90Sr and137Cs in fallout from Chernobyl in the Bucharest-Măgurele area during 1986–1987

This work shows the variation of⁹⁰Sr and¹³⁷Cs in atmospheric fallout in the Bucharest-Mgurele area during 1986–1987. The amount of⁹⁰Sr in the fallout was estimated to be about 900 Bq.m^–2 in 1986 and about 9.2 Bq.m^–2 in 1987. The amount of¹³⁷Cs was estimated to be 13300 and 615 Bq.m^–2 in 1986 and 1987, respectively.     

Liquid scintillation spectrometry of beta-emitters in marine samples

Liquid scintillation spectrometry has become the most widespread method for quantitative analysis of low level -emitters in environmental samples. This technique has been applied in the measurements of ²⁴¹Pu, ³H and ⁹⁰Sr in seawater and sediment samples. ²⁴¹Pu can be measured by direct analysis of an electrodeposited source using - discrimination or by extraction of electrodeposited plutonium into a liquid form compatible with scintillation cocktail. Sediment from Mururoa and Fangataufa atolls showed activities ranging from 18 to 44 Bq/kg. A sediment profile sampled around Bikini Atoll in 1997 showed ²⁴¹Pu activities ranging from 0.3 to 30 Bq/kg. ³H activities in pore water sediment from Mururoa and Fangataufa atolls were of the order of 10³ Bq/m³ which demonstrated its underground origin. ⁹⁰Sr was measured in the presence of ⁹⁰Y. The counting efficiency was 92.41.5% and the background 0.027±0.001 s^-1. The average chemical recovery for ⁹⁰Sr was 673%.     

Determination of137Cs and134Cs in air samples collected near Belgrade /Yugoslavia/ following the Chernobyl accident

This paper presents the results of measurements of¹³⁷Cs and¹³⁴Cs content in air sampled during May 1986. Maximum concentrations:¹³⁷Cs 2.94±0.01 Bq m^–3 and¹³⁴Cs 1.38±0.01 Bq m^–3 were registered on May 3. Several other long lived radionuclides having -energies in the region 33 keV to 1365 keV were registered in the same samples two years later. The results of measurements of the total -activity in air for the same period are also presented.     

Radiocesium concentration in milk after the Chernobyl accident in Japan

Radiocesium concentrations in cow's milk from two producing districts in Japan were measured monthly for three years following the Chernobyl accident. The Chernobyl contribution in¹³⁷Cs concentration was evaluated from the¹³⁴Cs concentration and the¹³⁷Cs/¹³⁴Cs ratio. The highest¹³⁷Cs concentration of 0.6 Bq l^–1 was observed in May 1986 and the Chernobyl contribution has decreased during three years to levels corresponding to the contribution from past nuclear weapons fallout. Annual values of child internal dose through milk consumption were estimated at 0.6, 0.3 and 0.1 Sv for the first, the second and the third year following the accident, respectively.     

The ambient gamma dose-rate and the inventory of fission products estimations with the soil samples collected at Canadian embassy in Tokyo during Fukushima nuclear accident

In this study, soil samples were collected at Canadian embassy in Tokyo (about 300 km from Fukushima) on 23 March and 23 May of 2011 for purposes of estimating concentrations of radionuclides in fallout, the total fallout inventory, the depth distribution of radionuclide of interest and the elevated ambient gamma dose-rate at this limited location. Some fission products and actinides were analyzed using gamma-ray spectrometry, alpha spectrometry and liquid scintillation counting. The elevated activity concentration levels of ¹³¹I, ¹³²I, ¹³⁴Cs, ¹³⁷Cs, ¹³⁶Cs, ¹³²Te, ¹²⁹mTe, ¹²⁹Te, ¹⁴⁰Ba and ¹⁴⁰La were measured by the gamma-ray spectrometer in the first sample collected on 23 March. Two months after the accident, the ¹³⁴Cs and ¹³⁷Cs became only detectable nuclides. A mass relaxation depth of 3.0 g/cm² was determined by the activities on the depth distribution of ¹³⁷Cs in a soil core. The total fallout inventory was thus calculated as 225 kBq/m² on March sampling date and 25 kBq/m² on May sampling date. The ambient gamma dose-rates in the sampling area estimated by the fallout fission products inventory and ¹³⁷Cs depth distribution ranged from 184 to 38 nGy/h. There was no detectable americium or plutonium in the soil samples by alpha spectrometry. Although ⁹⁰Sr or ⁸⁹Sr were detected supposedly as a result of this accident, it was less than the detection limit, which was about 0.4 Bq/kg in the soil samples.     

