Formation of Heavy Neutron-Deficient Nuclides in 3He-Induced Reactions

Peer reviewe

Plutonium in the air in Kurchatov, Kazakhstan

Weekly air samples of 25 000 m3 volume were taken with two air samplers over a period of one year in 2000–2001 in the town of Kurchatov in Kazakhstan. For another three-month period in 2001, the samplers were run in the city of Astana, about 500 km west of Kurchatov. 137Cs, Pu and U concentrations were determined from the filters. Pu activities in Kurchatov varied in a 100-fold range; median 239,240Pu activities were 100 nBq/m3 and 238Pu activities 34 nBq/m3. The corresponding values for Astana were considerably lower: 29 and 9 nBq/m3, respectively, and in half of the filters the 238Pu activity was below the detection limit. Plutonium concentration correlated with the amount of dust retained on the filters only at the highest dust loads. Also no correlation between wind speed and the plutonium activity in the filters was observed. Thus, resuspension does not seem to be the mechanism responsible for the airborne plutonium. No clear seasonal variation of Pu air concentration was observed, though levels were somewhat elevated in February to April. There was no correlation between the plutonium and 137Cs concentrations. In most of the filters the cesium concentration was below the detection limit, but in those filters where it could be detected the cesium concentration was practically constant at 3.9 ± 1.6 μBq/m3. Dose estimation for the inhalation of the airborne plutonium gave a low value of 0.018 μSv/a for the inhabitants in Kurchatov, which is about a thousand times lower than the dose caused by the naturally occurring 210Po. Air parcel trajectory analysis indicated that the observed Pu activities in the air could not unambiguously be attributed to the most contaminated areas at the Semipalatinsk Test Site

Formation of neutron-deficient heavy nuclides in He-3 induced reaction at intermediate energies

Section II. Experimental Investigations of Nuclear Reactions Mechanism

On the application of ICP-MS techniques for measuring uranium and plutonium: a Nordic inter-laboratory comparison exercise

Inductively coupled plasma mass spectrometry (ICP-MS) techniques are widely used for determination of long-lived radionuclides and their isotopic ratios in the nuclear fields. Uranium (U) and Pu (Pu) isotopes have been determined by many researchers with ICP-MS due to its relatively high sensitivity and short measurement time. In this work, an inter-laboratory comparison exercise among the Nordic countries was performed, focusing on the measurement of U and Pu isotopes in certified reference materials by ICP-MS. The performance and characters of different ICP-MS instruments are evaluated and discussed in this paper. <br/