced (GC: 4%; BS: 0.1% pre-Fukushima levels of individual dose rates received by human fish consumers; the addition was around 0.001 μSv following the consumption of 10 kg fish per year, which is not expected to cause concern according to present guidelines for radiation protection.

  9. Caesium sorption by hydrated cement as a function of degradation state: Experiments and modelling

    International Nuclear Information System (INIS)

    To provide reliable K d data for Cs required for the performance assessment of cement-based radioactive waste repositories, two complementary approaches were followed. First, Cs sorption was determined on a range of hydrated cement paste (HCP) and mortar samples of CEM I and CEM V for different degradation states and solution compositions, as well as on some single mineral phases. Second, a surface complexation-diffuse layer model previously developed by Pointeau et al. [Pointeau, I., Marmier, N., Fromage, F., Fedoroff, M., Giffaut, E., 2001. Cs and Pb uptake by CSH phases of hydrated cement. Material Research Society Symposium Proceedings, 663, 105-113] for Cs sorption on synthetic CSH phases was simplified to facilitate its application to whole HCP and mortars or concrete, following re-assessment of the model parameters. All measurements were compared with model predictions. The sorption data obtained on the different solid phases as a function of conditions corroborate that CSH minerals are the main sorbing phase for Cs in HCP. The data also clearly show the important influence of pH and the dissolved concentration of Na, K and Ca on K d. It is further suggested that a decrease of pH is concomitant with a decrease of the Ca/Si ratio and a corresponding increase in surface sites with high affinity for Cs and, thus, K d. Elevated concentrations of cations able to compete with Cs for these sites lead to a decrease of K d, on the other hand. The simplified model was applied to the sorption measurements performed within this study as well as to a variety of literature data, mainly K d values for a variety of fresh HCP and mortar or concrete samples based on different samples of Ordinary Portland Cement as well as blended cements. The results show that the model can be applied reasonably well to a very large variety of conditions in terms of solid and solution compositions that cover a range of K d values from 10-4 to ca. 3.2 m3/kg. The large scatter typically observed for Cs sorption, especially on fresh HCP samples prepared from different formulations, can be explained quantitatively by the variable concentrations of Na and K in the respective solutions, which compete with Cs for fixation sites. On the other hand, the comparatively uniform conditions in degraded HCP typically render the prediction of K d values less uncertain than in case of fresh HCP

  10. Fractionation of caesium (137Cs) in coniferous forest soil in central Sweden

    International Nuclear Information System (INIS)

    Sequential extraction procedure (SEP) was applied for fractionation of Chernobyl fallout 137Cs bound onto soils of a coniferous forest ecosystem located in central Sweden. Results of sequentially extracted 137Cs fractions demonstrated that 8% (mean value) of the total deposited 137Cs was water soluble (F1) and 13% was NH4OAc extractable (F2). Oxidation of F2 residuals by H2O2 led to a release of 15% of soil-bound 137Cs (F3). Acid digestion of F3 residuals showed a possibility of releasing an extra amount of soil-bound 137Cs, 22% of the total soil 137Cs inventory (F4). These two fractions (F3 and F4) include strongly bound 137Cs that seems to require longer biodegradation processes by soil microflora and microfauna before becoming available for uptake by plants and fungi. More than 37% of the total soil 137Cs inventory was bound onto soil residuals in a non-extractable form that includes slowly degradable organic matter and other soil residual compartments. The distribution coefficient (Kd) was rather low and shows an inverse relation with the increase of percentage of soil organic matter, which indicates a week binding of 137Cs onto forest soil. In contrast, chemical fractionation of soil bound 137Cs showed a substantial fraction of 137Cs was strongly bound onto soil as organically bound 137Cs. Apparently, the binding processes of radiocaesium onto forest soil seems to be time dependent

  11. Spatial distribution of caesium-137 in soil cover of background terrestrial ecosystems, Central European Russia

    Energy Technology Data Exchange (ETDEWEB)

    Paramonova, Tatiana A. [Radioecology and Ecotoxicology Department of Soil Science Faculty, Moscow State Lomonosov University, 119234 Moscow (Russian Federation); Shamshurina, Evgenia N. [Laboratory of soil erosion and fluvial processes of Geography Faculty, Moscow State Lomonosov University, 119234 Moscow (Russian Federation)

    2014-07-01

    ¹³⁷Cs - the main long-living anthropogenic radionuclide - arrived in mass at Russian terrestrial ecosystems after nuclear tests in the atmosphere in 1960-yy. and after Chernobyl accident in 1986 y., but in spite of a long period since these events soil cover contamination by ¹³⁷Cs is considered as extremely resistant due to its firmly fixation by soil solid matter and a long half-life of the radionuclide. Wide-scale investigation in maximal diversity of natural, semi-natural and anthropogenic landscapes of Central European Russia (more than 400 soils samples from Vologda, Yaroslavl, Ivanovo, Tver regions which are representative for the southern taiga zone) demonstrates that modern average specific activity of ¹³⁷Cs in the upper 15-cm layer of soil is 11±3 Bq/kg (contamination density 0.05±0.01 Ci/km²), that is fully ecologically acceptable. It is important that the average concentrations of ¹³⁷Cs in the soil cover of individual regions are close to each other. The most likely these average values are approximate assessment of background radioactive contamination of soils in central European Russia outside of the immediate Chernobyl trace. At the same time approximately 3% of soils are characterized by elevated ¹³⁷Cs content - 62-98 Bq/kg (0.24-0.43 Ci/km²), that indicates the presence of low radioactive spots on the territory and may be considered as local Chernobyl fallout. All of them attribute with forest soils which are commonly characterized by considerably more high accumulation of ¹³⁷Cs (18±5 Bq/kg, 0.06±0.01 Ci/km²) due to advanced absorbing surface of trees. Agricultural lands (plagued or under meadows) and soils of industrial plots with scarce vegetation contain only 6±2 Bq/kg (0.03±0.01 Ci/km²) of ¹³⁷Cs. About 84-92% of ¹³⁷Cs are concentrated in the upper 15-cm layer of natural soils or in Ap horizon of plagued soils, thus vertical migration of radionuclide is very slow in spite of ~30 years after Chernobyl accident. But it may by considerable lateral migration of ¹³⁷Cs in geochemically connected landscapes through the process of water erosion that leads to additional radionuclide accumulation in peat and foggy-podsolic soils of watershed depressions (migration coefficient 1.3). Thus, shallow depressions could be those 'critical' elements of the landscape with low-contrast areas of additional ¹³⁷Cs accumulation. Long-range transport of ¹³⁷Cs in moderate humid landscapes seems of little importance since alluvial soils and bottom sediments contain only 8±4 Bq/kg and 2±1 Bq/kg correspondingly. (authors)

  12. Caesium-137 in the foodchain lichen-reindeer-man during 1976 to 1978

    International Nuclear Information System (INIS)

    The behaviour of the 137Cs isotope in the subarctic environment has been an object of investigations in this laboratory since 1960. The 137Cs body burden of a group of about 100 Lapps has been determined annually each spring since 1962 using a mobile whole-body counting system accommodated in a truck. In spring 1977, 31 reindeer herders and reindeer herding fishermen residing in Inari were thus measured. In spring 1978, no 137Cs body burden measurements of the Lapps were carried out. Instead, analysis of 137Cs in lichen and reindeer muscle samples was continued in order to check possible changes in the environmental 137Cs level. In this paper 137Cs concentrations in lichen in 1977 and in reindeer muscle in 1977 and 1978 are reported. Using these results the 137Cs body burden of Finnish Lapps is estimated

  13. Uptake of caesium-137 from peat and compost mould by vegetables in a greenhouse experiment

    International Nuclear Information System (INIS)

    A pot experiment was conducted to study the root uptake of 137 Cs by vegetables grown in peat and composite mould in a greenhouse. The 137Cs in the growing media originated from Chernobyl fallout. The vegetables were cucumber (Cucumis sativus L. var. Farbio VDP SF 76), tomato (Lycopersicon esculentum L. Var. Virosa), parsley (Petroselinum crispum A.W. Hill var. Non plus ultra), radish (Raphanus Sativus L. var. Nondan) and lettuce (Lactuca sativa L. var Atraktion). The effect of adding potassium to the peat was also studied. The transfer factors (activity in plant dry weight/activity in soil dry weight) varied from 0.66 to 1.8 for peat and from 0.060 to 0.19 for compost mould. Addition of potassium did not have any clear effect on the transfer factors. (Author)

  14. Time dependent caesium-134 transfer factors for crops grown on different Greek soil types

    International Nuclear Information System (INIS)

    Corn and cabbage plants were grown in a greenhouse pot experiment in two volcanic and two 'representative' Greek soils artificially contaminated with 134Cs for a three year period. Results for the 3rd year of experimentation as well as the main findings for the whole period are presented in this paper. In the third year of the project, two sweet corn (Elite and Vilmorin) and two cabbage varieties, (Kozanitiko and Brunswick) were tested. These varieties, except Vilmorin, were also grown on the same soils the previous years. 134Cs transfer factors (TFs) were significantly higher in the two volcanic soils than in the other soils, in agreement with previous years' data. Irrespective of crop species or variety, the clay-calcareous soil continued to show the lowest TF values. Comparing 134Cs uptake by the two corn varieties, it was found that Vilmorin plants absorbed approximately two times more 134Cs than Elite plants. No such difference was observed for the cabbage varieties. 134Cs TFs for both seeds and vegetative part of Elite variety significantly decreased compared to the respective values of the previous year. A similar trend, rarely significant, was observed for the two cabbage varieties. The ratio TF cabbage/TF corn (seeds) in the four soils increased this year and ranged from 6-16 with a mean value of 9. This increase is due to the higher reduction of corn 134Cs TFs than that of cabbage TFs. For all studied varieties and in all possible combinations the mean value of the ratio TF cabbage/TF corn was 8, coinciding with the respective values of the previous two years (7 and 6 respectively). During the three years of experimentation, three different corn varieties were tested and mean reference TFs for corn seeds in the studied soils were calculated. (author)

  15. Uptake of caesium-137 by leafy vegetables and grains from calcareous soils

    International Nuclear Information System (INIS)

    137Cs was deposited on Bikini Island at Bikini Atoll in 1954 as a result of nuclear testing and has been transported and cycled in the ecosystem ever since. Atoll soils are of marine origin and are almost pure CaCO3 with high concentrations of organic matter in the top 40 cm. Data from previous experiments with mature fruit trees show very high transfer factors (TFs), [Bq kg-1 plant/Bq kg-1 soil, both in dry weight] into fruits from atoll calcareous soil. These TFs are much higher than reported for continental, silica-based soils. In this report TFs for five types of leafy vegetable crops and two types of grain crops are provided for use in predictive dose assessments and for comparison with other data from other investigators working with other types of soil in this CRP. Transfer factors for plants grown on calcareous soil are again very high relative to clay-containing soils and range from 2339 for grain crops and 21-113 for leafy vegetables. Results from these experiments, in this unique, high pH, high organic content, low potassium (K) soil, provide a boundary condition for models relating soil properties to TF. (author)

  16. Measurement of caesium-137 in the human body using a whole body counter

    Science.gov (United States)

    Elessawi, Elkhadra Abdulmula

    Gamma radiation in the environment is mainly due to naturally occurring radionuclides. However, there is also a contribution from anthropogenic radionuclides such as 137Cs which originate from nuclear fission processes. Since 1986, the accident at the Chernobyl power plant has been a significant source of artificial environmental radioactivity. In order to assess the radiological impact of these radionuclides, it is necessary to measure their activities in samples drawn from the environment and in plants and animals including human populations. The whole body counter (WBC) at the University Hospital of Wales in Cardiff makes in vivo measurements of gamma emitting radionuclides using a scanning ring of six large-volume thallium-doped sodium iodide (Nal(Tl)) scintillation detectors. In this work the WBC was upgraded by the addition of two high purity germanium (HPGe) detectors. The performance and suitability of the detection systems were evaluated by comparing the detection limits for Cs. Sensitivities were measured using sources of known activity in a water filled anthropomorphic phantom and theoretical minimum detectable count-rates were estimated from phantom background pulse height spectra. The theoretical minimum detectable activity was about 24 Bq for the combination of six Nal(Tl) detectors whereas for the individual HPGe detectors it was 64 Bq and 65 Bq, despite the much improved energy resolution Activities of 137Cs in the human body between 1993 and 2007 were estimated from the background Nal(Tl) spectra of 813 patients and compared with recent measurements in 14 volunteers. The body burden of Cs in Cardiff patients increased from an average of about 60 Bq in the early and mid 1990s to a maximum of about 100 Bq in 2000. By 2007 it had decreased to about 40 Bq. This latter value was similar to that of Cardiff residents at the time of the Chernobyl accident and to that of the volunteers measured in 2007 (51 Bq). However, it was less than the mean activity of Cardiff residents in 1988 (130 Bq) indicating an overall decrease over a period of about 20 years. The variation in the in vivo activity is probably due to complex inter-relationships between a number of factors such as the removal of deposited 137Cs into the sea by rainfall, individual dietary choices, the imposition and removal of restrictions on foodstuffs from Chernobyl-affected areas and travel to countries that suffered greater initial fall-out than the UK.

  17. Caesium sorption by hydrated cement as a function of degradation state: experiments and modelling.

    Science.gov (United States)

    Ochs, M; Pointeau, I; Giffaut, E

    2006-01-01

    To provide reliable K(d) data for Cs required for the performance assessment of cement-based radioactive waste repositories, two complementary approaches were followed. First, Cs sorption was determined on a range of hydrated cement paste (HCP) and mortar samples of CEM I and CEM V for different degradation states and solution compositions, as well as on some single mineral phases. Second, a surface complexation-diffuse layer model previously developed by Pointeau et al. [Pointeau, I., Marmier, N., Fromage, F., Fedoroff, M., Giffaut, E., 2001. Cs and Pb uptake by CSH phases of hydrated cement. Material Research Society Symposium Proceedings, 663, 105-113] for Cs sorption on synthetic CSH phases was simplified to facilitate its application to whole HCP and mortars or concrete, following re-assessment of the model parameters. All measurements were compared with model predictions. The sorption data obtained on the different solid phases as a function of conditions corroborate that CSH minerals are the main sorbing phase for Cs in HCP. The data also clearly show the important influence of pH and the dissolved concentration of Na, K and Ca on K(d). It is further suggested that a decrease of pH is concomitant with a decrease of the Ca/Si ratio and a corresponding increase in surface sites with high affinity for Cs and, thus, K(d). Elevated concentrations of cations able to compete with Cs for these sites lead to a decrease of K(d), on the other hand. The simplified model was applied to the sorption measurements performed within this study as well as to a variety of literature data, mainly K(d) values for a variety of fresh HCP and mortar or concrete samples based on different samples of Ordinary Portland Cement as well as blended cements. The results show that the model can be applied reasonably well to a very large variety of conditions in terms of solid and solution compositions that cover a range of K(d) values from 10(-4) to ca. 3.2m(3)/kg. The large scatter typically observed for Cs sorption, especially on fresh HCP samples prepared from different formulations, can be explained quantitatively by the variable concentrations of Na and K in the respective solutions, which compete with Cs for fixation sites. On the other hand, the comparatively uniform conditions in degraded HCP typically render the prediction of K(d) values less uncertain than in case of fresh HCP. PMID:16697176

  18. Estimation of soil erosion from caesium-137 measurements in a small, cultivated catchment in Australia

    International Nuclear Information System (INIS)

    Measurements are reported of the distribution of 137Cs within a 6.6 ha drainage basin on cultivated black earth soils located near Merriwa in New South Wales (N.S.W.). The results were used to estimate net loss as well as accumulation of soil. The losses of 137Cs from the catchment slopes were assessed relative to an estimated input of 137Cs of 100 mBq cm-2. A regression equation was developed which relates the net loss of soil by erosion of black earth soils (kg ha-1 y-1) as a function of the measured loss of 137Cs activity in the soil expressed as a percentage of the normal input value. Each input datum of 137Cs activity into the regression equation was obtained under similar conditions. Rates of soil losses, estimated at 19 sites, ranged between 420 and 2970 kg ha-1 y-1 with an average of 1530 kg ha-1 y-1. The results confirmed the usefulness of the 137Cs technique for estimating loss of soil by erosion. (author)

  19. Excitonic ionizations of the electron centres in caesium iodide crystal and exoemission of electrons

    International Nuclear Information System (INIS)

    In the wide-band-gap alkali halide crystals recombination of defects may result in formation of the excitons, which can ionize an electron F-centre; thus the phenomenon of exoelectron emission takes place. According to this excitonic model, the energy spectrum and mean energy of CsI exoelectrons were attained. The results of theoretical evaluation are compared with experimental and the reasons suggested for the explanation of the observed difference are discussed. The conclusion based on the peculiarities of exoemission from CsI and CsBr crystals, was done

  20. Excitonic ionizations of the electron centres in caesium iodide crystal and exoemission of electrons

    Energy Technology Data Exchange (ETDEWEB)

    Galiy, P.V. [Faculty of Electronics, Lviv National University 50 Dragomanov Str., Lviv 79005 (Ukraine); Mel' nyk, O.Ya. [Faculty of Electronics, Lviv National University 50 Dragomanov Str., Lviv 79005 (Ukraine)]. E-mail: moyafis@yahoo.com; Tsvetkova, O.V. [Faculty of Electronics, Lviv National University 50 Dragomanov Str., Lviv 79005 (Ukraine)

    2005-04-15

    In the wide-band-gap alkali halide crystals recombination of defects may result in formation of the excitons, which can ionize an electron F-centre; thus the phenomenon of exoelectron emission takes place. According to this excitonic model, the energy spectrum and mean energy of CsI exoelectrons were attained. The results of theoretical evaluation are compared with experimental and the reasons suggested for the explanation of the observed difference are discussed. The conclusion based on the peculiarities of exoemission from CsI and CsBr crystals, was done.

  1. Caesium cell coherent population trapping clock: main effects affecting the frequency stability

    International Nuclear Information System (INIS)

    Atomic clocks using coherent population trapping (CPT) allow to improve performances of vapour cell conventional microwave clocks, or else to miniaturize them thanks to of a full optical interrogation. In this paper, we describe a prototype developed at LNE-SYRTE. It combines two original techniques: an excitation scheme with two linearly and orthogonally polarized beams, and a Ramsey interrogation. This enables the observation of narrow resonances with a good signal-to-noise ratio. A few major effects influencing the frequency stability are addressed; they are the effect of the buffer gas, of the magnetic field, of the laser power, and finally the effect of the local oscillator noise or Dick effect. The measured frequency stability is 7x10-13 at 1 s and 2x10-14 at 2000 s. (authors)

  2. Synthesis and characterization of polycrystalline semiconductor Caesium-Tin tri-Iodide thin-films

    Science.gov (United States)

    Chen, Zhuo

    This thesis deals with a virtually unexplored semiconductor material CsSnI3 from material synthesis, structural, optical, and electrical characterization to the fabrication and validation of CsSnI3 thin-film solar cells. We started with synthesizing CsSnI3 thin films based on CsI and SnCl2 (or SnI2) by using an apparatus which consists of e-beam and thermal evaporators. The quality of polycrystalline CsSnI3 thin-films were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Experimental data on XRD and electron diffraction patterns taking from the synthesized thin-films match very well to the theoretically calculated ones based the first principles calculations, confirming that the synthesized CsSnI3 thin-films have an orthorhombic crystal structure. With the well-defined crystal structure, we theoretically studied the electronic band structure of CsSnI3. Extensive optical characterizations of CsSnI3 thin-films were then carried out revealing many extraordinary properties such as 1) direct band gap energy of 1.32 eV at 300 K with its abnormal temperature dependence, 2) extremely high photoluminescence quantum yield, 3) large exciton binding energy, and 4) strong two-phonon assisted excitonic absorption near band edge. These properties are interpreted in terms of the unique electronic and structural properties of CsSnI3. The value of 1.3 eV for the energy band gap of CsSnI3 suggests a unique application of CsSnI3 thin-films on solar cells. This is because this value is right in the small range of the optimal band gaps for the Shockley-Queisser maximum efficiency limit of a single-junction solar cell. A prototype Schottky solar cell was designed, fabricated, and validated. The measured power conversion efficiency (PCE) is 0.9 % which is presently limited by the series and shunt resistance. The improvement strategy on PCE is given at the end of my thesis. In order to make the CsSnI3 thin-film solar cells cost effective, various low cost materials synthesis methods for CsSnI3 are also described in this thesis. CsSnI3 thin-films can be now inexpensively deposited on to glass or other low-cost substrates. I believe that the CsSnI3 based materials are ideally suited for many applications such as lasers, light-emitting diodes, integrated photonic devices such as infrared electro-optic modulator, solar cells, and even more specialized applications such as spectral solar concentrators.

  3. A versatile dual-species Zeeman slower for caesium and ytterbium

    Science.gov (United States)

    Hopkins, S. A.; Butler, K.; Guttridge, A.; Kemp, S.; Freytag, R.; Hinds, E. A.; Tarbutt, M. R.; Cornish, S. L.

    2016-04-01

    We describe the design, construction, and operation of a versatile dual-species Zeeman slower for both Cs and Yb, which is easily adaptable for use with other alkali metals and alkaline earths. With the aid of analytic models and numerical simulation of decelerator action, we highlight several real-world problems affecting the performance of a slower and discuss effective solutions. To capture Yb into a magneto-optical trap (MOT), we use the broad 1S0 to 1P1 transition at 399 nm for the slower and the narrow 1S0 to 3P1 intercombination line at 556 nm for the MOT. The Cs MOT and slower both use the D2 line (62S1/2 to 62P3/2) at 852 nm. The slower can be switched between loading Yb or Cs in under 0.1 s. We demonstrate that within a few seconds the Zeeman slower loads more than 109 Yb atoms and 108 Cs atoms into their respective MOTs. These are ideal starting numbers for further experiments on ultracold mixtures and molecules.

  4. Modelling transport and deposition of caesium and iodine from the Chernobyl accident using the DREAM model

    Directory of Open Access Journals (Sweden)

    J. Brandt

    2002-01-01

    Full Text Available A tracer model, DREAM (the Danish Rimpuff and Eulerian Accidental release Model, has been developed for modelling transport, dispersion and deposition (wet and dry of radioactive material from accidental releases, as the Chernobyl accident. The model is a combination of a Lagrangian model, that includes the near source dispersion, and an Eulerian model describing the long-range transport. The performance of the transport model has previously been tested within the European Tracer Experiment, ETEX, which included transport and dispersion of an inert, non-depositing tracer from a controlled release. The focus of this paper is the model performance with respect to the total deposition of  137Cs, 134Cs and 131I from the Chernobyl accident, using different relatively simple and comprehensive parameterizations for dry- and wet deposition. The performance, compared to measurements, of using different combinations of two different wet deposition parameterizations and three different parameterizations of dry deposition has been evaluated, using different statistical tests. The best model performance, compared to measurements, is obtained when parameterizing the total deposition combined of a simple method for dry deposition and a subgrid-scale averaging scheme for wet deposition based on relative humidities. The same major conclusion is obtained for all the three different radioactive isotopes and using two different deposition measurement databases. Large differences are seen in the results obtained by using the two different parameterizations of wet deposition based on precipitation rates and relative humidities, respectively. The parameterization based on subgrid-scale averaging is, in all cases, performing better than the parameterization based on precipitation rates. This indicates that the in-cloud scavenging process is more important than the below cloud scavenging process for the submicron particles and that the precipitation rates are relatively uncertain in the meteorological model compared to the relative humidity. Relatively small differences are, however, seen in the statistical tests between the three different parameterizations of dry deposition.

  5. Structure alteration of C-S-H (calcium silicate hydrated phases) caused by sorption of caesium

    International Nuclear Information System (INIS)

    The sorption behavior of Cs onto C-S-H (calcium silicate hydrated phases) was investigated by evaluating the effect of sorption on the C-S-H structure. The C-S-H have a tobermorite-type layer structure. Each layer consists of central calcium and oxygen atoms sandwiched by silicate tetrahedral chains. Additional calcium and water are located in interlayer zones. The XRD spectra showed that the tobermorite-type layer degraded and that the sorption of Cs made the fragments of layer intergrowths much smaller. The fragmentation of the tobermorite-type layer was observed for C-S-H in contact with CsCl solution or with CsOH solution, but not for the C-S-H in contact with Na solution. Furthermore, 29Si NMR spectroscopy revealed that the sorption of Cs onto C-S-H induced cleavages of silicate chains in C-S-H. It was also suggested that the OH- ion contributed to breaking the silicate chains. (orig.)

  6. Factors affecting the leachability of caesium and strontium from cemented simulant evaporator wastes

    International Nuclear Information System (INIS)

    Leach rates of stable cesium and strontium from a range of simulated evaporator waste/cement formulations have been determined. Important factors in plant operation are assessed for their effect on leach rates. Increasing the curing time and lowering the water/cement ratio has been shown to reduce leach rates by up to a factor of four. Incorporation of additives such as clays and supplementary cementatious materials can reduce leach rates by up to three orders magnitude, and coating the surface of the waste form with a neat cement grout can reduce the cesium leach rate by up to four orders of magnitude. The effects of permeability of the matrix and its cesium absorption capacity on the leach rates have been analysed qualitatively. (U.K.)

  7. Gamma spectrometry inspection of TRIGA MARK II fuel using caesium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, S., E-mail: sam.karimzadeh@ati.ac.a [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria); Khan, R.; Boeck, H. [Vienna University of Technology, Institute of Atomic and Subatomic Physics (ATI), Stadionallee 2, A-1020 Vienna (Austria)

    2011-01-15

    Research highlights: Cs isotopes are the best choices for the burn up determination of spent fuel. Gamma spectrometer calibration using MCNP5. Cs-ratio can be applied by relative calibration method. - Abstract: Gamma spectrometry is one of the common methods to inspect the spent fuel from research reactors. This method has been applied to in-pool measurements of the Spent Fuel Elements (SPEs) of the TRIGA Mark II research reactor. Due to mixed nature of the reactor core and complicated irradiation history of the fuel elements (FEs), the gamma spectrometry of the FE establishes improvements in the calculation and measurement of the SPE. In order to inspect the TRIGA SPE from dry storage and cooled fuel from the reactor pool, the selected spend fuels are scanned and measured using the fuel-scanning machine. Gamma spectrometry is performed by HPGe detector for spend fuel inspection and determination of the {sup 137}Cs activity and {sup 134}Cs/{sup 137}Cs ratio. In this work, the steps of the detector calibration and the use of the Monte Carlo radiation transport code (MCNP5) have been described. In addition, the fuel-scanning machine and the gamma spectrometer are modelled by MCNP5 to simulate the gamma transport from fuel to detector. It also simulate the gamma spectrometer calibration for the burn up determination of the spend fuel. The results from MCNP5 simulation are applied to spectroscopic measurements and compared with the theoretical predictions of the neutronics code ORIGEN2 in this research work.

  8. Effect of agricultural countermeasures on the transfer factor of caesium-137 in onion (Allium cepa L.)

    International Nuclear Information System (INIS)

    A field experiment, with onion cv. Rampur as the test crop, was conducted to study the effect of two levels (3.7 and 7.4 MBq m-2) of 137Cs and three countermeasures (application of farmyard manure at 12.5 t ha-1, application of extra potassium 100% in excess of that recommended for onion, and deep ploughing with a mold board plough). The crop was harvested at maturity and separated into bulb and sheath and analysed for 137Cs activity using a NaI (Tl) gamma ray spectrometer. The level of 137Cs significantly influenced the transfer factor (TF) in bulbs and sheaths. The levels of 137Cs and TF values were inversely related. The countermeasures had significantly influenced the TF of 137Cs from soil to onion: the values ranged from 0.0009 to 0.0025 m2 kg-1. The TF was highest for the control and the three countermeasures had significantly reduced values. Application of FYM was the most effective of the countermeasures. The other two countermeasures were on a par. They greatly reduced the TF also in onion sheaths; all three countermeasures had similar effects, and recorded significantly lower TF values than did the control

  9. Speciation of caesium-137 and plutonium-isotopes in Chernobyl soil

    OpenAIRE

    Holmstrand, Marte Varpen

    2011-01-01

    The Chernobyl Nuclear Power Plant (ChNPP) accident (1986) in present day Ukraine, was the first INES level 7 nuclear accident in the history of nuclear power. About 6-8 tonnes of spend uranium fuel were released and the fallout contained a series of short- and long lived radionuclides. The main deposition was in an area 30 km around the ChNPP, and the southern parts of Belarus. The area was permanently evacuated and called the exclusion zone. Some of the most long lived radionuclides released...

  10. A versatile dual-species Zeeman slower for caesium and ytterbium.

    Science.gov (United States)

    Hopkins, S A; Butler, K; Guttridge, A; Kemp, S; Freytag, R; Hinds, E A; Tarbutt, M R; Cornish, S L

    2016-04-01

    We describe the design, construction, and operation of a versatile dual-species Zeeman slower for both Cs and Yb, which is easily adaptable for use with other alkali metals and alkaline earths. With the aid of analytic models and numerical simulation of decelerator action, we highlight several real-world problems affecting the performance of a slower and discuss effective solutions. To capture Yb into a magneto-optical trap (MOT), we use the broad (1)S0 to (1)P1 transition at 399 nm for the slower and the narrow (1)S0 to (3)P1 intercombination line at 556 nm for the MOT. The Cs MOT and slower both use the D2 line (6(2)S1/2 to 6(2)P3/2) at 852 nm. The slower can be switched between loading Yb or Cs in under 0.1 s. We demonstrate that within a few seconds the Zeeman slower loads more than 10(9) Yb atoms and 10(8) Cs atoms into their respective MOTs. These are ideal starting numbers for further experiments on ultracold mixtures and molecules. PMID:27131656

  11. A versatile dual-species Zeeman slower for caesium and ytterbium

    CERN Document Server

    Hopkins, S A; Freytag, R; Guttridge, A; Kemp, S; Hinds, E A; Tarbutt, M R; Cornish, S L

    2015-01-01

    We describe the design, construction and operation of a versatile dual-species Zeeman slower for both Cs and Yb, which is easily adaptable for use with other alkali metals and alkaline earths. With the aid of analytic models and numerical simulation of decelerator action, we highlight several real-world problems affecting the performance of a slower and discuss effective solutions. To capture Yb into a magneto-optical trap (MOT), we use the broad $^1S_0$ to $^1P_1$ transition at 399 nm for the slower and the narrow $^1S_0$ to $^3P_1$ intercombination line at 556 nm for the MOT. The Cs MOT and slower both use the D2 line ($6^2S_{1/2}$ to $6^2P_{3/2}$) at 852 nm. We demonstrate that within a few seconds the Zeeman slower loads more than $10^9$ Yb atoms and $10^8$ Cs atoms into their respective MOTs. These are ideal starting numbers for further experiments on ultracold mixtures and molecules.

  12. THE POTENTIAL MODEL INVESTIGATION OF STARK EFFECT IN CAESIUM RYDBERG STATE ATOMS AND COMPARISON WITH EXPERIMENT

    Institute of Scientific and Technical Information of China (English)

    HU ZHENG-FA; ZHOU SHI-KANG; GONG SHUN-SHENG; ZHAN MING-SHENG

    2000-01-01

    The potential model method for computation of Stark structure of Cs Rydberg states atoms and oscillator strength is described,for external electric fields varying from 0 to 600V/cm.Anticrossing,l-mixing and n-mixing phenomena are observed clearly from the map of Stark.Corresponding experiment is performed under the same condition,and the two results are in good agreement with each other within the experimental uncertainty.

  13. Laser spectroscopy of sub-micrometre- and micrometre-thick caesium-vapour layers

    Energy Technology Data Exchange (ETDEWEB)

    Cartaleva, S; Krasteva, A; Slavov, D; Todorov, P; Vaseva, K [Institute of Electronics, Bulgarian Academy of Sciences, boul. Tzarigradsko shosse 72, 1784 Sofia (Bulgaria); Moi, L [CNISM and Physics Department, University of Siena, via Roma 56, 53100 Siena - Italy (Italy); Sargsyan, A; Sarkisyan, D [Institute for Physical Research, National Academy of Sciences of Armenia, Ashtarak-0203 (Armenia)

    2013-09-30

    We present high resolution laser spectroscopy of Cs vapours confined in a unique optical cell of sub-micrometric and micrometric thickness, where a strong spatial anisotropy is present for the time of interaction between the atoms and laser radiation. Similarly to the spectra of selective specular reflection, the Doppler-free spectra of absorption and fluorescence are observed, not revealing cross-over resonances that will be useful for frequency stabilisation, provided the cell is cheap and compact. A new resonance in the fluorescence of closed transition is studied, demonstrating its high sensitivity to elastic atom – atom and atom – dielectric surface collisions. The theoretical modelling performed is in agreement with the experimental observations. (laser spectroscopy)

  14. Ecological half-life of caesium in roe deer (Capreolus capreolus)

    International Nuclear Information System (INIS)

    Biological half-lives for various radionuclides have been determined for many animals kept in the laboratory or under controlled conditions. Following the fallout from the Chernobyl accident and its subsequent ingestion by wildlife, no one knew how long it would take for the wild animals to eliminate the radionuclides, and in particular radiocaesium, from their bodies. In this study of roe dee (Capreolus capreolus), bucks (males) were shot at weekly/fortnightly intervals from mid-May till the end of July, as part of the annual cull on an area, which included some young forestry (Stone Chest - National Grid Reference NY480790), planted in 1971/72. The ratio of 137Cs:134Cs, typical of the Chernobyl fallout, was seldom observed in these animals due to the highly variable concentrations of 137Cs originating from bomb fallout. Therefore, 134Cs was used instead because its presence was almost entirely due to the Chernobyl fallout. After using a log10 transformation of the 134Cs concentrations, a significant (p134Cs was found to be 28.3 days. (author)

  15. The behaviour of caesium-137 in oxisols and in the Goiania soil

    International Nuclear Information System (INIS)

    The 137Cs soil-to-plant transfer factors obtained in oxisols accidentally contaminated in Goiania and in artificially contaminated soils are found to be higher than those of soils in temperate climates. These differences are discussed in the light of pedology and geochemical partitioning. Tropical soil characteristics such as acidity, the low availability of nutritive elements and low content of 2:1 clay types seem to determine a high availability of 137Cs. The results of sequential extraction showed 137Cs weakly bound to soil components and underlines the importance of Fe oxides in the control of the 137Cs in topical climates. (author)

  16. Evolution of caesium 137 levels in coconut water and copra in french Polynesia, since 1967

    International Nuclear Information System (INIS)

    Nuclear experiments have been carried out by France in french Polynesia since 1966. The tests were first atmospheric, they have been underground since 1975. The experiment monitoring programme includes monitoring of 137Cs contents in coconuts from the whole french polynesian territory. The methodology is described and the results of the 2 589 samples collected for 1967 to 1988 are presented. The maximum content found since 1967 is 52 Bq.kg-1 for coconut water and 289 Bq.kg-1 for coconut copra. The decrease of 137Cs content is constant without discontinuity, whatever the distance from the explosion sites. The committed dose equivalent from 137Cs delivered by coconut water and copra consumption represents only a few microsieverts a year

  17. Gamma spectrometry inspection of TRIGA MARK II fuel using caesium isotopes

    International Nuclear Information System (INIS)

    Research highlights: → Cs isotopes are the best choices for the burn up determination of spent fuel. → Gamma spectrometer calibration using MCNP5. → Cs-ratio can be applied by relative calibration method. - Abstract: Gamma spectrometry is one of the common methods to inspect the spent fuel from research reactors. This method has been applied to in-pool measurements of the Spent Fuel Elements (SPEs) of the TRIGA Mark II research reactor. Due to mixed nature of the reactor core and complicated irradiation history of the fuel elements (FEs), the gamma spectrometry of the FE establishes improvements in the calculation and measurement of the SPE. In order to inspect the TRIGA SPE from dry storage and cooled fuel from the reactor pool, the selected spend fuels are scanned and measured using the fuel-scanning machine. Gamma spectrometry is performed by HPGe detector for spend fuel inspection and determination of the 137Cs activity and 134Cs/137Cs ratio. In this work, the steps of the detector calibration and the use of the Monte Carlo radiation transport code (MCNP5) have been described. In addition, the fuel-scanning machine and the gamma spectrometer are modelled by MCNP5 to simulate the gamma transport from fuel to detector. It also simulate the gamma spectrometer calibration for the burn up determination of the spend fuel. The results from MCNP5 simulation are applied to spectroscopic measurements and compared with the theoretical predictions of the neutronics code ORIGEN2 in this research work.

  18. Variations of caesium isotope concentrations in air and fallout at Dalat, South Vietnam, 1986-91

    International Nuclear Information System (INIS)

    Monthly records of 137Cs and 134Cs concentrations in air and fallout at Dalat for the period 1986-91 are presented and discussed. The concentration variations exhibit distinct maxima during December-January, when dry fallout dominated. These peaks are explained by the intrusion of more radioactive cold air masses from temperature northern latitudes during the development of large-scale anticyclones frequently observed in the most active winter monsoon period. High dry fallout velocities (about 10 cm/s) determined from these data clearly demonstrate one of the most relevant characteristics of cold air masses: behind the cold front, vertical air motion is descending. (Author)

  19. Variations of Caesium Isotope Concentrations in Air and Fallout at Dalat, South Vietnam, 1986-91

    International Nuclear Information System (INIS)

    Monthly records of 137Cs and 134Cs concentrations in air and fallout at Dalat for the period 1986-91 are presented and discussed. The concentration variations exhibit distinct maxima during December-January, when dry fallout dominates. These peaks are explained by the intrusion of more radioactive cold air masses from temperate northern latitudes during the development of large-scale anticyclones frequently observed in the most active winter monsoon period. High dry fallout velocities (about 10 cm/s) determined from these data clearly demonstrate one of the most relevant characteristics of cold air masses: behind the cold front, vertical air motion is descending. (author)

  20. Variations of caesium isotope concentrations in air and fallout at Dalat, South Vietnam, 1986-91

    Energy Technology Data Exchange (ETDEWEB)

    Pham Zuy Hien; Nguyen Thanh Binh; Truong Y; Vuong Thu Bac; Nguyen Trong Ngo (Dalat Nuclear Research Inst. (Viet Nam))

    1994-01-01

    Monthly records of [sup 137]Cs and [sup 134]Cs concentrations in air and fallout at Dalat for the period 1986-91 are presented and discussed. The concentration variations exhibit distinct maxima during December-January, when dry fallout dominated. These peaks are explained by the intrusion of more radioactive cold air masses from temperature northern latitudes during the development of large-scale anticyclones frequently observed in the most active winter monsoon period. High dry fallout velocities (about 10 cm/s) determined from these data clearly demonstrate one of the most relevant characteristics of cold air masses: behind the cold front, vertical air motion is descending. (Author).

