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Isotope Hydrology: 85 Kr dating

Isotope Hydrology: 85 Kr dating. Peter Schlosser, February 28, 2008. Syllabus. Syllabus. Transient Tracers. Tracers: trace substances of natural or anthropogenic origin (stable and radioactive isotopes; chemical compounds. Sometimes toxic or otherwise harmful (contaminants)

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Isotope Hydrology: 85 Kr dating

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  1. Isotope Hydrology: 85Krdating Peter Schlosser, February 28, 2008

  2. Syllabus

  3. Syllabus

  4. Transient Tracers • Tracers: trace substances of natural or anthropogenic origin (stable and radioactive isotopes; chemical compounds. Sometimes toxic or otherwise harmful (contaminants) • Transient tracers: ‘Dyes’with known delivery rates to the environment (e.g.,3H, 3He,CFCs, 129I, SF6, 85Kr) • Radioactive clocks (e.g., 14C,39Ar, 3H/3He) • Special sources (e.g., 18O, Ba, nutrients, Ra isotopes, Rn isotopes) • Deliberately released tracers (e.g., SF6, 3He)

  5. 85Kr 85Kr is a radioactive isotope of the noble gas krypton. It is produced naturally, as well as by human activities, mainly the nuclear industry. Due to its chemical stability as a noble gas, it is an ideal tracer of environmental processes. Downsides of 85Kr as tracer in hydrology are the large amount of water required for measurement and the difficult methodology (ultra low-level β -counting). There are only very few laboratories worldwide that can measure 85Kr.

  6. 85Kr: natural background Natural production: 84Kr(n,γ)85Kr Fission: Natural spontaneous fission on 235U, 233U, and 239Pu The global inventory of natural 85Kr is about 10 Ci from the (n,γ) reaction and 4 Ci from fission.

  7. 85Kr: sources Nuclear weapons testing Power generation: Reactor Pu production: Reactor Ca. 1 per cent of 85Kr produced in a nuclear reactor escaped. The rest remains in the fuel rods until they are re-processed

  8. 85Kr: radioactive decay Radioactive decay: 85Kr -> 85Rb + e- + ν + Q T1/2 = 10.76 years Qmax: = 0.687 MeV

  9. 85Kr: atm. Inventory (1976) *: only released fraction

  10. 85Kr emissions Zimmermann et al.; Atm. Env., 1989

  11. 85Kr emissions Zimmermann et al.; Atm. Env., 1989

  12. 85Kr emissions Zimmermann et al.; Atm. Env., 1989

  13. 85Kr emissions Zimmermann et al.; Atm. Env., 1989

  14. 85Kr emissions

  15. 85Kr emissions

  16. 85Kr emissions

  17. 85Kr emissions

  18. 85Kr distribution Zimmermann et al.; Atm. Env., 1989

  19. 85Kr distribution Jacob et al., 1987; JGR Atm.

  20. 85Kr distribution

  21. 85Kr distribution Zimmermann et al.; Atm. Env., 1989

  22. 85Kr distribution Weiss et al., 1986; NIM

  23. 85Kr distribution

  24. 85Kr evolution Zimmermann et al.; Atm. Env., 1989

  25. 85Kr model simulations Zimmermann et al.; Atm. Env., 1989

  26. 85Kr groundwater ages

  27. 85Kr groundwater ages

  28. 85Kr groundwater ages

  29. 85Kr groundwater ages

  30. 85Kr groundwater ages

  31. 85Kr groundwater ages

  32. 85Kr measurement

  33. 85Kr measurement

  34. 85Kr measurement

  35. 85Kr measurement

  36. 85Kr measurement

  37. 85Kr measurement

  38. 85Kr measurement

  39. 85Kr measurement

  40. 85Kr measurement

  41. Tracer age comparison Delmarva Delmarva New Jersey

  42. 39Ar

  43. 39Ar

  44. 39Ar

  45. 39Ar dating

  46. 39Ar dating

  47. 39Ar dating

  48. 39Ar dating

  49. 39Ar dating

  50. 39Ar dating

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