Results of three years of monitoring239,240Pu and238Pu concentrations in airborne effluents from the V-1 nuclear power plant with VVER 440 reactors in Jaslovské Bohunice in Czechoslovakia

The concentration of^239,240Pu and²³⁸Pu in airborne effluents in the years 1985–1987 from two reactors VVER 440/total power of 880 MW/ of a nuclear power plant V-1 in Jaslovské Bohunice in Czechoslovakia, was determined. The concentration of^239,240Pu in effluents ranged from 1.0 to 30.8 Bq.m^–3 and of²³⁸Pu from 1.6 to 41.1 Bq.m^–3. The activity ratio²³⁸Pu/^239,240Pu in airborne effluents kept within the range of 1.0–2.4. Total annual discharged activities of^239,240Pu in 1985, 1986 and 1987 were 28.5, 12.7 and 12.2 kBq, respectively. Total annual discharged activities of²³⁸Pu in 1986 and 1987 were 16.6 and 15.1 kBq, respectively.     

On variations of volumetric activity of 90Sr and 137Cs in the Baltic Sea coastal waters near the shore of Lithuania in 2005–2009

The article presents the measurement results of the volumetric activity (VA) of artificial radionuclides ⁹⁰Sr and ¹³⁷Cs in the coastal waters of the Baltic Sea near the Curonian Peninsula in 2005–2009. The annual average values for this period of time were 12 Bq/m³ (⁹⁰Sr) and 40 Bq/m³ (¹³⁷Cs). Considerable variations in the VA of the radionuclide in individual measurements compared to the average results were observed. The extreme values were 6 and 16 Bq/m³ for ⁹⁰Sr and for ¹³⁷Cs—27 and 75 Bq/m³. It is proposed to allow such variations under the influence of a variety of external factors such as hydro meteorological situations, inflowing rivers and bays, storm activity and etc. Besides, a possibility of penetration of radionuclides into the sea waters from the additional radioactive sources is not excluded.     

Simultaneous determination of238Pu,239+240Pu,241Pu,241Am,242Cm,244Cm,89Sr,and90Sr in vegetation samples,and application to Chernobyl-fallout contaminated grass

A radiochemical procedure is described for the simultaneous determination of²³⁸Pu,^239+240Pu,²⁴¹Pu,²⁴¹Am,²⁴²Cm,²⁴⁴Cm,⁸⁹Sr, and⁹⁰Sr in vegetation samples. The method was applied for the determination of these, radionuclides in grass, collected near Munich after the fallout from the reactor accident at Chernobyl, USSR. The specific activities observed were (in Bq kg^–1 dry weight):²³⁸Pu, 0.077;^239+240Pu, 0.15;²⁴¹Pu, 3.9;²⁴¹Am, 0.031;²⁴²Cm, 3.0;²⁴⁴Cm, 0.008;⁸⁹Sr, 2000;⁹⁰Sr, 99.     

Determination of40K and137Cs concentration in selected honey samples

Seventeen honey samples collected at different sites during 1992 have been measured using the method of -spectroscopy. Measurements were performed by a low background high purity germanium spectrometer of a relative efficiency of 14.5% and an energy resolution of 1.7 keV. Using natural -ray sources to determine efficiency, it has been shown that out of 17 samples of natural honey only two (of meadow type) have specific activity of¹³⁷Cs greater than 0.5 Bq kg^–1. The remaining samples have the same¹³⁷Cs concentrations as before May, 1986. Predominant activity in all samples comes from the⁴⁰K radionuclide, indicating natural honey.     

A rapid and accurate method for the determination of strontium-90 in environmental soil

A rapid and accurate method for the determination of⁹⁰Sr in environmental soil has been developed; the procedure includes soil leaching by hydrochloric acid, oxalate precipitation, decontamination from²¹⁰Bi, separation by HDEHP extraction chromatography column, yttrium oxalate precipitation and -counting. The interference of²¹⁰Bi was found and studies have been made for the decontamination of⁹⁰Y from²¹⁰Bi by Bi₂S₃ precipitation giving a decontamination factor of 1.05·10³. The analytical results obtained by the improved rapid method for 12 soil samples were comparable to that obtained by a previous method within a relative error of 20%. Studies of vertical distribution of⁹⁰Sr in an environmental soil profile have shown that 90% of the⁹⁰Sr deposits in the 30 cm surface soil of the earth with a highest concentration of 3.40 Bq/kg. When 50 g soil was analyzed, the yield of yttrium was 73±17% with a detection limit of 0.26 Bq/kg.     