  1. Dominant wing spectroscopy of energy pooling collisions near the boundary layer involving thermal caesium vapour

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We have observed the dominant wing spectroscopy of energy pooling collision near the boundary layer involving Cs atoms under the condition of moderate-to-high optical depths at line-centre. It appears from our experimental investigations that the energy-pooling fluorescence presents about 16 spectral lines, and all the lines can be assigned to the Cs atomic transitions. We find that all lines of the energy-pooling retrofluorescence from the heated Cs atomic vapour cell show two-peak profiles. In addition, its pumping power linear dependence in the energy pooling process has been measured and analysed.

  2. Variations of caesium isotope concentrations in air and fallout at Dalat, South Vietnam, 1986-1991

    International Nuclear Information System (INIS)

    Monthly records of Cs-137 and Cs-134 concentrations in air and fallout at Dalat for the period 1986-1991 are presented and discussed. The concentration variations exhibit distinct maxima during December-January, when dry fallout dominated. These peaks are explained by the intrusion of more radioactive cold air masses from temperate northern latitudes during the development of large-scale anticyclones frequently observed in the most active winter monsoon period. High dry fallout velocities (about 10 cm/s) determined from this data clearly demonstrate one of the most relevant characteristics of cold air masses: behind the cold front, vertical air motion is descending

  3. Spatial distribution of caesium-137 in soil cover of background terrestrial ecosystems, Central European Russia

    International Nuclear Information System (INIS)

    137Cs - the main long-living anthropogenic radionuclide - arrived in mass at Russian terrestrial ecosystems after nuclear tests in the atmosphere in 1960-yy. and after Chernobyl accident in 1986 y., but in spite of a long period since these events soil cover contamination by 137Cs is considered as extremely resistant due to its firmly fixation by soil solid matter and a long half-life of the radionuclide. Wide-scale investigation in maximal diversity of natural, semi-natural and anthropogenic landscapes of Central European Russia (more than 400 soils samples from Vologda, Yaroslavl, Ivanovo, Tver regions which are representative for the southern taiga zone) demonstrates that modern average specific activity of 137Cs in the upper 15-cm layer of soil is 11±3 Bq/kg (contamination density 0.05±0.01 Ci/km2), that is fully ecologically acceptable. It is important that the average concentrations of 137Cs in the soil cover of individual regions are close to each other. The most likely these average values are approximate assessment of background radioactive contamination of soils in central European Russia outside of the immediate Chernobyl trace. At the same time approximately 3% of soils are characterized by elevated 137Cs content - 62-98 Bq/kg (0.24-0.43 Ci/km2), that indicates the presence of low radioactive spots on the territory and may be considered as local Chernobyl fallout. All of them attribute with forest soils which are commonly characterized by considerably more high accumulation of 137Cs (18±5 Bq/kg, 0.06±0.01 Ci/km2) due to advanced absorbing surface of trees. Agricultural lands (plagued or under meadows) and soils of industrial plots with scarce vegetation contain only 6±2 Bq/kg (0.03±0.01 Ci/km2) of 137Cs. About 84-92% of 137Cs are concentrated in the upper 15-cm layer of natural soils or in Ap horizon of plagued soils, thus vertical migration of radionuclide is very slow in spite of ∼30 years after Chernobyl accident. But it may by considerable lateral migration of 137Cs in geochemically connected landscapes through the process of water erosion that leads to additional radionuclide accumulation in peat and foggy-podsolic soils of watershed depressions (migration coefficient 1.3). Thus, shallow depressions could be those 'critical' elements of the landscape with low-contrast areas of additional 137Cs accumulation. Long-range transport of 137Cs in moderate humid landscapes seems of little importance since alluvial soils and bottom sediments contain only 8±4 Bq/kg and 2±1 Bq/kg correspondingly. (authors)

  4. Monitoring the genetic health of persons in Goiania accidentally exposed to ionizing radiation from caesium-137

    International Nuclear Information System (INIS)

    This work describes the long term genetic monitoring of the Goiania population exposed to ionizing radiation from 137Cs, using cytogenetic and molecular endpoints. Cytogenetically, micronucleus frequencies differentiated groups exposed to different levels of radiation. Two molecular methods were employed: 1) the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed four and a half years after original exposure. The spectrum of hprt mutations recovered from ten individuals exposed to relatively high doses of radiation revealed a fourfold increase in the frequency of A:T → G:C transitions. The increase is consistent with the effects of ionizing radiation in prokaryotes and lower eukaryotes. Additionally, a twofold increase in the frequency of deletions was observed which may reflect radiation induced DNA strand breakage; 2) determination of microsatellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distributions of somatic microsatellite alterations in exposed and non-exposed populations were not different. Our assay lacked sensitivity to discriminate between spontaneous and induced microsatellite instability and therefore, is not suitable for population monitoring. Finally, we estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased nearly twenty-fourfold. The risk of carcinogenesis was increased by a factor of 1.5. (author)

  5. Experimental contamination of margaritana margaritifera (L) (a Fresh water bivalve) by caesium 137

    International Nuclear Information System (INIS)

    The hydro biological research carried out in the Radio-Ecology Section has led the authors to study some Margaritana sampling stations situated down-stream from the Monts d'Arree nuclear power station. They describe the preservation and contamination methods used for fixing the 137Cs concentration factors in the case of Margaritana Margaritifera (L). The results of experiments carried out over a period of one hundred days show that the specific activity of the various organs is stabilized after thirty to thirty-five days. The authors have noticed a relatively low adsorption on the shell through the intermediary of micro-organisms, and a strong and rapid absorption in the soft parts. The concentration factors have values, at equilibrium, of around: 9 for the shell, 300 for all the organs, and 38 for the whole animal. A comparison of these results with work published by other authors makes it possible to draw general conclusions concerning the mechanism of 137Cs fixation by lamellibranch, as well as their capacity of fixation. (author)

  6. Influence of chemical composition of precipitation on migration of radioactive caesium in natural soils

    International Nuclear Information System (INIS)

    The aim of the present work was to study the impact of the chemical composition of precipitation on radiocaesium mobility in natural soil. This was done through column studies. Three types of precipitation regimes were studied, representing a natural range found in Norway: Acidic precipitation (southernmost part of the country); precipitation rich in marine cations (highly oceanic coastal areas); and low concentrations of sea salts (slightly continental inland areas). After 50 weeks and a total precipitation supply of ∼10 000 L m−2 per column, results indicate that acidic precipitation increased the mobility of 134Cs added during the experiment. However, depth distribution of already present Chernobyl fallout 137Cs was not significantly affected by the chemical composition of precipitation. - Highlights: • Mobility of freshly added Cs-134 was higher in soil receiving acidic precipitation. • Depth penetration of Cs-134 was higher in soil profiles with a thicker humus layer. • Depth distribution of Chernobyl Cs-137 was not affected by precipitation type

  7. Effective Half-Life of Caesium-137 in Various Environmental Media at the Savannah River Site

    International Nuclear Information System (INIS)

    During the operational history of the Savannah River Site (SRS), many different radionuclides have been released from site facilities into the SRS environment. However, only a relatively small number of pathways, most importantly 137Cs in fish and deer, have contributed significantly to doses and risks to the public. The “effective” half-lives (Te) of 137Cs (which include both physical decay and environmental dispersion) in Savannah River floodplain soil and vegetation and in fish and white-tailed deer from the SRS were estimated using long-term monitoring data. For 1974–2011, the Tes of 137Cs in Savannah River floodplain soil and vegetation were 17.0 years (95% CI = 14.2–19.9) and 13.4 years (95% CI = 10.8–16.0), respectively. These Tes were greater than in a previous study that used data collected only through 2005 as a likely result of changes in the flood regime of the Savannah River. Field analyses of 137Cs concentrations in deer collected during yearly controlled hunts at the SRS indicated an overall Te of 15.9 years (95% CI = 12.3–19.6) for 1965–2011; however, the Te for 1990–2011 was significantly shorter (11.8 years, 95% CI = 4.8–18.8) due to an increase in the rate of 137Cs removal. The shortest Tes were for fish in SRS streams and the Savannah River (3.5–9.0 years), where dilution and dispersal resulted in rapid 137Cs removal. Long-term data show that Tes are significantly shorter than the physical half-life of 137Cs in the SRS environment but that they can change over time. Therefore, it is desirable have a long period of record for calculating Tes and risky to extrapolate Tes beyond this period unless the processes governing 137Cs removal are clearly understood. - Highlights: • 137Cs Tes in SRS floodplain soil, floodplain vegetation, and deer were 13–17 years. • 137Cs Tes in fish from SRS streams were 4–7 years due to washout and sedimentation. • 137Cs Tes in SRS ecosystems were generally comparable to those at other sites. • 137Cs Tes at the SRS changed over time due to natural and anthropogenic factors. • 137Cs Tes should not be extrapolated unless 137Cs removal processes are understood

  8. Thermodynamic calculations for liquid alloys with an application to sodium-caesium

    OpenAIRE

    Visser, E.G.; Van Der Lugt, W.; De Hosson, J. Th. M.

    1980-01-01

    A semi-empirical model is presented for the analysis in liquid alloys of the long wavelength limit of the structure factor, the free energy of mixing and the electrochemical potential. The formalism is partly based on statistical mechanics assuming a concentration-dependent hard-sphere behaviour of liquid alloys. Although being conceptually quite different, our description incorporates the Flory-Huggins model as a first approximation.

  9. Determination of lithium, rubidium, and caesium in rock by flame spectrophotometry

    International Nuclear Information System (INIS)

    After sulfo-hydrofluoric attack of rock, and quantitative estimation of Na and K, the end solution is brought to 10 per cent in Na2O and K2O In order to prepare it under the same conditions as standards; interfering ions are precipitated with calcium carbonate, flame spectrophotometry is conducted with an hydrogen-oxygen flame. Limits of detection are: 2.10-6 g for Li, 4.10-6 g for Rb, and 6.10-6 g for Ca. (author)

  10. Radiation dose to Sri Lankan infants from Caesium-137 in contaminated milk

    International Nuclear Information System (INIS)

    The radiation dose to infants due to ingestion of milk containing the maximum limit of radioactivity in milk powder imported to Sri Lanka has been calculated. The radioactivity of Cs-137 was used as an index of fission products for setting radioactivity limits. The computation for milk powder was based on an average daily intake of 125 g by infants, (a critical group of population) during the first year after birth. The recommended dose commitment to the general public is 1 mSv/y. The maximum permissible limit of 20 Bq/kg of Cs-137 in milk powder as stipulated by the Atomic Energy Authority for milk powder imported to Sri Lanka would yield a dose equivalent of 12.6 micro seivert/y from Cs-137

  11. Transfer factor of caesium-137 in arid and semi-arid regions

    International Nuclear Information System (INIS)

    Transfer factors (TFs) for 137Cs were measured in two soils with a range of annual crops and olives. The values were towards the lower end of the ranges reported in the literature. Fertilization reduced TFs by 13-33%. TFs to the edible parts of arable crops were in the order cereals 137Cs concentration than any of the other food products. (author)

  12. A comparison of stable caesium uptake by six grass species of contrasting growth strategy

    International Nuclear Information System (INIS)

    Six plants in the family Gramineae were used to investigate the relationship between Cs uptake, nutrient regime and plant growth strategy sensu Grime (1979: Plant Growth Strategies and Vegetation Processes, John Wiley). The roots of 66 day old Elymus repens (L.) Gould., Bromus sterilis L., Agrostis stolonifera L., Anthoxanthum odoratum L., Festuca ovina L. and Nardus stricta L. plants grown in acid-washed sand at high and low nutrient levels were exposed to a 96 h pulse of stable Cs at 0.05 mM, 0.15 mM, 0.3 mM, 1.0 mM and 3.0 mM concentrations. Different nutrient regimes induced large differences in dry wt in E. repens, B. sterilis and A. stolonifera plants but only small differences in N. stricta and F. ovina plants. At high nutrient concentrations, A. stolonifera, A. odoratum, F. ovina and N. stricta shoots showed significantly greater increases in internal Cs concentration with rising external Cs concentrations than did E. repens and B. sterilis shoots. The relationship between increases in shoot and external Cs concentrations was statistically indistinguishable between species in plants grown at the low nutrient concentration. These patterns of Cs uptake ensured that with long-term high K concentrations the more competitive plants (E. repens and B. sterilis) accumulated higher concentrations of Cs from low external concentrations than did non-competitive plants or competitive plants grown at low nutrient levels. It is suggested that the relationship between plant growth strategy sensu Grime (1979) and Cs accumulation patterns may help to explain the different concentrations to which species accumulate radiocaesium from the soil. (author)

  13. Caesium-lithium phyllosilicate, Cs1.33Li0.67Si2O5

    International Nuclear Information System (INIS)

    The crystal structure of a (Cs,Li) phyllosilicate with composition Cs1.33Li0.67Si2O5 has been characterized by a single-crystal X-ray diffraction study. Its silica sheet is exceedingly tortuous with a four-eight-twelve-membered ring topology and a large variation in bridging-oxygen number density in the sheet, thus differing from the six-membered ring topology of Li phyllosilicate and the four-eight-membered ring topology in Cs and Rb phyllosilicate. The title compound lacks the characteristic sandwich structure of sheet silicates. It resembles a three-dimensional network in which Si atoms are replaced by strictly threefold O-coordinated Li atoms which form flat sheets at ca y = 0 and y = 1/2 with seven- to twelvefold O-coordinated Cs atoms between the silica-lithium sheets at y = 1/4 and y = 3/4. The Cs atoms recur in two types of honeycomb tunnels parallel to the b axis. (orig.)

  14. Caesium 137 in humus horizons of middle mountain depressions soils (Central Altai)

    International Nuclear Information System (INIS)

    Soils of Kansk, Abay and Uymon depressions in Altai were studied. It was found that the level of cesium 137 specific activity in humus horizons of depression soils considerably varies. The maximal values of cesium 137 activity are characteristic for top humus horizons. The levels of soil contamination by cesium 137 in mid depressions are harmless for stable functioning of living organisms

  15. Maximal Coordinator Number of Potassium, Rubidium, Caesium and Francium Ions in Gaseous Water

    International Nuclear Information System (INIS)

    To understand the molecular and electronic structure of alkali metal ions, we carry out the MP2 calculation and demonstrate that the maximal coordinator numbers for the hydrated K+ and Rb+ are 8, while those for the hydrated Cs+ and Fr+ are 10. Furthermore, on the basis of the binding energy, the HOMO-LUMO gap and the electron affinity, the stability of the molecular and electronic structures of M+ (H2O)8 (M = K, Rb, Cs, Fr) decreases with the increasing alkali metal atomic number and the stability of the molecular structures of M+ (H2O)8–10 (M = Cs, Fr) decreases with the increasing cluster size. (condensed matter: structure, mechanical and thermal properties)

  16. Iodine-129 and Caesium-137 in Chernobyl contaminated soil and their chemical fractionation

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Fogh, C.L.; Kucera, J.;

    2003-01-01

    Soil samples from areas in Belarus, Russia and Sweden contaminated by the Chernobyl accident were analysed for I-129 by radiochemical neutron activation analysis, as well as for Cs-137 by gamma-spectrometry. The atomic ratio of I-129/(CS)-C-137 in the upper layer of the examined soil cores ranged...... from 0.10 to 0.30, with an average of 0.18, and no correlation between I-129/Cs-137 ratio and the distance from Chernobyl reactor to sampling location was observed. It seems feasible to use the I-129/Cs-137 ratio to reconstruct the deposition pattern of I-131 in these areas. The association of I-129...

  17. A versatile dual-species Zeeman slower for caesium and ytterbium

    OpenAIRE

    Hopkins, S. A.; Butler, K; Freytag, R.; Guttridge, A.; Kemp, S.; Hinds, E.A.; Tarbutt, M. R.; Cornish, S. L.

    2015-01-01

    We describe the design, construction and operation of a versatile dual-species Zeeman slower for both Cs and Yb, which is easily adaptable for use with other alkali metals and alkaline earths. With the aid of analytic models and numerical simulation of decelerator action, we highlight several real-world problems affecting the performance of a slower and discuss effective solutions. To capture Yb into a magneto-optical trap (MOT), we use the broad $^1S_0$ to $^1P_1$ transition at 399 nm for th...

  18. Measuring the specific caesium sorption capacity of soils, sediments and clay minerals

    Energy Technology Data Exchange (ETDEWEB)

    De Koning, A. [aEnergy Research Centre of the Netherlands (ECN), Westerduinweg 3, P.O. Box 1, 1755 ZG, Petten (Netherlands); Konoplev, A.V. [Institute of Experimental Meteorology, 82 Lenin Avenue, Obninsk, Kaluga Region, 249020 (Russian Federation); Comans, R.N.J. [Wageningen University, Department of Soil Quality, P.O. Box 8005, 6700 EC Wageningen (Netherlands)

    2007-01-15

    Two methods to quantify the specific Cs sorption capacity of soils and sediments, which is generally believed to be associated with the Frayed Edge Sites (FES) of illitic clay minerals, are described in detail and are critically reviewed. The first method is a direct measurement of the FES capacity, while the second quantifies the combined parameter K{sub D}{sup C}s x [K{sup +}] (=K{sub C}(K-->Cs) x [FES]) i.e. the product of the FES capacity and the affinity of these sites for Cs. Both methods use the bulky AgTU-complex to mask non-specific sorption sites for Cs and are applied to a number of different soils and pure minerals. Measurement of the FES capacity of pure illite is straightforward. It is shown that the measured capacity is independent of the saturating ion, but does depend on particle size. This method could not be successfully applied to a peat bog soil with 90% organic matter, because the necessary correction for non-specific Cs sorption by the large pool of organic exchange sites overpasses the capacity of the small FES fraction. Measurement of the combined parameter K{sub D}{sup C}s x [K{sup +}] is shown to be more appropriate in such cases. Application of the FES capacity method to the hydrous aluminosilicate mineral allophane, an important soil constituent of Andisols, shows that the AgTU-complex is unable to block all non-specific sorption sites for Cs on this mineral. The K{sub D}{sup C}s x [K{sup +}] measurements show evidence of a very small number of specific Cs sorption sites on allophane, much smaller than inferred from the FES capacity measurement. The FES capacity of the clay mineral vermiculite is difficult to quantify because the high Cs concentrations that are needed to measure the FES capacity probably cause a collapse of the vermiculite interlayers, thereby creating more high-affinity sites for Cs. The K{sub D}{sup C}s x [K{sup +}] method, in which only trace concentrations of Cs are used, is shown to be more appropriate for soils containing substantial amounts of vermiculite. It is concluded that both the direct FES capacity measurement and the measurement of the combined parameter K{sub D}{sup C}s x [K{sup +}] can be very useful methods to isolate and characterise Cs-selective sorption sites in soils and sediments, but that results should be interpreted with great care.

  19. Sorption of caesium and strontium by graphite materials in gas cooled high temperature reactors

    International Nuclear Information System (INIS)

    The experiments have revealed that coked phenol resin binder has got an extremely high sorption capacity for Cs and Sr. For this reason the sorption capacity of A3 matrix graphite for fuel elements exceeds the capacity of the highly graphitized material that does not contain this component. The strong chemical binding for Cs and Sr by chemisorption indicates a retention of these elements when the nucleus is heated up by accident. The release calculations carried out with definite sorption isotherms revealed a larger retention effect by sorption for Sr than for Cs. In this respect the matrix graphite in the ball-shaped fuel elements is of special importance for the retention. It is applied at German high temperature reactors and contains non-graphitized phenol resin binder. (orig./DG)

  20. The relative significance of pathways and parameters for the caesium-137 soil decontamination scenario at Goiania

    International Nuclear Information System (INIS)

    The purpose of this work was to examine possible implications of parameter uncertainties on the estimates of population exposure to 137Cs following the Goiania (Brazil) accident. The relevance of these uncertainties in decision making at the time of the accident and in outlining future research aimed at reducing the critical uncertainties was examined. The derived limit for soil removal used at the time of the Goiania accident by conservative deterministic simulation was shown to be the 92nd percentile value of the probabilistic simulation. The primary exposure pathway to the public was confirmed to be the external exposure from the contaminated soil. (author)

  1. Ocean dynamic processes causing spatially heterogeneous distribution of sedimentary caesium-137 massively released from the Fukushima Daiichi Nuclear Power Plant

    Science.gov (United States)

    Higashi, H.; Morino, Y.; Furuichi, N.; Ohara, T.

    2015-12-01

    Massive amounts of anthropogenic radiocaesium 137Cs that were released into the environment by the Fukushima Daiichi Nuclear Power Plant accident in March 2011 are widely known to have extensively migrated to Pacific Ocean sediment off of eastern Japan. Several recent reports have stated that the sedimentary 137Cs is now stable with a remarkably heterogeneous distribution. The present study elucidates ocean dynamic processes causing this heterogeneous sedimentary 137Cs distribution in and around the shelf off Fukushima and adjacent prefectures. We performed a numerical simulation of oceanic 137Cs behaviour for about 10 months after the accident, using a comprehensive dynamic model involving advection-diffusion transport in seawater, adsorption and desorption to and from particulate matter, sedimentation and suspension on and from the bottom, and vertical diffusion transport in the sediment. A notable simulated result was that the sedimentary 137Cs significantly accumulated in a swath just offshore of the shelf break (along the 50-100 m isobath) as in recent observations, although the seabed in the entire simulation domain was assumed to have ideal properties such as identical bulk density, uniform porosity, and aggregation of particles with a single grain diameter. This result indicated that the heterogeneous sedimentary 137Cs distribution was not necessarily a result of the spatial distribution of 137Cs sediment adsorptivity. The present simulation suggests that the shape of the swath is mainly associated with spatiotemporal variation between bottom shear stress in the shallow shelf (simulation indicated that strong bottom friction suspending particulate matter from the seabed frequently occurred via a periodic spring tide about every 2 weeks and via occasional strong wind. The sedimentary 137Cs thereby could hardly stay on the surface of the seabed with the result that the simulated sediment-surface 137Cs activity tended to decrease steadily for a long term after the initial 137Cs migration. By contrast, in the offshore region, neither the spring tide nor the strong wind caused bottom disturbance. Hence, the particulate matter incorporated with 137Cs, which was horizontally transported from the adjacent shallow shelf, readily settled and remained on the surface of the sediment just offshore of the shelf break.

  2. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age

    International Nuclear Information System (INIS)

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author)

  3. Modelling of long-term behaviour of caesium and strontium radionuclides in the Arctic environment and human exposure

    International Nuclear Information System (INIS)

    In this paper a compartment model of the highly vulnerable Arctic terrestrial food chain 'lichen-reindeer-man' is outlined. Based upon an analysis of measured 137Cs and 90Sr contents in lichen and reindeer meat from 1961 up to 2001, site specific model parameters for two regions in north-western Arctic Russia and for Kautokeino municipality in Arctic Norway have been determined. The dynamics of radionuclide activity concentrations in the 'lichen-reindeer-man' food chain for all areas was satisfactorily described by a double exponential function with short-term and long-term effective ecological half-lives between 1-2 and 10-12 years, respectively, for both 137Cs and 90Sr. Using parameter values derived from the model, life-time internal effective doses due to consumption of reindeer meat by reindeer-breeders after an assumed single pulse deposit of 1 kBq m-2 of 137Cs were estimated to be 11.4 mSv (Kola Peninsula), 5 mSv (Nenets Autonomous Area), and 2 mSv (Kautokeino, Norway). Differences in vulnerability to radiocaesium deposition were due to differences in transfer between lichen and reindeer and in diet between the three regions

  4. Caesium radionuclides migration in an alluvial soil of the Po River Valley (Northern Italy) after the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Investigation was carried out to study the migration of Cs-137 and Cs-134 deposited by the radioactive cloud from Chernobyl. Distribution depth profiles and diffusion coefficients are reported and correlated to soil quality parameters. (orig./HP)

  5. Caesium-137 concentration in willow grouse (Lagopus lagopus) and black grouse (Tetrao tetrix) in Norway in relation to ground deposition

    International Nuclear Information System (INIS)

    After the Chernobyl accident in 1986, mid and northern part of Norway was contaminated by radioactive fallout. The total fallout of 137Cs in Norway was estimated at 2300 ± 200 TBq. The purpose of this study was to find out to what extent radiocaesium is transferred from fallout deposition after the Chernobyl accident to willow grouse and black grouse. Cs-137 activity concentration in willow grouse and black grouse pectoral muscle will be presented and compared with information on fallout from the Chernobyl accident. During the years 2000-2001 at total of 297 samples of willow grouse and black grouse from 67 localities in Norway were collected. The sample includes 208 adult willow grouse from 56 areas and 89 black grouse from 20 areas. All sample collection was carried out by local hunters. Levels of ground deposition of 137Cs in Norway were taken from two nationwide sampling programs carried out by the National Institute of Radiation Hygiene in 1986 and the Norwegian University of Science and Technology in 1995. A total of 450 soil samples were collected in 1986 and 455 samples in 1995. To quantify transfer of radionuclides from fallout to activity concentration in bird tissue, aggregated transfer coefficient will be presented in addition to activity concentration of 137Cs in willow grouse and black grouse. (author)

  6. Estimating sediment and caesium-137 fluxes in the Ribble Estuary through time-series airborne remote sensing.

    Science.gov (United States)

    Wakefield, R; Tyler, A N; McDonald, P; Atkin, P A; Gleizon, P; Gilvear, D

    2011-03-01

    High spatial and temporal resolution airborne imagery were acquired for the Ribble Estuary, North West England in 1997 and 2003, to assess the application of time-series airborne remote sensing to quantify total suspended sediment and radionuclide fluxes during a flood and ebb tide sequence. Concomitant measurements of suspended particulate matter (SPM) and water column turbidity were obtained during the time-series image acquisition for the flood and ebb tide sequence on the 17th July 2003 to verify the assumption of a vertically well mixed estuary and thus justifying the vertical extrapolation of spatially integrated estimate of surface SPM. The ¹³⁷Cs activity concentrations were calculated from a relatively stable relationship between SPM and ¹³⁷Cs for the Ribble Estuary. Total estuary wide budgets of sediment and ¹³⁷Cs were obtained by combining the image-derived estimates of surface SPM and ¹³⁷Cs with estimates of water volume from a two-dimensional hydrodynamic model (VERSE) developed for the Ribble Estuary. These indicate that around 10,000 tons of sediment and 2.72 GBq of ¹³⁷Cs were deposited over the tidal sequence monitored in July 2003. This compared favourably with bed height elevation change estimated from field work. An uncertainty analysis on the total sediment and ¹³⁷Cs flux yielded a total budget of the order of 40% on the final estimate. The results represent a novel approach to providing a spatially integrated estimate of the total net sediment and radionuclide flux in an intertidal environment over a flood and ebb tide sequence. PMID:21195513

  7. Estimating sediment and caesium-137 fluxes in the Ribble Estuary through time-series airborne remote sensing

    International Nuclear Information System (INIS)

    High spatial and temporal resolution airborne imagery were acquired for the Ribble Estuary, North West England in 1997 and 2003, to assess the application of time-series airborne remote sensing to quantify total suspended sediment and radionuclide fluxes during a flood and ebb tide sequence. Concomitant measurements of suspended particulate matter (SPM) and water column turbidity were obtained during the time-series image acquisition for the flood and ebb tide sequence on the 17th July 2003 to verify the assumption of a vertically well mixed estuary and thus justifying the vertical extrapolation of spatially integrated estimate of surface SPM. The 137Cs activity concentrations were calculated from a relatively stable relationship between SPM and 137Cs for the Ribble Estuary. Total estuary wide budgets of sediment and 137Cs were obtained by combining the image-derived estimates of surface SPM and 137Cs with estimates of water volume from a two-dimensional hydrodynamic model (VERSE) developed for the Ribble Estuary. These indicate that around 10,000 tonnes of sediment and 2.72 GBq of 137Cs were deposited over the tidal sequence monitored in July 2003. This compared favourably with bed height elevation change estimated from field work. An uncertainty analysis on the total sediment and 137Cs flux yielded a total budget of the order of 40% on the final estimate. The results represent a novel approach to providing a spatially integrated estimate of the total net sediment and radionuclide flux in an intertidal environment over a flood and ebb tide sequence. - Research highlights: → This paper provides a rare insight into the next flux of sediment and associated radionuclide loading into an estuary over and ebb and flood tide sequence. → The paper uses high temporal resolution airborne imagery coupled with concomitant sampling to convert total suspended sediment flux to 137Cs loading. → For the estuary and date studied, it is estimate that an 10,000 tonnes of sediment and 2.72 GBq of 137Cs are deposited into the estuary. → An uncertainty budget of about 40% on the final estimate is detailed.

  8. Estimating soil erosion using caesium-137 as radiotracer in cultivated land at watershed of bigger river, Cuba

    International Nuclear Information System (INIS)

    In Cuba, due to the climatic conditions and intensive land use, soil erosion is a serious threat to sustainable agricultural development and environmental preservation. The aim of this work was to introduce the use of environmental radionuclide 137Cs in soil erosion studies. In view of this, a research project on 137Cs technique was carried out on small selected study site at the watershed of bigger River. A total of 160 soil samples were collected at the study and reference sites and were dried and analysed for 137Cs using high resolution gamma spectrometry. By comparing 137Cs inventories at individual sampling points with a reference inventory representing the local fallout input and using the calibration models for converting 137Cs measurements to estimates of soil redistribution rates, estimates of soil loss were calculated to be between 7.2 and 12.4 t.ha- 1.year-1 depending on the assumptions and methods used. In general, Proportional Model and Gravimetric Method (7.3 t.ha-1.year-1) provided low erosion rates and simplified Mass Balance Model high values of erosion rates (12.4 t.ha-1.year-1). The high erosion rates derived from Simplified Mass Balance Model may be caused by the assumption that the total 137Cs fallout occurred in 1963 instead of over a longer period extending from the mid 1950s to the mid 1970s. This model poses an important improvement over the two mentioned models due to it takes into account the progressive reduction in the 137Cs concentration of the soil within the plough layer due to incorporation of soil containing negligible 137Cs from below the original plough depth. Further sampling is required to investigate both the local and regional variability of fallout input in the studied watershed region and to assess its influence on the error of erosion estimates. However, the results suggest that 137Cs technique may be of considerable value for developing of an adequate soil conservation program

  9. Modern parameters of caesium-137 root uptake in natural and agricultural grass ecosystems of contaminated post-Chernobyl landscape, Russia

    Directory of Open Access Journals (Sweden)

    Tatiana Paramonova

    2015-01-01

    Full Text Available The estimation of modern parameters of 137Cs root uptake was conducted in natural meadow and agricultural ecosystems of post-Chernobyl landscapes of Tula region. The agrosystems with main crops of field rotation (barley, potatoes, rape, maize occupying watersheds and slopes with arable chernozems are contaminated at a level 460-670 Bq/kg (4.7-6.0 Ci/km2; natural meadow ecosystems occupying lower parts of slopes and floodplains are contaminated at a level 620-710 Bq/kg (5.8-7.6 Ci/km2. In the arable soils 137Cs uniformly distributed to a depth of Ap horizon (20-30 cm of thickness, while in meadow soils 70-80% of the radionuclide is concentrated within the top Ad horizon (9-13 cm of thickness. These topsoil layer accords with rhizosphere zone, where >80-90% of plant roots are concentrated, and from which 137Cs is mostly consumed by vegetation. Total amount of 137Cs root uptake depends on the level of soil radioactive contamination (correlation coefficient 0.61. So 137Cs activity in meadow vegetation (103-160 Bq/kg is generally more than one in agricultural vegetation (9-92 Bq/kg. The values of 137Cs transfer factor in the studied ecosystems vary from 0.01 (rape to 0.20 (wet meadow, that confirms the discrimination of the radionuclide’s root uptake. The larger are the volume of roots and their absorbing surface, the higher are the values of transfer factor from soil to plant (correlation coefficients 0.71 and 0.64 respectively. 137Cs translocation from roots to shoots is also determined by biological features of plants. At the same level of soil contamination above-ground parts of meadow herbs accumulate more 137Cs than Gramineae species, and in agrosystems above-ground parts of weeds concentrate more 137Cs than cultivated cereals. Thus, the level of soil radioactive pollution and biological features of plants are determinants in the process of 137Cs root uptake and translocation and should be considered in land use policy.

  10. Analysis of the spatial and temporal evolution of caesium-137 and strontium-90 in waters of the Tagus river

    International Nuclear Information System (INIS)

    The River Tagus runs for 1370 km through Spain and Portugal, and receives the liquid effluent of three Spanish nuclear power plants. In this present work, the spatial and temporal evolution was analysed of the levels of Cs-137 and Sr-90 in the water of this river in its passage through various Spanish and Portuguese regions. Mathematical time-series techniques were used to analyse the experimental results. Firstly, with these techniques analytic expressions were obtained for the temporal trends of the activity levels of these radionuclides. This allowed us to calculate the rates of concentration in some cases, and of dilution in others, of these radionuclides at the different sampling points. Thus, in the cooling reservoir of the PWR-type Almaraz Nuclear Power Plant in Spain, we estimated a constant Cs-137 dilution rate of 4.67 mBq/L.month. In the case of Sr-90, the rates estimated were not constant but time dependent. A study of the seasonality of the time-series also allowed us to determine that the concentrations of the two radionuclides varied cyclically at some of the sampling points. The periods of these oscillations were around to 13-14 months for Cs-137 and around 17-18 months for Sr-90. Lastly, we determined the transit times of both these radionuclides between some of the sampling sites. The results indicate that the two radionuclides have similar speeds of displacement, with a mean value during the years of the study of 12 km/month. (author)

  11. Electronic relaxations of radiative defects of the anion sublattice in caesium bromide crystals and exoemission of electrons

    Science.gov (United States)

    Galiy, P.; Mel'Nyk, O.

    The thermostimulated exoelectron emission (TSEE) is applied for investigation of the processes of radiative defects recombination in the nearsurface layer. Results of TSEE studies of radiatively excited CsBr crystals are presented. Dose dependences of the decay kinetics, TSEE spectrum structure and exosums were studied. Concentration of exoemission-active centres (EAC) and TSEE kinetics parameters have been calculated on the base of the bulk thermoactivated anion sublattice defect recombination. The attained result correlate with the electron centres concentration for irradiated crystals. In the framework of the Auger-like anion defects recombinational bulk model of exoemission from irradiated wide-band-gap crystals, the energy spectra of the exoelectrons excited on the F-centres are attained.

  12. Estimating sediment and caesium-137 fluxes in the Ribble Estuary through time-series airborne remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Wakefield, R. [Atkins Limited, 200 Broomielaw, Glasgow, G1 4RU (United Kingdom); Tyler, A.N., E-mail: a.n.tyler@stir.ac.u [School of Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA (United Kingdom); McDonald, P. [Environmental Sciences Westlakes Scientific Consulting Ltd, The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3LN (United Kingdom); Atkin, P.A. [Atkins Limited, Wastwater Pavillion Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3JZ (United Kingdom); Gleizon, P. [Environmental Sciences Westlakes Scientific Consulting Ltd, The Princess Royal Building, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3LN (United Kingdom); Gilvear, D. [School of Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA (United Kingdom)

    2011-03-15

    High spatial and temporal resolution airborne imagery were acquired for the Ribble Estuary, North West England in 1997 and 2003, to assess the application of time-series airborne remote sensing to quantify total suspended sediment and radionuclide fluxes during a flood and ebb tide sequence. Concomitant measurements of suspended particulate matter (SPM) and water column turbidity were obtained during the time-series image acquisition for the flood and ebb tide sequence on the 17th July 2003 to verify the assumption of a vertically well mixed estuary and thus justifying the vertical extrapolation of spatially integrated estimate of surface SPM. The {sup 137}Cs activity concentrations were calculated from a relatively stable relationship between SPM and {sup 137}Cs for the Ribble Estuary. Total estuary wide budgets of sediment and {sup 137}Cs were obtained by combining the image-derived estimates of surface SPM and {sup 137}Cs with estimates of water volume from a two-dimensional hydrodynamic model (VERSE) developed for the Ribble Estuary. These indicate that around 10,000 tonnes of sediment and 2.72 GBq of {sup 137}Cs were deposited over the tidal sequence monitored in July 2003. This compared favourably with bed height elevation change estimated from field work. An uncertainty analysis on the total sediment and {sup 137}Cs flux yielded a total budget of the order of 40% on the final estimate. The results represent a novel approach to providing a spatially integrated estimate of the total net sediment and radionuclide flux in an intertidal environment over a flood and ebb tide sequence. - Research highlights: {yields} This paper provides a rare insight into the next flux of sediment and associated radionuclide loading into an estuary over and ebb and flood tide sequence. {yields} The paper uses high temporal resolution airborne imagery coupled with concomitant sampling to convert total suspended sediment flux to {sup 137}Cs loading. {yields} For the estuary and date studied, it is estimate that an 10,000 tonnes of sediment and 2.72 GBq of {sup 137}Cs are deposited into the estuary. {yields} An uncertainty budget of about 40% on the final estimate is detailed.

  13. Caesium-137 root uptake by agricultural and wild crops in post-Chernobyl landscape: the possibilities for phytoremediation?

    Science.gov (United States)

    Paramonova, Tatiana; Shamshurina, Eugenia; Komissarova, Olga; Belyaev, Vladimir

    2015-04-01

    In spite of long term period after Chernobyl fallout (≈25 years after the accident) the level of Cs-137 in soils of contaminated landscapes remains several times more than radiation safety standard (= 37 kBq/m2). In particular, within the area of Plavsk radioactive hot spot (Tula region, Russia) current Cs-137 activities in soil are 460-500 Bq/kg (170-200 kBq/m2) on watershed, 580-680 Bq/kg (200-220 kBq/m2) in arable lower parts of slopes and 620-710 Bq/kg (210-280 kBq/m2) in untilled foots of slopes and river floodplains. To estimate the process of Cs-137 root uptake and incorporation of the radionuclide in plant tissues 6 agricultural crops of typical field rotation (spring barley, maize, summer rape, galega, potatoes, amaranth) as well as natural ecosystems of dry and wet meadows were selected for the detailed study. Total bioproductivity of agricultural crops varies between 1.7-3.9 kg/m2, natural grass ecosystems - 1.9-2.2 g/m2, and is obviously unaffected by radioactive land contamination. At the same time Cs-137 activity in total biomass slightly increases with Cs-137 activity in soil (correlation coefficient r=0.45) and with total biomass (correlation coefficient r=0.51) in the row: rape (5 Bq/kg) rape (Brassicaceae family) and potatoes (Solanaceae family) are characterized by similar Cs-137 concentrations in the structural parts (but note, that belowground part of the last is mostly represented by modified shoots); while galega and amaranth (Fabaceae and Amaranthaceae families respectively) are characterized by higher Cs-137 activity in aboveground part (4-6 times more than in roots). Therefore, meadow grasses and cereals that are true accumulators of Cs-137 seem to be useless for phytoremediation purposes, as 86-97% of the radionuclide inventory is associated with roots and remains in soil after cutting of aboveground parts. On the other hand, galega and amaranth could be considered as agricultural crops potentially being used for phytoremediation, since 87-93% of Cs-137 inventory is located in shoots. Potatoes having rather high aboveground biomass and easily removed from soil underground part could be also used for phytoremediation. However, it should be clearly understood that in total Cs-137 inventory in "soil-plant" system the annual amount of the radionuclide's consumption (that may be alienated when harvesting) is less than 0.01%, while the rate of Cs-137 radioactive decay is estimated as about 2% per year. Study was conducted with the support from the Russian Foundation for Basic Research (project no. 14-05-00903).

