Measurements of low-level anthropogenic radionuclides from soils around Maralinga

The isotopes 239Pu and 240Pu are present in surface soils as a result of global fallout from nuclear weapons tests carried out in the 1950's and 1960's. These isotopes constitute artificial tracers of recent soil erosion and sediment movement. In practic

Determination of total I and 129

Total iodine and129-iodine in rivers and lakes of Argentina were measured by means of inductively coupled plasma mass spectrometry and accelerator mass spectrometry respectively. The obtained isotopic ratios, higher than the natural level, are explained as the delayed signal from nuclear weapon atmospheric tests. Besides, deposition fluences in catchment areas of the lakes are analyzed. Their latitudinal dependence, similar to the dependence of annual precipitation rates, favours wet deposition as the main 129I fallout mechanism for this region

Probing core polarization around 78Ni: intermediate energy Coulomb excitation of 74Ni

The study of the evolution of nuclear shells far from stability provides fundamental information about the shape and symmetry of the nuclear mean field. Nuclei with large neutron/proton ratio allow to probe the density dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Of particular interest is the region of 78Ni where the large neutron excess coincides with a double shell closure. We have recently measured the B(E2; 0+ → 2+) of the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory of the Michigan State University. The 74Ni secondary beam has been produced by fragmentation of 86Kr at 140 AMeV on a thick Be target. Selected radioactive fragments impinged on a secondary 197Au target where the measurement of the emitted γ-rays allows to extract the Coulomb excitation cross section and related structure information. Preliminary B(E2) values do not point towards an enhancement of the transition matrix element and the comparison to what was already measured by Aoi and co-workers in [1] opens new scenarios in the interpretation of the shell evolution of the Z=28 isotopes

Determination of the isotopic ratio 236 U/ 238 U in Austrian water samples

236U with a half life of 2.3 × 107 years is naturally produced in ultra-trace amounts (236U/238U < 10-10) in ores, soils and rocks, while a huge amount has been produced in nuclear power plants and possibly nuclear weapons tests by man. Thus, anthropoge

Determination of U, Pu and Am isotopes in Irish Sea sediment by a combination of AMS and radiometric methods

Samples from a marine sediment core from the Irish Sea (54.416 N, 3.563 W) were analyzed for the isotopic composition of uranium, plutonium and americium by a combination of radiometric methods and AMS. The radiochemical procedure consisted of a Pu separation step by anion exchange, subsequent U separation by extraction chromatography using UTEVA® and finally Am separation with TRU® Resin. Additionally to radiometric determination of these isotopes by alpha spectrometry, the separated samples were also used for the determination of 236U/238U and plutonium isotope ratios by Accelerator Mass Spectrometry (AMS) at the VERA facility. Keywords: Sellafield, sediment samples, 236U/238U, 240Pu/239Pu, 242Pu/239PuJRC.E.5-Nuclear chemistr

236 U/ 238 U and 240 Pu/ 239 Pu isotopic ratios in small (2 L) sea and river water samples

Accelerator Mass Spectrometry (AMS) and alpha spectrometry were used to determine uranium (236U, 238U, 234U) and plutonium isotopes (239Pu, 240Pu) in sea and river water samples. Plutonium was separated by Dowex® 1 × 8 resin and UTEVA® resin was used

Determination of U, Pu and Am isotopes in Irish Sea sediment by a combination of AMS and radiometric methods

Samples from a marine sediment core from the Irish Sea (54.416 N, 3.563 W) were analyzed for the isotopic composition of uranium, plutonium and americium by a combination of radiometric methods and AMS. The radiochemical procedure consisted of a Pu separation step by anion exchange, subsequent U separation by extraction chromatography using UTEVA® and finally Am separation with TRU® Resin. Additionally to radiometric determination of these isotopes by alpha spectrometry, the separated samples were also used for the determination of 236U/238U and plutonium isotope ratios by Accelerator Mass Spectrometry (AMS) at the VERA facility