Determination of 90Sr in soil, grass and cereals

⁹⁰Sr was measured in environmental samples in Upper Austria in the year 2005. After the nuclear weapon tests the average deposition of ⁹⁰Sr in Austria amounted to 3.3 kBq/m². In 1986 the average deposition was 0.9 kBq/m² [1]. To assess the actual condition in soil, grass and cereals ⁹⁰Sr was measured in these samples. For all samples oxalate precipitation was conducted and strontium specific columns (Eichrom Industries, Inc.) were used. The calcium concentration in these samples was determined to estimate the amount of resin needed for the preparation. For grass and cereal samples columns were packed with the 100–150 μm resin to gain a lower limit of detection LLD below 2 and below 0.1 Bq/kg_{dry matter} respectively. The prepacked 2 mL columns with particle size 100–150 μm were used for soil (LLD below 2 Bq/kg_{dry matter}). After digestion of soil samples, hydroxide precipitation was used as an additional separation step. The ⁹⁰Sr was measured by liquid scintillation counting. For quality control reasons, first the initial strontium concentration in the sample was determined then a strontium carrier solution was added and after the separation steps the chemical recovery was determined by ICP-MS. Thus, no radioactive tracer and just a small amount of the measuring solution were needed. The results are presented and discussed. These results will be used as reference for further ⁹⁰Sr analyses which will be conducted in a 5 year period to detect any radiological impact of the nuclear power plant Temelin on the environment of Austria.     

Distributions of Pu isotopes and 137Cs in soil from Semipalatinsk Nuclear Test Site detonations throughout southern districts

Soil samples collected mainly from the southern areas, including Kainar and Karaul settlements, around the Semipalatinsk Nuclear Test Site of the former USSR were analyzed for ¹³⁷Cs and Pu isotopes (²³⁸Pu,²³⁹Pu and ²⁴⁰Pu) by γ-ray and α-ray spectrometry and ICP-MS. The ¹³⁷Cs inventories varied widely from 170 to 13,600 Bq/m². The ^239,240Pu inventories, values of which are scare in the literature, also varied in the range of 34-2,050 Bq/m² (most of date being 100-300 Bq/m²). In the areas around Tailan, Sarzal and Karaul settlements where the radioactive cloud related to the first thermonuclear explosion passed through, higher inventories of these nuclides were observed and especially their ²³⁸Pu/^239,240Pu activity ratios (0.0064-0.0076) were markedly lower than those attributed to global fallout (0.03-0.04). The observed ratios might be used as a fingerprint to identify the Pu source of the first thermonuclear event. Most of the ²⁴⁰Pu/²³⁹Pu atomic ratios were lower than those of global fallout (0.18) commonly accepted. The contribution of local fallout ^239,240Pu was higher (more than 80-90%) in the areas around the Tailan, Sarzal and Karaul settlements than that (30-ca. 60%) in the other areas. This high Pu contribution was related to the Pu source from the first thermonuclear event. This revised version was published online in July 2006 with corrections to the Cover Date.     

Environmental radioactivity level in the Ceranavodă area /Romania/ between 1981 and 1983

The environmental factors considered are: surface water, ground water, drinking water, soil, sediment and spontaneous vegetation. The analyses performed showed a low level of radioisotopes. The mean values recorded were: 4.22×10^–3 Bq dm^–3 for¹³⁷Cs, 2.97×10^–3 Bq dm^–3 for⁹⁰Sr, 14.9 Bq dm^–3 for³H and 1.07 g dm^–3 for U, in the Danube waters. The -spectrometric analysies revealed lines corresponding to⁴⁰K and the to the natural decay series of U and Th. There have been also identified the artificial radionuclides¹³⁷Cs and⁶⁰Co in sediment,⁹⁵Zr and⁹⁵Nb in the 1981 vegetation. All artificial isotopes resulted from atmospheric fallout.     

90Sr and 137Cs radioisotopes and heavy metal concentrations in pharmaceutical herbal plants from the Lublin (Poland) region

Radioactivity of ⁹⁰Sr and ¹³⁷Cs in several species of herbs collected at Fajsawice and Góra Puawska located in Lublin (Poland) region was examined. Depending on the type of herb the radioactivity of strontium ranged from 0.004 to 1.808 Bq/kg dry weight whereas that from cesium varied from 0.053 to 9.853 Bq/kg. Calculated transfer factors of the radioisotopes in the plants studied revealed much stronger accumulation of strontium than cesium. Concentration of calcium and potassium in these plants has no influence on the concentration of measured radioisotopes.     

