Plutonium Biokinetics in Human Body A. Luciani - Kit-Bibliothek - FZK

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the minimum detectable activity of the adopted measuring technique because of difficulties in fitting model with values “less than” a certain quantity. The contamination event should be characterized by a unique path of intake because of the difficulties in evaluating the contributions to the urinary excretion from different intake patterns. Furthermore the time modality of intake should be acute or approximately analogous in order to avoid the uncertainty due to hardly verifiable hypothesis on constant rates of intake, or times of repetitive singles intakes. Finally patients subjected to chelating therapy (as with DTPA) should be avoided too because of the enhancement of Plutonium urinary excretion observed in such subjects. Complying the aforementioned conditions nine contamination cases were extracted from the Manhattan Project Workers and United States Transuranium and Uranium Registries data sets. In Table 2.1.1 they are shortly presented, together with the number of urine samples suitable for checking model’s predictions of urinary excretion. In fact in the present work for each considered subject those urine samples collected and analyzed before 1957 were disregarded because only after this year corrections were systematically determined and applied for chemical and physical analysis [121]. As for all the selected cases the most significant intakes occurred in the period 1945-1946 and in any case before 1950, the long period between the intake and the chosen measurements assures also that the same measurements are not significantly influenced by the actual time modalities of intake. Therefore these cases of contamination can be reasonably considered as due to an acute intake. Table 2.1.1 Occupational contamination cases selected from Manhattan Project Workers (MPW) and United States Transuranium and Uranium Registries (USTUR) data sets. Subject’s code Data set Birth year Number of useful samples of Pu urinary excretion 242 USTUR 1909 107 193* USTUR 1920 105 4 MPW 1919 105 208 USTUR 1915 64 25 MPW 1918 21 10 MPW 1912 21 18 MPW 1922 20 7 MPW 1907 10 21 MPW 1924 8 * it is also present in MPW under the code “27”. 42
2.2 A DESCRIPTION OF THE UPDATED CONTAMINATION CASE The contamination incident investigated in the present work is one of the best documented cases of a single intake of transuranium elements worldwide ( 238 Pu, 239 Pu, 240 Pu, 241 Pu, and 241 Am). This contamination case complies quite well the requirements previously described for using a data set of occupational exposure for model verification purposes. Furthermore it shows two important aspects: • The measurements carried out in recent years in occasion of dose assessments intercomparisons showed a significant enhancement of Plutonium urinary excretion, particularly at long time after contamination. This was already pointed out, but at a lesser extent, in other contaminated subjects [122]; • The Plutonium mixture introduced by the subject contains 241 Am too, giving the possibility of carrying out direct measurements of organs activity burden, otherwise hardly detectable in case of a contamination of pure Plutonium. For such characteristics it was already proposed as a case study in different intercomparisons on dose assessment. It is present as “Case 8” in the IAEA intercomparison [123] and it is the base for “Case 6” in the 3 rd European intercomparison [124]. At the time of the intercomparisons there was already a set of excretion and organ burden data from the first day after the intake up to almost ten years [125]. Since 1983 direct measurements of Americium burden in different organs were carried out also in Forschungszentrum Karlsruhe [126]. In the frame of the present work in 1999 a complete follow-up of this case was carried out in Forschungszentrum Karlsruhe and new data for the Plutonium and Americium amounts in bioassays (urine, feces and blood) and for the Americium organs burdens were obtained. The results of these direct and indirect measurements are extensively presented in the two paragraphs 2.3.3 and 2.4.3, respectively. 2.2.1 THE CONTAMINATION EVENT The working area where the contamination event occurred was a radiochemical laboratory for the development of advanced nuclear fuel in a nuclear research centre. In the laboratory nuclear fuels microspheres had been produced in a glove box using a special gelling technique. The waste water resulting from this technique was routineously collected and evaporated in the box. The residual waste water deriving from this process was transferred into a second glove box for further evaporation and successive disposal. The subject (male, 26 years old at that time, 91 kg weight, 179 cm height) was working at the first glove box where the fuel microspehre were produced. On 24.05.83 at 4:15 PM an explosion occurred in the second glove box during the evaporation of three litres waste water as a consequence of a unexpected exothermic reaction. The subject left the laboratory immediately after the explosion, yet he resulted strongly contaminated at face, hairs and clothes. He was immediately decontaminated in the radiation protection unit of the research centre and nose swabs with bronchial slime samples were collected. In the glove boxes the washing water contained Plutonium and Uranium in a mixture of hydroxide gel with 10 % of ammonium nitrate and about 3.5 % of hexamethylentetramine. The α activity composition of the substance causing the internal contamination of the subject was 9 % 238 Pu, 55 % 239 Pu, 26% 240 Pu and 10 % 241 Am. The 241 Pu activity was 750 % of the total α activity. Size distribution analysis of dust samples collected in the laboratory was also carried out by means of scanning electron microscope exposures and x ray analyses. The diameter of the particles containing Plutonium resulted to be between 3 and 40 µm. 43
Page 1: Forschungszentrum Karlsruhe in der