  14. Strontium-90 and caesium-137 deposition in New Zealand and the resulting contamination of dairy products - a historical analysis

    International Nuclear Information System (INIS)

    This paper summarises a recent review of records of fallout deposition and milk radioactivity in New Zealand during the period 1961 - 1990. The purpose of the review was two-fold: to summarize an extensive set of data in a form which was accessible to other researchers, and to draw as many conclusions as possible from the history of fallout in order to aid decision making in any future environmental contamination events. Milk 90Sr and 137Cs levels were found to vary cyclically throughout the year with 137Cs levels displaying, on average, a peak during the January - March period, and minimum levels in July - August; while 90Sr levels in the North Island regions peaked sharply in the July - September period

  15. Radioactive caesium concentration of lowland rice grown in the decontaminated paddy fields in Iitate-village in Fukushima

    International Nuclear Information System (INIS)

    We investigated the relationship between radiocaesium (134Cs and 137Cs) concentration (specific radio activity: Bq/kg) in rice and the paddy soil in Iitate village where people evacuated because of the high levels of radioactive contamination caused by the Fukushima Daiichi nuclear disaster. The radiocaesium concentration was measured of paddy soil and of lowland rice grown on variously decontaminated paddy soil in the year 2012 and 2013. The results showed that the concentration of radiocaesium in the brown rice cultured in the field of Sasu and Maeda with 2000 - 6000 Bq/kg(DW) soil (0 - 15 cm depth) was below 40 Bq/kg, which was below the new standard for food (100 Bq/kg), and the concentration of radiocaesium in the brown rice depended on the decontamination level of the paddy soil. In addition, the radiocaesium in rice was reduced depending on the exchangeable K content of the soil, which comes to plateau around 20 mg K2O/100 g dry soil. However, in 2013, in the fields of Komiya where the radiocaesium concentration was higher than 8000 Bq/kg(DW) even after decontamination, brown rice with higher than 100 Bq/kg was harvested, indicating the necessity of further decontamination. Overall, our results show that the suitable decontamination and additional fertilization of K can make the radiocaesium concentration of rice much lower than the new standard. (author)

  16. Caesium-137 and Strontium-90 temporal series in the Tagus River: experimental results and a modelling study

    International Nuclear Information System (INIS)

    The objective of this work consisted of analysing the spatial and temporal evolution of two radionuclide concentrations in the Tagus River. Time-series analysis techniques and numerical modelling have been used in this study. 137Cs and 90Sr concentrations have been measured from 1994 to 1999 at several sampling points in Spain and Portugal. These radionuclides have been introduced into the river by the liquid releases from several nuclear power plants in Spain, as well as from global fallout. Time-series analysis techniques have allowed the determination of radionuclide transit times along the river, and have also pointed out the existence of temporal cycles of radionuclide concentrations at some sampling points, which are attributed to water management in the reservoirs placed along the Tagus River. A stochastic dispersion model, in which transport with water, radioactive decay and water–sediment interactions are solved through Monte Carlo methods, has been developed. Model results are, in general, in reasonable agreement with measurements. The model has finally been applied to the calculation of mean ages of radioactive content in water and sediments in each reservoir. This kind of model can be a very useful tool to support the decision-making process after an eventual emergency situation. - Highlights: ► Analysis of the evolution of two radionuclide concentrations in the Tagus River. ► Time-series analysis techniques and numerical modelling have been used. ► Model is very useful tool to support the decision-making process after an emergency situation.

  17. Optical pumping and population transfer of nuclear-spin states of caesium atoms in high magnetic fields

    Institute of Scientific and Technical Information of China (English)

    Luo Jun; Sun Xian-Ping; Zeng Xi-Zhi; Zhan Ming-Sheng

    2007-01-01

    Nuclear-spin states of gaseous-state Cs atoms in the ground state are optically manipulated using a Ti:sapphire laser in a magnetic field of 1.516 T, in which optical coupling of the nuclear-spin states is achieved through hyperfine interactions between electrons and nuclei. The steady-state population distribution in the hyperfine Zeeman sublevels of the ground state is detected by using a tunable diode laser. Furthermore, the state population transfer among the of Cs in the ground state due to stochastic collisions between Cs atoms and buffer-gas molecules, is studied at different of the hyperfine interaction can strongly cause the state population transfer and spin-state interchange among the hyperfine Zeeman sublevels. The calculated results maybe explain the steady-state population in hyperfine Zeeman sublevels in terms of rates of optical-pumping, electron-spin flip, nuclear spin flip, and electron-nuclear spin flip-flop transitions among the hyperfine Zeeman sublevels of the ground state of Cs atoms. This method may be applied to the nuclear-spin-based solid-state quantum computation.

  18. Transfer factor of caesium-137 in natural and agricultural grass ecosystems in the area of Plavsk radioactive spot, Russia

    International Nuclear Information System (INIS)

    Root uptake and translocation of 137Cs from soil to plant is the key for estimation of general ecological situation and land use on radioactive contaminated territories. There are numerous researches concerning the relationship between the level of the radionuclide presence in soils and its accumulation in vegetation that usually describes as transfer factor (TF) for 137Cs (the ratio of the specific 137Cs activity in the plant tissue and the soil). But in most cases only edible organs or above-ground parts of plants are taken into account in evaluating TF. It is reasonable from the standpoint of practical use, but does not provide accurate information in the study of 137Cs biogeochemical cycle features. The study of the 137Cs root uptake from the radioactive contaminated chernozem soil and its distribution between above-ground and below-ground fractions of grass vegetation was conducted in the natural conditions on the territory of Plavsk radioactive spot (Tula region, Russia) ∼25 years after Chernobyl accident. The main crops of field rotation in this landscape (wheat, barley, potatoes, rape, maize) which occupy watersheds and slopes with arable chernozems contaminated at a level 460-670 Bq/kg (170-220 kBq/m2) and natural grassland ecosystems which occupy lower parts of slopes and flood plains with dry and wet meadows contaminated at a level 620-710 Bq/kg (210-250 kBq/m2) were examined. Total accumulation of 137Cs in vegetation strongly depends on the level of soil radioactive contamination (correlation coefficient 0.87). So specific 137Cs activity in vegetation of meadows (103-160 Bq/kg) in general more than one in agricultural crops (9-92 Bq/kg). Other reason may be the predominance of perennial herbs in natural meadows whereas agricultural systems contain annual crops. The values of 137Cs TF in the studied ecosystems vary within a relatively narrow range: from 0.01 (rape) to 0.20 (wet meadow), that confirms the discrimination of the radionuclide root uptake. At the same time the distribution of 137Cs between above-ground and below-ground fractions of plants in all observed cases is quite non-uniformly: below-ground parts of vegetation accumulate 3-5 times more than above-ground ones. An exception is potatoes agrocenosis where the TF values for different parts are almost identical, but below-ground fraction of potatoes consists of grater modified shoots, but no roots. There is a pronounceable difference in 137Cs TF values for root tissues of various plant associations. The highest TF values in below-ground fraction are typical for vegetation with agricultural or wild cereals (0.15-0.26) having fibrous root system, the lowest TF values are characterized for rape agrocenosis (0.02) having stem root system. Thus, the major differences in the 137Cs TF from contaminated soil to plant may be closely related to the features of the root system and the further translocation of the radionuclide into shoot, which requires quantitative account of 137Cs accumulation not only in above-ground green parts, but also in roots. (authors)

  19. Use of Caesium 137 to estimate rates and patterns of soil redistribution on agricultural land in Cuba: models and validation

    International Nuclear Information System (INIS)

    A research project on 137Cs technique for soil erosion studies was undertaken in Cuba under the Nuclear Program and was carried out on small selected study site at the watershed of Maximo River. Estimates of soil loss were calculated to be between 11 and 23 t.ha 1.year 1 for the field 9 and between 3 and 6 t.ha-1.year-1 for the field 17 depending on the assumptions and calibration model used. Local erosion rate estimated by 137Cs technique were also found to be in good agreement with the measured sediment loss from erosion plots installed in the upper part of the field 9. The calculated erosion rates for 8 sampling points surrounding the erosion plot varied from 11.1 to 23 t. ha-1.year-1 .This is similar to the mean annual sediment loss from the corresponding plot of 10 12 t. ha-1.year-1 if we take into account values reported for Proportional and Mass Balance Model 2. The soil redistribution rates quantified by the 137Cs technique also were compared with the soil redistribution rates estimated using pedological observations, which also reflect the cumulative effect of past soil redistribution processes and both evidence a similar pattern of spatial distribution to the soil redistribution rates. The aim of this work was to introduce the use of environmental radionuclide 137Cs in soil erosion studies in Cuba and preliminary results suggest that 137Cs technique may be of considerable value in assembling data on the rates and spatial distribution of soil loss and a reliable tool for developing of an adequate soil conservation program

  20. Transfer factor of caesium-137 in natural and agricultural grass ecosystems in the area of Plavsk radioactive spot, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Paramonova, Tatiana A.; Machaeva, Ekaterina N. [Radioecology and Ecotoxicology Department of Soil Science Faculty, Lomonosov Moscow State University, 119234 Moscow (Russian Federation); Belyaev, Vladimir R. [Laboratory of soil erosion and fluvial processes of Geography Faculty, Lomonosov Moscow State University, 119234 Moscow (Russian Federation)

    2014-07-01

    Root uptake and translocation of ¹³⁷Cs from soil to plant is the key for estimation of general ecological situation and land use on radioactive contaminated territories. There are numerous researches concerning the relationship between the level of the radionuclide presence in soils and its accumulation in vegetation that usually describes as transfer factor (TF) for ¹³⁷Cs (the ratio of the specific ¹³⁷Cs activity in the plant tissue and the soil). But in most cases only edible organs or above-ground parts of plants are taken into account in evaluating TF. It is reasonable from the standpoint of practical use, but does not provide accurate information in the study of ¹³⁷Cs biogeochemical cycle features. The study of the ¹³⁷Cs root uptake from the radioactive contaminated chernozem soil and its distribution between above-ground and below-ground fractions of grass vegetation was conducted in the natural conditions on the territory of Plavsk radioactive spot (Tula region, Russia)~25 years after Chernobyl accident. The main crops of field rotation in this landscape (wheat, barley, potatoes, rape, maize) which occupy watersheds and slopes with arable chernozems contaminated at a level 460-670 Bq/kg (170-220 kBq/m²) and natural grassland ecosystems which occupy lower parts of slopes and flood plains with dry and wet meadows contaminated at a level 620-710 Bq/kg (210-250 kBq/m²) were examined. Total accumulation of ¹³⁷Cs in vegetation strongly depends on the level of soil radioactive contamination (correlation coefficient 0.87). So specific ¹³⁷Cs activity in vegetation of meadows (103-160 Bq/kg) in general more than one in agricultural crops (9-92 Bq/kg). Other reason may be the predominance of perennial herbs in natural meadows whereas agricultural systems contain annual crops. The values of ¹³⁷Cs TF in the studied ecosystems vary within a relatively narrow range: from 0.01 (rape) to 0.20 (wet meadow), that confirms the discrimination of the radionuclide root uptake. At the same time the distribution of ¹³⁷Cs between above-ground and below-ground fractions of plants in all observed cases is quite non-uniformly: below-ground parts of vegetation accumulate 3-5 times more than above-ground ones. An exception is potatoes agrocenosis where the TF values for different parts are almost identical, but below-ground fraction of potatoes consists of grater modified shoots, but no roots. There is a pronounceable difference in ¹³⁷Cs TF values for root tissues of various plant associations. The highest TF values in below-ground fraction are typical for vegetation with agricultural or wild cereals (0.15-0.26) having fibrous root system, the lowest TF values are characterized for rape agrocenosis (0.02) having stem root system. Thus, the major differences in the ¹³⁷Cs TF from contaminated soil to plant may be closely related to the features of the root system and the further translocation of the radionuclide into shoot, which requires quantitative account of ¹³⁷Cs accumulation not only in above-ground green parts, but also in roots. (authors)

  1. The release of caesium-137 from plant litters and the effects of microbial activity on this process

    International Nuclear Information System (INIS)

    Plant material form three different species was artificially labelled by root uptake from solutions labelled with 137Cs activity. Measurements were made of 137Cs activity, pH and potassium content on the leachates from litter samples over a three month period. Microbial activity was assessed by measuring the respiration rate of each litter sample. Rates of release of both 137Cs and K from Calluna vulgaris litter were slower than those from Trifolium repens and Agrostis capillaris, but the two elements had different release patterns. For T. repens and A. capillaris repeated drying and rewetting of the litter during the experimental period changed the pattern of 137Cs release when compared with continuously moistened litter samples. (author)

  2. Analysis of Collisional Cross Sections of Rydberg nS and nD States of Ultracold Caesium Atoms

    Science.gov (United States)

    Feng, Zhigang; Miao, Jingyuan; Zhao, Kejia; Li, Difei; Yang, Zhijun; Wu, Fan; Wu, Zhaochun; Zhao, Jianming; Jia, Suotang

    2016-05-01

    We present a simple analytical formula derived from an existing theoretical model and a detailed theoretical investigation of effects of the van der Waals interaction and dipole–dipole interaction on collisional cross sections as functions of various parameters. We analyze the main mechanism leading to large collisional cross sections on the basis of our previous experimental results using the present formula and also analyze the effects of some other factors on collisional cross sections.

  3. Caesium-137 root uptake by agricultural and wild crops in post-Chernobyl landscape: the possibilities for phytoremediation?

    Science.gov (United States)

    Paramonova, Tatiana; Shamshurina, Eugenia; Komissarova, Olga; Belyaev, Vladimir

    2015-04-01

    In spite of long term period after Chernobyl fallout (≈25 years after the accident) the level of Cs-137 in soils of contaminated landscapes remains several times more than radiation safety standard (= 37 kBq/m2). In particular, within the area of Plavsk radioactive hot spot (Tula region, Russia) current Cs-137 activities in soil are 460-500 Bq/kg (170-200 kBq/m2) on watershed, 580-680 Bq/kg (200-220 kBq/m2) in arable lower parts of slopes and 620-710 Bq/kg (210-280 kBq/m2) in untilled foots of slopes and river floodplains. To estimate the process of Cs-137 root uptake and incorporation of the radionuclide in plant tissues 6 agricultural crops of typical field rotation (spring barley, maize, summer rape, galega, potatoes, amaranth) as well as natural ecosystems of dry and wet meadows were selected for the detailed study. Total bioproductivity of agricultural crops varies between 1.7-3.9 kg/m2, natural grass ecosystems - 1.9-2.2 g/m2, and is obviously unaffected by radioactive land contamination. At the same time Cs-137 activity in total biomass slightly increases with Cs-137 activity in soil (correlation coefficient r=0.45) and with total biomass (correlation coefficient r=0.51) in the row: rape (5 Bq/kg) phytoremediation purposes, as 86-97% of the radionuclide inventory is associated with roots and remains in soil after cutting of aboveground parts. On the other hand, galega and amaranth could be considered as agricultural crops potentially being used for phytoremediation, since 87-93% of Cs-137 inventory is located in shoots. Potatoes having rather high aboveground biomass and easily removed from soil underground part could be also used for phytoremediation. However, it should be clearly understood that in total Cs-137 inventory in "soil-plant" system the annual amount of the radionuclide's consumption (that may be alienated when harvesting) is less than 0.01%, while the rate of Cs-137 radioactive decay is estimated as about 2% per year. Study was conducted with the support from the Russian Foundation for Basic Research (project no. 14-05-00903).

  4. A method for a simultaneous decrease of strontium, caesium and iodine retention after oral exposure in rats

    International Nuclear Information System (INIS)

    Measurements were made of the combined action in rats of sodium alginate, iron (111) ferrocyanide and sodium perchlorate as dietary additives, and of the effect of each of them on the separate absorption and retention of 85Sr, 137Cs and 131I. Food consumption and body weight were practically unchanged by the additives, and there was no appreciable interference between the additives in producing substantial reduction in the retention of oral doses of 85Sr, 137Cs and 131I. The body burden of these three important fission products could be reduced by this single remedial procedure. (U.K.)

  5. The uptake and storage of caesium and strontium by spring wheat - a modelling study based on a field experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gaerdenaes, Annemieke I.; Linnea Berglund, S.; Bengtsson, Stefan B.; Rosen, Klas [Dept. of Soil and Environment, Swedish University of Agricultural Sciences (SLU), P.O. Box 7001, 750 07 Uppsala (Sweden)

    2014-07-01

    The aim was to model, quantify, and analyse the dynamics of uptake (foliar and root) and grain storage of wet-deposited radionuclides by a growing crop. The dynamic trace element model, Tracey, for terrestrial ecosystems was used after extension with descriptions for contamination by wet-deposition, interception, and foliar uptake. Tracey contains two alternative root uptake descriptions, one driven by transpiration and one by growth. Radionuclide fluxes were assumed proportional to the corresponding water or carbon fluxes in the soil-plant-atmosphere system, simulated with the CoupModel. The extended Tracey was calibrated against data from the wet-deposition experiment at Ultuna, central Sweden. {sup 134}Cs and {sup 85}Sr were deposited on spring wheat at six growth stages in 2010 and 2011. The sensitivity for different radionuclide, plant, and soil properties were assessed by Monte Carlo simulations using the sensitivity toolbox Eikos. One thousand simulations were made for each of the 48 scenarios (2 radionuclides, 2 root uptake approaches, 6 deposition treatments, 2 years). The simulated dynamics of grains' storage of radionuclides were accepted if the simulated values were within the 95% confidence interval of the measured values at all available samplings of a deposition treatment. A ten percentage of all {sup 134}Cs and {sup 85}Sr simulations were accepted. Highest percentage of accepted simulations was found for the scenarios with deposition shortly before harvest, indicating that the added model descriptions of deposition and interception performed well. The model mimicked well that the grain storage of radionuclides increased exponentially the later in the growing season the deposition took place; the storage of radionuclides when deposited at full ripening was 250 times higher than the storage when deposition took place at tillering. The model results confirmed that foliar uptake i.e. direct atmosphere-plant transfer, fully dominates total plant uptake when deposition takes place during the growing season. The estimated accumulated foliar uptake formed on average 99% of the Cs and 93% of Sr total plant uptake. We identified the governing factors of radionuclide storage in grains and how they varied with growth stage; the stem and leaves fixation rates dominate before flowering; the flowers/grain fixation rates dominate between flowering and ripening; and the interception retention capacity of the grains dominates from full ripening. We conclude that Tracey can accurately simulate the storage dynamics of radionuclides in plant parts that are a major ingredient in human food. We showed the dependency of the storage dynamics on the local weather, growth and soil conditions. The model and results can be used to tailor counter-measures to local conditions in the case of a radioactive deposition and to improve preparedness for radioactive deposition on growing crops. (authors)

  6. Performance evaluation of of caesium, iodine, strontium and ruthenium isotopes in urban areas after contamination by accidental release

    International Nuclear Information System (INIS)

    The exposures of urban populations to the radiation derived from the deposition, after accidental atmospheric releases, of I37Cs, 134Cs, 129I, 131I, 133I, 89Sr, l03Ru and 106Ru were assessed, using the integrated system for the evaluation of environmental radiological impact in emergency situations (SIEM), developed by the Instituto de Radioprotecao e Dosimetria (IRD) / Comissao Nacional de Energia Nuclear (CNEN). These radionuclides are fission products likely to be emitted in the occurrence of severe nuclear reactor accidents. Their environmental behaviour in urban areas, due to their deposition in soil, in urban surfaces and in vegetable-garden food products, such as leafy and non-leafy vegetables, were analyzed, and dose assessments at the short, medium and long terms were performed, with and without the application of protective measures for reduction of doses. Simulations of unitary initial deposition for each radionuclide and of two different potential accidents involving pressurized water reactors (PWR), with different source terms and distinct deposition for each radionuclide, were performed. Results were analyzed on the basis of the relative relevance of radionuclides and pathways for the exposure of members of the public, as a function of age and time after the release. It was also performed an assessment of the effectiveness of protective measures as a function of the moment of their implementation. (author)

  7. Trends in caesium activity concentrations in milk from agricultural and semi-natural environments after nuclear fallout

    International Nuclear Information System (INIS)

    The radiocaesium contamination of milk and milk products is directly related to that in grass or hay and therefore the time trend to the effective half-life in these fodders. In the early phase the half-life in grass predominantly depends on effects such as dilution due to plant growth, translocation and weathering effects. The average effective half-life during this period (growing season) lies between 5 and 18 days. In upland pastures values of up to 25 days are observed. Studies performed on a great number of sites in particular countries after the Chernobyl accident showed half-lives for 137Cs in grass from 7.9±1.5 d to 10.5±1.4 d for the period of May to July. An equivalent biological half-life for 131I was observed. Only one measurement of half-lives in winter was performed up to now indicating a substantially longer value (50 d). No reliable data on effective half-lives at other periods of the year (late summer, fall) are available and would require further research. The long-term decline is determined by soil properties. Soils with low fixation capacity and low pH show higher aggregated transfer factors into milk than others. In certain semi-natural alpine pastures these factors remain high for years which cannot be explained by extreme soil properties only. Other reasons such as water logging, little dilution due to low plant growth, cycling of radionuclides within living and dead plant biomass and runoff effects have to be considered as main causes. A classification system for the long-term trend in Cs-availability to milk is proposed, but further research on the differences and possible measures with respect to seasonal variations and climatic conditions is required. (author)

  8. The uptake and storage of caesium and strontium by spring wheat - a modelling study based on a field experiment

    International Nuclear Information System (INIS)

    The aim was to model, quantify, and analyse the dynamics of uptake (foliar and root) and grain storage of wet-deposited radionuclides by a growing crop. The dynamic trace element model, Tracey, for terrestrial ecosystems was used after extension with descriptions for contamination by wet-deposition, interception, and foliar uptake. Tracey contains two alternative root uptake descriptions, one driven by transpiration and one by growth. Radionuclide fluxes were assumed proportional to the corresponding water or carbon fluxes in the soil-plant-atmosphere system, simulated with the CoupModel. The extended Tracey was calibrated against data from the wet-deposition experiment at Ultuna, central Sweden. 134Cs and 85Sr were deposited on spring wheat at six growth stages in 2010 and 2011. The sensitivity for different radionuclide, plant, and soil properties were assessed by Monte Carlo simulations using the sensitivity toolbox Eikos. One thousand simulations were made for each of the 48 scenarios (2 radionuclides, 2 root uptake approaches, 6 deposition treatments, 2 years). The simulated dynamics of grains' storage of radionuclides were accepted if the simulated values were within the 95% confidence interval of the measured values at all available samplings of a deposition treatment. A ten percentage of all 134Cs and 85Sr simulations were accepted. Highest percentage of accepted simulations was found for the scenarios with deposition shortly before harvest, indicating that the added model descriptions of deposition and interception performed well. The model mimicked well that the grain storage of radionuclides increased exponentially the later in the growing season the deposition took place; the storage of radionuclides when deposited at full ripening was 250 times higher than the storage when deposition took place at tillering. The model results confirmed that foliar uptake i.e. direct atmosphere-plant transfer, fully dominates total plant uptake when deposition takes place during the growing season. The estimated accumulated foliar uptake formed on average 99% of the Cs and 93% of Sr total plant uptake. We identified the governing factors of radionuclide storage in grains and how they varied with growth stage; the stem and leaves fixation rates dominate before flowering; the flowers/grain fixation rates dominate between flowering and ripening; and the interception retention capacity of the grains dominates from full ripening. We conclude that Tracey can accurately simulate the storage dynamics of radionuclides in plant parts that are a major ingredient in human food. We showed the dependency of the storage dynamics on the local weather, growth and soil conditions. The model and results can be used to tailor counter-measures to local conditions in the case of a radioactive deposition and to improve preparedness for radioactive deposition on growing crops. (authors)

  9. Field investigations of the transfer of caesium-137 in the pasture-cow-milk pathway in West Cumbria

    International Nuclear Information System (INIS)

    Routine discharges from the nuclear fuel reprocessing installation at Sellafield provide an opportunity to study the behaviour in the environment of several artificially produced radionuclides. Two investigations of the transfer of radionuclides in the pasture-cow-milk pathway are described. The uptake of 137Cs by cattle grazing sea-washed pasture near Ravenglass has been investigated by in vivo measurements of the animals. A very low coefficient of transfer from feed to meat was estimated. The transfer of several radionuclides, notably 90Sr, 137Cs, 239Pu and 241Am, is being studied at a dairy farm near Sellafield. Preliminary results for 137Cs are reported and are found to be in reasonable agreement with model predictions. (author)

  10. Caesium-137 soil-to-plant transfer for representative agricultural crops of monocotyledonous and dicotyledonous plants in post-Chernobyl steppe landscape

    Science.gov (United States)

    Paramonova, Tatiana; Komissarova, Olga; Turykin, Leonid; Kuzmenkova, Natalia; Belyaev, Vladimir

    2016-04-01

    The accident at the Chernobyl nuclear power plant in 1986 had a large-scale action on more than 2.3 million hectares agricultural lands in Russia. The area of radioactively contaminated chernozems of semi-arid steppe zone with initial levels of Cs-137 185-555 kBq/m2 in Tula region received the name "Plavsky radioactive hotspot". Nowadays, after the first half-life period of Cs-137 arable chernozems of the region are still polluted with 3-6-fold excess above the radioactive safety standard (126-228 kBq/m2). Therefore, qualitative and quantitative characteristics of Cs-137 soil-to-plant transfer are currently a central problem for land use on the territory. The purpose of the present study was revealing the biological features of Cs-137 root uptake from contaminated arable chernozems by different agricultural crops. The components of a grass mixture growing at the central part of Plavsky radioactive hotspot with typical dicotyledonous and monocotyledonous plants - galega (Galega orientalis, Fabaceae family) and bromegrass (Bromus inermis, Gramineae family) respectively - were selected for the investigation, that was conducted during the period of harvesting in 2015. An important point was that the other factors influenced on Cs-137 soil-to-plant transfer - the level of soil pollution, soil properties, climatic conditions, vegetative phase, etc. - were equal. So, biological features of Cs-137 root uptake could be estimated the most credible manner. As a whole, general discrimination of Cs-137 root uptake was clearly shown for both agricultural crops. Whereas Cs-137 activity in rhizosphere 30-cm layer of arable chernozem was 371±74 Bq/kg (140±32 kBq/m2), Cs-137 activities in plant biomass were one-two orders of magnitude less, and transfer factor (TF) values (the ratio of the Cs-137 activities in vegetation and in soil) not exceeded 0.11. At the same time bioavailability of Cs-137 for bromegrass was significantly higher than for galega: TFs in total biomass of the crops were 0.11 and 0.01 correspondingly. But the most dramatic difference between the investigated crops was connected with peculiarities of Cs-137 distribution within above- and belowground parts of biomass. While TF in aboveground fraction of galega (0.02) was slightly higher than in belowground fraction (0.01), the bulk of Cs-137 in bromegrass was detected not in shoots but in roots (TFs 0.05 and 0.11 correspondingly). More extensive examination of Cs-137 behavior in "soil-plant" systems of agricultural crops in the area of Plavsky radioactive hotspot has revealed that all investigated dicotyledonous plants with taproot system (potatoes, soya, amaranth, rape) accumulated 71±14% of Cs-137 inventories in aboveground biomass, whereas monocotyledonous plants with fibrous root system (wheat, barley, maize, cereal pasture species) deposited 94±5% of Cs-137 supplies in their belowground biomass. Thus, the first had effective biological root barrier protecting vegetation from general Cs-137 incorporation into biomass, but relatively active radionuclide translocation into shoots, while the second were characterized by slight rhizofiltration property and occurrence an additional barrier between roots and shoots determining only moderate radionuclide translocation into aboveground biomass. Such biological features should be taken into account in deciding on rehabilitation strategy of radioactively contaminated lands. The study was conducted with the support from the Russian Foundation for Basic Research (project no. 14-05-00903).

  11. A novel use of the caesium-137 technique to estimate human interference and historical water level in a Mediterranean Temporary Pond

    International Nuclear Information System (INIS)

    The sustainability of, and the effects of human pressures on, Omalos Mediterranean Temporary Pond (MTP), Chanea, Greece was assessed. The 137Cs technique was used to identify alleged anthropogenic interference (excavation) in the studied area. It was found that about one third of the ponds bed surface material had been removed and disposed of on the northeast edge, confirming unplanned excavations that took place in the MTP area some years ago. Nonetheless, five years after the excavation, the MTP's ecosystem (flora and fauna) had recovered, which indicates that these small ecosystems are resilient to direct human pressures, like excavations. Moreover, with the 137Cs technique it was possible to identify the historical water level of Omalos MTP, when the fallout from the Chernobyl accident reached this area, in May of 1986. Therefore, the 137Cs technique can be useful in the identification of the historical water level of small MTPs and other ephemeral water bodies. Applications include the verification and validation of hydrological models. -- Highlights: • We apply the 137Cs technique to estimate human interference of Omalos MTP. • We apply the 137Cs technique to identify the historical water level of Omalos MTP. • Excavated works that occurred in the MTP area were identified. • The place where the excavated soil material was disposed was recognized. • The historical water level (May 1984) of the MTP was estimated

  12. OBSERVING OF RADIOACTIVE CAESIUM 137Cs VALUE IN BEEF MEAT (CZECH PIED CATTLE IN LESS-FAVOURED AREAS OF THE CZECH REPUBLIC

    Directory of Open Access Journals (Sweden)

    Ivan Holko

    2012-02-01

    Full Text Available Value of radiocaesium 137Cs as one of Risk Factors in beef meat is very important for human health. Beef meat (m. longissimus lumborum et thoracis from Czech Pied cattle in two less-favoured areas located more then 500 meters above sea level (Bohemian Forest Bohemian and Moravian Highland was dependent on Sex (decrease by female, increase by male, P<1.10-6 and on area (P<1.10-6. Value of radiocaesium 137Cs in beef meat ( = 0,42 Bq.kg-1; sx = 0,28 was less then food standard (600 Bq.kg-1. This observed result are responding to finding another authors and could be used for next more detailed research in optimal utilization of Czech Pied cattle in less-favoured areas.

  13. A Composite Membrane of Caesium Salt of Heteropolyacids/Quaternary Diazabicyclo-Octane Polysulfone with Poly (Tetrafluoroethylene for Intermediate Temperature Fuel Cells

    Directory of Open Access Journals (Sweden)

    Keith Scott

    2012-07-01

    Full Text Available Inorganic-organic composite electrolyte membranes were fabricated from CsXH3−XPMo12O40 (CsPOMo and quaternary diazabicyclo-octane polysulfone (QDPSU using a polytetrafluoroethylene (PTFE porous matrix for the application of intermediate temperature fuel cells. The CsPOMo/QDPSU/PTFE composite membrane was made proton conducting by using a relatively low phosphoric acid loading, which benefits the stability of the membrane conductivity and the mechanical strength. The casting method was used in order to build a thin and robust composite membrane. The resulting composite membrane films were characterised in terms of the elemental composition, membrane structure and morphology by EDX, FTIR and SEM. The proton conductivity of the membrane was 0.04 S cm−1 with a H3PO4 loading level of 1.8 PRU (amount of H3PO4 per repeat unit of polymer QDPSU. The fuel cell performance with the membrane gave a peak power density of 240 mW cm−2 at 150 °C and atmospheric pressure.

  14. Ocean dynamic processes causing spatially heterogeneous distribution of sedimentary caesium-137 massively released from the Fukushima Dai-ichi Nuclear Power Plant

    Science.gov (United States)

    Higashi, H.; Morino, Y.; Furuichi, N.; Ohara, T.

    2015-08-01

    Massive amounts of anthropogenic radiocaesium 137Cs that was released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident on March 2011 are widely known to have extensively migrated to Pacific oceanic sediment off of east Japan. Several recent reports have stated that the sedimentary 137Cs is now stable with a remarkably heterogeneous distribution. The present study elucidates ocean dynamic processes causing this heterogeneous sedimentary 137Cs distribution in and around the shelf off Fukushima and adjacent prefectures. We performed a numerical simulation of oceanic 137Cs behaviour for about 10 months after the accident, using a comprehensive dynamic model involving advection-diffusion transport in seawater, adsorption and desorption to and from particulate matter, sedimentation and suspension on and from the bottom, and vertical diffusion transport in the sediment. A notable simulated result was that the sedimentary 137Cs significantly accumulated in a swath just offshore of the shelf break (along the 50-100 m isobath) as in recent observations, although the seabed in the entire simulation domain was assumed to have ideal properties such as identical bulk density, uniform porosity, and aggregation of particles with a single grain diameter. This result indicated that the heterogeneous sedimentary 137Cs distribution was not necessarily a result of the spatial distribution of 137Cs sediment adsorptivity. The present simulation suggests that the shape of the swath is mainly associated with spatiotemporal variation between bottom shear stress in the shallow shelf (simulation indicated that strong bottom friction suspending particulate matter from the seabed frequently occurred via a periodic spring tide about every 2 weeks and via occasional strong wind. The sedimentary 137Cs thereby could hardly stay on the surface of the seabed with the result that the simulated sediment-surface 137Cs activity tended to decrease steadily for a long term after the initial 137Cs migration. By contrast, in the offshore region, neither the spring tide nor the strong wind caused bottom disturbance. Hence, the particulate matter incorporated with 137Cs, which was horizontally transported from the adjacent shallow shelf, readily settled and remained on the surface of the sediment just offshore of the shelf break. The present simulation also clearly demonstrated that the bottom disturbance influenced the sedimentary 137Cs distributions not only horizontally but also vertically. In particular, within a part of the near-shore off the nuclear power plant, the simulation indicated that large amounts of the sedimentary 137Cs were present in both upper and deeper sediments. As a result, total sedimentary 137Cs in the entire simulation domain (1.4 x 105 km2) at the end of 2011 was 3.2 x 1015 Bq, more than 10 times that in previous estimates using samples of upper sediments.

  15. Final report on a field study of soil-to-plant transfer radioactive caesium, strontium and zinc in Tropical Northern Australia

    International Nuclear Information System (INIS)

    Soil-to-plant radionuclide transfer factors for cesium (134Cs), strontium (85Sr) and zinc (65Zn) into sorghum and mung plants grown in tropical Australia have been determined over a four-year study period. The crops were grown on two types of red earth soils. Transfer factors for Cs and Sr are not substantially different from the expected values based on previous studies, reported in the general literature and compiled in the IUR database, mainly performed within temperate climates. In contrast, the values for zinc (Zn) are more than an order of magnitude greater than anticipated. Most of the radioactivity added to the soils has been retained in the top 5 cm of both soils. There has been a general decline in soil-to-plant transfer of Cs and Zn as time has increased

  16. Poly[μ3-aqua-aqua(μ3-3,5-dinitrobenzoato-κO1:O3:O5caesium

    Directory of Open Access Journals (Sweden)

    Graham Smith

    2012-10-01

    Full Text Available In the structure of the title complex, [Cs(C7H3N2O6(H2O2]n, the Cs salt of 3,5-dinitrobenzoic acid, the metal complex centres have have irregular CsO8 coordination, comprising two water molecules (one triply bridging and the other monodentate and four O-atom donors from two nitro groups and one bridging carboxylate O-atom donor from the ligand. Intra-unit O—H...O hydrogen-bonding interactions involving both water molecules are observed in the three-dimensional polymeric complex structure.

  17. Plant induced changes in concentrations of caesium, strontium and uranium in soil solution with reference to major ions and dissolved organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Akira [Department of Radioecology, Institute for Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan)], E-mail: takeda@ies.or.jp; Tsukada, Hirofumi; Takaku, Yuichi; Akata, Naofumi; Hisamatsu, Shun' ichi [Department of Radioecology, Institute for Environmental Sciences, 1-7 Ienomae, Obuchi, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan)

    2008-06-15

    For a better understanding of the soil-to-plant transfer of radionuclides, their behavior in the soil solution should be elucidated, especially at the interface between plant roots and soil particles, where conditions differ greatly from the bulk soil because of plant activity. This study determined the concentration of stable Cs and Sr, and U in the soil solution, under plant growing conditions. The leafy vegetable komatsuna (Brassica rapa L.) was cultivated for 26 days in pots, where the rhizosphere soil was separated from the non-rhizosphere soil by a nylon net screen. The concentrations of Cs and Sr in the rhizosphere soil solution decreased with time, and were controlled by K + NH{sub 4}{sup +} and Ca, respectively. On the other hand, the concentration of U in the rhizosphere soil solution increased with time, and was related to the changes of DOC; however, this relationship was different between the rhizosphere and non-rhizosphere soil.

  18. Ocean dynamic processes causing spatially heterogeneous distribution of sedimentary caesium-137 massively released from the Fukushima Dai-ichi Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    H. Higashi

    2015-08-01

    Full Text Available Massive amounts of anthropogenic radiocaesium 137Cs that was released into the environment by the Fukushima Dai-ichi Nuclear Power Plant accident on March 2011 are widely known to have extensively migrated to Pacific oceanic sediment off of east Japan. Several recent reports have stated that the sedimentary 137Cs is now stable with a remarkably heterogeneous distribution. The present study elucidates ocean dynamic processes causing this heterogeneous sedimentary 137Cs distribution in and around the shelf off Fukushima and adjacent prefectures. We performed a numerical simulation of oceanic 137Cs behaviour for about 10 months after the accident, using a comprehensive dynamic model involving advection–diffusion transport in seawater, adsorption and desorption to and from particulate matter, sedimentation and suspension on and from the bottom, and vertical diffusion transport in the sediment. A notable simulated result was that the sedimentary 137Cs significantly accumulated in a swath just offshore of the shelf break (along the 50–100 m isobath as in recent observations, although the seabed in the entire simulation domain was assumed to have ideal properties such as identical bulk density, uniform porosity, and aggregation of particles with a single grain diameter. This result indicated that the heterogeneous sedimentary 137Cs distribution was not necessarily a result of the spatial distribution of 137Cs sediment adsorptivity. The present simulation suggests that the shape of the swath is mainly associated with spatiotemporal variation between bottom shear stress in the shallow shelf (137Cs thereby could hardly stay on the surface of the seabed with the result that the simulated sediment-surface 137Cs activity tended to decrease steadily for a long term after the initial 137Cs migration. By contrast, in the offshore region, neither the spring tide nor the strong wind caused bottom disturbance. Hence, the particulate matter incorporated with 137Cs, which was horizontally transported from the adjacent shallow shelf, readily settled and remained on the surface of the sediment just offshore of the shelf break. The present simulation also clearly demonstrated that the bottom disturbance influenced the sedimentary 137Cs distributions not only horizontally but also vertically. In particular, within a part of the near-shore off the nuclear power plant, the simulation indicated that large amounts of the sedimentary 137Cs were present in both upper and deeper sediments. As a result, total sedimentary 137Cs in the entire simulation domain (1.4 x 105 km2 at the end of 2011 was 3.2 x 1015 Bq, more than 10 times that in previous estimates using samples of upper sediments.

