Soil-Plant Tc-99 (student preso)

637 views
547 views

Published on

student presentation
M. K.
Nuclear and Radiochemistry
Thailand

Published in: Education
0 Comments
2 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
637
On SlideShare
0
From Embeds
0
Number of Embeds
4
Actions
Shares
0
Downloads
0
Comments
0
Likes
2
Embeds 0
No embeds

No notes for slide
  • Presented by Michael Mergy Krause
  • Soil-Plant Tc-99 (student preso)

    1. 1. Soil-to-Plant Transfer Factors of Technetium-99 for Various Plants Collected in the Chernobyl Area by Keiko Tagami and Shigeo Uchida
    2. 2. Content <ul><li>Background </li></ul><ul><li>Methodology </li></ul><ul><li>Outcome </li></ul>
    3. 3. Background <ul><li>Technetium-99 </li></ul><ul><li>Is Manmade, only exists in nature due to: </li></ul><ul><li>Nuclear Weapons </li></ul><ul><li>Leakage from Power Plants </li></ul><ul><li>Medicinal used </li></ul>
    4. 4. Background <ul><li>Technetium-99 </li></ul><ul><li>beta emitter (E max = 0.29 keV) </li></ul><ul><li>half-life : 2.11 x 10 ^ 5 y ears </li></ul><ul><li>Made by fissions of 235U and 239Pu </li></ul>
    5. 5. Background <ul><li>Technetium-99 </li></ul><ul><li>Most stable form in nature TcO4−, </li></ul><ul><li>Usually not very abundant </li></ul><ul><li>Abundant in Chernobyl Area </li></ul>
    6. 6. Methodology <ul><li>concentrations of 99Tc in plant leaves from Twenty seven plant samples were collected at the Chernobyl site in 1994 and 1995 : </li></ul><ul><li>raspberry, strawberry and pink plants, blackalder, birch, cowberry and oak trees, and ferns </li></ul>
    7. 7. Methodology <ul><li>S eparated into three groups : </li></ul><ul><li>Fern </li></ul><ul><li>Herb (raspberry, strawberry and pink) </li></ul><ul><li>Tree (black alder, birch, cowberry and oak) </li></ul><ul><li>All samples were oven dried at 110 ˚C and thoroughly milled </li></ul>
    8. 8. Methodology <ul><li>1−45 g portions of samples were incinerated ( 450 ˚C , 2 h ) to decompose organic matter </li></ul><ul><li>95mTc was added </li></ul><ul><li>Tc was extracted with 4 M HNO3 </li></ul><ul><li>Separation of 99Ru and 99Tc via column </li></ul><ul><li>Inductively coupled plasma mass spectrometry </li></ul>
    9. 9. Methodology Varian ICP - MS
    10. 11. Outcome <ul><li>Transfer factor for 99Tc : TF is defined as the ratio of activity concentration in plant (in Bq g−1 dry weight (DW)) to activity concentration in soil (in Bq g−1 DW) </li></ul>
    11. 12. Outcome
    12. 13. Outcome <ul><li>T he low TFs we observed in this study implied that 8−9 years after 99Tc release from the Chernobyl Nuclear Power Plant, Tc should have been transformed to insoluble or less plant-available forms. </li></ul>

    ×