Page 4 and 5: Für diesen Bericht behalten wir un
Page 7 and 8: i ABSTRACT The biokinetic model pre
Page 9 and 10: ZUSAMMENFASSUNG Das von der Interna
Page 11 and 12: 1 INDEX OF CONTENTS INDEX OF SYMBOL
Page 13 and 14: 3 INDEX OF SYMBOLS Here a short glo
Page 15: Chapter 1 Introduction 5
Page 18 and 19: the duties of the Department for Ra
Page 20 and 21: adionuclide. Therefore only isotope
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Page 24 and 25: techniques adopted in the early pha
Page 26 and 27: present in spent and MOX reactor fu
Page 28 and 29: INTRAVENOUS INJECTION skin WOUND bl
Page 30 and 31: functions, defined as retained and
Page 32 and 33: the contamination event, of such as
Page 34 and 35: Table 1.3.2 Indicative 239 Pu detec
Page 36 and 37: The kinetics of Plutonium in the ki
Page 38 and 39: 1.4.2 COMMENTS ON THE ICRP 67 MODEL
Page 41: Chapter 2 Data and measurements 31
Page 44 and 45: Therefore the radiolysis process, m
Page 46 and 47: Recent technologic developments in
Page 48 and 49: eu(t) = 0.19e −0.272t + 0.023e
Page 50 and 51: function for each of the considered
Page 54 and 55: 2.2.2 AVAILABLE MEASUREMENTS Immedi
Page 56 and 57: Table 2.2.4 Daily fecal excretion o
Page 58 and 59: elements the spectral distribution
Page 60 and 61: The phoswich detector is based on t
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Page 64 and 65: This quantity is normally expressed
Page 66 and 67: The peak is located in the region B
Page 68 and 69: To introduce the second quantity, t
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Page 72 and 73: Figure 2.3.8 The Lawrence Livermore
Page 74 and 75: three detectors are used. Two detec
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Page 78 and 79: • the necessity of performing mea
Page 80 and 81: Table 2.3.7 Impulses in the measure
Page 82 and 83: 2.4 ACTIVITY MEASUREMENTS IN BIOASS
Page 84 and 85: If more then one radionuclide is ma
Page 86 and 87: L A is the air layer in µgcm -2 ;
Page 88 and 89: The electrodeposition cell used for
Page 90 and 91: Table 2.4.1 238 Pu, 239 Pu and 241
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Page 95 and 96: calculating the amount of Plutonium
Page 97 and 98: 3.1.2 ANALYSIS OF THE ICRP 67 MODEL
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leave the total clearance from the
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Figure 3.1.4 shows that the use of
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3.1.3 MODIFICATION OF ICRP 67 MODEL
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The structure of Polig’s skeleton
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Percentage daily urinary excretion
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of 0.693d -1 . The values of the F
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the basis of all the reference data
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Table 3.1.10 Transfer rates of the
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3.1.4 VERIFICATION OF THE OPTIMIZED
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Table 3.1.13 Intakes and percentage
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soft tissue ST2 soft tissue ST0 sof
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For the routine application of Mode
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excreted by individuals aged sixty
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Table 3.1.20 Exponents and coeffici
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tract [57] to consider a contaminat
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The sensitivity coefficients for th
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Sensitivity coefficients S i Figure
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transfer rates on the Plutonium uri
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Geometric standard deviations rangi
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3.2 APPLICATION OF THE OPTIMIZED MO
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lymph nodes, as in the LLNL phantom
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Americium in the lungs [Bq] 1000 10
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Daily urinary excretion [Bqd -1 ] 1
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long time is not yet described by t
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excretion that is one of the main i
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The comparison of model’s predict
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Americium in the lungs [Bq] 1000 10
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153 CONCLUSIONS The optimized model
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Annex Quantities used in Radiologic
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present. As the radiation weighting
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w R is the radiation weighting fact
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161 BIBLIOGRAPHY 1. Plutonium. W. K
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29. Nenot, J.-C. and Stather, J. W.
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55. International Atomic Energy Age
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81. Crowley, J., Lanz, H., Scott, K
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107. Hempelmann, L.H., Langham,W.H.
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137. Breitestein, B.D., Newton, C.E
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167. Harrison, J.D., Khursheed, A.,
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JOURNALS OWN PUBLICATIONS RELATED T
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177 ACKNOWLEDGEMENTS Special thanks
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Name: Andrea Luciani Date and place
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Plutonium Biokinetics in Human Body A. Luciani - Kit-Bibliothek - FZK

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