  19. Investigating the gas phase emitter effect of caesium and cerium in ceramic metal halide lamps in dependence on the operating frequency

    Science.gov (United States)

    Ruhrmann, C.; Westermeier, M.; Bergner, A.; Luijks, G. M. J. F.; Awakowicz, P.; Mentel, J.

    2011-09-01

    The work function and with it the temperature of tungsten electrodes in HID lamps can be lowered and the lifetime of lamps increased by the gas phase emitter effect. A determination of the emitter effect of Cs and Ce is performed by phase resolved measurements of the electrode tip temperature Ttip(phiv), plasma temperature Tpl(phiv) and particle densities N(phiv) by means of pyrometric, optical emission and broadband absorption spectroscopy in dependence on the operating frequency. The investigated HID lamps are ceramic metal halide lamps with transparent discharge vessels made of YAG, filled with a buffer gas consisting of Ar, Kr and predominantly Hg and seeded with CsI or CeI3. In the YAG lamp seeded with CsI and CeI3 as well as in a YAG lamp seeded with DyI3 (corresponding results can be found in a preceding paper) a gas phase emitter effect is observed in the cathodic phase due to a Cs, Ce or Dy ion current. In the YAG lamp seeded with CsI the phase averaged coverage of the electrode surface with emitter atoms decreases and the electrode temperature rises with increasing frequency, whereas the emitter effect of Ce and Dy is extended to the anodic phase, which leads to a decreased average temperature Ttip(phiv) with increasing frequency. This different behaviour of the averaged values of Ttip(phiv) for increasing frequency is caused by the differing adsorption energies Ea of the respective emitter materials. In spite of the influence of Ea on the coverage of the electrode with emitter atoms, the cathodic gas phase emitter effect produces in the YAG lamps seeded with CsI, CeI3 and DyI3 a general reduction in the electrode tip temperature Ttip(phiv) in comparison with a YAG lamp with Hg filling only.

  20. Radioactivity distribution of the fruit trees ascribable to radioactive fall out (5). Transfer of caesium-137 from scion to other organs in 'Kyoho' grapes

    International Nuclear Information System (INIS)

    We examined the effect on shifts of 137Cs from old organs to newly other organ with grafting scion contaminated by radionuclides onto non-radioactive contamination tree in grapes. 137Cs of about 20% in the scion had transferred to newly organs. In the scion, the concentration of 137Cs in bark after harvest was similar to that measured before grafting, but the concentration of 137Cs in wood after harvest was lower than that measured before grafting. We concluded that transferability of 137Cs from old branches to fruits had contributed much more than that from soil known in previous research. (author)

  1. Irradiation of members of the general public from radioactive caesium following the Chernobyl reactor accident. Field studies in a highly contaminated area in the Bryansk region, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Thornberg, C

    2000-11-01

    From 1990 to 1999, estimations of the effective dose from external as well as internal irradiation from {sup 137}Cs and {sup 134}Cs were carried out for inhabitants in rural villages in the Bryansk region, Russia, highly contaminated due to the Chernobyl accident in 1986. The villages were situated about 180 km from the Chernobyl power plant and the deposition of {sup 137}Cs was in the range 0.9-2.7 MBq/m{sup 2}. Yearly expeditions were conducted in autumn by members of the Departments of Radiation Physics in Malmoe and Goeteborg, Institute of Radiation Hygiene, St. Petersburg and the the first 5 years also by the Norwegian Radiation Protection Authority. The dose levels and their change in time were estimated for various groups of the general public. The body burden of {sup 134,137}Cs and hence, the effective dose, was estimated from measurements of the urinary concentration of cesium radionuclides, together with direct measurements of the body content using a portable detector. The effective dose from external irradiation was estimated from measurements with thermoluminescent dosemeters worn by the participants during one month each year. In a special case study, the changes in biokinetics of {sup 137}Cs during pregnancy was investigated in a woman with an unintended intake of {sup 137}Cs via mushrooms from a highly contaminated forest in the area. During pregnancy there is an increased excretion of cesium resulting in a biological half-time of cesium which was 54% of the half-time before pregnancy. The ratio of the {sup 137}Cs concentration in breast milk (Bq/l) to that in the mother's body (Bq/kg) was 15% one month after the child was born. The body burden of {sup 137}Cs in the Russian individuals calculated from the concentration of {sup 137}Cs in urine showed a good agreement with the body burden estimated from in vivo measurements in the same individuals. Normalisation of the cesium concentration in the urine samples by the use of potassium or creatinine excretion was found to introduce systematic differences as well as larger spread in the calculated values of the {sup 137}Cs body burden as compared with calculations without normalisation, using the urinary concentration of {sup 137}Cs only. The yearly effective dose from external and internal irradiation to inhabitants in the Russian villages varied between 1.2 and 2.5 mSv as a mean for all villages studied between 1991 and 1998 and the internal effective dose was, on average, 30-50% of the total effective dose during that period. The effective dose from external irradiation decreased on average 15% per year, while the effective dose from internal irradiation varied, depending to a great extent on dietary habits and especially the availability of mushrooms. The cumulated effective dose for a 70-year period after the accident was calculated to be around 100 mSv with the assumption that the effective dose will decrease by only the physical decay of {sup 137}Cs (2% per year) after 1999. Individuals may receive considerably higher effective doses, up to 0.5 Sv during a life-time considering the large spread in dose values among individuals.

  2. Human metabolism and ecological transfer of radioactive caesium. Comparative studies of Chernobyl debris and nuclear weapons fallout, in southern Sweden and in Bryansk, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Raeaef, C.L

    2000-05-01

    The whole-body content of radiocaesium was measured in a South Swedish urban group of people residing in the city of Lund between 1960 and 1994. The results from the survey have been analysed in order to estimate the ecological half time, T{sub eff,eco} of fallout radiocaesium, and the aggregate transfer from ground deposition to man in the region. After 1987, the biological half times, T{sub e} of {sup 137}Cs and {sup 40}K in man were also determined in the reference group through whole-body content measurements in combination with 24-hour urine sampling. Relationships between 24-hour urinary excretion and body burden of {sup 137}Cs in the group together with data from the literature were then applied to urine samples collected in 1994 and 1995 from adult subjects living in the highly contaminated region of Bryansk, Russia, in order to estimate their average body burden of {sup 137}Cs. The equivalent biological half-time for {sup 137}Cs in females of the Lund reference group was, on average 66{+-}3 d, which agrees with other findings, whereas the value for the males, 81{+-}4 d, was, on average, significantly lower than what is found in the literature. This is partly explained by the elevated mean age and relatively low mean body muscle mass of the males investigated. The {sup 137}Cs from nuclear weapons tests in the 1950s and 1960s still gave a significant contribution to the total {sup 137}Cs levels in man during the post-Chernobyl study period (1987-1994). About 10% of the peak post-Chernobyl concentration level of {sup 137}Cs (3.5-4 Bq/kg) in 1987, was attributed to pre-Chernobyl {sup 137}Cs. The effective ecological half-time for {sup 137}Cs from Chernobyl was found to be 1.8{+-}0.2 y. The time-integrated aggregate transfer of {sup 137}Cs from ground deposition to mean activity concentration in man was estimated to be 0.4 Bq/kg/kBq/m{sup 2}. These values may be compared with an effective ecological half-time of 1.3 years found in the Lund reference group in the 1960s, and in time-integrated aggregate transfer factor of 4.4 Bq/kg/kBq/m{sup 2}. The average committed effective dose from ingested {sup 137}Cs Chernobyl fallout in the study group was estimated to be 0.02 mSv and from the nuclear weapons fallout to 0.20 mSv. The estimates of whole-body content of {sup 137}Cs in the Russian subjects obtained through creatinine normalisation of the {sup 137}Cs content in urine were, on average, a factor of 2 higher than estimates obtained through a potassium normalisation procedure; 55{+-}8 kBq for creatinine and 29{+-}4 kBq for potassium normalisation in the year 1994. This was due to a significant difference in the relationship between the urinary potassium and creatinine concentration between the Swedish and Russian group. The elevated potassium concentration found in the rural Russian subjects indicated a higher dietary intake of potassium, which greatly influence the accuracy and applicability of the potassium normalization method when estimating body burden of {sup 137}Cs through urine assay. It is therefore recommended not to use the potassium normalisation procedure in cases where the daily intake of potassium is unknown. The estimated body burden of {sup 137}Cs in the Bryansk group in 1994 corresponds to a contribution to the estimated annual effective dose of 1.8 mSv/y, which is approximately 200 times greater than the average annual dose received from ingested {sup 137}Cs by the subjects of the Lund reference group during the period 1987-1994.

  3. The Use of Excess Lead-210, Beryllium-7 and Caesium-137 in Investigations of Sediment Delivery Dynamics in the Homerka and Dunajec Catchments in the Polish Flysh Carpathians

    International Nuclear Information System (INIS)

    The paper summarizes the findings of the research conducted in the small (19.7 km2) instrumented Homerka catchment and the larger basin of the Dunajec River upstream from the Roznowski reservoir in the Polish Flysch Carpathians, where a combination of conventional and fallout radionuclide methods have been used over the past 35 years to investigate sediment mobilization, transfer and deposition. This paper focuses on the use of 210Pbex, 7Be and 137Cs to trace the main sources of the suspended sediment exported from the study catchment and to investigate sediment delivery dynamics during high energy flood events. Information on sediment sources has been assembled using the 'fingerprinting' approach. Monitoring of the spatial distribution of 7Be activity immediate after each period of heavy rainfall provided a basis for investigating sediment mobilised by dispersed overland flow and linear flow. The results show that 7Be transport is connected with land use and soil surface cover. Since changes in land use affected the volume of sediment mobilized from a small catchment, these changes may prove to be significant within larger basins. The depth distribution of 210Pbex, 7Be and 137Cs in undisturbed soils provided a means for establishing the intensity of surface erosion during different flood events. Changes in the 210Pbex, 7Be and 137Cs content of suspended sediment transported during flood events reflected changes in the relative contribution of different sediment sources. During extreme storm events, the contributing area was greatly expanded and sediment mobilized from areas which are unconnected to the stream during 'normal' events. The information on soil erosion and sediment delivery dynamics provided by 210Pbex, 7Be and 137Cs measurements were compared with existing results from conventional investigations. Unmetalled roads were identified as the main source for sediment in suspension, with the channels and active gullies also providing significant contributions. (author)

  4. A field study of soil-to-plant transfer of strontium-90 and caesium-137 based on a calcaric cambisol in sub-tropical southwest China

    International Nuclear Information System (INIS)

    Root uptake is one of the most important pathways of radionuclide transfer from a contaminated environment to the terrestrial food chain. For this pathway Bv, which is defined as 'Concentration of radionuclide per unit weight of plant organ' divided by 'Concentration of radionuclide per unit weight of dry soil', is necessary for dose assessment models. In China assessment generally uses Bv values derived from American or European countries. In 1994, IAEA published the Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Temperate Environments. The data are mostly drawn from North America and Europe, much of which was compiled through projects of IUR and CEC. However, there are only limited data for crops cultivated in Asian countries, especially in China. Since Bv changes with factors such as soil properties, crop species, and climatic characteristics, it is necessary to obtain TF data on radionuclides for major agriculture crops grown in typical soils in different regions or countries. In this study the transfer of 90Sr (half-life:28.78y) and 137Cs (half-life:30.07y) from soil to wheat, maize, broad bean, spinach, Chinese cabbage, potato, radish, tomato and lettuce were investigated in field conditions in Sichuan Province from 1999 to 2002. The soil involved is a Calcaric Cambisol which was contaminated artificially with 90Sr and 137Cs in 1999. Each Bv (soil to plant transfer factor) was determined from 5 replicates of crop and related soil samples taken at harvest time. Soil characteristics are analysed and other parameters important to the experiments are provided. The variability of the 90Sr and 137Cs Bv is rather wide. The year to year variations suggest climatic factors may be important. For both radionuclides, the Bv to cereals were close to, or below, the bottom of the range predicted on the basis of the data of IUR and IAEA. There was no clear trend for Bv to change with time for both. (authors)

  5. Irradiation of members of the general public from radioactive caesium following the Chernobyl reactor accident. Field studies in a highly contaminated area in the Bryansk region, Russia

    International Nuclear Information System (INIS)

    From 1990 to 1999, estimations of the effective dose from external as well as internal irradiation from 137Cs and 134Cs were carried out for inhabitants in rural villages in the Bryansk region, Russia, highly contaminated due to the Chernobyl accident in 1986. The villages were situated about 180 km from the Chernobyl power plant and the deposition of 137Cs was in the range 0.9-2.7 MBq/m2. Yearly expeditions were conducted in autumn by members of the Departments of Radiation Physics in Malmoe and Goeteborg, Institute of Radiation Hygiene, St. Petersburg and the the first 5 years also by the Norwegian Radiation Protection Authority. The dose levels and their change in time were estimated for various groups of the general public. The body burden of 134,137Cs and hence, the effective dose, was estimated from measurements of the urinary concentration of cesium radionuclides, together with direct measurements of the body content using a portable detector. The effective dose from external irradiation was estimated from measurements with thermoluminescent dosemeters worn by the participants during one month each year. In a special case study, the changes in biokinetics of 137Cs during pregnancy was investigated in a woman with an unintended intake of 137Cs via mushrooms from a highly contaminated forest in the area. During pregnancy there is an increased excretion of cesium resulting in a biological half-time of cesium which was 54% of the half-time before pregnancy. The ratio of the 137Cs concentration in breast milk (Bq/l) to that in the mother's body (Bq/kg) was 15% one month after the child was born. The body burden of 137Cs in the Russian individuals calculated from the concentration of 137Cs in urine showed a good agreement with the body burden estimated from in vivo measurements in the same individuals. Normalisation of the cesium concentration in the urine samples by the use of potassium or creatinine excretion was found to introduce systematic differences as well as larger spread in the calculated values of the 137Cs body burden as compared with calculations without normalisation, using the urinary concentration of 137Cs only. The yearly effective dose from external and internal irradiation to inhabitants in the Russian villages varied between 1.2 and 2.5 mSv as a mean for all villages studied between 1991 and 1998 and the internal effective dose was, on average, 30-50% of the total effective dose during that period. The effective dose from external irradiation decreased on average 15% per year, while the effective dose from internal irradiation varied, depending to a great extent on dietary habits and especially the availability of mushrooms. The cumulated effective dose for a 70-year period after the accident was calculated to be around 100 mSv with the assumption that the effective dose will decrease by only the physical decay of 137Cs (2% per year) after 1999. Individuals may receive considerably higher effective doses, up to 0.5 Sv during a life-time considering the large spread in dose values among individuals

  6. Applications of environmental Caesium-137 for the determination of sedimentation rates in reservoirs and lakes and related catchment studies in developing countries

    International Nuclear Information System (INIS)

    Environmental 137Cs adsorbed on fine sediments has many uses as a tracer in erosion and sedimentation studies. The determination of sedimentation rates in lakes and reservoirs using 137Cs as a geochronological marker is described in detail. From a survey of literature sources it is shown that 137Cs levels in soils and sediments can be a powerful tool for the identification and quantification of soil erosion processes in catchment. It is suggested that 137Cs studies can be profitably applied by developing countries whose limited soil resources are at high risk. (author)

  7. Analytical Performance of 14 Laboratories Taking Part in Proficiency Test for the Determination of Caesium-137 and Total Lead-210 in Spiked Soil Samples

    International Nuclear Information System (INIS)

    One of the most widespread threats to agricultural development is soil erosion. Soil erosion further impoverishes low-income farm households by reducing soil quality and consequently agricultural yields. It also affects productivity in irrigated farming systems by contributing suspended sediment to waterways and reducing storage capacity of reservoirs. The costs of these effects are substantial in many developing and developed countries. To combat soil erosion there is an urgent need for reliable quantitative data on the extent and rates of soil erosion and sedimentation. Fallout radiouclides (FRN) 210Pb and 137Cs are widely used for soil erosion and sedimentation studies. FRN measurements for soil redistribution involve gamma analysis on soil samples. It is therefore important that the analytical data are correct to ensure that the conclusions of such studies are based on reliable and validated analytical results and to ensure the comparability of the results of different countries. Through a collaboration between the Chemistry Unit and the Soil Science Unit of the IAEA's laboratories IAEA organized an intercomparison exercise in order to assess the validity and reliability of the analytical measurements of 137Cs and total 210Pb carried out by the different laboratories participating in the IAEA Co-ordinated Research Project D1.50.08 'Assessing the effectiveness of soil conservation measures for sustainable watershed management using fallout radionuclides' lead by the Soil Water Management and Crop Nutrition Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. In this proficiency test 90 samples (Proficiency Test (PT) materials) were distributed to the participating laboratories. The laboratories were requested to analyse the samples employing the same methods used in their daily routine gamma measurements. In total 14 out of 18 initially registered laboratories reported their results. The analytical results of the laboratories were compared with the reference values assigned to the PT materials, and a rating system was applied. In the case of 137Cs, the analytical results were satisfactory with 66% of the participants producing acceptable results (only the sample with low 137Cs activity 2.6±0.2 Bq kg-1 gave less accurate results) while the 210Pb analysis indicated a clear need for corrective actions in the analytical process. 63% of the laboratories involved in the proficiency test did not fulfil the proficiency test criteria for total 210Pb, while this was only 21% for 137Cs. It is recommended that further inter-comparison exercises be organized by IAEA or regional laboratories to ensure the quality of the analytical data produced in Member States through Co-ordinated Research Projects and Technical Co-operation Projects. (author)

  8. Cesium-137 in the soils of forest ecosystems of the Saarland (South-western Germany); Caesium-137 in Boeden saarlaendischer Waldoekosysteme

    Energy Technology Data Exchange (ETDEWEB)

    Kastenholz, U. [Universitaet des Saarlandes, Saarbruecken (Germany). Zentrum fuer Umweltforschung

    2000-07-01

    Scopes and main features: In order to explain the behaviour of the artificial radioisotope {sup 137}Cs towards landscape resources in the Saar-Lor-Lux-Region, the cross-border region between southwestern Germany/Saarland, France/Lorraine and Luxembourg, regional distribution as well as downward translocation and depth functions of {sup 137}Cs in the main soil substrates of forest ecosystems in the Saarland were investigated. Results: The study shows that the highest {sup 137}Cs activities are found in the north of the Saarland, whereas the south and south-easten regions show distinctly lower concentrations of {sup 137}Cs. Migration rates range between 0.25 cm/a and 1.0 cm/a. On an average, the highest migration rates were found in the clayey-silty substrates of the lime stone areas in the Muschelkalk regions (Middle Triassic) (0.66 cm/a), followed by the loamy substrates of Lower Permian clastic sediments (Unterrotliegendes) (0.53 cm/a) and the sandy substrates of the Buntsandstein areas (Lower Triassic sandstone) (0.41 cm/a). 90 to 95% of the {sup 137}Cs activities in the clay-poor soils of the Unterrotliegendes and the Buntsandstein were traced in the upper 10 cm of the humus topsoil. The substrates of the lime stone areas (Muschelkalk), in contrast to this, reveal a {sup 137}Cs activity of only 70-76% at the same depth. Conclusions: Due to the fact that the primary and secondary pores of the soil pore system, in their function as translocation pathways, decrease with increasing soil depth, a significant reduction in the migration rates of {sup 137}Cs can be expected with increasing soil depth. On the other hand, the maximal migration depth of 40 cm found in shallow soils on jointed parent material, as well as on sites with high groundwater tables, implies a possible contamination of near-surface groundwater. Future outlook: Based on the results of this study, a permanent monitoring of {sup 137}Cs was added to the long-term Soil Monitoring Program run by the Federal Administrative Office of Environment of the Saarland (Landesamt fuer Umweltschutz des Saarlandes). (orig.) [German] Ziel und Schwerpunkte: Um das Verhalten des kuenstlichen Radionuklids {sup 137}Cs im Landschaftshaushalt der Saar-Lor-Lux Region zu klaeren, wurden die raeumliche Verteilung sowie das dezendente Migrationsverhalten und die Tiefenfunktionen des Radioisotops in den wichtigsten Bodensubstraten saarlaendischer Waldoekosysteme untersucht. Ergebnisse: Demnach finden sich die hoechsten {sup 137}Cs-Aktivitaeten im Norden des Landes, waehrend die Gebiete im Sueden und Suedosten deutlich geringere Konzentrationen aufweisen. Es konnten deszendente Migrationsraten zwischen 0,25 cm/a und 1,0 cm/a festgestellt werden. Durchschnittlich treten die hoechsten Migrationsraten in den tonig-schluffigen Substraten des Muschelkalks auf (0,66 cm/a), gefolgt von den lehmig ausgepraegten Substraten des Unterrotliegenden (0,53 cm/a) und den sandigen Substraten des Buntsandsteins (0,41 cm/a). In den tonarmen Bodensubstraten des Unterrotliegenden und des Buntsandsteins lassen sich 90-95% der Aktivitaeten in den oberen 10 cm der humusreichen Oberboeden nachweisen, wohingegen in den tonreichen Substraten des Muschelkalks bis zur gleichen Tiefe nur etwa 70-76% zu finden sind. Schlussfolgerungen: Mit einem Abnehmen der als Leitbahnen fungierenden Primaer- und Sekundaerporen in zunehmender Tiefe ist kuenftig mit einer deutlichen Reduzierung der Verlagerungsgeschwindigkeit von {sup 137}Cs in den Substraten des Muschelkalks zu rechnen. Insbesondere bei geringmaechtigen Boeden auf kluftreichem Ausgangsgestein impliziert die maximale Eindringtiefe des Isotops von 40 cm in den Unterboden jedoch eine moegliche Kontamination des oberflaechennahen Grundwassers, ebenso wie an Standorten mit hohem Grundwasserstand. Ausblick: Aufgrund der hier vorgestellten Ergebnisse wurden ein {sup 137}Cs-Monitoring in das Boden-Dauerbeobachtungsprogramm des Landesamts fuer Umweltschutz des Saarlandes aufgenommen. (orig.)

  9. Human metabolism and ecological transfer of radioactive caesium. Comparative studies of Chernobyl debris and nuclear weapons fallout, in southern Sweden and in Bryansk, Russia

    International Nuclear Information System (INIS)

    The whole-body content of radiocaesium was measured in a South Swedish urban group of people residing in the city of Lund between 1960 and 1994. The results from the survey have been analysed in order to estimate the ecological half time, Teff,eco of fallout radiocaesium, and the aggregate transfer from ground deposition to man in the region. After 1987, the biological half times, Te of 137Cs and 40K in man were also determined in the reference group through whole-body content measurements in combination with 24-hour urine sampling. Relationships between 24-hour urinary excretion and body burden of 137Cs in the group together with data from the literature were then applied to urine samples collected in 1994 and 1995 from adult subjects living in the highly contaminated region of Bryansk, Russia, in order to estimate their average body burden of 137Cs. The equivalent biological half-time for 137Cs in females of the Lund reference group was, on average 66±3 d, which agrees with other findings, whereas the value for the males, 81±4 d, was, on average, significantly lower than what is found in the literature. This is partly explained by the elevated mean age and relatively low mean body muscle mass of the males investigated. The 137Cs from nuclear weapons tests in the 1950s and 1960s still gave a significant contribution to the total 137Cs levels in man during the post-Chernobyl study period (1987-1994). About 10% of the peak post-Chernobyl concentration level of 137Cs (3.5-4 Bq/kg) in 1987, was attributed to pre-Chernobyl 137Cs. The effective ecological half-time for 137Cs from Chernobyl was found to be 1.8±0.2 y. The time-integrated aggregate transfer of 137Cs from ground deposition to mean activity concentration in man was estimated to be 0.4 Bq/kg/kBq/m2. These values may be compared with an effective ecological half-time of 1.3 years found in the Lund reference group in the 1960s, and in time-integrated aggregate transfer factor of 4.4 Bq/kg/kBq/m2. The average committed effective dose from ingested 137Cs Chernobyl fallout in the study group was estimated to be 0.02 mSv and from the nuclear weapons fallout to 0.20 mSv. The estimates of whole-body content of 137Cs in the Russian subjects obtained through creatinine normalisation of the 137Cs content in urine were, on average, a factor of 2 higher than estimates obtained through a potassium normalisation procedure; 55±8 kBq for creatinine and 29±4 kBq for potassium normalisation in the year 1994. This was due to a significant difference in the relationship between the urinary potassium and creatinine concentration between the Swedish and Russian group. The elevated potassium concentration found in the rural Russian subjects indicated a higher dietary intake of potassium, which greatly influence the accuracy and applicability of the potassium normalization method when estimating body burden of 137Cs through urine assay. It is therefore recommended not to use the potassium normalisation procedure in cases where the daily intake of potassium is unknown. The estimated body burden of 137Cs in the Bryansk group in 1994 corresponds to a contribution to the estimated annual effective dose of 1.8 mSv/y, which is approximately 200 times greater than the average annual dose received from ingested 137Cs by the subjects of the Lund reference group during the period 1987-1994

  10. Low-energy electron scattering from caesium atoms -comparison of a semirelativistic Breit-Pauli and a full relativistic Dirac treatment

    International Nuclear Information System (INIS)

    The discrepancies between a previous Breit-Pauli R-matrix calculation and a recent calculation using the Dirac Hamiltonian are further analysed and partially resolved. When comparable methods are applied to obtain the best possible target description in both approaches, a reduced Breit-Pauli formulation, with only the one-body spin-orbit operator included to account for relativistic effects explicitly, seems sufficient for an accurate description of most of the low-energy collision processes in this system. There remain, however, some interesting differences between the Breit-Pauli and the Dirac results for spin polarization and asymmetry functions, as well as for very sensitive resonance parameters. (author)

  11. Radioactive fallout in the South Pacific : a history. Part 3: strontium-90 and caesium-137 deposition in New Zealand and resulting contamination of milk

    International Nuclear Information System (INIS)

    The report provides a comprehensive analysis of milk radioactivity data, principally pertaining to 90Sr and 137Cs, collected in nine regions of New Zealand. Fallout deposition data are also reviewed and relationships between deposition and resulting milk contamination described. This report provides further information on 90Sr deposition in New Zealand and summarises period from 1961 to 1990. Trends in levels of 90Sr and 137Cs in milk over long periods and also annual trends are described, together with variations between regions, modelled relationships between fallout deposition and milk contamination levels, measurements of 131I and 89Sr in milk, and estimates of resulting dietary radiation exposure in New Zealand. A major aim of the present report was to summarise as much of the information contained in the deposition and dairy product databases as possible through the description of trends and derivation of relationships in order to improve understanding of the behaviour of artificial radioactive contaminants in the environment and their passage through food-chains. 34 refs., 29 tabs., 50 figs., 1 ill

  12. Transfer of some artificial (strontium 85 and caesium 137) and natural (potasium 40 and radium 226) radionuclides from milk to its products

    International Nuclear Information System (INIS)

    Transfer of some artificial radionuclides (137Cs and 85Sr) and natural radionuclides (226Ra and 40K) from milk (cheep and cows) to its products processed according to local manufacturing procedures (home made cheese, kashkawan cheese, shelal cheese, haloom cheese, kareshah cheese, sharkasiah cheese, liquid cheese, yogurt, butter and keshdah) has been studied. The results showed that the retention percent of radium 226 in milk products has reached %100 in the home made cheese and %72 for strontium 85 in the shelal cheese and %40 for cesium 137 in yogurt and %46 for potassium 40 also in yogurt. In addition, most of the retention percent ratios of the studied radionuclides in yogurt were relatively low (about %25 and % 40 in the yogurt processed from the milk of the cows and cheep respectively) with a high processing efficiency, so that making yogurt from the contaminated milk is the best way to reduce the contamination ratio and to make use of the contaminated milk. Furthermore, home made cheese was processed with salty solutions of different concentrations and the results showed that about %90 of cesium and potassium has transferred to the salty solution of %5 soaked for 48 hours, while %40 of the radium and %80 of strontium were removed from the contaminated cheese after 48 hours soaking in a salty solution of %2.5. However, the results of the present work can be used for processing of contaminated milk with artificial radionuclides in order to be utilized. (Authors)

  13. Plant induced changes in concentrations of caesium, strontium and uranium in soil solution with reference to major ions and dissolved organic matter

    International Nuclear Information System (INIS)

    For a better understanding of the soil-to-plant transfer of radionuclides, their behavior in the soil solution should be elucidated, especially at the interface between plant roots and soil particles, where conditions differ greatly from the bulk soil because of plant activity. This study determined the concentration of stable Cs and Sr, and U in the soil solution, under plant growing conditions. The leafy vegetable komatsuna (Brassica rapa L.) was cultivated for 26 days in pots, where the rhizosphere soil was separated from the non-rhizosphere soil by a nylon net screen. The concentrations of Cs and Sr in the rhizosphere soil solution decreased with time, and were controlled by K + NH4+ and Ca, respectively. On the other hand, the concentration of U in the rhizosphere soil solution increased with time, and was related to the changes of DOC; however, this relationship was different between the rhizosphere and non-rhizosphere soil

  14. Determination by on-line mass spectrometry of the isotopic distribution of rubidium and caesium produced during low, medium and high energy fission

    International Nuclear Information System (INIS)

    The on-line mass spectrometric method described by us elsewhere was used to determine the independent yields of alkaline fission products of the following fissioning systems: 235U + thermal n, 238U and Th by 150 MeV protons, 238U, Th and Ta by 24 GeV protons. The target consists of a 1 to 2 mg/cm2 layer of uranium or thorium deposited on some 20 small graphite plates of 70-80 μ. The assembly, located in a thin tantalum container, is heated to a temperature of 1800 deg. C. The fission fragments are stopped by the graphite and, as is shown in the paper, the alkaline elements escape very quickly by diffusion. On the surface of the hot tantalum the Rb and Cs isotopes are ionized selectively because of their weak ionization potential. Mass analysis of the re-accelerated ions is carried out with a mass spectrometer with an angle of 90 deg and a resolving power of ΔM/M 1/200 (at 1% of the peak), ensuring complete resolution of the Rb and Cs isotopes. The ions are counted with an electron multiplier and the mass spectra are recorded by means of a multi-channel analyser. The method can be used for the measurement of both stable isotopes and very short-lived isotopes (100 ms for 97Rb). The sensitivity limit under the usual conditions is about 10 μb. At low energy, irradiation in a flux of 108 n cm-2 s-1 in the EL3 reactor at Saclay permitted measurements of A=89 to A=97 for Rb and A=139 to A=145 for Cs. The distributions are approximately Gaussian and are centred on A=92.3 for Z=37 (Rb) and A=141 for Z=55 (Cs). For these complementary fragments an average value of the number of neutrons emitted has been deduced, confirming the results obtained by other methods. The isotopic distributions, which broaden at medium energy (150 MeV), extend at high energy (10 and 24 GeV) much further in the neutron-deficient direction than could be shown experimentally hitherto. Comparison of Ta, Th and U targets makes it possible to discuss the respective contributions of high-energy fission and spallation. (author)

  15. Poly[μ3-aqua-aqua(μ3-3,5-dinitrobenzoato-κO1:O3:O5)caesium

    OpenAIRE

    Graham Smith

    2012-01-01

    In the structure of the title complex, [Cs(C7H3N2O6)(H2O)2]n, the Cs salt of 3,5-dinitrobenzoic acid, the metal complex centres have have irregular CsO8 coordination, comprising two water molecules (one triply bridging and the other monodentate) and four O-atom donors from two nitro groups and one bridging carboxylate O-atom donor from the ligand. Intra-unit O—H...O hydrogen-bonding interactions involving both water molecules are observed in the three-dimensional polymeric complex s...

  16. Poly[μ3-aqua-aqua(μ3-3,5-dinitro­benzoato-κO 1:O 3:O 5)caesium

    OpenAIRE

    Smith, Graham

    2012-01-01

    In the structure of the title complex, [Cs(C7H3N2O6)(H2O)2] n , the Cs salt of 3,5-dinitro­benzoic acid, the metal complex centres have have irregular CsO8 coordination, comprising two water mol­ecules (one triply bridging and the other monodentate) and four O-atom donors from two nitro groups and one bridging carboxyl­ate O-atom donor from the ligand. Intra-unit O—H⋯O hydrogen-bonding inter­actions involving both water mol­ecules are observed in the three-dimensional polymeric complex struct...

  17. Assessing the Impacts of Riparian Zones on Sediment Retention in Brazilian Sugarcane Fields by the Caesium-137 Technique and WEPP Modeling

    International Nuclear Information System (INIS)

    Erosion and sediment deposition studies are essential for understanding the functional aspects and impacts of riparian zones on sediment retention. This understanding is useful to improve the related environmental legislation and to increase the probability of success of public intervention in restoring the riparian systems in private lands. However, one of the main difficulties to carry out this approach is the choice of the method to predict soil loss and sediment deposition in complex landscapes. In more recent years, process based models like WEPP are being used for this purpose which has the advantage to be applicable in conditions where no long term statistical relations are available and for environmental studies that also consider soil deposition and sediment enrichment processes (and not only soil loss as estimated by first empirical models). On the other hand, the number of input parameters needed to run process based models increases significantly if compared to statistical models, contributing to rising costs and some times making its practical application unfeasible. Sensitivity analysis can be performed in order to reduce this problem, identifying the more relevant parameters to be calibrated. However, it is necessary to compare the model results with other direct measures of soil erosion and deposition (validation). In this project techniques based on the measurement of fallout radionuclide 137Cs, the soil organic carbon isotopic ratios and soil morphology were used and integrated as tools for this purpose. Comparable results were obtained by 137Cs and WEPP for different slope transects showing abrupt changes from soil loss (sugarcane field) to sediment deposition (riparian forest). Complementary soil carbon isotopic ratio analysis and soil morphology allowed a better interpretation of sediment redistribution along the transects. (author)

  18. Feasibility studies on the decontamination of caesium-137 in purex process streams by use of inorganic ion exchanger ammonium molybdo phosphate

    International Nuclear Information System (INIS)

    In the purex process condensate streams it is essential to bring down the gamma activity due to 137Cs to an acceptable limit prior to its discharge. Application of the inorganic ion exchanger micro cystal salt of heteropoly acid ammonium molybdo phosphate has been investigated. (author). 7 refs

  19. Sympathetic cooling in a rubidium cesium mixture: Production of ultracold cesium atoms; Sympathetisches Kuehlen in einer Rubidium-Caesium-Mischung: Erzeugung ultrakalter Caesiumatome

    Energy Technology Data Exchange (ETDEWEB)

    Haas, M.

    2007-07-01

    This thesis presents experiments for the production of ultracold rubidium cesium mixture in a magnetic trap. The long-termed aim of the experiment is the study of the interaction of few cesium atoms with a Bose-Einstein condensate of rubidium atoms. Especially by controlled variation of the cesium atom number the transition in the description of the interaction by concepts of the one-particle physics to the description by concepts of the many-particle physics shall be studied. The rubidium atoms are trapped in a magneto-optical trap (MOT) and from there reloaded into a magnetic trap. In this the rubidium atoms are stored in the state vertical stroke f=2,m{sub f}=2 right angle of the electronic ground state and evaporatively cooled by means of microwave-induced transitions into the state vertical stroke f=1,m{sub f}=1] (microwave cooling). The cesium atoms are also trppaed in a MOT and into the same magnetic trap reloaded, in which they are stored in the state vertical stroke f=4,m{sub f}=4 right angle of the electronic ground state together with rubidium. Because of the different hyperfine splitting only rubidium is evaporatively cooled, while cesium is cooled jointly sympathetically - i.e. by theramal contact via elastic collisions with rubidium atoms. The first two chapters contain a description of interatomic interactions in ultracold gases as well as a short summary of theoretical concepts in the description of Bose-Einstein condensates. The chapters 3 and 4 contain a short presentation of the methods applied in the experiment for the production of ultracold gases as well as the experimental arrangement; especially in the framework of this thesis a new coil system has been designed, which offers in view of future experiments additionally optical access for an optical trap. Additionally the fourth chapter contains an extensive description of the experimental cycle, which is applied in order to store rubidium and cesium atoms together into the magnetic trap. The last chapter finally contains the experimental results as well as the analysis of which. In experiments, which involve only rubidium, rubidium is coolde by means of microwave cooling; thereby an unwanted population of the state vertical stroke f=2,m{sub f}=1 right angle is observed, which hinders the condensation. The population of the state vertical stroke f=2,m{sub f}=1 right angle is systematically studied. The continuous depopulation of the state vertical stroke 2,1 right angle by means of a second microwave frequency radiated upon allows the production of rubidium condensates of 10{sup 5} atoms after 23 s evaporative cooling. By selective microwave cooling of the rubidium atoms the rubidium cesium mixtures are cooled until 700 mK. By means of a simple model the sympathetic cooling of cesium is analyzed, which allows a first characterization of the rubidium-cesium interaction.

  20. Determination of lithium, rubidium, and caesium in rock by flame spectrophotometry; Dosage du lithium, du rubidium et du cesium dans les roches par spectrophotometrie de flamme

    Energy Technology Data Exchange (ETDEWEB)

    Pouget, R. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1963-07-01

    After sulfo-hydrofluoric attack of rock, and quantitative estimation of Na and K, the end solution is brought to 10 per cent in Na{sub 2}O and K{sub 2}O In order to prepare it under the same conditions as standards; interfering ions are precipitated with calcium carbonate, flame spectrophotometry is conducted with an hydrogen-oxygen flame. Limits of detection are: 2.10{sup -6} g for Li, 4.10{sup -6} g for Rb, and 6.10{sup -6} g for Ca. (author) [French] Apres attaque sulfofluorhydrique de la roche et dosage du sodium et du potassium, on amene la solution finale a 10 pour cent en Na{sub 2}O et K{sub 2}O afin de la preparer dans les memes conditions quelles etalons. Les ions interferents sont precipites a l'aide du carbonate de calcium. La spectrophotometrie est executee avec une flamme hydrogene-oxygene. Les limites de sensibilite sont: 2.10{sup -6} g pour Li, 4.10{sup -6} g pour Rb, et 6.10{sup -6} g pour Ca. (auteur)

  1. Concentration of caesium-137, cobalt-60 and potassium-40 in some wild and edible plants around the nuclear power plant in Bulgaria.

