Plutonium and uranium contamination in soils from former nuclear weapon test sites in Australia

236U and 239,240Pu ratios from soils around an Australian nuclear weapons test site

“…The low 236 U/ 239 Pu ratios at sites T007 and T008, which we interpret in terms of additional input of 239 Pu from the safety trials, are similar to those observed at the Montebello test site, and larger than those reported for the Totem tests at Emu Field (Child and Hotchkis, 2013). Even a few km to the south, however, at sites T001eT006, ratios are an order of magnitude higher and within the range of that reported for Northern Hemisphere global fallout, which is not yet well defined at~0.2.…”

“…Sites T001-T007 have inventories that are much closer to that reported by Srncik et al (2014) (but typically greater by factors of 2e10), and lower than those reported for the Northern Hemisphere. The 236 U concentrations are also lower, by factors 2e10, than those reported around the Totem-1 test site at Emu field~150 km NNE of Maralinga (Child and Hotchkis, 2013). As was the case for the Pu isotopes to the south of Maralinga (Tims et al, 2013b) the tests do not appear to have made a significant contribution to the total 236 U fallout, but more data is needed to determine if this is also the case elsewhere.…”

233U/236U signature allows to distinguish environmental emissions of civil nuclear industry from weapons fallout

“…Recent technical developments at the Vienna Environmental Research Accelerator (VERA) enable low-level Accelerator Mass Spectrometry (AMS) measurements of anthropogenic 233 U (T 1=2 = 1.592Á10 5 years 1 ) in the environment. The low environmental abundance of 233 U is a challenge even for the highly sensitive detection technique AMS so that previous publications on 233 U either analyzed its concentration in samples collected close to a contamination source 23,24 or used 233 U, which had been added to the environmental sample, to normalize the 236 U results for mass spectrometric measurements. The combination of environmental 233 U and 236 U could play a similar role for the U isotopic system as 240 Pu/ 239 Pu for the Pu system.…”

Derivation of a speciic activity limit for plutonium for near surface disposal a case study at a potential site in northwest China

“…To date, is sues con cern ing with the plu to nium iso topes ac cu mu la tion in near sur face en vi ron ment, e. g., its long-term stor age and dis posal, have been dis cussed and an a lyzed ex ten sively. These in clude re views of the en vi ron men tal trans port of pluto nium [12,13], eval u a tions of global fall out from atmo spheric nu clear weap ons tests of the 1950s and 1960s [14][15][16], anal y ses of plu to nium iso topes in the air [17,18], and ex per i men tal and mod el ling stud ies of trans port mech a nisms [19][20][21][22]. Nev er the less, re ports on ap proaches to es tab lish ing ac tiv ity lim its for transuranic nuclides, i. e., 239 Pu, as well as their il lus trations, are lack ing, par tic u larly in China, where lim ited gen eral re search on the con cept of in ter me di ate depth dis posal for ra dio ac tive waste is avail able [23].…”