Gergely Surányi

Rapid sequential determination of americium and plutonium in sediment and soil samples by ICP-SFMS and alpha-spectrometry

An improved sample preparation method for the determination of americium and plutonium in sediment and soil samples by inductively coupled plasma sector field mass spectrometry (ICP-SFMS) and alpha-spectrometry is described. The developed procedure involves a selective CaF2 co-precipitation for pre-concentration and matrix removal followed by a sequential extraction chromatographic separation. The average chemical recovery of sample preparation was between 81–94% for both americium and plutonium. The method development also focused on the elimination of possible interferences in mass spectrometric analysis caused by molecular ions (e.g.238U 1H+, 204Pb 36Ar+ or 208Pb 16O2+) employing the suitable matrix separation prior to ICP-SFMS analysis coupled with a desolvation sample introduction system. For 239Pu, 240Pu, 241Pu and 241Am limits of detection of 15, 9.2, 14 and 23 fg g-1 was achieved by ICP-SFMS, respectively. The applied sample preparation and measurement can be carried out within 6 h for one batch of samples. Results of certified reference materials (IAEA-384 and IAEA-385) analysed by the two different measurement techniques agreed well with the recommended or information values.

Detection of previous neutron irradiation and reprocessing of uranium materials for nuclear forensic purposes

The paper describes novel analytical methods developed for the detection of previous neutron irradiation and reprocessing of illicit nuclear materials, which is an important characteristic of nuclear materials of unknown origin in nuclear forensics. Alpha spectrometry and inductively coupled plasma sector-field mass spectrometry (ICP-SFMS) using solution nebulization and direct, quasi-non-destructive laser ablation as sample introduction were applied for the measurement of trace-level (232)U, (236)U and plutonium isotopes deriving from previous neutron irradiation of uranium-containing nuclear materials. The measured radionuclides and isotope ratios give important information on the raw material used for fuel production and enable confirm the supposed provenance of illicit nuclear material.

Cosmic Muon Detection for Geophysical Applications

A portable cosmic muon detector has been developed for environmental, geophysical, or industrial applications. The device is a tracking detector based on the Close Cathode Chamber, an MWPC-like technology, allowing operation in natural underground caves or artificial tunnels, far from laboratory conditions. The compact, low power consumption system with sensitive surface of 0.1 m2 measures the angular distribution of cosmic muons with a resolution of 10 mrad, allowing for a detailed mapping of the rock thickness above the muon detector. Demonstration of applicability of the muon telescope (REGARD Muontomograph) for civil engineering and measurements in artificial underground tunnels or caverns are presented.

Close Cathode Chamber technology for cosmic particle tracking

The Close Cathode Chamber (CCC) technology has been developed and found useful in a portable tracking system under harsh and varying environmental conditions due to their mechanical and operational stability. The muon flux have been measured on ground and at shallow depths underground (< 70 m.r.e.) which provides a good reference for other experiments. The multiple scattering in rock and the soft contamination of the track sample have been investigated experimentally and by GEANT4. The applicability of the sensor to detect underground rock density inhomogeneities has been demonstrated via reconstruction of an underground tunnel system. A modified muon tomograph has been built with sensitive area of 0.25 m2 and angular resolution of 15 mrad which is useful for material discrimination via the measurement of multiple scattering and absorption of muons. The reliable tracking performance, low power consumption and fair angular resolution make the CCC technology useful also in large area tracking detectors.