    Science.gov (United States)

    Djingova, R; Kuleff, I

    2002-01-01

    The activities of 137Cs, 60Co and 40K were determined in samples of wild (Taraxacum officinale, Plantago lanceolata and Populus nigra 'Italica') and edible (vegetable, corn, fruit) plants as well as soil collected from the 30 km safety zone of the Bulgarian NPP "Kozloduy" and comparisons with earlier measurements and analyses of samples from other regions and with literature values were performed. The derived transfer factors for 137Cs and 40K from soil to plants ranged between 0.002 and 0.009 for 137Cs, and between 0.09 and 0.35 for 40K. The individual effective dose (calculated from the present results and data on the activity of other foodstuffs and from information about dietary habits) comprises 4.5% of the annual dose limit. PMID:11848152

  2. Estimates of Long and Short Term Soil Erosion Rates on Farmland in Semi-Arid West Morocco Using Caesium-137, Excess Lead-210 and Beryllium-7 Measurements

    International Nuclear Information System (INIS)

    The aim of the present work was to investigate both long and short term soil erosion and deposition rates on agricultural land in Morocco and to assess the effectiveness of soil conservation techniques by the combined use of environmental radionuclides (137Cs, excess 210Pb and 7Be) as tracers The study area is an experimental station located in Marchouch 68 km from Rabat (western part of Morocco). Experimental plots have been installed in the study field to test the no-till practice under cereals as a soil conservation technique, and comparing it to the conventional tillage system. Fallout 137Cs and 210Pbex allowed a retrospective assessment of long term (50 and 100 yrs respectively) soil redistribution rates while fallout 7Be with a short half-life (53 days) was used to document short term soil erosion associated with short rainfall events for different tillage systems and land uses. From 137Cs and 210Pbex measurements the rates of soil redistribution induced by water erosion were quantified by using the Mass Balance 2 model. The net soil erosion rates obtained were 14.3 t ha-1 a-1 and 12.1 ha-1 a-1 for 137Cs and 210Pbex respectively resulting in a high sediment delivery ratio of about 92%. Data on soil redistribution generated by the use of both radionuclides are similar, indicating that the soil erosion rate did not change significantly during the last 100 years. In addition, the soil redistribution rates due to tillage were estimated using the Mass Balance 3 model. The global results obtained from 7Be measurements during the period 2004-2007 suggest that the soil loss is reduced by up to 30% when no-till management is practised when compared to the conventional tillage or uncultivated soil. (author)

  3. Using Caesium-137 Techniques to Estimate Soil Erosion and Deposition Rates on Agricultural Fields with Specific Conservation Measures in the Tutova Rolling Hills, Romania

    International Nuclear Information System (INIS)

    In the period from 2003 until 2007 a study was conducted at four representative micro-catchments in the Tutova Rolling Hills of Romania to estimate soil erosion and deposition rates on agricultural fields and to assess the efficiency of soil conservation measures. In the study several categories of soil conservation measures were evaluated, such as strip farming, bench terraces and forest belts. As a first step in the analysis, two reference sites were selected on an uneroded meadow and in an old rural cemetery. The 137Cs inventory calculated for the first site was 6.90 kBq m-2 and for the second site 4.98 kBq m-2. The 137Cs results revealed that the highest erosion rates could be found in the centre of the strip crops where 137Cs inventory varied between 2.12 and 4.77 kBq m-2, while deposition of sediments was the largest on the bench terraces with a maximum inventory of 137Cs of 14 kBq m-2 (exceptionally 44 kBq m-2). The forest belts were characterized by high spatial variability in the deposition pattern; 137Cs inventory ranged between 7.98 and 11.22 kBq m-2. The comparative analysis between in situ and laboratory measurements of the 137Cs inventories revealed that the portable detector has to be used with care, especially on steep slopes with strong roughness. Nevertheless, generally in situ measurements gave good estimates of soil erosion and sedimentation rates. Conventional measurements made on the runoff plots at the Perieni Center in the period of 1985-2006 indicated that annual erosion rates ranged between 2.1 and 8.9 t ha-1 a-1, depending on the crop rotation. A maximum value of 52.3 t ha-1 a-1 was registered for the plot of 150 m2 under bare fallow. The smallest differences between the conventionally measured and the empirically and 137Cs based estimated values have been observed in the case of those plots well covered by vegetation throughout the years, especially by brome grass. On the plots with annual crops like maize, bean, soybean and especially under bare fallow the values measured were often higher than those estimated by the empirical ROMSEM model, but came closer to the values calculated with the conversion models. This study showed that the use of the 137Cs technique on agricultural lands from the Tutova Rolling Hills region, Romania, represents an alternative tool that can provide a valuable means for investigating soil erosion and assessing the efficiency of soil conservation measures. Nevertheless because of the complex landscapes further fine-tuning of the tool using fallout radionuclides is recommended. (author)

  4. A process-based model for the partitioning of soluble, suspended particulate and bed sediment fractions of plutonium and caesium in the eastern Irish Sea.

    Science.gov (United States)

    Vives I Batlle, J; Bryan, S; McDonald, P

    2008-01-01

    A dynamic model of plutonium behaviour in the marine environment has been developed, representing the oxidation state distribution and partitioning of plutonium between the soluble, colloidal, suspended particulate and seabed sediment fractions. With simple re-parameterisation, this model can also be applied to (137)Cs. The model, which is calibrated and validated against field data, has been used to predict concentrations of Pu(alpha) and (137)Cs in both water and seabed sediments from the vicinity of the Sellafield Ltd. reprocessing plant in Cumbria, UK. The model predicts that sediment reworking and transport are the key environmental processes as the Sellafield Pu(alpha) and (137)Cs discharge continues to decline. Inventory calculations generated by the model are consistent with previous estimations. For a hypothetical post-discharge scenario, the concentrations of these radionuclides in both seawater and surface sediments are predicted to decrease sharply, concurrent with a downward vertical migration of the activity retained in sediments. PMID:17719705

  5. Application of Caesium-137 and Beryllium-7 to Assess the Effectiveness of Soil Conservation Technologies in the Central Highlands of Vietnam

    International Nuclear Information System (INIS)

    Over the last decade large areas in Vietnam have become more vulnerable to erosion due to fast economic changes leading to increasing and often unsustainable land use intensification. In the present study soil erosion rates at medium (40-50 years) and short (event based) term have been assessed for steep farmland protected by or without soil conservation measures in the Central Highlands of Vietnam using fallout radionuclide (137Cs and 7Be) based techniques. A 2.5 ha mulberry field with a slope gradient of about 15% was selected as study site in the Lamdong province, which is located in the south-east part of the Central Highlands. Widely spaced shrubby contour hedgerows composed of Leucaena glauca and Lantana camara have been utilized at this site as a soil conservation measure for 22 years. In order to assess the effectiveness of additional novel soil conservation measures, such as the use of Vetiver grass barriers (Vetiveria zizanioides L.), additional research plots were installed in the year 2000 on a field with a slope gradient of about 15%, adjacent to the previous study site. On the mulberry field, where widely spaced hedges have been utilized as a soil conservation measure for 22 years, about 55% of the area suffered from erosion with rates varying between 0.6 and 70 t ha-1 a-1 (an average of 31 t ha-1 a-1). Deposition occurred on 45% of the area with deposition rates ranging between 0.2 and 74 t ha-1 a-1, (an average of 36 t ha-1 a-1), resulting in a sediment delivery ratio of only 9%. The medium term erosion rate assessed by the use of the 137Cs radionuclide was 1.2 ± 0.6 t ha-1 a-1. The short term soil erosion rate at this field estimated by 7Be in 2006 was 1.5 ± 0.24 t ha-1 a-1, coming close to the medium term soil erosion rate. For the mulberry plot without hedgerows, net erosion rates assessed by the runoff plot method in the period of 2000 - 2003 ranged between 21 t ha-1 a-1 and 41 t ha-1 a-1, i.e. 18 to 35 times the net erosion rate at the mulberry field with shrubby hedgerows. The 137Cs and 7Be techniques were also used for assessing novel soil conservation measures. For the plot without soil conservation, soil erosion could be observed at all sampled points, with medium term erosion rates ranging between 1 t ha-1 a-1 and 35 t ha-1 a-1 (the average erosion rate was 23 ± 1 t ha-1 a-1). The short term soil erosion rate estimated by the 7Be technique in the year 2005 was 33 ± 6 t ha-1 a-1 for this plot. However, the short term soil erosion rate at the plot with Vetiver grass barriers was for the same year 2 t ha-1 a-1 (estimated by the 7Be technique), and showed that by using this kind of grass barriers as a soil conservation measure soil erosion was almost completely controlled. (author)

  6. Application of Caesium-137 and Berylium-7 to Assess the Effectiveness of Soil Conservation Technologies in the Central Highlands of Vietnam

    International Nuclear Information System (INIS)

    Over the last decade large areas in Vietnam have become more vulnerable to erosion due to fast economic changes leading to increasing and often unsustainable land use intensification. In this study, soil erosion rates at medium (40-50 years) and short (event based) term have been assessed for steep farmland protected by or without soil conservation measures in the Central Highlands of Vietnam using fallout radionuclide (137Cs and 7Be) based techniques. A 2.5 ha mulberry field with a slope gradient of about 15% was selected as study site in the Lam dong province, which is located in the south-east part of the Central Highlands. Widely spaced shrubby contour hedgerows composed of Leucaena glauca and Lanata camara have been utilized at this site as a soil conservation measure for 22 years. In order to assess the effectiveness of additional novel soil conservation measures, such as the use of vetiver grass barriers (Vetiveria zizanioides L.), additional research plots were installed in the year 2000 on a field with a slope gradient of about 15%, adjacent to the previous study site. On the mulberry field, where widely spaced hedges have been utilized as a soil conservation measure for 22 years, about 55% of the area suffered from erosion with rates varying between 0.6 and 70 t ha-1 a-1 (an average of 31 t ha-1 a-1). Deposition occurred on 45% of the area with deposition rates ranging between 0.2 and 74 t ha-1 a-1, ( an average of 36 t ha-1 a-1), resulting tin a sediment delivery ratio of only 9%. The medium term erosion rate assessed by the use of the 137Cs radionuclide was 1.2 ± 0.6 t ha-1 a-1. The short term soil erosion rate at this field estimated by 7Be in 2006 was 1.5 ± 0.24 t ha-1 a-1, coming close to the medium term soil erosion rate. For the mulberry plot without hedgerows, net erosion rates assessed by the runoff plot method in the period of 2000-2003 ranged between 21 t ha-1 a-1 and 41 t ha-1 a-1, i.e, 18 to 35 times the net erosion rate at the mulberry field with shrubby hedgerows. The 137Cs and 7Be techniques were also used for assessing novel soil conservation measures. For the plot without soil conservation, soil erosion could be observed at all sampled points, with medium term erosion rates ranging between 1 t ha-1 a-1 and 35 t ha-1 a-1 (the average erosion rate was 23 ± 1 t ha-1 a-1). The short term soil erosion rate estimated by the 7Be technique in the year 2005 was 33 ± 6 t ha-1 a-1 for this plot. However, the short term soil erosion rate at the plot with Vetiver grass barriers was for the same year 2 t ha-1 a-1 (estimated by the 7Be technique), and showed that by using this kind of grass barriers as a soil conservation measure soil erosion was almost completed controlled. (author)

  7. Sorption and migration of radiocaesium in natural zeolite-water systems

    International Nuclear Information System (INIS)

    The sorption properties for caesium and its migration in a system zeolite-aqueous solution were studied for natural zoelites from Zaloshka gorica. It was found that zeolites are rather efficient sorbents for caesium even in the presence of some other electrolytes. A correlation between the rate of migration of caesium in the system zeolite-water and the sorption intensity was established. Migration of caesium from a zeolite layer by diffusion is described. (author) 7 refs.; 2 figs,; 1 tab

  8. Use of Fallout Caesium-137 and Beryllium-7 to Assess the Effectiveness of Changes in Tillage Systems in Promoting Soil Conservation and Environmental Protection on Agricultural Land in Chile

    International Nuclear Information System (INIS)

    The current study developed a simplified method for using 137Cs depth distribution datasets to estimate soil loss or accumulation at a sampling point under conventional tillage and after the shift to a no-till system. Previous applications of 137Cs measurements had been limited to the estimation of erosion rates during the period extending from the beginning of fallout receipt to the time of sampling. The new procedure allows the change in erosion rates associated with a shift in land tillage practices to be estimated. In an additional study to assess no-till systems with and without burning of crop residues after harvesting, 7Be was used to quantify the erosion that occurred within the same field area, as a result of burning and a period of extreme rainfall (400 mm in 27 days, May 2005). The studied site is located in the Coastal Mountains of the Araucania Region, Chile. The soil is Ultisol (Typic Hapludult), and the area has a temperate climate and a mean annual precipitation of 1100 mm year-1. The obtained fallout radionuclide (FRN) data showed that 16 years after implementing the no-till system there was a reduction in the erosion rate of about 87% (from 11 t ha-1 year-1 to 1.4 t ha-1 year-1). In addition, the proportion of the study area, subject to erosion, decreased from 100% to 57%. The net erosion associated with crop residue burning and an extreme rainfall event (400 mm in 27 days occurring in May 2005) as estimated from the FRN was approximately 12 t ha-1. This indicated that large proportions of soil and ashes were mobilized by erosion and transported beyond the study area during the period of heavy rainfall. Comparing these results with those estimated for the medium long term net erosion rate (1.4 t ha-1 year-1) during a prolonged period of no-till without the burning of crop residues, it would appear that burning in autumn is a highly undesirable practice, since it could promote soil loss in the following rainy season, especially under high magnitude erosive events. In combination, the use of 137Cs and 7Be provided a valuable means of investigating soil erosion and assessing erosion risk associated with the changes in tillage system. (author)

  9. Dispersal of the radionuclide caesium-137 (137Cs) from point sources in the Barents and Norwegian Seas and its potential contamination of the Arctic marine food chain: Coupling numerical ocean models with geographical fish distribution data

    International Nuclear Information System (INIS)

    Dispersal of 137Cs from the nuclear submarine wrecks Komsomolets and K-159, which are resting on the seabed in the Norwegian and Barents Seas, respectively, is simulated using realistic rates and hypothetical scenarios. Furthermore, spatiotemporal 137Cs concentrations in Northeast Arctic cod and capelin are estimated based on survey data. The results indicate that neither continuous leakages nor pulse discharges will cause concentrations of 137Cs in cod muscle or whole body capelin exceeding the intervention level of 600 Bq/kg fw. Continuous leakages from Komsomolets and K-159 and pulse discharges from Komsomolets induced negligible activity concentrations in cod and capelin. A pulse discharge of 100% of the 137Cs-inventory of K-159 will, however, result in concentrations in muscle of cod of above 100 times the present levels in the eastern Barents Sea. Within three years after the release, 137Cs levels above 20 Bq/kg fw in cod are no longer occurring in the Barents Sea. -- Highlights: •The dispersal of 137Cs from the wrecks of Komsomolets and K-159 are simulated. •The submarine wrecks are resting on the seabed in the Norwegian and Barents Seas. •Both realistic rates of discharges and what-if scenarios are simulated. •Concentrations of 137Cs are estimated in observational records of cod and capelin. •Only pulse discharges from K-159 causes high 137Cs concentrations in cod and capelin. -- A pulse discharge of 137Cs from K-159 may cause concentrations in muscle of cod up to 63 and 123 Bq/kg fresh weight in the near-surface and near-bottom layer, respectively

  10. The dynamics of the transfer of caesium-137 to animal fodder in areas of Russia affected by the Chernobyl accident and doses resulting from the consumption of milk and milk products

    International Nuclear Information System (INIS)

    Data on the concentration of 137Cs in animal fodder from collective farms in Russia on which no countermeasures were applied following the Chernobyl accident have been evaluated for the period 1987 to 1994. The aggregated transfer factor (Bq.kg-1 per Bq.m-2) was found to increase in the order fodder beet 137Cs of between 1 and 3 years have been calculated for the period up to 1989. From 1989 onwards the data are somewhat more variable and effective half-lives between 3 and 10 years are observed. Mean individual effective doses in 1987 from the consumption of milk and milk products produced from cattle fed on a typical diet of fodder crops produced on sandy soils are calculated as 3.1, 3.3 and 4.0 μSv per kBq.m-2 for Russia, Belarus and the Ukraine respectively, with 95% confidence intervals for the three Republics jointly of 2.2 to 6.0 μSv per kBq.m-2. The corresponding values are some three times higher for production on peat soils and about ten times lower in the case of clay soils. (author)

  11. Retrospective dosimetry of Iodine-131 exposures using Iodine-129 and Caesium-137 inventories in soils--A critical evaluation of the consequences of the Chernobyl accident in parts of Northern Ukraine.

    Science.gov (United States)

    Michel, R; Daraoui, A; Gorny, M; Jakob, D; Sachse, R; Romantschuk, L D; Alfimov, V; Synal, H-A

    2015-12-01

    The radiation exposure of thyroid glands due to (131)I as a consequence of the Chernobyl accident was investigated retrospectively based on (129)I and (137)Cs inventories in soils in Northern Ukraine. To this end, soil samples from 60 settlements were investigated for (129)I, (127)I, and (137)Cs by AMS, ICP-MS and gamma-spectrometry, respectively. Sampling was performed between 2004 und 2007. In those parts of Northern Ukraine investigated here the (129)I and (137)Cs inventories are well correlated, the variability of the individual (129)I/(137)Cs ratios being, however, high. Both the (129)I and (137)Cs inventories in the individual 5 samples for each settlement allowed estimating the uncertainties of the inventories due to the variability of the radionuclide deposition and consequently of the retrospective dosimetry. Thyroid equivalent doses were calculated from the (129)I and the (137)Cs inventories using aggregated dose coefficients for 5-year old and 10-year-old children as well as for adults. The highest thyroid equivalent doses (calculated from (129)I inventories) were calculated for Wladimirowka with 30 Gy for 5-years-old children and 7 Gy for adults. In 35 settlements of contamination zone II the geometric mean of the thyroid equivalent doses was 2.0 Gy for 5-years-old children with a geometric standard deviation (GSD) of 3.0. For adults the geometric mean was 0.47 Gy also with a GSD of 3.0. In more than 25 settlements of contamination zone III the geometric means were 0.82 Gy for 5-years old children with a GSD of 1.8 and 0.21 Gy for adults (GSD 1.8). For 45 settlements, the results of the retrospective dosimetry could be compared with thyroid equivalent doses calculated using time-integrated (131)I activities of thyroids which were measured in 1986. Thus, a critical evaluation of the results was possible which demonstrated the general feasibility of the method, but also the associated uncertainties and limitations. PMID:26254721

  12. Radioactivity distribution of the fruit trees ascribable to radioactive fall out (6). Effect of heterogeneity of caesium-137 concentration in soil on transferability to grape trees and fig trees

    International Nuclear Information System (INIS)

    We examined the effects of the heterogeneity of 137Cs concentration in soil on transferability to shallow rooted fig and non-shallow rooted grapes. Three-year-old trees were planted into the pots filled with soil changed to the concentration of radioactivity Cs in surface (0 - 5cm) and deep soil (5 - 15cm). Transfer rate of radioactive 137Cs to plants from the soil was higher in fig than in grapes when grown under the same conditions. In fig trees, transfer rate of radioactive 137Cs to plants from the soil was higher the plants cultivated under high concentration of 137Cs in surface soil than in deep soil. (author)

  13. Development, control and counter-measures regarding radioactive caesium in Swedish reindeer after the Chernobyl accident; Utveckling, oevervakning och aatgaerder naer det gaeller radioaktivt cesium i renar efter Tjernobylolyckan

    Energy Technology Data Exchange (ETDEWEB)

    Aahman, Birgitta [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Reindeer Husbandry Unit

    2005-10-01

    Since the Chernobyl accident in 1986, monitoring of {sup 137}Cs in reindeer has been made at slaughter, by measuring muscle samples or by direct monitoring of gamma radiation on reindeer carcasses. Carcasses above the accepted limit have been discarded. Many carcasses were discarded during the first years, but now the number is only some per cent of the total slaughter. The radiocaesium intake in reindeer varies with season, which is reflected in the levels in reindeer, which are low in summer and high in winter. The levels of {sup 137}Cs have declined from 1986 to 2004 with an average effective half-life of 5.3 years. The decline was faster during the first years than during later years. Presently, 16 out of totally 51 reindeer herding districts in Sweden are included in the control of {sup 137}Cs in reindeer. Control is often necessary only in defined areas or at certain periods of the year. Monitoring of {sup 137}Cs in live reindeer is made in addition to the monitoring at slaughter. Counter-measures have been applied in areas where many reindeer are above the accepted limit for {sup 137}Cs. Change of slaughter time and feeding are the most used counter-measures. The reindeer owners are compensated economically from the state for costs related to these counter-measures. The need for measures, and thereby the costs, have decreased with time. In the southern parts of the county of Vaesterbotten and in the northernmost part of Jaemtland, where the Chernobyl fallout was the highest, it will probably still take at least ten to twenty years until measures and control are no longer needed.

  14. Non cancerous diseases following a chronic intern contamination by caesium 137: cataracts and cardiac arrhythmias; Pathologies non cancereuses potentiellement consecutives a une contamination interne chronique par le cesium 137: cataractes et arythmies cardiaques

    Energy Technology Data Exchange (ETDEWEB)

    Landon, G

    2008-07-15

    This work of thesis joins within the framework of an analysis of the sanitary consequences of the nuclear accident of Chernobylsk. Since 2005, the I.R.S.N. is interested in the not cancerous pathologies (cataracts, and cardiac arrhythmias) observed among the children living on the contaminated territories after the fallout of Chernobylsk and has in this aim implemented a research programme called E.P.I.C.E. (Evaluation of the pathologies induced by a chronicle contamination by cesium) whom objective is to show an eventual link between the chronicle ingestion of contaminated food and these pathologies emergence. An exploitation of the results of the pilot study,first phase of the E.P.I.C.E. program was realized. The analysis was completed by two bibliographical reviews relative to the knowledge available on these diseases. The results of this pilot study suggest: on one hand, an absence of link between the activity in cesium 137 at the level of the heart, of the whole body and the emergence of disorder of the heart rhythm; on the other hand, for the cases of cataract, a link between the load in cesium 137 at the neck level and the emergence of the disease in 40 % of the cases. However, these results must be considered with caution because several limits and, in particular, a way of selection affect this study. concerning the scientific literature, this one stays rather poor because only thee articles make reference to a relationship between cesium 137 and the emergence of these non cancerous pathologies. After having exposed the context, this thesis draws up the situation of knowledge relative to cataracts and to cardiac arrhythmias and their possible relationship with ionizing radiations, collect the results stemming from the analysis of the pilot study and envisages future epidemiological studies. (N.C.)

  15. Assessment of Soil Erosion Severities and Conservation Effects on Reduction of Soil Loss and Sediment Yield by Using the Caesium-137 and Excess Lead-210 Tracing Techniques in the Upper Yangtze River Basin, China

    International Nuclear Information System (INIS)

    In one of the most eroded regions of China, the Upper Yangtze River Basin, 137Cs and 210Pbex tracing techniques have been used to identify sediment sources and assess erosion rates and to evaluate soil conservation benefits and impacts of deforestation and reforestation on soil erosion. Dating of reservoir deposits by 137Cs concentration variations in profiles provided reliable information on sediment yields and average soil losses in a catchment in the Hilly Sichuan Basin and the Three Gorge Region. The collected data indicated that specific sediment yields ranged between 566 t km-2 a-1 and 1869 t km-2 a-1. Further investigation of sediment sources by comparison of the 137Cs and 210Pbex concentrations in reservoir sediment and those in surface soils provided relative sediment contributions of 18%, 46% and 36% from steep forest slopes, gentle cultivated terraces and bare slopes, respectively, in a micro-catchment located in the Hilly Sichuan Basin. Additionally two forest and shrub fires, which occurred in 1960 and 1998, respectively, in the catchment, were identified from the variations of 137Cs and 210Pbex concentrations in a deposit profile in the Jiulongdian Reservoir (Yunnan Plateau). Dating of these reservoir deposits showed that sediment yields are highly respondent to vegetation changes in the catchment. Finally, assessment of soil losses from 137Cs and 210Pbex measurements on the sloping cultivated land in the Sichuan Hilly Basin showed that the traditional and centuries-old soil conservation measures (a drainage system combined with the 'Tiaoshamiantu' cultivation) have reduced soil losses up to 35% compared to losses on sloping land without conservation measures monitored by runoff plots. (author)

  16. The whole-body incorporation of radioactive caesium in Switzerland during the last 30 years: a survey of young persons in Geneva and some measurements of Belarusian and Ukrainian children

    International Nuclear Information System (INIS)

    In a cross-sectional study, at least 40 young men and women about 18 years old (half of each sex) were selected each year, and the body concentration of 137Cs was measured in a whole-body counter. This radioisotope, with a half-life of 30 years, originates from the atom bomb explosions in the atmosphere, which were stopped in 1963, or from the accident at Chernobyl. The concentrations due to the emissions from this reactor remained below one-third of the values due to atomic bombs. The results in children from Belarus who spent a few weeks in Switzerland in the summer are lower than would have been expected according to the literature from Russia, but correspond to those recently obtained in situ by international scientific teams. 6 refs, 1 fig., 1 tab

  17. Experimental contamination of margaritana margaritifera (L) (a Fresh water bivalve) by caesium 137; Contamination experimentale de margaritana margaritifera (L) (bivalve d'eau douce) par le cesium 137

    Energy Technology Data Exchange (ETDEWEB)

    Foulquier, L.; Bovard, P.; Grauby, A. [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1966-07-01

    The hydro biological research carried out in the Radio-Ecology Section has led the authors to study some Margaritana sampling stations situated down-stream from the Monts d'Arree nuclear power station. They describe the preservation and contamination methods used for fixing the {sup 137}Cs concentration factors in the case of Margaritana Margaritifera (L). The results of experiments carried out over a period of one hundred days show that the specific activity of the various organs is stabilized after thirty to thirty-five days. The authors have noticed a relatively low adsorption on the shell through the intermediary of micro-organisms, and a strong and rapid absorption in the soft parts. The concentration factors have values, at equilibrium, of around: 9 for the shell, 300 for all the organs, and 38 for the whole animal. A comparison of these results with work published by other authors makes it possible to draw general conclusions concerning the mechanism of {sup 137}Cs fixation by lamellibranch, as well as their capacity of fixation. (author) [French] Les etudes hydrobiologiques effectuees au sein de la Section de Radio-Ecologie ont amene les auteurs a etudier des stations de prelevement de Margaritana en aval de la Centrale Nucleaire des Monts d'Arree. Ils decrivent les methodes de conservation et de contamination utilisees pour l'etablissement des facteurs de concentration du {sup 137}Cs par Margaritana margaritifera (L). Les resultats des experimentations menees pendant cent jours montrent que les activites specifiques de la coquille et des differents organes se stabilisent au bout de trente a trente-cinq jours. Les auteurs constatent une adsorption relativement faible sur la coquille par l'intermediaire des micro-organismes et une absorption forte et rapide dans les parties molles. Les facteurs de concentration se situent, a l'equilibre, autour de: 9 pour la coquille, 300 pour l'ensemble des organes et 38 si l'on considere l'animal total. Cette etude comparee a celles deja effectuees par d'autres auteurs permet de degager des idees generales sur le mode et la capacite de fixation du {sup 137}Cs par les lamellibranches. (auteur)

  18. Optimization of electrochemical soil decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, M. [Czech Technical Univ., Prague (Czech Republic). Dept. of Nuclear Chemistry; John, J. [Czech Technical Univ., Prague (Czech Republic). Centre for Radiochemistry and Radiation Chemistry

    2004-07-01

    At the Czech Technical University in Prague, soil decontamination techniques have been studied for several years. The leaching procedures (batch or 'sorption' leaching) did not allow to achieve more than 30% caesium desorption. Caesium thermodesorption was demonstrated not to be very efficient either; quantitative caesium separation could be achieved only from solutions resulting from fusion of the soil with special fluxes. The most promising results were achieved by electrolytic decontamination. In preliminary experiments, more than 97% of caesium was released from soils contaminated long time ago. The aim of this study was to perform optimisation of the parameters of this method. (orig.)

  19. The intrusion of low-level radioactive waste into Dublin Bay

    International Nuclear Information System (INIS)

    Artificial radionuclides principally caesium-137 and caesium-134, derived from Sellafield effluents are present at low concentrations in the marine environment of Dublin Bay. Results of a survey of radioactivity levels in the Western Irish Sea are presented in this report and an estimate is given of the annual dose equivalent to members of the Irish fish consuming population from radiocaesium

  20. Evaluation of Light Frequency Shift in a Cesium Beam Frequency Standard with Sharp Angle Incident Detecting Laser

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-Hai; WANG Feng-Zhi; WANG Yi-Qiu; YANG Dong-Hai

    2004-01-01

    @@ Light frequency shift measured in a smalloptically pumped caesium beam frequency standard is reported and analysed. Two light sources, the diffused laser light scattered from the caesium beam tube parts and the fluorescence light from the beam atoms excited by the laser light, for the light frequency shift are discussed.

  1. The Enhanced Radiocaesium Levels of People in Northern Sweden

    International Nuclear Information System (INIS)

    After the discovery of the high caesium-137 body activity of Swedish Lapps early in 1961 measurements were performed on large groups of Lapps and other Swedes on a similar diet. In September, 1961 162 persons from an area close to the arctic circle were measured in a semi-portable whole-body counter. In the Lapp group caesium-137 levels ranging from 15 to 690 nc were found. At the same place a group of 157 persons were counted in April, 1962. At that time the caesium-137 range was 30 to 740 nc. During a five weeks expedition to seven different centres in northern Sweden in April, 1963 a total number of 458 persons were studied by means of the same counter set up in a bus. The caesium-137 range for Lapps in the above mentioned area was then 50 to 900 nc. The average caesium-137 body activity of all the adult male reindeer breeders (78 persons) measured in April, 1963 was 461 nc. The maximum body activity found was 1340 nc caesium-137. Details are presented on the variation of caesium-137 in human beings with age, sex, occupation and diet as well as on the seasonal and geographical variations found. An increase in the average caesium-137 body activity has been observed from 1961 to 1963. For comparison, non-Lapps have also been counted. Almost all of them also show a substantially enhanced caesium-137 level if compared with persons in southern Sweden. The radiation dose from caesium-137 is in many cases two to three times as large as the potassium-40 dose, the observed maximum giving a dose eight times that of the potassium dose. (author)

  2. Environmental radioactivity surveillance programme: Results for 1987

    International Nuclear Information System (INIS)

    This report is the seventh of a series in which the results of the Board's environmental radioactivity surveillance programme are presented. Samples of airborne dust, rainwater and milk are collected routinely throughout the UK and in the Channel Islands and the Isle of Man; the concentrations of various radionuclides are measured and the exposure of the population is evaluated. The radionuclides detected result from nuclear weapons testing in the atmosphere, and from the nuclear reactor accident at Chernobyl in the Ukraine in April 1986, although the programme is able to detect any other sources of significant environmental contamination. During 1987 the isotopes caesium-134 and caesium-137 were detected in air and rainwater, their presence most probably resulting from resuspension of small amounts of the radioactive material deposited on the ground in May 1986. The mean isotopic ratio of caesium-137 to caesium-134 was 2.7, which is consistent with the expected ratio of the caesium isotopes of Chernobyl origin. The presence of caesium isotopes in rainwater is attributed to washout of the resuspended material. The contributions to the average annual effective dose equivalent from inhalation of particulate material and from external radiation from additional deposits on the ground during 1987 were not significant. Concentrations of caesium isotopes in milk continued to decline, slowly at the beginning of the year due to the use of winter fodder contaminated during 1986 and then much more rapidly in the spring with the availability of fresh pasture. The UK population weighted average concentrations of caesium-134 and caesium-137 in milk resulted in an average committed effective dose equivalent to an adult of 5μSv during 1987 compared with 8 μSv in 1986. The average annual effective dose equivalents from nuclear weapons testing fallout, and from radioactive material deposited as a result of the Chernobyl accident, have been evaluated and are compared with that from

  3. Delayed and late impact of the Chernobyl accident on the Greek environment

    International Nuclear Information System (INIS)

    The impact of the Chernobyl nuclear accident on the Greek environment during and after the winter 1986-87 and the estimated long-term doses to the population are discussed. This includes the delayed peak of caesium concentrations observed in animal products, the contamination of pastry and bread, the additional external exposure in areas of peak caesium deposition, the soil-to-plant transfer of caesium, the contamination of marine and lake fish and the residual contamination in air, deposition and surface waters. (author)

  4. Transport processes of Cs-137 in lake environments

    International Nuclear Information System (INIS)

    Radiocesium levels in the waters of the Lake District dropped after the initial deposition following the Chernobyl reactor accident. However they continued to be measurable several years after the event. Caesium 137 concentrations were measured in the sediments of Esthwaite water and Windermere to determine the input of caesium 137 from the catchment area to the lakes. Experiments were conducted to ascertain the chemical conditions such as pH value, adsorption, competing ions which might contribute to maintaining caesium levels in the lakes. (U.K.)

  5. Literature study of the radiobiological parameters of Caesium-137 required for evaluating internal irradiation doses as a function of age; Etude bibliographique des parametres radiobiologiques du cesium-137 necessaires a l'evaluation des doses d'irradiation interne en fonction de l'age

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, A. [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    This document reassembles information published in scientific literature on radiobiological parameters of Cs-137, necessary for the estimate of the internal irradiation dose of man according to his age (during growth). The data are completed by a commented review of the mathematical models, proposed in order to value the irradiation doses from ingested cesium and the biological parameters. (author) [French] Ce document rassemble les informations publiees dans la litterature scientifique, concernant les parametres radiobiologiqueo du cesium-137, necessaires a l'evaluation des doses d'irradiation interne de l'homme en fonction de l'age. Ces donnees sont completees par une revue commentee des modeles mathematiques proposes en vue de l'evaluation des doses d'irradiation a partir des quantites de cesium ingerees et des parametres biologiques. (auteur)

  6. Radioactive contamination in reindeer herders and other people in Kautokeino 1965-2010; Radioaktiv forurensning i befolkningen. Reindriftsutoevere og andre personer i Kautokeino 1965-2010

    Energy Technology Data Exchange (ETDEWEB)

    Thoerring, H.; Skuterud, L.

    2012-07-01

    NRPA's measurements of radioactive caesium in reindeer herders and other people from Kautokeino in northern Norway were finalised in December 2010. This report summarises the monitoring program which was started in 1965.(Author)

  7. Radioactivity in Scottish soils and grassy vegetation

    International Nuclear Information System (INIS)

    In June 1987, soil and graminoid vegetation samples were collected from 159 randomly selected Scottish sites and analysed for radioactivity due to potassium-40, caesium-134 and caesium-137. Activity due to plutonium-238 and plutonium-239/240 was also measured in soils from 47 of the sites. The main aims of this survey were to determine: (a) the geographic distribution of radiocaesium activity due to fallout from the Chernobyl reactor disaster, (b) the pattern of radiation due to the naturally occurring isotope potassium-40, (c) the activity attributable to caesium-137 fallout from nuclear weapons testing prior to the Chernobyl deposition, (d) the uptake of caesium-137 by vegetation from different soil types. (author)

  8. Improvement of practical countermeasures: the urban environment post-Chernobyl action

    International Nuclear Information System (INIS)

    This study of practical countermeasures against nuclear contamination of the urban environment in the aftermath of a nuclear accident concentrates almost entirely on radio-caesium, which would be expected to pose the greatest threat to the population in the medium and long term. Surfaces which selectively absorb caesium fall-out were identified, and the chemical and physical factors relevant to take-up of caesium by, and removal of caesium from, these surfaces were studied. The study includes a critical review of strategies for decontamination and reclamation of the urban environment. The work in this report was sponsored by the Commission of the European Communities as one of a series of post-Chernobyl actions under its radiation protection programme

  9. Studies of Sorption and Migration of Radioactive Elements in Soils

    International Nuclear Information System (INIS)

    The paper presents the results of investigations into the sorption and migration of radioelements during radioactive filtering flow through the soil. For this purpose the authors used the types, of sand, oi average coarseness and effective porosity, which are to be found widely disseminated throughout the central belt of the Soviet Union. It is shown that the sorption of strontium and caesium take place separately and that the capture of caesium by soils is an irreversible process. It is also shown that sorption processes inhibit the filter-diffusion process at low diffusion rates and that die strontium movement is 40-60 times slower than the filtering and the caesium movement 100 times slower. Trials were made with a method of calculating the basic kinetic parameters of sorption, thus making it possible to characterize the movement of radioactive strontium and describe the migration of radioactive caesium. (author)

  10. Radioactivity monitoring of the Irish marine environment 1987

    International Nuclear Information System (INIS)

    This report represents the results of the Board's monitoring of radioactivity levels in the Irish marine environment during 1987. The principal objective of the monitoring programme is to obtain estimates of radiation doses to the Irish public arising from caesium-137 and caesium 134, the main contaminating radionuclides. Estimates are presented of the radiation doses to the Irish public arising from the consumption of fish and shellfish contaminated with radiocaesium

  11. Measurement of soil erosion from fallout of 137Cs

    International Nuclear Information System (INIS)

    The measurement of relative caesium-137 content in soil is a powerful tool for the estimation of contemporary erosion rates, especially on soils with consistent land use. Data from runoff plots gave the relationship Y = 0.419 Xsup(0.646), where Y is the diminution in caesium-137 content expressed as a percentage of local input and X is the average soil loss in kg ha-1 y-1

  12. Apparatus and method for generating high density pulses of electrons

    International Nuclear Information System (INIS)

    An apparatus and method are described for the production of high density pulses of electrons using a laser energized emitter. Caesium atoms from a low pressure vapour atmosphere are absorbed on and migrate from a metallic target rapidly heated by a laser to a high temperature. Due to this heating time being short compared with the residence time of the caesium atoms adsorbed on the target surface, copious electrons are emitted which form a high current density pulse. (U.K.)

  13. Bichromatic State-Insensitive Trapping of Cold 133Cs-87Rb Atomic Mixtures

    OpenAIRE

    Metbulut, M. M.; Renzoni, F.

    2015-01-01

    We investigate simultaneous state-insensitive trapping of a mixture of two different atomic species, Caesium and Rubidium. The magic wavelengths of the Caesium and Rubidium atoms are different, $935.6$ nm and $789.9$ nm respectively, thus single-frequency simultaneous state-insensitive trapping is not possible. We thus identify bichromatic trapping as a viable approach to tune the two magic wavelengths to a common value. Correspondingly, we present several common magic wavelength combinations...

  14. Ten years terrestrial radioecological research following the Chernobyl accident. Proceedings of the international symposium on radioecology 1996

    International Nuclear Information System (INIS)

    This proceeding volume includes papers which contain the following topics: radioecological research after the Chernobyl accident including radionuclide migration in the soil, in plants and in food; seasonal changes in the distribution of radionuclides (caesium 137, strontium 90); influence of radionuclide transport in agricultural ecosystems; investigation of transfer factors of caesium and strontium; analytical models of distribution of nuclides in soil and the role of food in the transfer of nuclides in ecosystems. (Suda)

  15. The environmental chemistry of radiocaesium and other nuclides

    International Nuclear Information System (INIS)

    This thesis reports studies on the environmental chemistry of radiocaesium, and is related particularly to upland ecosystems and grazing animals. The underlying philosophy of this thesis is that fallout radiocaesium will act as a tracer for naturally occuring stable caesium. Therefore, investigations into radiocaesium distribution and mobility within environmental and biological systems are complemented by studies of the stable caesium concentrations and transfer mechanisms within that ecosystem. (author)

  16. Activities of the Joint FAO/IAEA Division on Nuclear Techniques in Food and Agriculture in Relation to the Japanese Nuclear Emergency

    International Nuclear Information System (INIS)

    The magnitude 9.0 earthquake and subsequent tsunami that struck off the east coast of Honshu, Japan on 11 March 2011 resulted in significant damage to the nuclear power plant (NPP) at Fukushima Daiichi, with the consequent release of radioactive material into the environment. Air, soil, water and agricultural produce around the damaged NPP were contaminated with radionuclides, chiefly iodine-131, caesium-134 and caesium-137. Several activities were initiated by the IAEA and FAO in relation to this emergency.