Physical and chemical investigation of water and sediment of the Keban Dam Lake, Turkey:

Summary The gross alpha- gross beta-activity, ¹³⁷Cs and ⁹⁰Sr in the water and sediment samples taken from the Keban Dam Lake, Uluova Region, was investigated in 2003 and 2004. We have found that in spring the concentration of ¹³⁷Cs in the surface water and deep sediment changed between 0.001-0.01 Bq/l (0.4-2.5 Bq^.kg^-1) that of ⁹⁰Sr between 0.0001-0.009 Bq/l (0.1-9 Bq^.kg^-1) and in autumn the values were 0.0001-0.009 Bq/l (0.4-8 Bq^.kg^-1) for ¹³⁷Cs and 0.0002-0.005 Bq/l (0.6-4 Bq^.kg^-1) for ⁹⁰Sr, respectively. The results were presented in form of iso-curves.     

Determination of239+240Pu in surface air in several localities in Czechoslovakia in 1986 in connection with the Chernobyl radiation accident

In connection with the radiation accident at the Chernobyl nuclear power plant, the concentration of^239+240Pu was determined in surface air at several localities of Czechoslovakia during the year 1986.^239+240Pu was found in the surface air in the period of April 29–May 5 in amounts ranging from 10 to 140 Bq.m^–3. In the period of June–December, 1986, the^239+240Pu concentration in the surface air was comparable with that before the Chernobyl radiation accident.     

Observation of111Ag and110mAg in the Chernobyl fallout

Evidence for the presence of¹¹¹Ag in Chernobyl fallout at Monaco is given. This fission radionuclide has not been previously reported in Chernobyl fallout. Peak values were as high as 1.9 Bq m^–3. Arguments are presented that the observed^110mAg content in the fallout originated from volatilisation of silver neutron flux monitors in the reactor rather than production by other nuclear reactions.     

Separation of strontium from calcium by the use of sodium hydroxide and its application for the determination of long-term background activity concentrations of <Superscript>90</Superscript>Sr in 100 km area around Kozloduy Nuclear Power Plant (Bulgaria)

The method for the determination of ⁹⁰Sr which employs sodium hydroxide for the separation of strontium from calcium was further improved introducing the use of elevated temperatures. The results from 11-year study of background activity concentrations of ⁹⁰Sr in different environmental objects in 100 km zone around Kozloduy Nuclear Power Plant (Bulgaria) are presented as an application of the analytical method. The measured mean values are as follows: air precipitation − 0.0015±0.0009 Bq(m^2.d), tap water − 0.0017±0.0012 Bq/L, soil − 1.90±1.26 Bq/kg, grass − 1.54±0.80 Bq/kg, milk − 0.023±0.012 Bq/L and for the Danube river: water − 0.0046±0.0026 Bq/L, bottom sediments − 0.64±0.60 Bq/kg, algae − 1.99±1.56 Bq/kg. The calculated transfer coefficients (soil-grass) are in the range of 0.33–0.84. Between 2 and 5 times reduction in actual background activities of ⁹⁰Sr is observed compared to 1972–1974.     

Determination of strontium-90 in various kinds of water after Chernobyl accident in Austria

As a consequence of the reactor-accident of Chernobyl on Tuesday 29 April 1986 the environmental radioactivity in Austria increased for above the level recorded before. Depending on the amount of precipitation the deposition of radioactive fallout showed great differences. Many water samples /rain water, lake water, swimming pool water, drinking water, underground water/ collected /during period of April 29 to May 30/ from Vienna, Lower Austria and Steiermark were analyzed for⁹⁰Sr. The following concentrations in /nCi 1^–1/ of⁹⁰Sr was found: 8.69±2.3 for rain water, 0.09±0.12 for lake water, 0.08–0.18 for swimming pool, 0.04–0.13 for drinking water, 0.07–0.2 for underground water. The⁹⁰Sr concentration was not higher than the maximal permissible /0.004–0.4 nCi 1^–1/ except for rain water.     

A Simple and Rapid Method for the Preparation of 87Y/87mSr Generator

A simple and efficient process for the preparation of ⁸⁷Y/^87mSr generator with adsorption chromatography on -Fe₂O₃ was developed. A 0.25 g pallet of natural SrCl₂ was employed as a solid target which was irradiated at INER TR30/15 cyclotron. After irradiation the target was dissolved into a saline solution and adjusted with HCl/NaOH to a pH of 6.3. This solution was then passed directly through the column (1 cm×4 cm), loaded with appropriate amounts of -Fe₂O₃, at a flowrate of 1.0 ml/min for adsorption of ⁸⁷Y. Nonradioactive Sr was unadsorbed and washed out from the column. Above 90% of the available ^87mSr with a ⁸⁷Y breakthrough less than 10^–3% could be obtained with 10 ml of 0.9% saline solution per elution from the generator system. The chemical contaminants of Fe and Sr in the eluates were found below 0.04 and 0.1 ppm, respectively.