Retrospective determination of fallout radionuclides and 236U/238U, 233U/236U and 240Pu/239Pu atom ratios on air filters from Vienna and Salzburg, Austria

J Environ Radioact. 2022 Dec:255:107030. doi: 10.1016/j.jenvrad.2022.107030. Epub 2022 Sep 30.

Abstract

137Cs and 241Pu (via 241Am) concentrations were measured γ-spectrometrically on air filters from the early 1960s (mainly from 1964-66) from Vienna, Austria, and an alpine station in Salzburg, Austria. Accelerator mass spectrometry (AMS) was used to determine 240Pu/239Pu, 236U/238U and 233U/236U atom ratios as well as 236U, 239Pu and 240Pu atom concentrations. The maximum 236U/238U atom ratio of these unique undisturbed global fallout samples was (1.19 ± 0.31) × 10-5 in spring 1964. The 233U/236U atom ratios were found within (0.15-0.49) × 10-2 and indicate that the weapons tests of the early 1960s can be excluded as 233U source. The 236U/239Pu atom ratios were calculated in the range of 0.22-0.48.

Keywords: (233)U/(236)U; (236)U/(238)U; (240)Pu/(239)Pu; AMS; Air filters; Bomb peak.

MeSH terms

  • Air Filters*
  • Austria
  • Plutonium* / analysis
  • Radiation Monitoring* / methods
  • Radioactive Fallout* / analysis
  • Retrospective Studies
  • Uranium* / analysis

Substances

  • Plutonium
  • Radioactive Fallout
  • Uranium