  17. Preliminary assessment of the potential for using cesium-137 technique to estimate rates of soil erosion on cultivated land in La Victoria I, Camaguey province of cuba

    International Nuclear Information System (INIS)

    Despite a growing awareness that erosion on cultivated land in Cuba is a potential hazard to long term productivity, there is still only limited information on the rates involved, particularly long term values. The potential for using the radionuclide Caesium-137 as an environmental tracer to indicate sources of soil erosion on cultivated soils in La Victoria catchment is introduced. Use of Caesium-137 measurements to estimate rates of erosion and deposition is founded on comparison of the Caesium-137 inventories at individual sampling points with a reference inventory representing the local Caesium fallout input and thus the inventory to be expected at the site experiencing neither erosion nor deposition. Two models for converting Caesium-137 measurements to estimates of soil redistribution rates on studied site have been used, the Proportional Model and Mass Balance Model. Using the first one net soil erosion was calculated to be 17.6 t. Ha 1 - .year 1 - . Estimates of soil loss using a Mass Balance Model (Simplified Model 1 and Model 2) were found to be 30.2 and 30.6 t. Ha 1 - .year 1 - ,respectively. Preliminary results suggest that Caesium-137 technique may be of considerable value in assembling data on the rates and spatial distribution of soil loss and a reliable tool for developing of soil conservation program

  18. Honey-dew honey as a long term indicator of 137Cs pollution

    International Nuclear Information System (INIS)

    137Cs, produced as a by-product of the atmospheric testing of thermonuclear weapons during the period extending from the 1950s to the 1970s, was distributed globally within the stratosphere and deposited as wet and/or dry fallout. The last great amount of radioactive caesium was deposited on the earth surface after Chernobyl accident. Significant variations in caesium activity levels in soils are caused by Chernobyl-derived fallout with relatively short period of contamination and great variabilities in activity and/or quantity of rainfall. However, total weapon testing-derived caesium pollution can be treated as generally uniform, i.e., numerous events over an extended period that minimise any local variation. Meanwhile, caesium, as well as the other radionuclides that behave like cations, can be moved upward by plant's uptake depending on various factors: plant species, sorption and desorption processes in soil, mineral soil composition, grain size and soil types, lateral caesium migration, etc. Certain plant species are known as caesium pollution indicators, but the uptake by an individual plant can be very different

  19. Half-Life Studies of Radiocaesium in Humans

    International Nuclear Information System (INIS)

    The retention of caesium-137 in humans has been studied in several cases. Two adult men were intravenously administered a small quantity of caesium-137. They were followed about 300 days by frequent whole-body counting and with excreta collection during the initial period. The retention decreased as a sum of two exponentials. The slowest compartment decreased with a half-life of about 75 d. One of them was also given caesium-137 orally 2 years later with the same excretion pattern obtained as after intravenous injection. The excretion rate of caesium-137 has also been studied in a different way for large groups of men, women and children through comparison with diet data. From a group of 10 people, voluntarily changing their diet, the average excretion rate could be calculated from whole-body counting at an interval of six weeks. The excretion also has been obtained from a study on two people after an oral administration of caesium-132. Detailed results on these studies will be given particularly with respect to the elimination rate of caesium, i.e. the biological half-life and its variation with sex and age. On the average, half-lives ranging from 30 to 90 d have been obtained. (author)

  20. Returning land contaminated as a result of radiation accidents to farming use

    International Nuclear Information System (INIS)

    An assessment is given of the possibility of sorbents based on natural aluminosilicates (glauconite and clinoptilolite) being used for remediation of radioactively contaminated land with the aim of returning it to farming use. A comparative study of selectivity and reversibility of radiocaesium and radiostrontium sorption by natural aluminosilicates as well as by modified ferrocyanide sorbents based on these aluminosilicates was made. It was found that surface modification of aluminosilicates by ferrocyanides increases the selectivity of synthesized sorbents to caesium by 100–1000 times, increases sorption capacity and makes caesium sorption almost irreversible, whereas, selectivity of these sorbents to strontium radionuclides remains approximately the same as for natural aluminosilicates. The caesium distribution coefficient for mixed nickel–potassium ferrocyanide on glauconite is 10(5.0±0.6) L kg−1, the static exchange capacity (SEC) is 63 mg g−1; for mixed nickel–potassium ferrocyanide based on clinoptilolite caesium distribution coefficients in various concentration ranges are 10(7.0±1.0), 10(5.7±0.4) and 10(3.2±0.7) L kg−1, total SEC was 500 mg g−1. Caesium leaching by various leaching solutions from saturated mixed nickel–potassium ferrocyanide based on clinoptilolite was lower than 2%; from saturated mixed nickel–potassium ferrocyanide based on glauconite it was 1.5–14.6%. Ferrocyanide sorbents, based on glauconite and clinoptilolite are recommended for remediation of land, contaminated by caesium as a result of the Fukushima accident in Japan. Use of these sorbents should decrease the transfer of caesium to agricultural vegetation up to a factor of 20

  1. Negative hydrogen ion production in fusion dedicated ion sources

    International Nuclear Information System (INIS)

    Graphical abstract: In RF sources the acceleration of positive ions to a few tens of eV by the plasma potential difference between the driver and the extraction regions can have an important effect on negative ion production by enhancing the negative ion yield from caesiated surfaces and by charge exchange reactions with caesium atoms. The presence of energetic positive ions can have other implications: modifying the virtual cathode in front of the plasma grid, ionizing caesium atoms. Highlights: ► The physics of volume and surface production of hydrogen negative ions is reviewed. ► Effects of positive ion acceleration by plasma potential difference are investigated. ► Caesium ionization in extraction region by electrons and charge exchange are compared. ► Charge exchange with energetic positive hydrogen ions dominates caesium ionization. ► Negative ion production by charge exchange of positive ions with caesium is discussed. - Abstract: A brief description is given of the basic processes in negative ion sources dedicated to fusion. It is considered that in these sources negative ions are produced by ions and atoms interacting with a caesiated surface, but this mechanism is not unique: the volume production, based on dissociative electron attachment to rovibrationally excited molecules, is also active. We suggest that in RF sources the acceleration of positive ions to a few tens of eV by the plasma potential difference between the driver and the extraction regions can have an important effect on negative ion production by enhancing the negative ion yield from caesiated surfaces, and by charge exchange reactions with caesium atoms. The presence of energetic positive ions can have other implications (modifying the virtual cathode in front of the plasma grid, participating in caesium ionization).

  2. Iodine Chemistry and aerosol composition in the reactor coolant system of a nuclear power plant in case of a severe accident

    International Nuclear Information System (INIS)

    In case of a severe accident on a nuclear reactor, radioactive iodine may be released into the environment, impacting significantly the radiological consequences. Determination of the amount released, and of the physical state of iodine (gaseous form or solid aerosol form), is thus a major issue. The release of iodine from the damaged reactor core and its transport in the different parts of the reactor up to the reactor containment, have been extensively studied, particularly in the Phebus-FP large scale experiments. Phebus-FP results notably showed that a significant fraction of iodine under gaseous form can reach the containment. The models used in severe accident codes did not (and still does not) fully account for this iodine speciation. A likely explanation is that iodine keeps a gaseous form up to the containment due to some processes that limit the formation of caesium iodide in the reactor coolant system (RCS) (caesium iodide was assumed to be the dominant form of iodine in the RCS). Caesium iodide formation would be limited due to chemical kinetic limitations and due to the presence of other elements (molybdenum or boron) responsible for 'trapping' the caesium. An experimental research program has been developed with the aim to study the chemical behaviour of iodine during its transport in the RCS, with presence of water steam, caesium and molybdenum or boron. Experiments are compared to calculations performed with the IRSN severe accident code ASTEC where a chemical kinetic model has been implemented. (author)

  3. Separation of Cs from acid radwaste solutions using substituted tetraphenyl borates

    International Nuclear Information System (INIS)

    It was the aim of this study to selectively separate active caesium (Cs-134 and Cs-137) from acid, radioactive waste solutions (especially MAW and HAWC). The following strategy was designed for a separating process: synthesis of acid-resistant reagents selective to caesium; precipitation of Cs+ and separation of the precipitates by filtration or centrifugation; precipitation of Cs+ and separation of the precipitates by flotation; caesium separation by means of liquid-liquid extraction. Different fluorophenyl derivatives of sodium tetraborate were synthesized and tested with regard to acid stability and selectivity with regards to caesium ions. Furthermore, the solubility products of the caesium salts of these compounds also in dependence on the concentration of NaNO3, were determined. With regard to the separation of precipitates the best result for the MAW was obtained with sodium tetrakis (2,4 difluorophenyl) by which inactive Cs+ can be used as carrier. The pentafluorophenyl derivative, however, is the most suitable for the highly active waste concentrates (5M HNO3) due to its better acid stability; because of its comparatively high solubility the quantity of precipitants to be used is larger. In the pH range 7-10 the liquid-liquid extractions of these precipitates showed very good separation results with nitrobenzene. Apart from process-oriented aspects, also the physical and chemical processes are discussed. (orig./RB)

  4. Radioactivity of the environment and food in Poland in 1986-1990

    International Nuclear Information System (INIS)

    The Chernobyl accident caused the growth of the radioactive contamination of the environment and foodstuffs in Poland as compared with the pre-accident situation. The level of this contamination was not yet so high, to consider the intake dose of the Polish population as the substantial hazard. In the first month after Chernobyl accident the significant values attained the iodine isotopes contamination, especially iodine 131. Later on the higher level of caesium isotopes contamination was noticed only. This level of contamination is decreasing distinctly. This paper provides the results of environment and foodstuffs contamination measurements. In order to estimate the effective dose equivalent for Polish population the caesium content of the diet have been calculated and analysed. The results of the studies showed that the effective dose equivalent in the first year after the accident was nearly 0.3 mSv and in the next years 0.04 mSv and 0.02 mSv. The level of effective dose equivalent depends of isotopes ingested via foodstuff consumption. In the first year there were: iodine 131, caesium 134 and caesium 137, later on the caesium isotopes only. In the contamination of average annual diet the greatest part consist of milk consumption. (author)

  5. Radioactive contamination of the forests in Southern Poland in the year 1987

    International Nuclear Information System (INIS)

    Experimental data of caesium and ruthenium radioactivity in chosen parts of forests ecosystems in Southern Poland are presented. Samples were taken from 19 experimental areas placed in the standard net of Academy of Agriculture areas in the summer of 1987. Samples of plants and of two upper layers of forest soil were analysed. Measurements were performed with a low-background gamma-rays spectrometer with the Ge(Li) detector. Caesium and 137 activity (decay corrected for 1 August 1987) in litter reaches 2.5 kBq per kg of dry mass. The correlation factors between contamination levels in various kinds of samples were calculated. Caesium 137 contamination level before Chernobyl accident in moulder layer of soils was estimated. 15 refs., 3 figs., 6 tabs. (author)

  6. Investigation of the performance of macromycetes as bioindicators of radioactive contamination

    International Nuclear Information System (INIS)

    The work aims at assessing the usefulness of macromycetes as indicators of migration of radiocaesium in undisturbed soils of natural ecosystems. On purpose macromycetes of different species have been collected in sites of Friuli-Venezia Giulia region (NE Italy) during a 3-year period after the Chernobyl accident, for a total of 600 samples. To evaluate caesium migration, samples have been divided into 4 ecological groups corresponding to different average mycelium depths. The comparison of contamination levels in the groups with the profile of contamination in soil seems to validate the assumption that it is possible to monitor downward migration of caesium in soil by using macromycetes, since caesium migration differently affects the contamination of the 4 ecological groups. (author)

  7. Considerations on the ICRP model predictions of the transfer of (137)Cs from food to the milk and urine of lactating mothers.

    Science.gov (United States)

    Giussani, Augusto; Risica, Serena

    2014-06-01

    A recent work has shown that the current ICRP biokinetic model for the transfer of caesium radionuclides from food to human breast milk was able to describe with satisfactory accuracy (137)Cs activity concentrations in human breast samples collected a few weeks after the Chernobyl accident as well as in samples collected some years later. However, systematic discrepancies were observed for the predictions of the activity concentrations in urine samples. In the present work, modifications to the model were investigated with the aim of improving the agreement between model predictions and data. It turned out that the disagreement for the urine data was ascribable to the mathematical simplifications used by the ICRP to describe urinary excretion in the first few days after delivery. However, the predictive performances of the model remained unchanged even when differences in the bioavailability of caesium from the ingested food types were considered or metabolic interactions between caesium and potassium were introduced into the model formulation. PMID:24705367

  8. Synthesis of derivatives of tetronic acid and pulvinic acid. Total synthesis of norbadione A; Synthese de derives de l'acide tetronique et de l'acide pulvinique. Synthese totale de la norbadione A

    Energy Technology Data Exchange (ETDEWEB)

    Mallinger, A

    2008-11-15

    When vegetables like mushrooms are contaminated by radioactive caesium 137, this radioactive caesium is associated to norbadione A, a natural pigment present in two mushroom species and which can be used as a caesium decorporation agent or maybe as protection agent against ionizing radiations. Within this perspective, this research report describes the biosynthesis and the structure and properties of the norbadione A and of pulvinic acids (physicochemical properties, anti-oxidizing properties). Then, it presents the various tetronic acids (3-acyl-, 3-alkyl-, 3-alkoxy-, 3-aryl-tetronic acids and non 3-substituted tetronic acids), their synthesis path as they are described in the literature, and presents a new synthesis approach using a tandem reaction (with different esters or hydroxy esters) and the synthesis of tetronic acids. The author also proposes a new synthesis way for methyl pulvinates, and finally reports the work on the development of a total synthesis of the norbadione A.

  9. Considerations on the ICRP model predictions of the transfer of 137Cs from food to the milk and urine of lactating mothers

    International Nuclear Information System (INIS)

    A recent work has shown that the current ICRP biokinetic model for the transfer of caesium radionuclides from food to human breast milk was able to describe with satisfactory accuracy 137Cs activity concentrations in human breast samples collected a few weeks after the Chernobyl accident as well as in samples collected some years later. However, systematic discrepancies were observed for the predictions of the activity concentrations in urine samples. In the present work, modifications to the model were investigated with the aim of improving the agreement between model predictions and data. It turned out that the disagreement for the urine data was ascribable to the mathematical simplifications used by the ICRP to describe urinary excretion in the first few days after delivery. However, the predictive performances of the model remained unchanged even when differences in the bioavailability of caesium from the ingested food types were considered or metabolic interactions between caesium and potassium were introduced into the model formulation. (note)

  10. Assessment of the radiocaesium levels in irish soils and its transfer to crops

    International Nuclear Information System (INIS)

    The behaviour of radiocaesium deposited by the Chernobyl fall-out was investigated in eleven different permanent pastures and arable lands. Samples of grass and subjacent soil at various depths were collected and analysed for their caesium content during a period extending from the Spring of 1987 (one year after the accident) to the Autumn of 1988. Soil from tillage land along with vegetable and grain crops from this land were also sampled and subjected to gamma spectrometric analysis. The results for the pasture soils show that there has been limited downward migration of Chernobyl caesium. In October 1988 more than 88% of caesium of Chernobyl origin was still retained in the 0-10 cm layer of undisturbed pasture soil. It would also appear that at most sites more than 70% of weapons deposited caesiym is still contained in the 0-15 cm soil layer

  11. Analysis of fission product transport parameters in the fuel element for temperatures up to 25000C based on heat-up experiments and their application to heat-up incidents using the PNP-500 as example

    International Nuclear Information System (INIS)

    Important predictions relating to instationary release behaviour are given, in particular with regard to the movement of caesium from the particle, via coating buffer, matrix and shell graphite through to the cooling gas. Of special note is the strong increase in activation energy of the fission product transport parameters in the temperature range above 16000C. The calculations were applied to HTR-core heat up accidents with an intact primary cycle and with prior loss of coolant. The starting point of the calculation is the reactor core ''history'', in particular the inventory distribution, not only in the individual core areas but also over the various fuel element zones. The liberation of the noble gases iodine and caesium with temperature were calculated, the chief emphasis being given to caesium. (orig./DG)

  12. High temperature studies of simulant fission products: part IV

    International Nuclear Information System (INIS)

    A thermal gradient system has been used to study the interaction of caesium iodide with boric acid in various atmospheres over the temperature range from 400 to 10000C. Specific analytical techniques have been used to determine the reaction products, and differential thermal analysis-thermogravimetric studies have been undertaken to assess the reaction kinetics. Solid caesium iodide and molten boric acid react in a diffusion-controlled manner with an activation energy of 190 ± 30 kJ mol-1 to give complex caesium borates (eg Cs2B10O16) and hydrogen iodide. This volatile iodine species interacts with 304 stainless steel to produce nickel and iron-based iodides within the surface oxide layer of the metal. (author)

  13. High temperature studies of simulant fission products. Pt. 3

    International Nuclear Information System (INIS)

    The interaction of caesium hydroxide vapour with 304 stainless steel has been studied over the temperature range 500 to 1000degC in a variety of atmospheres (argon, argon-4% hydrogen, argon-4% hydrogen-3 to 55% water vapour, and 100% steam). Vapour deposition velocities for the formation of soluble and insoluble caesium species have been derived and found to be only slightly affected by variations in the composition of the carrier gas. As the metal surface temperature increased, the soluble component decreased and the insoluble component increased. Temperature-dependent equations have been derived for these two forms of behaviour to quantify the interaction of caesium hydroxide vapour with oxidised stainless steel surfaces. (author)

  14. Synthesis of derivatives of tetronic acid and pulvinic acid. Total synthesis of norbadione A

    International Nuclear Information System (INIS)

    When vegetables like mushrooms are contaminated by radioactive caesium 137, this radioactive caesium is associated to norbadione A, a natural pigment present in two mushroom species and which can be used as a caesium decorporation agent or maybe as protection agent against ionizing radiations. Within this perspective, this research report describes the biosynthesis and the structure and properties of the norbadione A and of pulvinic acids (physicochemical properties, anti-oxidizing properties). Then, it presents the various tetronic acids (3-acyl-, 3-alkyl-, 3-alkoxy-, 3-aryl-tetronic acids and non 3-substituted tetronic acids), their synthesis path as they are described in the literature, and presents a new synthesis approach using a tandem reaction (with different esters or hydroxy esters) and the synthesis of tetronic acids. The author also proposes a new synthesis way for methyl pulvinates, and finally reports the work on the development of a total synthesis of the norbadione A

  15. Migration of 137Cs and 134Cs in different forest soil layers

    International Nuclear Information System (INIS)

    Caesium-134 and 137Cs measurements in about 250 samples from L-, Of-, Oh-, Ah- and B-horizons of a Bavarian forest from 1987 to 1994 are analysed with respect to migration by using a compartment model. The derived ecological half-lives are 2.8 years, 3.8 years, 4.4 years and 7.7 years, respectively. By using these results, caesium behaviour can be predicted for about 25 years. The resulting profile is similar to that found nowadays for weapons fallout caesium, migrating within about 25 years in the same forest. Therefore, the model is suitable for the estimation of future behaviour of radiocaesium in the forest investigated for a period of about 25 years after deposition. (Author)

  16. Radionuclide transfer from forage plants into milk

    International Nuclear Information System (INIS)

    There is a lot of information regarding the transfer of radionuclides (iodine, caesium, strontium) which allows the transfer factor being calculated with high certainty. The transfer coefficients (forage-)plant/milk laid down in Paragraph 45 of the Radiation Protection Ordinance (Strahlenschutzverordnung) amount to 1.0x10-2 for iodine-131, 1.2x10-2 for caesium-137 and 2.0x10-3 for strontium-90. More recent calculated factors are markedly lower at the average. During milk processing, the greatest amount of radionuclides gets access to the whey or into the permeate after ultrafiltration of whey. In butter and cheese only minute amounts of caesium can be expected. (orig.)

  17. Chemical reactions of fission product deposits and iodine transport in primary circuit conditions

    International Nuclear Information System (INIS)

    Highlights: • With CsI precursor, 20% of released iodine was in gaseous form in steam flow at 650 °C. • In similar conditions with Mo, gaseous iodine fraction was increased to 38–79%. • Boron trapped most of the caesium and iodine was almost completely released as gas. - Abstract: The objective of this work was to examine the chemical reactions taking place on primary circuit surfaces and their effect on fission product transport in a severe nuclear reactor accident. Especially transport of gaseous and aerosol phase iodine was studied. Caesium iodide (CsI) was used as precursor material for iodine species. Also, effects of molybdenum and boron on transport of iodine were investigated. The experimental work showed that when CsI alone was used as a precursor, as much as 20% of the released iodine was in gaseous form and the rest as aerosol particles. Aerosol particles were most likely CsI. When the amount of hydrogen in the carrier gas was increased, the fraction of gaseous iodine decreased. When Boron was added to the precursor, a glassy caesium borate surface was formed on the crucible. Boron trapped most of the caesium and also a fraction of iodine, causing almost all released iodine to be in gaseous form. When Mo was introduced in the precursor, most of the iodine was again released in gaseous form. Oxidised Mo reacted with caesium releasing iodine from CsI. The effect of Mo on iodine transport depended much on H2 concentration and was observed to be substantially greater on stainless steel surface. When stainless steel crucible was used, Mo was found in small amounts from aerosol particles, indicating that it was probably released as caesium molybdate or as molybdenum oxide

  18. Radioactivity monitoring of the Irish marine environment 1988 - 1990

    International Nuclear Information System (INIS)

    This report presents estimates of the radiaiton doses to the Irish public arising from caesium-137 and caesium-134, the contaminating radionuclides of greatest radiological significance. The doses are expressed in terms of individual and collective doses and are assessed against the system of dose limitation recommended by the International Commission on Radiological Protection (ICRP) which is embodied in the Basic Safety Standards Directive of the European Community. The doses are also compared with doses arising from background radiation and the associated risks are considered in the context of some of the common risks in everyday life

  19. The distribution and dynamics of radionuclides in the terrestrial environment

    International Nuclear Information System (INIS)

    Caesium-137, plutonium-238 and plutonium-239/240 have been determined in soils and vegetation from West Cumbria. Determinations have been made with reference to the land use which is dominated by grassland management. It can be shown statistically that with respect to caesium-137 land use can affect all soil and vegetation inventory. Indications are that a similar situation holds for the plutonium isotopes. A small data bank of information has been gathered on the land management and farming practices of the study area. (author)

  20. Monitoring of internal exposure of the population in regions close to the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    In the first month and a half after the accident, the dose burden on the population was determined by radioactive iodine deposited in the thyroid gland. Later, the dose burden was governed by caesium-134 and caesium-137. The measurements made are generally reliable. Departures from the norm in extreme cases (in the event of marked differences from the standard body build) were no more than 50% of the actual activity (at levels above 150-200 nCi). Since there is no effective method of measuring nuclides incorporated into the bodies of children, it is necessary to develop special phantoms simulating the human body at different ages. (author). 4 tabs

  1. Synthesis of available information in Japan about the contamination of food products by radionuclides remaining in the environment after the Fukushima accident

    International Nuclear Information System (INIS)

    This report first proposes an overview of the general status of contamination of the land environment in Japan after the Fukushima accident (maps indicate level of Caesium 134 and 137). It outlines and comments that these radioactive caesium deposits are generally the reason of a persistent contamination of some food products. It describes the measures and arrangements implemented in Japan to control the contamination of food products and to restrict their marketing, comments the assessment of the contamination of food products according to results published in Japan since the accident for the different types of food products: agriculture, fishing, meat and milk, mushrooms, other land vegetal products

  2. Radioactivity in freshwater systems in Cumbria (UK) following the Chernobyl accident

    International Nuclear Information System (INIS)

    Sampling of fish, water, sediments and plants was carried out in freshwater systems in Cumbria (UK) to study the effects of Chernobyl fallout. Radionuclide concentrations were determined by gamma spectrometry and potassium and calcium ion concentrations in water were measured using atomic absorption spectrometry. The results contained in this report cover the period May 1986-March 1988. Caesium-134 and -137 were readily detected in all materials but ruthenium-103 and -106 were also found in a few samples. Trends in caesium concentrations in fish are difficult to establish because of the wide variation between fish of the same species. (author)

  3. Bichromatic state-insensitive trapping of cold133Cs-87Rb atomic mixtures

    Science.gov (United States)

    Metbulut, M. M.; Renzoni, F.

    2015-12-01

    We investigate simultaneous state-insensitive trapping of a mixture of two different atomic species, Caesium and Rubidium. The magic wavelengths of the Caesium and Rubidium atoms are different, $935.6$ nm and $789.9$ nm respectively, thus single-frequency simultaneous state-insensitive trapping is not possible. We thus identify bichromatic trapping as a viable approach to tune the two magic wavelengths to a common value. Correspondingly, we present several common magic wavelength combinations appropriate for simultaneous state-insensitive trapping of the two atomic species.

  4. A rapid method for the in vivo monitoring of radiocaesium activity in sheep

    International Nuclear Information System (INIS)

    Following the accident at Chernobyl there was a need to determine caesium activity in individual sheep on farms. This need arose so that animals on farms within a restricted area could be released from restrictions provided the tissue caesium activity was below the recommended limit. This paper describes the development of a rapid method for the in vivo monitoring of sheep using a lead-shielded sodium iodide scintillation detector coupled to a portable single channel analyser. The method enables one sheep per minute to be monitored and the results showed a good correlation with laboratory measurements of meat from sheep which had previously been monitored in vivo prior to sacrifice. (author)

  5. Radioactive contamination of the forests of southern Poland and Finland

    International Nuclear Information System (INIS)

    Experimental data of caesium and ruthenium radioactivity in chosen parts of forest ecosystems in Finland and Southern Poland are presented and compared. Measurements were performed with a low-background gamma-rays spectrometer with the Ge(Li) detector. The maximum caesium 137 activity in litter from Poland is 2.5 kBq, in that from Finland 3.9 kBq, in spruce needles it is 0.4 kBq (Poland), 0.9 kBq (Finland) and in fern leaves it is as high as 15.9 kBq per kg of dry mass in one sample from Poland. (author)

  6. Treatment of low-level radioactive waste using Volcanic ash

    International Nuclear Information System (INIS)

    The effective application of volcanic ash, an indigenous adsorptive material abundant in the Mt. Pinatubo area, in the removal of radioiodine from radioactive waste streams was demonstrated. Factors such as availability, low cost and comparative retention capacity with respect to activated charcoal make volcanic ash an attractive alternative in the conditioning of radioactive waste containing radioiodine. Chemical precipitation was employed in the treatment of low level aqueous waste containing 137Cs. It was shown that there exists an optimum concentration of ferric ion that promotes maximum precipitation of caesium. It was further demonstrated that complete removal of caesium can be achieved with the addition of nickel hexacyanoferrate. (author). 5 refs, 3 figs

  7. Environmental radioactivity in the North Atlantic region including the Faroe Islands and Greenland. 1992 and 1993

    International Nuclear Information System (INIS)

    Measurements of fallout radioactivity in the North Atlantic region including Faroe Islands and Greenland are reported. Strontium-90, caesium-137 and caesium-134 were determined in samples of precipitation, sea water, vegetation, various foodstuffs (including milk in the Faroes), and drinking water. Estimates are given on the mean contents of 90Sr and 137Cs in human diet in the Faroes and Greenland in 1992 and 1993. Pu-239,240 data from a Canadian sediment-sampling at Thule in 1991 are reported. (au) 126 tabs., 63 ills., 17 refs

  8. Measurement of natural radioactivity with REGe detectors at the MPI fuer Physik

    International Nuclear Information System (INIS)

    Two Reverse Electrode Coaxial Germanium Detectors are used to monitor the natural radioactivity at the Max-Planck-Institut fuer Physik in Munich since March 2011, two weeks after the reactor accident in Fukushima, Japan. The count rate for prominent elements have been monitored continuously over this long time period. The rate of Cs-137 is particularly interesting, as caesium is a tracer for nuclear disasters. A detailed statistical analysis of the data shows that only statistical fluctuations are observed. However, it was noted that the ratio of caesium to bismuth within the laboratory is significantly larger than outside due to old radioactive depositions inside the building.

  9. Observation of single neutral atoms in a large-magnetic-gradient vapour-cell magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; He Jun; Qiu Ying; Yang Bao-Dong; Zhao Jiang-Yan; Zhang Tian-Cai; Wang Jun-Min

    2008-01-01

    Single caesium atoms in a large-magnetic-gradient vapour-cell magneto-optical trap have been identified. The trapping of individual atoms is marked by the steps in fluorescence signal corresponding to the capture or loss of single atoms. The typical magnetic gradient is about 29 mT/cm, which evidently reduces the capture rate of magneto-optical trap.

  10. Creation of an Ultracold Plasma by Photoionizing Laser-Cooled Cesium Atom

    Institute of Scientific and Technical Information of China (English)

    JING Qun; FENG Zhi-Gang; ZHANG Lin-Jie; LI Chang-Yong; ZHAO Jian-Ming; JIA Suo-Tang

    2008-01-01

    @@ The signals of ultracold plasma are observed by two-photon ionization of laser-cooled atom in a caesium magneto-optical trap.A simple model has been introduced to explain the creation of plasma, and the mechanism is further investigated by changing the energy of a pulsed dye laser and the number of initial cooled atoms.

  11. A comparison of the predicted and observed low energy radiation from the thorax of a normal human male

    International Nuclear Information System (INIS)

    The normal human male emits a continuum of low energy photons (< 100 KeV) whose magnitude depends on the body content of potassium-40 and caesium-137 and the physical parameters of the body. An experiment is described from which it has been possible to devise a method of forecasting the level of this continuum with an accuracy of ± 6%. (author)

  12. Radioactivity in Norwegian Waters: Distribution in seawater and sediments, and uptake in marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Heldal, Hilde Elise

    2001-07-01

    Prior to the detonation of the first thermonuclear bomb, small amounts of radioactivity, for example in mineral water, were considered to be health enriching. Negative experiences related to thermonuclear bombs and several nuclear accidents have, however, changed people's attitude towards radioactivity during the past 40-50 years. Today, there is a common concern for regular and potential accidental releases of radioactivity from sources such as Sellafield. Although this is important, incorrect assessments of the effects of these releases (e.g. created by uncritical journalism) have the potential to harm the country's fisheries and economy. Therefore, it is of major importance to document up-to-date levels of radioactive contamination of the marine environment, and be able to place these into the proper perspectives. The main topics of the thesis may be summarised as follows: (1) Distribution of Caesium-137, Plutonium-238, Plutonium-239,240 and Americium-241 in sediments with emphasis on the Spitsbergen-Bear Island area, (2) Uptake of Caesium-137 in phytoplankton representative for the Barents and Norwegian Seas phytoplankton communities (laboratory experiments), (3) Bioaccumulation of Caesium-137 in food webs in the Barents and Norwegian Seas, (4) Geographical variations of Caesium-137 in harbour porpoises (Phocoena phocoena) along the Norwegian coast, (5) Transport times for Technetium-99 from Sellafield to various locations along the Norwegian coast and the Arctic Ocean.

  13. Environmental radioactivity surveillance programme: results for the UK for 1981

    International Nuclear Information System (INIS)

    The 1981 results of a NRPB report on a UK environmental radioactivity surveillance programme are presented. The concentrations in air of long-lived radionuclides produced by weapons testing were higher than those observed in 1980 due to the intermediate level atmospheric nuclear weapon explosion in Central Asia in October 1980. The concentrations of fission products were the highest observed since 1978; the annual average caesium-137 concentration was three times the value for 1980. The average depositions of strontium-90 and caesium-137 in the UK were also elevated above those in recent years. An average effective dose equivalent commitment of 2 μSv from external irradiation by radionuclides deposited in 1981 added less than 1% to that accumulated from atmospheric nuclear explosions in earlier years. The concentrations of strontium-90 and caesium-137 in milk were higher than that reported for 1980. For a typical adult, the average committed effective dose equivalent attributable to contamination of diet with these radionuclides is estimated to be 4 μSv. The estimate for caesium is consistent with that obtained from direct measurement of this radionuclide in the body. The average annual effective dose equivalent from fallout is evaluated and compared with that from natural background radiation. (author)

  14. Alkali metal and ammonium chlorides in water and heavy water (binary systems)

    CERN Document Server

    Cohen-Adad, R

    1991-01-01

    This volume surveys the data available in the literature for solid-fluid solubility equilibria plus selected solid-liquid-vapour equilibria, for binary systems containing alkali and ammonium chlorides in water or heavy water. Solubilities covered are lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride and ammonium chloride in water and heavy water.

  15. Solidification of highly active wastes

    International Nuclear Information System (INIS)

    Final reports are presented on work on the following topics: glass technology; enhancement of off-gas aerosol collection; formation and trapping of volatile ruthenium; volatilisation of caesium, technetium and tellurium in high-level waste vitrification; deposition of ruthenium; and calcination of high-level waste liquors. (author)

  16. Update on photo cathodes for RF-Guns at DESY

    OpenAIRE

    Schreiber, Siegfried; Hansen, Ingo; Lederer, Sven; Michelato, Paolo; Monaco, Laura; Sertore, Daniele

    2013-01-01

    At DESY, caesium telluride photocathodes are successfully used for the RF Guns at DESY,namely FLASH, PITZ, and REGAE. Their high quantum efficiency and long lifetime allow toproduce routinely thousands of bunches per second with a single bunch charge in the nCrange. We report on the status of the preparation system and updates on lifetime, quantumefficiency, darkcurrent, and operating experience.

  17. Removal of radionuclides at a waterworks

    DEFF Research Database (Denmark)

    Gäfvert, T.; Ellmark, C.; Holm, E.

    2002-01-01

    filtration and from the municipal distribution network. The samples were analysed with respect to their content of uranium, thorium, polonium, radium, plutonium and caesium. The results show a high removal capacity for uranium (about 85%), thorium (>90%), plutonium (>95%) and polonium (>90...... concentrations for the naturally occurring radionuclides and plutonium....

  18. Measured transfer factors in milk and meat after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    After the nuclear reactor accident at Chernobyl the radioactivity in the environment in Aachen was measured in detail at the Lehrgebiet Strahlenschutz in der Kerntechnik. The change of the different radionuclides in the eco-system made it possible to obtain radioecological parameters especially for iodine and caesium. The knowledge about the transport of iodine into cow's milk could be very much improved

  19. Concentration of 137Cs and 40K in meat of omnivore and herbivore game species in mountain forest ecosystems of Gorski Kotar, Croatia

    International Nuclear Information System (INIS)

    The aim of this study was to investigate 137Cs and 40K load in large mammal game species in the mountain forest region of Gorski Kotar in Croatia approximately a quarter of century after the Chernobyl accident. 137Cs and 40K activity were determined by the gamma-spectrometric method in 49 meat samples of five large game species: brown bear (Ursus arctos), wild boar (Sus scrofa), roe deer (Capreolus capreolus), red deer (Cervus elaphus), and chamois (Rupicapra rupicapra). The results indicated that herbivore game species (roe deer, red deer and chamois) show significantly lower 137Cs concentrations than omnivore species (brown bear, wild boar), thereby confirming the hypothesis that different dietary strategy impact caesium concentrations in meat. The measured caesium load in brown bear meat was in the range of two orders of magnitude, while caesium load in wild boar meat was found in the range of one order of magnitude. The estimated effective equivalent dose showed that uptake of the highest caesium doses would be from consumption of omnivore species meat, while much lower doses could be taken in with the consumption of meat from herbivore species. (author)

  20. Measurement of soil erosion from fallout of 137Cs

    International Nuclear Information System (INIS)

    Caesium-137, whose presence in the environment is almost totally attributable to atmospheric nuclear explosions, is strongly and stably adsorbed by soil colloids. Its depletion in eroded soils by comparison with accumulation in stable soils provides a means of estimating erosion rates over broad and various areas and lengthy periods of time. A calibration relationship for southeastern Australia is presented

  1. Psycho-social impact of the cesium-137 accident in the Brazilian society

    International Nuclear Information System (INIS)

    The author intends to question the assumed current public opinion that the psycho-social impact, resulting from the Goiania accident, is related with the ignorance of those who handled the caesium-137 source capsule, as well as the way media explained the accident. Some important aspects related to social behaviour during and after the accident are also shown. (B.C.A.)

  2. The amount of 137Cs in chosen parts of food chains from localities in the East of Slovakia

    International Nuclear Information System (INIS)

    The aim of this study was to compare the amount of radiocaesium in chosen parts of food chains from localities in the Eastern Slovakia. Prevailing part of radiocaesium is in the upper layer of soils and specific activity of 137Cs in the first layer for locality Stara Voda in 2000 achieved 152.4 Bq/kg1. On the base of results from modified Tessier sequential extraction method we determined that more than 50 % of this radionuclide is in the soil in not extractable fraction. From studied species of mushrooms the highest value was determined in sample of Rozites caperata the and specific activity achieved 1822.0 Bq/kg1 d. w. The aim of our study was to determine the amount of caesium in chosen parts of food chains from localities in Eastern Slovakia for period 2000-2004. On the base of obtained results we can conclude that radiocaesium migrates vertically in soils very slowly and prevailing part of caesium is in the upper layer. Prevailing part of radiocaesium is in the not extractable fraction. Extremely low concentration of caesium in soil solution is the factor limiting caesium uptake by the root systems, too. Mushrooms are characterised by high ability to accumulate radiocaesium. (authors)

  3. Run-off from roofs

    International Nuclear Information System (INIS)

    In order to find the run-off from roof material a roof has been constructed with two different slopes (30 deg C and 45 deg C). Beryllium-7 and caesium-137 has been used as tracers. Considering new roof material the pollution removed by runoff processes has been shown to be very different for various roof materials. The pollution is much more easily removed from silicon-treated material than from porous red-tile roof material. Caesium is removed more easily than beryllium. The content of caesium in old roof materials is greater in red-tile than in other less-porous materials. However, the measured removal from new material does not correspond to the amount accumulated in the old. This could be explained by weathering and by saturation effects. This last effect is probably the more important. The measurements on old material indicates a removal of 44-86% of the caesium pollution by run-off, whereas the measurement on new showed a removal of only 31-50%. It has been demonstrated that the pollution concentration in the run-off water could be very different from that in rainwater. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIO-F-423-DK(SD) under contract No. BIO-F-423-81-F. (author)

  4. Nursering assistance to the radiological accident patients in Goiania-an experience report

    International Nuclear Information System (INIS)

    In september, 1987, a caesium-137 source was disrupted and caused a serious radiological acident. The victims were hospitalized in the General Hospital in city of Goiania, Goias state, Brazil. This is a report of a personal experience, during the two months of nursering care. (author)

  5. Studies on the role of molybdenum on iodine transport in the RCS in nuclear severe accident conditions

    International Nuclear Information System (INIS)

    Highlights: • In oxidising conditions, Mo reacts with Cs and thus promotes gaseous iodine release. • In reducing conditions, CsI remains the dominant form for released iodine. • The nature of released iodine is well reproduced by the ASTEC code. - Abstract: The effect of molybdenum on iodine transport in the reactor coolant system (RCS) under PWR severe accident conditions was investigated in the framework of the EU SARNET project. Experiments were conducted at the VTT-Institute and at IRSN and simulations of the experimental results were performed with the ASTEC severe accident simulation code. As molybdenum affects caesium chemistry by formation of molybdates, it may have a significant impact on iodine transport in the RCS. Experimentally it has been shown that the formation of gaseous iodine is promoted in oxidising conditions, as caesium can be completely consumed to form caesium polymolybdates and is thus not available for reacting with gaseous iodine and leading to CsI aerosols. In reducing conditions, CsI remains the dominant form of iodine, as the amount of oxygen is not sufficient to allow formation of quantitative caesium polymolybdates. An I–Mo–Cs model has been developed and it reproduces well the experimental trends on iodine transport

  6. The Impact of Agricultural Soil Erosion on the Global Carbon Cycle

    Science.gov (United States)

    Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 Pg/year to a sink of the same magnitude. By using Caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced...

