[en] he activity-concentrations of several long-lived gamma-emitting radionuclides present in technetium generators and in eluates from these generators have been determined by means of Ge(Li) gamma-spectrometry. The principal contaminants of the eluates were: ¹⁹²Ir(T sub (1/2) = 74.3 d), ¹³⁴Cs (2.05 a), ¹³¹I (8.05 d), ¹¹⁰Ag sup (m) (255 d), ¹⁰³Ru (39.5 d), ⁹⁹Mo (66.7 h) and ⁶⁰Co (5.26 a). Thhe impurity-concentrations were found to vary considerably from generator to generator. Changes in the impurity-concentrations in eluates from the same generator have also been recorded during an elution-period of one week. In accord with their ability to be eluted from the generators, the long-lived radionuclide-impurities may be arranged in the following sequence ¹³⁴Cs > ¹⁰³Ru greater than or equal to ¹¹⁰Ag sup (m) > ¹⁹²Ir > ⁶⁰Co. (author)

No abstract available

[en] The geographic distribution of the human population within 120 km radius from the Swedish nuclear power plants is presented in tables and diagrams. The population data round Barsebaeck, Ringhals, Oskarshamn and Forsmark are stored in a computerized form. The data are used for the calculation of population doses of uncontrollable release of radioaktivity. (G.B.)

[en] A measurement of the resuspension of radionuclides during cultivation has been performed at a farm in northern Sweden where the deposition from the Chernobyl accident is high. The resuspension was found to increase 10 to 30 times during cultivation as compared to normal conditions in the same region. It can be estimated that the resuspension could be as high as 3000 times the normal conditions if cultivation is performed directly after fallout during dusty conditions. The resuspension of cesium-nuclides should normally not imply any radiation hazard due to inhalation if the ground deposition is not very high. (authors)

No abstract available

[en] Shielding factors for external irradiation from the Chernobyl fallout were measured by in situ gamma spectrometry in four different types of dwellings in Sweden. The measurements were performed in the Gaevle area which received the largest quantities of fallout in Sweden from the Chernobyl accident. The shielding factors obtained from in situ measurements were compared to the shielding factors given by theoretical calculations for nuclear weapons fallout by the use of the 'DCPA Standard Method for Fallout Gamma Radiation Shielding Analysis'. The shielding effect of snow cover in different parts of Sweden was determined from published results of long term measurements of the radiation level. Based on a previously published survey of building types and building shielding factors the average and the time averaged shielding factors for people living in different regions of Sweden and the whole of Sweden were also calculated. (au) (45 refs.)

[en] Fourteen different ⁹⁹Tcsup(m)- generators manufactured by the Radiochemical Centre, Amersham, England, and in clinical use, were studied. The generators consist of ⁹⁹Mo as molybdate absorbed onto a column of Al₂O₃, and 0.9% NaCl is used periodically to elute ⁹⁹Tcsup(m)O₄^-, while ⁹⁹Mo-molybdate remains fixed on the sorbent. Other radioactive impurities, some with long half-lives, are also eluted together with ⁹⁹Tcsup(m)O₄^-, and may be responsible for high patient doses in procedures such as brain and skeletal scintigraphy. Samples of eluate were collected for analysis before, during and after a normal week's use of the generators (5 days), and the radionuclide-impurities in the eluates varied considerably from generator to generator. Their concentrations varied as a function of eluted volume. The elution efficiences for the long-lived radionuclide impurities were in the sequence ¹³⁴Cs > ¹⁰³Ru >= ¹¹⁰Agsup(m) > ¹⁹²Ir > ⁶⁰Co. Estimates have been made of the absorbed dose in various organs from these impurities. The results demonstrate the importance of making routine quantitative measurements of the contents of different radionuclide impurities in eluates from all molybdenum-technetium generators. (U.K.)

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No abstract available

[en] The biophysical behaviour of the radioactive corrosion products ⁵¹Cr, ⁵⁴Mn, ⁵⁸Co, ⁶⁰Co, ⁶⁵Zn and ¹¹⁰Agsup(m) has been studied in the marine environment up to 150 km from a nuclear power station using the brown seaweeds Fucus vesiculosus and F. serratus as bioindicators. The activity concentration in Fucus per unit activity released from the nuclear power station is about equal for ⁵⁴Mn, ⁵⁸Co, ⁶⁰Co and ⁶⁵Zn but lower by a factor of 3 for ¹¹⁰Agsup(m) and by a factor of 10 for ⁵¹Cr. The biological half-time of radioactive cobalt in naturally growing F. vesiculosus was 60 +- 15 days during the summer. Approximately the same value was found for ⁵⁴Mn and ⁶⁵Zn. The results show that 85 to 90% of the activity released from the nuclear power plant follows the dominating north-bound water stream and 10 to 15% is transported southwards. For ⁵⁴Mn, ⁵⁸Co, ⁶⁰Co and ⁶⁵Zn the decrease in activity concentration C(z) with distance, z(km) north of the power plant can be described by a power function, C(z) = α.zsup(-1.4), where α is a constant. (author)