  7. Influence of the vegetative rests with a different parity C:N on transition Cs 137 from soil in plants

    International Nuclear Information System (INIS)

    On sod-podsolic sandy soil in field experiment with vegetative material (the vegetative rests) and different doses of entering of nitric fertilizers radio caesium accumulation in plants depending on a source of brought nitrogen - nitrogen of fertilizers or nitrogen of the vegetative rests is studied. (authors)

  8. Environmental radioactivity in Greenland in 1976

    International Nuclear Information System (INIS)

    Measurements of fall-out radioactivity in Greenland in 1976 are reported. Strontium-90 (and Caesium-137 in most cases) was determined in samples of precipitation, sea water, vegetation, animals, and drinking water. Estimates are given of the mean contents of 90Sr and 137Cs in the human diet in Greenland in 1976. (author)

  9. Order of 29 December 1988 on treatment of strawberries by ionizing radiation

    International Nuclear Information System (INIS)

    This order specifies the conditions for authorizing with a view to selling or putting on sale strawberries whose preservation has been obtained through exposure to cobalt 60 or caesium 137 radiation or to electron beams with an energy below or equal to 10 million electron-volts (10 MeV). (NEA)

  10. Radioactivity in Norwegian Waters: Distribution in seawater and sediments, and uptake in marine organisms

    International Nuclear Information System (INIS)

    Prior to the detonation of the first thermonuclear bomb, small amounts of radioactivity, for example in mineral water, were considered to be health enriching. Negative experiences related to thermonuclear bombs and several nuclear accidents have, however, changed people's attitude towards radioactivity during the past 40-50 years. Today, there is a common concern for regular and potential accidental releases of radioactivity from sources such as Sellafield. Although this is important, incorrect assessments of the effects of these releases (e.g. created by uncritical journalism) have the potential to harm the country's fisheries and economy. Therefore, it is of major importance to document up-to-date levels of radioactive contamination of the marine environment, and be able to place these into the proper perspectives. The main topics of the thesis may be summarised as follows: (1) Distribution of Caesium-137, Plutonium-238, Plutonium-239,240 and Americium-241 in sediments with emphasis on the Spitsbergen-Bear Island area, (2) Uptake of Caesium-137 in phytoplankton representative for the Barents and Norwegian Seas phytoplankton communities (laboratory experiments), (3) Bioaccumulation of Caesium-137 in food webs in the Barents and Norwegian Seas, (4) Geographical variations of Caesium-137 in harbour porpoises (Phocoena phocoena) along the Norwegian coast, (5) Transport times for Technetium-99 from Sellafield to various locations along the Norwegian coast and the Arctic Ocean

  11. Chemical data for the calculation of fission product releases in design basis faults in PWRs

    International Nuclear Information System (INIS)

    This review considers the chemistry of caesium and iodine and their volatility under the conditions which would exist during a number of design-basis faults. It recommends values which should be used for the distribution of these elements between liquid and gas phases. (author)

  12. Forms of radioactive fallout and mobility of radionuclides in Ukrainian aqueous landscapes

    International Nuclear Information System (INIS)

    The mechanisms underlying the kinetics of caesium-137 and strontium-90 washout from bed sediments were studied. Migratory radiostrontium was shown to be present mainly in the form of cations, and radiocaesium was present in both mineral and organic forms bound to both humic acids and oil products. Radiocaesium migration in surface waters was mainly technogenic in character. (author)

  13. Nursering assistance to the radiological accident patients in Goias-Brazil

    International Nuclear Information System (INIS)

    A report of a personal experience, during two months of nursering care to the radiological accident victims, due to the disruption of a caesium-137 source, is presented. The biological radiation effects, the radiation hazards due to the doses received and the Kind of exposure, are studied. (M.A.C.)

  14. Cs removal cuts waste and costs at Loviisa

    International Nuclear Information System (INIS)

    At the Loviisa VVER plant in Finland, a new system for removing caesium from evaporator concentrates, called the IVO-CsTreat System, is providing substantial savings in waste management costs. The system uses an innovative ion exchanger based on an inorganic material packed in stainless steel columns. (author)

  15. Order of 17 May 1985 on treatment by ionizing radiation of gum-arabic, dehydrated vegetables and cereal flakes and seeds

    International Nuclear Information System (INIS)

    This Order fixes the licensing conditions for the sale of gum-arabic, dehydrated vegetables and cereal flakes and seeds for use in dairy products, whose microbial decontamination was obtained through exposure to cobalt 60 or caesium 137 gamma-rays or electron beams with an energy below or equal to 10 MeV. (NEA)

  16. A beta and gamma radiation counter device

    International Nuclear Information System (INIS)

    Between 1988 and 1990, 1800 small Geiger-Mueller counters have been distributed in French high schools (caesium 137 as the radioactive source) for pupils' information about radioactivity (vocabulary, protection, ...). The INSTN (Institute for nuclear science and technology) has set up seminars for teachers' formation

  17. Alkali metals in fungi of forest soil

    International Nuclear Information System (INIS)

    The high affinity of forest soil fungi for alkali metals such as potassium, rubidium, caesium as well as radiocaesium is shown and discussed. Good positive correlation was found between K: Rb concentration ratios in soil and in fungi, when correlation between K: Cs concentration ratios was less pronounced. (LN)

  18. Hexacyanoferrates and bentonite as binders of radiocaesium for reindeer

    International Nuclear Information System (INIS)

    The effects of varying doses of caesium binders (Bentonite and several forms of iron-hexacyanoferrates) on radiocaesium accumulation in red blood cells and on radiocaesium transfer to urine and faeces were studied in feeding experiments with reindeer calves. The caesium binders were added to a ration of lichen (containing 9.5 kBq of 134Cs+137Cs originating from the Chernobyl accident) and fed together with a pelleted reindeer feed (RF-71) for 42 days. A 50% reduction in red blood cell radiocaesium concentration was obtained with a daily dose of 1 mg/kg body weigth of ammoniumironhexacyanoferrate (AFCF) and with 500 mg/kg of bentonite. Three mg/kg of AFCF or 2 g/kg of bentonite reduced both urinary excretion and RBC concentrations with more than 80%. It is concluded that iron-hexacyanoferrates, as a result of their high caesium binding capacity, are particularly useful as caesium binders for free ranging ruminants like the reindeer. (author)

  19. Fibrous sorbents for decontamination of complex composition solutions and milk in order to remove Cs-radionuclides

    International Nuclear Information System (INIS)

    Novel methods for the preparation of fibrous sorbents on the base of cellulose and heavy metals (iron, copper, zinc) ferrocyanides are proposed. Information on the sorptive properties of the caesium radionuclides and on the hydrolytic stability of these sorbents are presented. Some examples of their practical application (decontamination of drinking water, milk, meat, analysis of liquids) are given. (author)

  20. Cesium-137 global fallout into the Ob river basin and its influence on the Kara sea contamination - Weapons fallout cesium-137 in the Ob' catchment landscapes and its influence on radioactive contamination of the Kara sea: Western Siberia, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Semenkov, Ivan N.; Miroshnikov, Alexey Yu. [The Organization of Russian Academy of Sciences Institute of geology of ore deposits, petrography, mineralogy and geochemistry Russian Academy of Sciences (Russian Federation)

    2014-07-01

    There are several high level {sup 137}Cs anomaly zones detected in the deposits of the SW part of the Kara Sea. These anomaly zones were formed in the Ob' and the Enisey river estuaries due to the geochemical 'river-sea' boarder barrier. Level of radiocaesium specific activity reaches 120 Bq*kg{sup -1} in the deposits from these zones. Radiochemical enterprises occur in the both river basins. Their activity results in caesium-137 transfer into the river net. Vast area is contaminated by {sup 137}Cs after nuclear weapons in Semipalatinsk test-site and Kyshtym disaster in the Ob' river basin. Moreover, caesium comes to the Ob' and the Enisey river basins with global atmospheric fallout. The inflow of global fallout caesium-137 to the catchments is 660 kCi (320 kCi including radioactive decay) that is 4 times higher than {sup 137}Cs emission due to Fukushima disaster. Therefore, these river basins as any other huge catchment are an important sources of radioactive contamination of the Arctic Ocean. The aim of our research is to study behavior of global fallout caesium-137 in the landscapes of the Ob and the Enisey river basins. We studied caesium-137 behavior on the example of first order catchments in taiga, wetland, forest-steppe, steppe, and semi-arid landscapes. Geographic information system (GIS) was made. The tenth-order catchments (n=154, Horton coding system) shape 20-groups due to topsoil properties controlling cesium mobility. Eleven first-order basins, characterized 7 groups of tenth order catchments, were studied. And 700 bulk-core soil samples were collected in 2011-2013. Cesium runoff is calculated for 3 first-order river basins in taiga and forest-steppe landscapes. Storage of global fallout caesium-137 declines from undisturbing taiga first-order river basin (90% of cumulative fallout including radioactive decay)> arable steppe and fores-steppe (70 - 75%)> undisturbing wetland (60%). Caesium-137 transfer is high in arable lands

  1. Thermochemical data acquisition - Part II

    International Nuclear Information System (INIS)

    The study was a joint effort of the four laboratories AEA Harwell, Winfrith, ECN Petten and the Free University of Brussels. Thermochemical data have been determined for a number of fission product and reactor material compounds. Critical assessments have also been made of the available thermochemical data on a number of systems. These data complement the results from similar studies conducted in 1990 (see EUR 14004 EN), and can be used in the appropriate computer codes for calculations of the speciation and transport properties of the fission products during a severe reactor accident. The work load was subdivided as follows: experimental studies of Harwell, Winfrith and Petten (Chapters 1 to 7) have focused on the vaporization of tellurium dioxide, caesium ruthenate, strontium and barium borate, indium hydroxide, caesium telluride, caesium phosphate, caesium hydroxide and caesium iodate and on the thermodynamic properties of the condensed phases Cdl2, Cs2Cdl4, Cs2Si4O9, Cs2ZrO3, SrB4O7, and Ba3B2O6. Critical evaluations have been made of a number of tellurides of importance in severe accident assessments, and analysis have been made of the Fe-Te, Ni-Te and Cr-Te systems. Tables of thermodynamic properties over the temperature range 298.15 to 3 000 K are given. The data are believed to predict the fission product species and their transport in case of severe reactor accidents with greater confidence. The Free University of Brussels (Chapter 8) carried out thermodynamic studies of the systems Cs-Te, In-Te and Cs-In-Te using the mass spectrometric Knudsen cell method. The gas phases formed between 800 and 1 300 K were investigated and the partial pressure and relative ionization cross-sections of the system components were determined

  2. Influence of alkali and alkaline earth elements on the uptake of radionuclides by Pleurototus eryngii fruit bodies

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, J., E-mail: fguillen@unex.es [LARUEX, Dpt. Applied Physics, Faculty of Veterinary Science, University of Extremadura, Avda. Universidad, s/n, 10071 Caceres (Spain); Baeza, A.; Salas, A. [LARUEX, Dpt. Applied Physics, Faculty of Veterinary Science, University of Extremadura, Avda. Universidad, s/n, 10071 Caceres (Spain)

    2012-04-15

    In the literature, there are many data available on radionuclide contents and their transfer to different species of mushrooms. There are some variables, however, which affect the transfer but are very difficult to observe in collected wild mushrooms. An example is the effect of different concentrations of alkali and alkaline earth elements in the soil. Modification of these concentrations in the soil solution has traditionally been used as a countermeasure to deal with radioactively contaminated areas. In the present work, fruiting bodies of Pleurotus eryngii, a saprophytic mushroom, were grown under controlled laboratory conditions, varying the content of alkali (potassium and caesium) and alkaline earth (calcium and strontium) elements. The transfer of {sup 134}Cs, {sup 85}Sr, and {sup 60}Co (added to the cultures) and of natural {sup 210}Pb was analysed by increasing the content of each stable element considered. A significant, but nonlinear, enhancement of stable caesium and {sup 134}Cs was observed with increasing content of stable caesium in the substrate/mycelium. The transfer of {sup 85}Sr decreased with the addition of each stable cation, whereas the {sup 60}Co and {sup 210}Pb transfers were unaffected. - Highlights: Black-Right-Pointing-Pointer The addition of stable potassium did not affect the uptake of radiocaesium. Black-Right-Pointing-Pointer The addition of stable caesium increased the stable caesium and {sup 134}Cs content in the fruiting bodies of Pleurotus eryngii. Black-Right-Pointing-Pointer The addition of calcium reduced the content of calcium and {sup 85}Sr in the fruiting bodies. Black-Right-Pointing-Pointer These countermeasures did not work properly in the case of {sup 60}Co and {sup 210}Pb, no effect was observed.

  3. Soils electroremediation

    International Nuclear Information System (INIS)

    This paper presents data on decontamination experiments performed with soils contaminated by long-lived radioactive caesium isotopes. The contamination was formed about 30 years ago during an accident in the first nuclear power station in the former Czechoslovakia. Because of the large soil quantities that make excavation and storage of these soils in nuclear waste repositories inconvenient from economical and spatial point of view, various methods for in situ or ex situ remediation were sought and tested. For soil contamination by caesium, the time of contact of caesium with the soil is crucial because the caesium ions diffuse inside the crystalline structures of clay minerals where they are virtually irreversibly bound. For such materials, the efficiency of the classic 'soft' decontamination methods, such as leaching, phytoremediation etc., is rather low. Electrochemical decontamination was proposed as the decontamination technique for ex situ application. The method is based on electrolysis at a relatively high current density in a suitable electrolyte. The soil is kept in suspension close to the anode, and owing to the high acidity together with both the high temperature and ion flux, the soil structures are opened or partially disrupted and caesium ions are released. The ions can be separated from the solution, e.g., by using selective ion exchangers. The experimental electrolytic cell was designed for the treatment of thin soil layers containing about 3 g of the soil and about 100 mL of electrolyte. The influence of various system parameters, such as electrolyte composition, current-voltage, temperature, and time, on the decontamination efficiency was examined. In the most efficient configuration, a 99+% decontamination level was achieved. For the next step, a bench-scale apparatus was designed that should allow treatment of batches of up to 0.5 kg of soil in one step. (author)

  4. Formation of cold molecules through the photo-association of cold atoms of Cesium. Existence of long range forces between between cold excited atoms of Cesium; Formation de molecules froides par photoassociation d'atomes froids de cesium. Mise en evidence de forces a longue portee entre atomes froids excites de cesium

    Energy Technology Data Exchange (ETDEWEB)

    Comparat, D

    1999-09-01

    This thesis deals with the experimental study and the theoretical interpretation of the processes involved in photo-association and the formation of cold caesium molecules. It also presents a study of the dipolar forces between a pair of cold excited caesium atoms. We present here the first photo-association experiment on cold caesium atoms: two cold atoms absorb a photon to form an excited electronically excited molecules in a rotation-vibration level. The first production of cold molecules which was realised experimentally, after the spontaneous deexcitation of the photo-associated molecules, is described, stressing the role of the potential well of the molecular states O{sub g}{sup -}(6s+6p{sub 3/2}) or 1{sub u} (6s+6p{sub 3/2}) of caesium. The detection of the formed caesium molecules is based on a two-photons resonant ionisation that creates Cs{sub 2}{sup +} ions, afterwards selectively detected. Temperatures around 20-200 {mu}K have been measured. The photo-associative spectroscopy is described on the theoretical point of view: a detailed theoretical study allows to calculate precisely the asymptotic parts of the potential curves. On the experimental point of view, we present the spectroscopy of the extern potential well of the caesium state O{sub g}{sup -}(6s+6p{sub 3/2}) and the construction of an effective potential curve of the RKR type. A unified theory of photo-association in weak field, considered as a collision assisted by laser, is developed. The cold atoms experiments allow to study and control the collision between two atoms whose mutual interaction is of the dipole-dipole type. Two different physical systems are studied: a sample of Rydberg atoms, and the photo-association process which is a laser-assisted collision. A modification of the motion of one pair of atoms makes it possible to control the bipolar forces and to choose the atoms relative speeds. (author)

  5. Development of negative hydrogen ion sources for fusion: Experiments and modelling

    International Nuclear Information System (INIS)

    Graphical abstract: Large and powerful negative hydrogen ion sources have to be developed for the neutral beam injection system of the international fusion experiment ITER which is currently under construction. In order to fulfil the ITER requirements — high negative ion current densities and low co-extracted electron currents at low pressure operation (0.3 Pa) — caesium is seeded into the discharges which lowers the work function of the converter surface. The paper addresses the development program at the three test facilities of the Max-Planck-Institut für Plasmaphysik (IPP) in Garching. Emphasis is given on a comparison of deuterium with hydrogen operation as well as on the complex caesium chemistry and the plasma surface interaction which are at present the most critical issues for optimising the source performance. An insight into the plasma chemistry and the processes relevant for source optimisation is provided by the well diagnosed plasma accompanied by modelling which is strongly coupled to the physics relevant for the experiments. Highlights: ► Development of large and powerful negative hydrogen sources. ► Stable long pulse operation with caesium. ► Comparison of deuterium with hydrogen operation. ► Discussion on complex caesium dynamics. - Abstract: Large and powerful negative hydrogen ion sources have to be developed for the neutral beam injection system of the international fusion experiment ITER which is currently under construction. In order to fulfil the ITER requirements — high negative ion current densities and low co-extracted electron currents at low pressure operation (0.3 Pa) — caesium is seeded into the discharges which lowers the work function of the converter surface. The paper addresses the development program at the three test facilities of the Max-Planck-Institut für Plasmaphysik (IPP) in Garching. Emphasis is given on a comparison of deuterium with hydrogen operation as well as on the complex caesium chemistry and the

  6. Chemical aspects of fission product transport in the primary circuit of a light water reactor

    International Nuclear Information System (INIS)

    The transport and fission products in the primary circuit of a light water reactor are of fundamental importance in assessing the consequences of severe accidents. Recent experimental studies have concentrated upon the behaviour of simulant fission product species such as caesium iodide, caesium hydroxide and tellurium, in terms of their vapour deposition characteristics onto metals representative of primary circuit materials. An induction furnace has been used to generate high-density/structural materials aerosols for subsequent analysis, and similar equipment has been incorporated into a glove-box to study lightly-irradiated UO/sub 2/ clad in Zircaloy. Analytical techniques are being developed to assist in the identification of fission product chemical species released from the fuel at temperatures from 1000 to 25000C. Matrix isolation-infrared spectroscopy has been used to identify species in the vapour phase, and specific data using this technique are reported

  7. Monitoring of the general population with an installed whole body counter at West Cumberland Hospital, Whitehaven

    International Nuclear Information System (INIS)

    Body radioactivity in the general public has been measured in 395 volunteers in the Whitehaven area, using a whole-body monitor at West Cumberland Hospital. Between October 1986 and October 1987, estimates of total body radiocaesium in 240 volunteers ranged from below detection level to 1844 Bq with a mean of 415 Bq. From October 1987 until May 1988, a further 155 volunteers were monitored, and radiation levels ranged from 34 Bq to 685 Bq, with a mean of 257 Bq. In all volunteers, the ratio of body radiocaesium to body potassium, was well below unity. The average ratio of caesium-137 to caesium-134 from October 1987 to May 1988 was 3.28, corresponding to a ratio of 1.99 at the date of Chernobyl accident. This is consistent with a Chernobyl origin as the primary source for the radiocaesium. There were discernible, but not marked, trends of increasing body radiocaesium with milk and meat/fish consumption. (author)

  8. Saturation of Photoassociation in Cs Magneto-optical Trap

    Institute of Scientific and Technical Information of China (English)

    MA Jie; WANG Li-Rong; JI Wei-Bang; XIAO Lian-Tuan; JIA Suo-Tang

    2007-01-01

    An ultrahigh resolution photoassociation spectrum of caesium atoms in a magneto-optical trap is presented. Hyperfine structure of the excited state molecule is obtained by using the lock-in method based on modulated cold atoms in this spectrum. Amplitude of resonant lines related to the rotational levels increases with photoassociation laser intensity, and saturation effect of photoassociation of cold atoms is observed in our experiment. The saturation intensity of photoassociation is deduced by fitting the experimental data to a saturation model based on scattering theory. Differences among saturation intensities of different rotational progressions in the v = 55vibrational state of the caesium molecular long-range O-g state have been found.

  9. Contributions by emissions from nuclear installations to concentrations of radionuclides in milk

    CERN Document Server

    Green, N

    1983-01-01

    A year-long study has been carried out to determine whether milk produced near nuclear sites contains concentrations of radionuclides that can be attributed to discharges from the installations, and, as a consequence, whether there is enhanced exposure of those members of the public who consume this milk. Eight creameries were chosen and monthly samples of milk were taken for analysis. The concentrations of caesium-137 and strontium-90 were measured and compared with results from a national survey conducted as part of the Board's environmental radioactivity surveillance programme. No effect attributable to discharges from the nuclear establishments was identified. The activity concentrations ranged between 0.1 and 3 times the national average; the variation relates mainly to rainfall in the area, although other factors may also have an effect. However, milk contributes only a small fraction of the total dietary intake of caesium-137 and strontium-90, and so the exposure of persons consuming the milk varies on...

  10. Status of the atomic fountain clock at the National Research Council of Canada

    Science.gov (United States)

    Beattie, S.; Alcock, J.; Jian, B.; Gertsvolf, M.; Bernard, J.

    2016-06-01

    Despite the rapid advances in optical frequency standards, caesium fountain clocks retain a critical role as the most accurate primary frequency standards available. At the National Research Council Canada, we are working to develop a second generation caesium fountain clock. Work is currently underway to improve several systems of FCs1, such as the laser system and microwave local oscillator, which will be incorporated into its refurbished version, FCs2. In addition, we have added an optical pumping stage which has increased the detected atom number by over a factor of six. In collaboration with the National Physical Laboratory (NPL), we are planning on replacing the physics package of FCs1. We will report on several recent improvements to FCs1, along with our progress in the development of FCs2.

  11. WWER Expert System for Fuel Failure Analysis Using Data on Primary Coolant Activity

    International Nuclear Information System (INIS)

    The computer expert system for fuel failure analysis of WWER during operation is presented. The diagnostics is based on the measurement of specific activity of reference nuclides in reactor primary coolant and application of a computer code for the data interpretation. The data analysis includes an evaluation of tramp uranium mass in reactor core, detection of failures by iodine and caesium spikes, evaluation of burnup of defective fuel. Evaluation of defective fuel burnup was carried out by applying the relation of caesium nuclides activity in spikes and relations of activities of gaseous fission products for steady state operational conditions. The method of burnup evaluation of defective fuel by use of fission gas activity is presented in detail. The neural-network analysis is performed for determination of failed fuel rod number and defect size. Results of the expert system application are illustrated for several fuel campaigns on operating WWER NPPs. (authors)

  12. WWER expert system for fuel failure analysis using the RTOP-CA code

    International Nuclear Information System (INIS)

    The computer expert system for fuel failure analysis of WWER during operation is presented. The diagnostics is based on the measurement of specific activity of reference nuclides in reactor primary coolant and application of a computer code for the data interpretation. The data analysis includes an evaluation of tramp uranium mass in reactor core, detection of failures by iodine and caesium spikes, evaluation of burnup of defective fuel. Evaluation of defective fuel burnup was carried out by applying the relation of caesium nuclides activity in spikes and relations of activities of gaseous fission products for steady state operational conditions. The method of burnup evaluation of defective fuel by use of fission gas activity is presented in details. The neural-network analysis is performed for determination of failed fuel rod number and defect size. Results of the expert system application are illustrated for several fuel campaigns on operating WWER NPPs. (authors)

  13. Evaluation of 137Cs internal contamination in children by means of whole body counter measurements

    International Nuclear Information System (INIS)

    Two series of internal contamination measurements were performed on children from Byelorussia by means of whole body and urine counting. The body contamination was related to 134Cs and 137Cs emitted in the accident at the Chernobyl Nuclear Power Station on April 26, 1986. The data have been analysed in order to have an experimental estimation of the caesium metabolic parameters and make a comparison with those indicated in ICRP 56, point out the effect of sex and age in relation to 137Cs body activity and half-time of caesium long term retention fraction and obtain indications concerning the statistical distributions of internal contamination in children of both sexes living in different areas of Byelorussia. (author)

  14. Searching for an Oscillating Massive Scalar Field as a Dark Matter Candidate Using Atomic Hyperfine Frequency Comparisons.

    Science.gov (United States)

    Hees, A; Guéna, J; Abgrall, M; Bize, S; Wolf, P

    2016-08-01

    We use 6 yrs of accurate hyperfine frequency comparison data of the dual rubidium and caesium cold atom fountain FO2 at LNE-SYRTE to search for a massive scalar dark matter candidate. Such a scalar field can induce harmonic variations of the fine structure constant, of the mass of fermions, and of the quantum chromodynamic mass scale, which will directly impact the rubidium/caesium hyperfine transition frequency ratio. We find no signal consistent with a scalar dark matter candidate but provide improved constraints on the coupling of the putative scalar field to standard matter. Our limits are complementary to previous results that were only sensitive to the fine structure constant and improve them by more than an order of magnitude when only a coupling to electromagnetism is assumed. PMID:27541455

  15. Negative hydrogen ion production mechanisms

    International Nuclear Information System (INIS)

    Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed

  16. Spatial 137Cs distribution in forest soil

    International Nuclear Information System (INIS)

    This work presents the distribution of radioactive caesium in several types of forest soil originating from the Lesisko reserve (Opole Province, Poland). Vertical distribution of 137Cs isotope was determined in the profiles related to physicochemical properties of different types of soils and their location. Thickness of emerging genetic horizons, structure and morphology of soil profiles were determined. The highest 137Cs activities were found in Of and A horizons. At the same time, there was a sudden drop of 137Cs activity in mineral horizons of soil profiles. By analysis of caesium radioisotope content and its distribution in soil profiles significant correlations were observed between certain physicochemical properties (e.g. pH value, hydrolytic acidity, granulometric composition) of soils in selected forest habitats. (author)

  17. National survey of human body radioactivity measured by a mobile whole-body counter and installed whole-body counters

    International Nuclear Information System (INIS)

    Body radioactivity in the general public has been measured in 2339 volunteers throughout the U.K. A mobile whole-body monitor visited collaborating Medical Physics Departments and data were also contributed by Medical Physics Departments possessing installed counters. Levels of body radiocaesium ranged from below detection level to 4149 Bq. Radiocaesium levels were normalised by dividing by the content of natural body potassium-40. In all cases, the dose rate to the body from radiocaesium was less than that from potassium-40. Radiocaesium levels were 2-3 times higher in N.W. England, Scotland and N. Wales than the rest of the country, but this factor is much less than the variation in deposition of Chernobyl radiocaesium. This discrepancy may be accounted for by the nationwide distribution of foodstuffs. At all sites where volunteers were monitored, the ratio of caesium-137/caesium-134 was consistent with a radiocaesium intake attributable primarily to fallout from the Chernobyl fire. (author)

  18. Radiocaesium in the seas of northern Europe: 1980-84

    International Nuclear Information System (INIS)

    A computer data base of measurements of caesium-134 and caesium-137 in sea water has been compiled. The measurements were carried out by the UK Ministry of Agriculture, Fisheries and Food and include data for the Irish Sea, Bristol Channel, English Channel, North Sea, Scottish waters and other parts of the marine environment of northern Europe. This report covers the sampling period 1980-84 and further information will be published as the data base is expanded. It is hoped that the information will be useful to scientists modelling radionuclide dispersion in the area. In order to assist in the development of new models, diskettes of the data in ASCII files are available, on request, from the first author. The data include the locations of sample collection, collection date, depth salinity, concentration of activity and counting errors. Plots of the geographical scope of the data are also provided to assist the user. (author)

  19. Searching for an oscillating massive scalar field as a dark matter candidate using atomic hyperfine frequency comparisons

    CERN Document Server

    Hees, A; Abgrall, M; Bize, S; Wolf, P

    2016-01-01

    We use six years of accurate hyperfine frequency comparison data of the dual Rubidium and Caesium cold atom fountain FO2 at LNE-SYRTE to search for a massive scalar dark matter candidate. Such a scalar field can induce harmonic variations of the fine structure constant, of the mass of fermions and of the quantum chromodynamic mass scale, which will directly impact the Rubidium/Caesium hyperfine transition frequency ratio. We find no signal consistent with a scalar dark matter candidate but provide improved constraints on the coupling of the putative scalar field to standard matter. Our limits are complementary to previous results that were only sensitive to the fine-structure constant, and improve them by more than an order of magnitude when only a coupling to electromagnetism is assumed.

  20. Realization of a time-scale with an optical clock

    CERN Document Server

    Grebing, C; Dörscher, S; Häfner, S; Gerginov, V; Weyers, S; Lipphardt, B; Riehle, F; Sterr, U; Lisdat, C

    2015-01-01

    Optical clocks are not only powerful tools for prime fundamental research, but are also deemed for the re-definition of the SI base unit second as they surpass the performance of caesium atomic clocks in both accuracy and stability by more than an order of magnitude. However, an important obstacle in this transition has so far been the limited reliability of the optical clocks that made a continuous realization of a time-scale impractical. In this paper, we demonstrate how this dilemma can be resolved and that a time-scale based on an optical clock can be established that is superior to one based on even the best caesium fountain clocks. The paper also gives further proof of the international consistency of strontium lattice clocks on the $10^{-16}$ accuracy level, which is another prerequisite for a change in the definition of the second.

  1. Estimation and forecast of the radiation situation on the territory of the republic of Belarus after the Chernobyl NNP catastrophe

    International Nuclear Information System (INIS)

    During 10 years after the accident et the ChNPP the large amounts of the date on the content of radionuclides in the soil have been collected, using the network of the radiation monitoring stations. In the after-accident period, the aerial photography of the territory of Belarus has been done, all populated areas have been investigated, including the agricultural and forest areas. The information has been processed with use of the geoinformation RECASS system of construction of maps of distribution of caesium-137, strontium-90 and plutonium isotopes on the territory of the Republic. The maps of the distribution of caesium-137, strontium-90 and plutonium isotopes on the territory of Belarus after the accident have been presented. (author)

  2. Searching for an Oscillating Massive Scalar Field as a Dark Matter Candidate Using Atomic Hyperfine Frequency Comparisons

    Science.gov (United States)

    Hees, A.; Guéna, J.; Abgrall, M.; Bize, S.; Wolf, P.

    2016-08-01

    We use 6 yrs of accurate hyperfine frequency comparison data of the dual rubidium and caesium cold atom fountain FO2 at LNE-SYRTE to search for a massive scalar dark matter candidate. Such a scalar field can induce harmonic variations of the fine structure constant, of the mass of fermions, and of the quantum chromodynamic mass scale, which will directly impact the rubidium/caesium hyperfine transition frequency ratio. We find no signal consistent with a scalar dark matter candidate but provide improved constraints on the coupling of the putative scalar field to standard matter. Our limits are complementary to previous results that were only sensitive to the fine structure constant and improve them by more than an order of magnitude when only a coupling to electromagnetism is assumed.

  3. Report of the radiological protection procedures adapted in the Goiania General Hospital for assistance to the victims of the radiological accident with Cesium 137

    International Nuclear Information System (INIS)

    A caesium-137 capsule, illegal removed from a desactivated health center of the Instituto Goiano de Radioterapia, was disrupted causing a serious radiological accident. The dimensions of the accident were worsened due to some facts such as: the caesium-137 was in the chloride from, which is a very soluble compound the accident was notify to the competent authorities only several days after the capsule was removal and during this period of time some people handled the souce directly, without knowing its potential danger. This paper descibes the measures adopted in the Goiania General Hospital to restrict the exposure of workers and members of the public and to minimize the consequences of unavoidable exposures in such a way to assure that the annual dose limits were not exceeded. An efficiency evaluation of the methods adopted for the decontamination of the victims was made and its described in the report. (author)

  4. Evaluation of decontamination method conducted at children's parks located in Chiba prefectural housing complexes

    International Nuclear Information System (INIS)

    This study evaluates the decontamination methods that were examined at 4 different children's parks located in Chiba prefectural housing complexes with measurement of 1cm dose equivalent rate, monitoring γ ray count rates of playground equipment surface, and determining the concentration of radioactive caesium in the soil. Two decontamination methods were examined. 1) Stripped and removed the topsoil containing radioactive caesium in the range of 3 - 5cm depth, subsequently coverage with uncontaminated soil to the thickness of 3cm to the subsoil layer. 2) Replacement with uncontaminated sand 20cm depth in sandbox. Range of the observed 1cm dose equivalent reduction rate were 41 - 91%. With the combination of these decontamination methods described above, the measurement value of 1cm dose equivalent rate decreased below 0.23μSv/h. The results of this study indicate that decontamination processes performed at children's parks showed significant efficacy. (author)

  5. Results of the Black Sea and Baltic Sea radioactive pollution monitoring in 1986-1992 years

    International Nuclear Information System (INIS)

    The results of the Black Sea and the Baltic Sea radioactive pollution regular monitoring carried out from June 1986 till present time are presented.It is revealed that after the Chernobyl Nuclear Power Station accident a considerable amount of long-lived radionuclides got into the Black Sea and the Baltic Sea in May-June of 1986. The conclusion about the atmospheric transport as the main source of radionuclide coming into the marine environment of the Black Sea was substantiated. The data on the vertical profile of the radioactive caesium distribution on years of observation are presented. This results make it possible to judge about the rate of penetration of the products of the accident into the deep layers of sea. It is shown that caesium-137 concentration in the estuarine waters of Dnieper and in the Dnieper-Bug Liman is ten times lower than in the open areas of the Black Sea

  6. Experimental investigation of the radiation exposure of inhabitants of contaminated areas in Northern Ukraine

    International Nuclear Information System (INIS)

    Large areas of northern Ukraine have been contaminated as a consequence of the accident of Chernobyl in April 1986 with various radionuclides from the reactor. Presently, of all the radionuclides of the Chernobyl-fallout, mainly 137Cs is dangerous for those people, who are occasionally returning to the contaminated areas, after having been evacuated ten years ago. These persons are, besides some exceptions, living from what they plant, produce and collect there. For the question of resettlement it is important to estimate the radiation exposure from the remaining caesium in the soil. In order to access the external radiation exposure, deposition and downward migration of 137Cs were examined in different contaminated areas of the Ukraine. To measure the internal radiation exposure of the returned habitants, the transfer of fallout-caesium from the soil via relevant food to man has been examined under the conditions of the contaminated villages by freeland- and feeding-experiments in an animal model. (orig.)

  7. Presentation and analysis of a model simulating the response of potash treatment of lakes

    International Nuclear Information System (INIS)

    The potassium concentration in a lake may influence the caesium levels in lake biota. The biouptake and potential ecosystem effects of a caesium fall-out can be limited by addition of potassium, for example, by a potash treatment. This work presents for the first time a simple and practically useful model to facilitate the planning and to predict the outcome of potash treatments by simulating the processes that regulate the water chemical response of such a treatment. The model is a mixed model in the sense that it contains both statistical regressions and dynamic interactions within a lake ecosystem. This paper focuses on the dynamic processes and gives both calibrations and extensive validations of the model. A few examples on the practical use of the model are presented. The results indicate that the model, using only easily accessible input data, can, in fact, give good predictions on the increase and duration in potassium concentration following a potash treatment. (author)

  8. Validation of Cs-137 measurement in food samples using gamma spectrometry system

    International Nuclear Information System (INIS)

    Cs-137 was found to be one of major radionuclide contaminant present in foods consumed by human. In some countries, regulations required consumption foods moving in international trade to be scanned for caesium (Cs-134 and Cs-137) to ensure it does not exceeding the maximum permissible level. This is to ensure that the intake of such foods will not accumulate radionuclide until the significant level inside the human body. Gamma Spectrometry System was used to perform the measurement of caesium isotopes, because it was one of the easiest methods to be performed. This measuring method must be validated for several parameters include specificity, precision (repeatability), bias (accuracy), linearity, range, detection limit, robustness and ruggedness in order to ensure it is fit for the purpose. This paper would summarise how these parameters were fulfilled for this analytical method using several types certified reference materials. The same validated method would be considered workable on Cs-134 as well. (Author)

  9. Changes in the tryptophan fluorescence in gamma-irradiated human haemoglobin

    International Nuclear Information System (INIS)

    The effect of gamma-radiation on human haemoglobin was studied by means of fluorescence spectroscopy. Irradiation with doses in the range of 0-2.4 Mrad led to an increase in fluorescence intensity, and a red shift of the fluorescence maximum. Such spectral changes should be attributed mainly to a more polar environment of tryptophan residues in irradiation haemoglobin caused by protein unfolding and to a concomitant increase in separation between tryptophan residues and haem groups. Differences in fluorescence intensity but not spectral distribution between control and irradiated samples denatured in guanidinium hydrochloride indicate a radiation-induced decrease in tryptophan content. Fluorescence quenching by caesium ions was observed in irradiated haemoglobin but not in native haemoglobin. The Stern-Volmer constant calculated for caesium quenching indicates tht the fraction of tryptophan residues accessible to the quencher increases after irradiation. (author)

  10. Immobilisation of hazardous waste

    International Nuclear Information System (INIS)

    Hazardous waste, e.g. radioactive waste, particularly that containing caesium-137, is immobilised by mixing with cement and solidifiable organic polymeric material. When first mixed, the organic material is preferably liquid and at this time can be polymerisable or already polymerised. The hardening can result from cooling or further polymerisation e.g. cross-linking. The organic material may be wax, or a polyester which may be unsaturated and cross-linkable by reaction with styrene. (author)

  11. Radioactivity in the Canadian environment

    International Nuclear Information System (INIS)

    A report by the National Research Council of Canada Associate Committee on Scientific Criteria for Environmental Quality summarizes data on exposures of human and non-human biota to radioactivity. For the radionuclides tritium, krypton 85, strontium 90, iodine 131, caesium 137, radium 226, radon 222 and plutonium 239. The report gives details of radioactive transformations, production, release, nuclear data, deposition, pathways for irradiation of human beings, occupational exposures, escape to the atmosphere, and annual limits on uptake. (D.N.)

  12. Restriction endonuclease analysis of Aspergillus fumigatus DNA.

    OpenAIRE

    Burnie, J P; Coke, A.; Matthews, R. C.

    1992-01-01

    AIMS: To develop a genome based DNA fingerprinting system for Aspergillus fumigatus mould. METHODS: DNA was extracted from 21 isolates obtained from eight patients with an aspergilloma. This was with a freeze-dried mycelial extract fragmented in liquid nitrogen. DNA was subsequently purified by phenol-chloroform extraction followed by ultracentrifugation on a caesium chloride gradient. The DNA was restricted by EcoRI and Xba I. RESULTS: All isolates were identical when cut by EcoRI; Xba I del...

  13. Performance of dose calibrators used for nuclear medicine services

    International Nuclear Information System (INIS)

    This work show the results of the quality control tests from two different dose calibrators of a Nuclear Medicine Clinic in Sao Paulo. One of them has an ionization chamber (well type) and the other, Geiger-Mueller detectors (well configuration). As reference sources, Cobalt-57, Barium-133 and Caesium-137 were utilized. Also, an unsealed Technetium-99m source was used in some tests. Finally, the performance of both instruments was compared. (author)

  14. Ascophyllum nodosum (L.) Le Jolis as a bioindicator of radioactivity in the Irish Sea

    OpenAIRE

    Bourne, G S; Assinder, D J

    1991-01-01

    The response of Ascophyllum nodosum to a sudden increase in radioactivity analogous to a nuclear incident is examined in the field. super(137)Cs, super(241)Am and super(239+240)Pu showed net accumulation with exposure time, unlike natural super(228)Th, which was used as a control. Caesium had the highest accumulation rate followed by americium and finally plutonium. Younger plant sections were found to accumulate all the radionuclides significantly faster than older plant sections. Americium ...

  15. Historie závažných havárií na jaderných zařízeních

    OpenAIRE

    DRAŽANOVÁ, Kristýna

    2016-01-01

    The bachelor thesis maps all the accidents assessed by the INES scale level 5 and above. It is not only concerning events at nuclear power plants, but also at nuclear weapons production facilities, whose construction preceded the development of the nuclear power plants in several countries. An attention is paid also to the unfortunate event, which was originated as a result of unauthorized manipulation with a part of the radiotherapy device containing radioactive isotopes of caesium 137Cs. Th...

  16. Review of countermeasures used in agriculture following a major nuclear accident

    International Nuclear Information System (INIS)

    Various accident scenarios for the contaminated agricultural environment are presented and various countermeasures with their advantages and disadvantages are discussed. The important pathways for exposure are external irradiation and uptake into the food chain. The alpha emitting nuclides can enter the food chain but, in addition, they present a hazard through the inhalation of resuspended material. The countermeasures discussed focus on caesium, strontium and plutonium but they would also be effective on most other radioelements. Radionuclides may be removed from land by taking away vegetation and/or a layer of soil or by being mixed into the soil. Land management techniques involving the addition of chemicals offer some attractive alternatives to soil disturbance. On soils with low calcium content, strontium uptake may be reduced by the addition of calcium, and caesium uptake can be reduced by the addition of potassium. Production of fruit and vegetables might be replaced by the production of oil crops or sugar. Some food processing methods would result in the extraction of the contamination and prevent it from entering the food chain. In upland areas of low fertility, the generally organic soils lead to enhanced uptake of radiocaesium and subsequent contamination of domestic grazing animals. In these cases, little can be done in terms of treatment of the land, but food additives have been employed successfully to render caesium less available for gut uptake. The animals can then be fed for just a matter of days or weeks to reduce their body burdens to an acceptable level. In some cases, the soil's own defence mechanism would be effective and no action other than suppression of resuspension would be called for: this would apply to strontium on calcareous soils and caesium on clay soils. An advance knowledge of the sensitivity of the various soils with respect to potential radioactive contaminations would be of benefit in the event of a nuclear accident. (author

  17. Immobilization of RF and IDA ion-exchange resins in cement at WIP Kalpakkam. Contributed Paper PE-02

    International Nuclear Information System (INIS)

    Radio-cesium and radio-strontium are the main isotopes present in the Intermediate level waste (ILW) generated from Kalpakkam Reprocessing Plant (KARP). Indigenously developed Resorcinol Formaldehyde (RF) poly condensate resin and Imino-diacetic acid (IDA) resin are used to remove caesium and strontium from ILW. The spent resins are fixed in Ordinary Portland Cement (OPC). The cured homogeneous samples were examined for compressive strength and leach rate. The leach rates are estimated on sodium basis and Cesium-137 basis. (author)

  18. Radioactive contamination in sediments near the sunken nuclear submarine Komsomolets, SW of Bear Island in the Norwegian Sea

    OpenAIRE

    Flo, Janita Katrine

    2014-01-01

    The Soviet nuclear submarine Komsomolets sank on the 7th of April 1989, 185 km southwest of the Bear Island in the Norwegian Sea to a depth of about 1655 m. The submarine contains one nuclear reactor, containing long-lived radionuclides such as caesium-137 (137Cs) along with other fission and activation products, in addition to two mixed uranium (U)/plutonium (Pu) nuclear warheads containing weapons grade plutonium. The Institute of Marine Research (IMR) has, in cooperation with the Norwe...

  19. Radiation monitoring of local foodstuffs in some settlements in Belarus located not far from woodlands

    International Nuclear Information System (INIS)

    Here are the results of radiation monitoring performed by the local centres for radiation control in some settlements located in radiation contaminated territories not far from woodlands. It is shown that within the decennial period from 1993 to 2003 the Caesium 137 radiation contamination of mushrooms, game and milk from private household makes significant values and do not have the decreasing tendency. It is recommended to use possible radioprotective measures of the population under above stated circumstances. (authors)

  20. Gramicidin-mediated currents at very low permeant ion concentrations.

    OpenAIRE

    Hainsworth, A H; Hladky, S B

    1987-01-01

    Current-voltage relations have been measured for the fluxes of caesium ions through pores formed by gramicidin in lipid bilayer membranes. The ionic currents have been separated from capacitative currents using a bridge circuit with an integrator as null-detector. The conductances during brief voltage pulses were small enough to avoid the effects of diffusion polarization and the ionic strength was raised using choline chloride or magnesium sulfate to reduce the effects of double-layer polari...

  1. Status of non-destructive bunch length measurement based on coherent Cherenkov radiation

    CERN Document Server

    Zhang, Jianbing; Yu, Tiemin; Deng, Haixiao; Shkitov, Dmitry; Shevelev, Mikhail; Naumenko, Gennady; Potylitsyn, Alexander

    2013-01-01

    As a novel non-destructive bunch length diagnostic of the electron beam, an experimental observation of the coherent Cherenkov radiation generated from a dielectric caesium iodide crystal with large spectral dispersion was proposed for the 30MeV femtosecond linear accelerator at Shanghai Institute of Applied Physics (SINAP). In this paper, the theoretical design, the experimental setup, the terahertz optics, the first angular distribution observations of the coherent Cherenkov radiation, and the future plans are presented.

  2. Atom gravimeters and gravitational redshift

    CERN Document Server

    Wolf, Peter; Borde, Christian J; Reynaud, Serge; Salomon, Christophe; Cohen-Tannoudji, Claude; 10.1038/nature09340

    2010-01-01

    In a recent paper, H. Mueller, A. Peters and S. Chu [A precision measurement of the gravitational redshift by the interference of matter waves, Nature 463, 926-929 (2010)] argued that atom interferometry experiments published a decade ago did in fact measure the gravitational redshift on the quantum clock operating at the very high Compton frequency associated with the rest mass of the Caesium atom. In the present Communication we show that this interpretation is incorrect.

  3. Experimental Research of Spontaneous Evolution from Ultracold Rydberg Atoms to Plasma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lin-Jie; FENG Zhi-Gang; LI An-Ling; ZHAO Jian-Ming; LI Chang-Yong; JIA Suo-Tang

    2008-01-01

    @@ The spontaneous evolution from ultracold Rydberg atoms to plasma is investigated in a caesium MOT by using the method of field ionization. The plasma transferred from atoms in different Rydberg states (n = 22-32) are obtained experimentally. Dependence of the threshold time of evolving to plasma and the threshold number of initial Rydberg atoms on the principal quantum number of initial Rydberg states is studied. The experimental results are in agreement with hot-cold Rydberg-Rydberg atom collision ionization theory.

  4. Polymorphism in Cs[AgZn(NCS)4].

    Science.gov (United States)

    Güneş, Minna; Valkonen, Jussi

    2002-12-01

    The title compound, caesium silver zinc tetrathiocyanate, crystallizes in two polymorphic forms, in space groups P2(1)/n and C2/c. Both structures form a continuous three-dimensional network. The structure in C2/c contains a delocalized Ag atom in a binuclear-like anion, where two [Ag(NCS)(4)] units (delocalized Ag as an average) share two common NCS(-) ligands. PMID:12466595

  5. Radioactive fallout in air and rain: results to the end of 1976

    International Nuclear Information System (INIS)

    Samples of atmospheric dust and rainwater have been collected from the United Kingdom and elsewhere. Results are presented an analyses of these samples for various fission products and certain other radionuclides. The average concentration of the long-lived fission product caesium-137 in air in the United Kingdom was, in 1976, about one-third of that in 1975 and about 1% of the maximum which was reached in 1963 to 64. The concentration in rain and the deposition of caesium-137 and strontium-90 averaged over the United Kingdom for 1976 were about half those for 1975. No barium-140 or iodine-131, indicative of recent atmospheric tests, was detected in the United Kingdom after the Chinese explosion on 24 January 1976 but measurable concentrations were detected in air at Hong Kong during February. Fresh activity from the Chinese explosion on 26 September 1976 was detected in the United Kingdom. The peak deposition of iodine-131 that occurred in the second week in Octber was greater than at any time since January 1963 although the total deposition of iodine-131 was less than one-tenth of that in 1962 to 63. Trace amounts of fresh activity attributable to the high-yield Chinese explosion of 17 November were detected in the United Kingdom in December 1976. In the southern hemisphere the mean concentration of caesium-137 in air in 1976 was about half that in 1975. An estimate is made of the worldwide deposit of caesium-137 and strontium-90. The gamma and beta-ray dose rates from fallout at Chilton are estimated from the observed deposition. Measurements of short-lived fission products in air and rain are given in an Appendix. (author)

  6. AErP.sub.2./sub.O.sub.7./sub. (A = Rb, Cs) and HEuP.sub.2./sub.O.sub.7./sub..3H.sub.2./sub.O: Crystal structures, vibrational studies and thermal behaviours

    Czech Academy of Sciences Publication Activity Database

    Essehli, R.; Lamhamdi, A.; Tahiri, A. A.; El Bali, B.; Mejdoubi, E.; Dušek, Michal; Fejfarová, Karla

    2012-01-01

    Roč. 42, č. 5 (2012), s. 475-485. ISSN 1074-1542 R&D Projects: GA ČR(CZ) GAP204/11/0809 Institutional research plan: CEZ:AV0Z10100521 Keywords : erbium * europium * rubidium * caesium * diphosphate * crystal structure * TG and TDA * IR and Raman Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.513, year: 2012

  7. Food irradiation facilities at Trombay

    International Nuclear Information System (INIS)

    The process parameters for radiation preservation of foods including grain, fruits, vegetables and seafoods are being evaluated with the experimental cobalt-60 and caesium-137 irradiators. The design features of three irradiators that are being used were considered mainly on the basis of obtaining variable throughputs and variable dose rates, making these facilities flexible for operation for a variety of purposes and the products. The paper highlights certain aspects of these irradiators, modifications carried out, dosimetry and maintenance requirements. (auth.)

  8. Training the Trainers in the Use of Fallout Radionuclide-Based Techniques for Assessing Land Degradation and Improving Soil Conservation Strategies

    International Nuclear Information System (INIS)

    The objective of this course was to train the fellows in the use of Fallout Radionuclides (FRNs) with an emphasis on the application of the radio-caesium tracer technique (i.e. 137Cs) to study soil erosion. The training aimed to transfer to the participants knowledge on tracking and quantifying soil redistribution at various spatial and temporal scales (from field to watershed scale) to improve soil resource sustainability and evaluate the effectiveness of soil conservation measures

  9. Accumulation radionuclides bodes of living cover plants woods cenosis

    International Nuclear Information System (INIS)

    Features of accumulation radionuclides by bodies of living cover plants woods cenosis are investigated. Researches have shown, that in elevated bodies kinds now in the greater measure strontium 90, than caesium 137 is accumulated. In root systems accumulation radionuclides is lower, than in elevated bodies. There is a specific specificity of accumulation radionuclides various bodies of plants. Accumulation radionuclides depends on weather conditions of year of supervision

  10. Experimental Research of Spontaneous Evolution from Ultracold Rydberg Atoms to Plasma

    International Nuclear Information System (INIS)

    The spontaneous evolution from ultracold Rydberg atoms to plasma is investigated in a caesium MOT by using the method of field ionization. The plasma transferred from atoms in different Rydberg states (n = 22-32) are obtained experimentally. Dependence of the threshold time of evolving to plasma and the threshold number of initial Rydberg atoms on the principal quantum number of initial Rydberg states is studied. The experimental results are in agreement with hot-cold Rydberg–Rydberg atom collision ionization theory

  11. Experimental Test of Alternating-Current Zeeman Interference Effect in Ramsey Separated Oscillating Fields

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-Hai; WANG Feng-Zhi; YANG Dong-Hai

    2004-01-01

    An experimental test of ac Zeeman effect in an optically pumped caesium beam frequency standard is reported and analysed. An interference pattern of the atomic energy level shift as a function of the applied microwave field near the atomic transition frequency was observed. It was superimposed on the dispersion lineshape of a normal ac Zeeman effect. This effect was analysed with the atomic wavefunction phase analysing method.

  12. Magneto-optic spectroscopy with linearly polarized modulated light: Theory and experiment

    OpenAIRE

    Bevilacqua, Giuseppe; Breschi, Evelina

    2014-01-01

    We investigate the polarization modulation between two linear orthogonal states of the laser beam that synchronously pumps time-dependent atomic alignment in caesium atoms exposed to a static magnetic field. Because of the atomic alignment symmetry two independent groups of resonances can be distinguished in the transmitted light: when modulation frequency matches either the Larmor frequency or its second harmonics, ωL and 2ωL, respectively. We report on our experiments, and discuss a model t...

  13. Laser cooling and trapping of atoms

    OpenAIRE

    Townsend Christopher G.

    1995-01-01

    A detailed experimental and theoretical investigation of a magneto-optical trap for caesium atoms is presented. Particular emphasis has been placed on achieving high spatial number densities and low temperatures. Optimizing both of these together enables efficient evaporative cooling from a conservative trap, a procedure which has recently led to the first observations of Bose-Einstein condensation in a dilute atomic vapour. The behaviour of a magneto-optical trap is nomina...

  14. Exploring techniques applied to select a candidate repository site for cesium-137 radioactive waste from the Goiania accident

    International Nuclear Information System (INIS)

    A methodology covering aspects of geosciences such as geophysical, geochemical, hydrogeological, geotechnical and surface geological research, were applied to select a candidate site for caesium-137 waste deposition from the Goiania accident. Among the options one with the best characteristics was selected, located about 300 meters west from the provisional site. This article presents a summary of the studies involved. (B.C.A.). 10 refs, 01 fig, 02 tabs

  15. Management of the radioactive wastes arising from the accident in Goiania, Brazil

    International Nuclear Information System (INIS)

    The radiological accident that occurred during the month of September, 1987, in Goiania, Brazil, involving a 50,9 TBq (1375 Ci) of a Caesium-137 source has led to the contamination of a large number of individuals and several urban area. The objective of the present article is to describe the waste management program that was implemented in order to deal with the c.a. 3340 m3 of wastes generated as a result of decontamination works performed

  16. Transmissible mupirocin resistance in Staphylococcus aureus.

    OpenAIRE

    Rahman, M.; Noble, W. C.; Cookson, B

    1989-01-01

    The spread of two strains of Staphylococcus aureus with high level resistance to mupirocin is described. The resistance proved to be easily transferred to other S. aureus strains by filter mating experiments and on the skin of mice. No plasmid band corresponding to the resistance could be demonstrated by agarose gel electrophoresis or by caesium chloride gradient centrifugation but cleavage of 'chromosomal' DNA from resistant recipients showed bright bands of DNA absent from sensitive controls.

  17. Selective decontamination of cesium and strontium from evaporation concentrates of spent fuel reprocessing plants with crown ethers by transport through supported liquid membranes

    International Nuclear Information System (INIS)

    Reprocessing operations lead to the production of radioactive medium activity liquid waste which is treated by evaporation and solutions of very high salinity are thus formed. The concentrates from reprocessing plant evaporators have to be stored in geological storage sites in view of their strong caesium, strontium and actinides activity. These elements, contained in acid and high sodium nitrate content liquid waste, are removed by means of selective extractants, using the supported liquid membrane technique (SLM), which allows them to be stored in surface sites, the actinides and long-life fission products being respectively recycled and concentrated into reduced volumes. The removal of the actinides is done by means of an Octyl N.N Diisobutyl Carbamoyl Methyl Phosphine Oxide (C.M.P.O.) based liquid membrane, whereas the removal of the caesium and strontium involves crown ethers. Supported liquid membranes (S.L.M.s) have the advantage of implementing very small quantities of extractant, but they generally have poor stability. The extractant, the diluent and the phase modifier impregnating the membrane play a vital role in SLM stability; the support also affects stability by its nature and geometry. For the extraction of strontium, the most lipophilic extractant, DtBu 18 C 6, enables higher strontium transfer kinetics to be attained. As regards caesium, the extremely lipophilic nDec B21 C7 is the most efficient. Caesium cannot be quantitatively removed, due to the competition of the very high content of sodium ions in the concentrate. Stable membranes are obtained with DC18 C6 or DtBu18 C6 diluted in alkylbenzenes with an added phase modifier such as decanol or especially isotridecanol

  18. Comparison of the measured specific activities of cesium in mushrooms, pine tree twigs, blueberries, honey and game in Aachen after 1986

    International Nuclear Information System (INIS)

    After the nuclear reactor accident at Chernobyl the specific activity in mushrooms originating from the region of Aachen was continuously measured until today. At the same time the specific activity was determined in pine tree twigs, blueberries, honey and game. There is a strong connection of the living organisms and the inanimate environment within the forest ecosystem. The decrease of the specific caesium activity in living organisms is slower than in the other environment. (orig.)

  19. Is Scottish honey radioactive?

    International Nuclear Information System (INIS)

    Eleven samples of heather honey harvested in 1993 from 9 locations in SW Scotland were analysed for radioactive isotopes of caesium. All contained 137Cs (52-690 Bq/kg) and 10 contained 134Cs (1.3-21 Bq/kg); in most samples the concentration was close to the detection limit. The activity ratio for these isotopes suggested that 90% of the activity resulted from the Chernobyl accident

  20. Selective decontamination for cesium and strontium in evaporation concentrates from reprocessing plants with crown ethers by transport through supported liquid membranes

    International Nuclear Information System (INIS)

    Reprocessing operations lead to the production of radioactive medium activity liquid waste which is treated by evaporation. The concentrates from reprocessing plant evaporators have to be stored in geological storage sites in view of their strong caesium, strontium and actinides activity. These elements, contained in acid and high sodium nitrate content liquid waste, are removed by means of selective extractants, using the supported liquid membrane technique (SLM), which allows them to be stored in surface sites, the actinides and long-life fission products being respectively recycled and concentrated into reduced volumes. The removal of the actinides is done by means of an Octyl N.N Diisobutyl Carbamoyl Methyl Phosphine Oxyde (C.M.P.O.) based liquid membrane, whereas the removal of the caesium and strontium involves crown ethers. Supported liquid membranes (S.L.M.s) have the advantage of implementing very small quantities of extractant, but, they generally have poor stability. The extractant, the diluent and the phase modifier that constitute the organic phase impregnating the membrane play a vital role in SLM stability; the support also affects stability by its nature and geometry. For the extraction of strontium, DtBu 18 C6 enables higher strontium transfer kinetics to be attained than with DC18 C6. As regards caesium, nDec B21 C7 is the most efficient. Unlike strontium, caesium cannot be quantitatively removed, due to the competition of sodium ions in the concentrate. Stable membranes are obtained with DC18 C6 or DtBu18 C6 diluted in alkylbenzene with an added phase modifier such as decanol or isotridecanol. The highest strontium transfer kinetics were obtained with the DC18 C6/hexylbenzene/isotridecanol mixture

  1. Influence of chronic irradiation of tobacco and carrot plants on the regeneration in the tissue culture

    International Nuclear Information System (INIS)

    The influence of chronic irradiation of tobacco and carrot donor plants on the regeneration processes in vitro has been studied. The plants were grown on the soil containing different concentrations of caesium-137 and strontium-90. The morphogenesis intensity was decreased after irradiation of the tobacco plants by the dose of 0,5 Gy and the carrot plants by the dose of 0.07-0.4 Gy

  2. Experimental comparison of gamma attenuations by glasses, lead, iron and concretes

    International Nuclear Information System (INIS)

    The authors report the experimental determination, for lead glasses of density 3.3, 4.2, 5.2 and 6.2, of thicknesses equivalent to thicknesses given for lead, iron, ordinary concrete and barite concrete for Cobalt 60 and Caesium 137 radiations. Results are presented under the form of curves. Attenuation measurements made on this opportunity and those made on various hot cells have been compared with theoretical attenuation curves produced in another CEA document

  3. Fukushima Dai-Ichi and the Economics of Nuclear Decontamination

    OpenAIRE

    Alistair Munro

    2012-01-01

    Economic analysis of nuclear accidents and their aftermath is comparatively rare. In this paper, in the light of the Japanese government’s intensive efforts to decontaminate areas affected by radioactive Caesium from Fukushima dai-ichi nuclear power plant, we create a cost-benefit framework for assessing the merits of decontamination strategies. Using some benchmark data for Japan we estimate that optimal delay is positive for most reasonable parameter values. For low value land, optimal dela...

  4. Specific features of 137Cs migration and accumulation in chernozem soils of forest ecosystems in the zone contaminated due to the Chornobyl accident

    International Nuclear Information System (INIS)

    A number of factors influencing 137Cs fate and biological availability in chernozem soils under the forest vegetation were assessed for various climatic zones. The migration rates of 137Cs in the profile of chernozem soils were shown to depend primary on forest litter composition and structure. In the absence of forest litter the soil mineralogical composition and humus content become the most influential factors of caesium mobility

  5. Process for separating cesium ions from aqueous solutions

    International Nuclear Information System (INIS)

    A precipitation agent is added to the aqueous solution and the resulting precipitate containing Cs+ ions is separated from the solution. By this process, caesium is to be separated selectively compared with other alkaline metal ions with great efficiency from aqueous solutions, particularly aqueous MAW (medium activity waste). This is achieved by using a sodium tetraphenyl borate attracting electrons to the phenyl rings and having substitutes. (orig./PW)

  6. Analysis of the radioactive material adhering to doctor-helicopter in the disaster relief of the Great East Japan Earthquake

    International Nuclear Information System (INIS)

    We detected higher dose of radiation than background radiation from the surface of Doctor-Hericopter in the disaster relief of the great East Japan earthquake. We analyzed radionuclides emitting γ-rays with the Ge semiconductor detector, and detected fission products such as tellurium, iodine and caesium derived from the accident at Fukushima Daiichi Nuclear Power Plant. We reported the results of measuring a same sample in time course, and discussed on the decay of the sample in detail. (author)

  7. Structure, spectra and dynamics of alkali cation microhydration clusters

    OpenAIRE

    Schulz, Franziska

    2005-01-01

    The main focus of this work was the theoretical investigation of alkali cation microhydration clusters with sodium, potassium, and caesium as central ion and up to 24 water molecules per cluster. Structures were obtained applying global geometry optimisation, using a specialised version of genetic algorithms and the common TIP4P/OPLS model potential. The global and most important local minimum energy structures have been investigated and the results obtained constitute a first complete and sy...

  8. Situation review concerning the impact on the marine environment after the accident which occurred at the Fukushima Dai-Ichi power station - 6 November 2012

    International Nuclear Information System (INIS)

    After a brief recall of the accident, this document briefly describes the current situation of the installations (reactors, storage pools, releases), gives an overview of the different origins of sea pollution after the accident (atmospheric fallouts, liquid releases from the installations and due to rivers washing contaminated lands) and evokes some measurements of radioactive caesium made in some sea species. It finally briefly describes works performed by TEPCO to limit releases into the sea

  9. Radionuclide transfer in forest ecosystems

    International Nuclear Information System (INIS)

    The behaviour of radionuclides in forest ecosystems differs substantially from the other ecosystems. The contamination of various forest products is commonly quantified using the Aggregated Transfer Factor (Tag in m2 kg-1) which integrates various environmental parameters including soil and plant type, root distribution as well as nature and vertical distribution of the deposits. This review aims at compiling the most relevant quantitative information on radionuclide transfers to forest biota including trees, understorey vegetation, mushrooms, berries and game animals. For both radiocaesium and radiostrontium in trees, the order of magnitude of mean Tag values is 10-3 m2.kg-1 (dry weight). The transfer of radionuclides to mushrooms and berries is high, in comparison with foodstuffs grown in agricultural systems. Concerning caesium uptake by mushrooms, the transfer is characterized by a very large variability of Tag, from 10-3 to 101 m2.kg-1 (dry weight). For berries, typical values are around 0.01 to 0.1 m2.kg-1 (dry weight). Transfer of radioactive caesium to game animals and reindeer and the rate of activity reduction, quantified as an ecological half-life, reflect the soil and pasture conditions at individual locations. Even if, the importance of radioactive contamination of forests as a significant source of the population exposure is recognized, most of the data refer to caesium and to a lesser extent, strontium. Data for other radionuclides are rather limited. (author)

  10. Preparation and chemical crystallographic study of new hydrides and hydro-fluorides of ionic character

    International Nuclear Information System (INIS)

    Within the context of a growing interest in the study of reversible hydrides with the perspective of their application in hydrogen storage, this research thesis more particularly addressed the case of ternary hydrides and fluorides, and of hydro-fluorides. The author reports the development of a method of preparation of alkaline hydrides, of alkaline earth hydrides and of europium hydride, and then the elaboration of ternary hydrides. He addresses the preparation of caesium fluorides and of calcium or nickel fluorides, of Europium fluorides, and of ternary fluorides. Then, he addresses the preparation of hydro-fluorides (caesium, calcium, europium fluorides, and caesium and nickel fluorides). The author presents the various experimental techniques: chemical analysis, radio-crystallographic analysis, volumetric mass density measurement, magnetic measurements, ionic conductivity measurements, Moessbauer spectroscopy, and nuclear magnetic resonance. He reports the crystallographic study of some ternary alkaline and alkaline-earth hydrides (KH-MgH2, RbH-CaH2, CsH-CaH2, RbH-MgH2 and CsH-MgH2) and of some hydro-fluorides (CsCaF2H, EuF2H, CsNiF2H)

  11. Environmental radioactivity surveillance programme: results for the UK for 1980

    International Nuclear Information System (INIS)

    The first in a series of reports on the NRPB's environmental radioactivity surveillance programme in the UK is given. The intermediate-yield weapon explosion in central Asia in October 1980 resulted in increased concentrations of fission products in November and December 1980 and preliminary data for 1981 indicate significant increases over levels in recent years. UK average depositions of strontium-90 and caesium-137 were less than in previous years and less than 2% of those reported for 1963/64, the years of maximum fallout. An average effective dose equivalent commitment of 0.4 μSv from radionuclides deposited in 1980 added less than 1% to that accumulated from atmospheric nuclear explosions in earlier years. The concentrations of strontium-90 and caesium-137 in milk were less than that reported for 1979 and were about 7% and 2%, respectively, of the highest values reported in 1964. The average committed effective dose equivalent attributable to contamination of diet with these radionuclides is estimated to be 3 μSv. The estimate for caesium-137 is consistent with that obtained from direct measurement of this radionuclide in the body. The average annual effective dose equivalent from fallout is evaluated and compared with that from natural background radioactivity. (author)

  12. The Effective Dose Due to Radionuclides Intake Via Ingestion in Poland in 1986-1999

    International Nuclear Information System (INIS)

    Full text: One of the pathways of radiation exposure in humans is consumption of contaminated food. The composition of an average diet is diversified for various groups within the population and depends on age, sex, consumption habit and performed work. To asses the dose obtained by people due to ingestion of contaminated food, the activity of main products of Polish diet has been analysed for period 1986 - 1999. The samples of milk, meat, vegetables, fruit and cereals were collected all over the territory of Poland to determine the activity of caesium isotopes. In the first two-year after the Chernobyl accident the differences in contamination were observed in various regions. Later on the differences were less pronounced except in milk and meat. The calculation of an average annual intake of caesium isotopes was based on statistical data consumption and contamination of certain product important in daily diet. Annual intake of caesium was different among regions. Mean annual effective dose related to the ingestion of contaminated food of 137Cs was assessed on 54μSv in 1986 and 28μSv in 1987 and of 134Cs on 34μSv and 13μSv respectively. In next years the dose was diminishing and from 1993 the average annual effective dose from 137Cs has been on level 6-7 μSv. (author)

  13. Modelling of radionuclide migration in forest ecosystems. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Avila, R.; Moberg, L.; Hubbard, L.

    1998-03-01

    The Chernobyl accident has clearly shown the long-term effects of a radioactive contamination of forest ecosystems. This report is based on a literature review of models which describe the migration of radionuclides, radioactive caesium in particular, in forest ecosystems. The report describes the particularities of the forest ecosystem, the time dynamics of the contamination, the transfer processes and factors influencing caesium migration. This provides a basis for a discussion of different approaches for modelling caesium migration in the forest. It is concluded that the studied dynamic models include the most relevant transfer processes both for the acute and the long-term phase after a radioactive deposition. However, most models are site specific and do not consider some of the factors responsible for the differences in radionuclide behaviour and distribution in different types of forests. Although model improvements are constrained by the availability of experimental data and by the lack of knowledge of the migration mechanisms some possible improvements are discussed. This report is part of the LANDSCAPE project. -An integrated approach to radionuclide flow in the semi-natural ecosystems underlying exposure pathways to man. 42 refs, 3 tabs, 9 figs.

  14. The removal of 134Cs from radioactive process waste water by coprecipitate flotation

    International Nuclear Information System (INIS)

    The coprecipitate flotation of 134Cs from radioactive process waste water using copper ferrocyanide as a coprecipitating agent and sodium lauryl sulphate, cetyl trimethyl ammonium bromide or gelatin as collector was extensively investigated to establish the best conditions for caesium removal with each of the collectors under test. The investigated parameters include the collector dosage, the Cu2+/Fe(CN)64- ratio, the caesium, potassium, sodium and calcium ion concentrations, the ageing time period of the Cu2+ - Fe(CN)64- - 134Cs - water system and the bubbling time duration. The results indicate that copper ferrocyanide has a high affinity for caesium and can preferentially co-precipitate it in presence of relatively high amounts of other alkali or alkaline earth cations. For the alkali metals the affinity increases in the order Na < K < Cs. Under the optimal conditions removals higher than 99% could be achieved with any of the tested collectors. The results are discussed in terms of the ion exchange properties of copper ferrocyanide and collector behaviour. Advantages of the coflotation technique over other methods are enumerated. (Auth.)

  15. {sup 40}K/{sup 137}Cs discrimination ratios to the aboveground organs of tropical plants

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, N. [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, Gragoata, Niteroi, CEP 24210-346, RJ (Brazil); Anjos, R.M. [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, Gragoata, Niteroi, CEP 24210-346, RJ (Brazil)], E-mail: meigikos@if.uff.br; Mosquera, B. [Instituto de Fisica, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n, Gragoata, Niteroi, CEP 24210-346, RJ (Brazil)

    2008-07-15

    In the present work, the accumulation of caesium and potassium in aboveground plant parts was studied in order to improve the understanding on the behaviour of monovalent cations in several compartments of tropical plants. We present the results for activity concentrations of {sup 137}Cs and {sup 40}K, measured by gamma spectrometry, from five tropical plant species: guava (Psidium guajava), mango (Mangifera indica), papaya (Carica papaya), banana (Musa paradisiaca), and manioc (Manihot esculenta). Caesium and potassium have shown a high level of mobility within the plants, exhibiting the highest values of concentration in the growing parts (fruits, leaves, twigs, and barks) of the woody fruit and large herbaceous shrub (such as manioc) species. In contrast, the banana and papaya plants exhibited the lowest levels of {sup 137}Cs and {sup 40}K in their growing parts. However, a significant correlation between activity concentrations of {sup 137}Cs and {sup 40}K was observed in these tropical plants. The {sup 40}K/{sup 137}Cs discrimination ratios were approximately equal to unity in different compartments of each individual plant, suggesting the possibility of using caesium to predict the behaviour of potassium in several tropical species.

  16. Modelling of radionuclide migration in forest ecosystems. A literature review

    International Nuclear Information System (INIS)

    The Chernobyl accident has clearly shown the long-term effects of a radioactive contamination of forest ecosystems. This report is based on a literature review of models which describe the migration of radionuclides, radioactive caesium in particular, in forest ecosystems. The report describes the particularities of the forest ecosystem, the time dynamics of the contamination, the transfer processes and factors influencing caesium migration. This provides a basis for a discussion of different approaches for modelling caesium migration in the forest. It is concluded that the studied dynamic models include the most relevant transfer processes both for the acute and the long-term phase after a radioactive deposition. However, most models are site specific and do not consider some of the factors responsible for the differences in radionuclide behaviour and distribution in different types of forests. Although model improvements are constrained by the availability of experimental data and by the lack of knowledge of the migration mechanisms some possible improvements are discussed. This report is part of the LANDSCAPE project. -An integrated approach to radionuclide flow in the semi-natural ecosystems underlying exposure pathways to man

  17. 40K/137Cs discrimination ratios to the aboveground organs of tropical plants

    International Nuclear Information System (INIS)

    In the present work, the accumulation of caesium and potassium in aboveground plant parts was studied in order to improve the understanding on the behaviour of monovalent cations in several compartments of tropical plants. We present the results for activity concentrations of 137Cs and 40K, measured by gamma spectrometry, from five tropical plant species: guava (Psidium guajava), mango (Mangifera indica), papaya (Carica papaya), banana (Musa paradisiaca), and manioc (Manihot esculenta). Caesium and potassium have shown a high level of mobility within the plants, exhibiting the highest values of concentration in the growing parts (fruits, leaves, twigs, and barks) of the woody fruit and large herbaceous shrub (such as manioc) species. In contrast, the banana and papaya plants exhibited the lowest levels of 137Cs and 40K in their growing parts. However, a significant correlation between activity concentrations of 137Cs and 40K was observed in these tropical plants. The 40K/137Cs discrimination ratios were approximately equal to unity in different compartments of each individual plant, suggesting the possibility of using caesium to predict the behaviour of potassium in several tropical species

  18. The influence of a number of decorporates on the state of lipid peroxidation system of blood of experimental animals

    Energy Technology Data Exchange (ETDEWEB)

    Mazhul, L. M.; Volykhina, V. E.; Gatsko, G. G.; Bagel, J. M. [Institute of Radiobiology of NASB, Minsk (Belarus)

    2002-07-01

    The investigations directed to the search for the substants of radioprophylactic and radiotherapeutical action have important theoretical and practical importance. Since the base of damaging effect of ionizing radiations is the chain free radical reactions initiating the processes of lipid peroxidation in the organism, we carried out the study of the influence of a number of decorporates on the content of Strontium-85 and Caesium-137 in the organism and on the lipid peroxidation system in blood of experimental animals too. The experiments were carried out on the 4-month old male rats to which Strontium-85 (2282 Bq) and Caesium-137 (3101 Bq) - group 4 were administered per os during 30 days. Against a backgourd of daily incorporation of radionuclides, the animals were treated with a number of decorporates and food products: group 1 - 1% alginic acid, 2% - the bone protein and 0.05% - vitamin PP; group 2 - 20 g of laminaria, group 3 - ferrocin in dose of 0.02 g/rat per day. It was shown, that the most favourable effect was exerted by laminaria not causing the increase of he weight, decorporating both strontiu and caesium, reducing verifiably the content of primary products of lipid peroxidation in the blood. It allows to recommend it for inclusion in the ration of population of radiocontaminated areas.

  19. Migration peculiarities of long-lived radionuclides in soils in areas contaminated by the Chernobyl NPP accident

    International Nuclear Information System (INIS)

    We studied migration of long-lived radionuclides of caesium-134/137, cerium-144 and ruthenium-106 in soil samples from regions contaminated by the Chernobyl accident. Samples of three types of contamination - fuel (A), quasi-fuel (B) and aerosol (C) - were taken at calibration sites in August 1988 down to a depth of 5 cm using conventional core samplers. The radioactivity of the samples was measured at intervals of 0.5 cm, as was the activity of three mechanical fractions of the samples: 1-2 (> 2) mm; 0.25-1.0 mm; 2) mm fractions (grass, roots and tillering nodes) in the 0-1 (to 2) cm layer, which reflects the increasing role of biogenic migration processes in mass transfer of radionuclides despite their apparent lack of mobility in biocenoses. The soil's dust and clay fraction (< 0.25 mm) helps to fix the radionuclides in the crystal structures of soil minerals and organic matter. The ratio of caesium-134/caesium-137 in soils exhibiting the quasi-fuel type of contamination varies from 0.17-0.55 in the 1-2 mm and < 0.25 mm sample fractions, evidently reflecting the various radionuclide occurrence forms and topographies in the fallout matrix, isotope separation included. (author)

  20. Study of the behaviour of inorganic ion exchangers in the treatment of medium active effluents. Part 5

    International Nuclear Information System (INIS)

    This report describes some results obtained from a generic programme of work for the Department of the Environment on the potential application of inorganic ion exchangers for the treatment of medium active effluents. The results from a preliminary investigation of the encapsulation of six ion exchangers (hydrous titanium oxide, hydrous manganese oxide, titanium and zirconium phosphates, polyantimonic acid and copper hexacyanoferrate (II) (CuFC)) in cement are reported. Compression strength tests showed the presence of the exchangers reduced the strength of the cement but in all cases 33.3 wt% loadings of the exchangers resulted in homogeneous waste forms with adequate strength (≥ 4.5 MNm-2) for disposal in a waste repository. The results from a series of leach tests investigating the rate of release of caesium from cement samples containing caesium-loaded CuFC, are also reported. It was found that the presence of CuFC reduces the cumulative fraction of caesium leached but not the overall leach rate. (author)