Disproportionately High Contributions of 60 Year Old Weapons-Cs Explain the Persistence of Radioactive Contamination in Bavarian Wild Boars.

Radionuclides released from nuclear accidents or explosions pose long-term threats to ecosystem health. A prominent example is wild boar contamination in central Europe, which is notorious for its persistently high Cs levels. However, without reliable source identification, the origin of this decades old problem has been uncertain.

Determination of Characteristic vs Anomalous Cs/Cs Isotopic Ratios in Radioactively Contaminated Environmental Samples.

A contamination with the ubiquitous radioactive fission product Cs cannot be assigned to its source. We used environmental samples with varying contamination levels from various parts of the world to establish their characteristic Cs/Cs isotope ratios and thereby allow their distinction. The samples included biological materials from Chernobyl and Fukushima, historic ashed human lung tissue from the 1960s from Austria, and trinitite from the Trinity Test Site, USA.

Identification of a chemical fingerprint linking the undeclared 2017 release of Ru to advanced nuclear fuel reprocessing.

The undeclared release and subsequent detection of ruthenium-106 (Ru) across Europe from late September to early October of 2017 prompted an international effort to ascertain the circumstances of the event. While dispersion modeling, corroborated by ground deposition measurements, has narrowed possible locations of origin, there has been a lack of direct empirical evidence to address the nature of the release. This is due to the absence of radiological and chemical signatures in the sample matrices, considering that such signatures encode the history and circumstances of the radioactive contaminant.

Non-natural ruthenium isotope ratios of the undeclared 2017 atmospheric release consistent with civilian nuclear activities.

Understanding the circumstances of the undeclared 2017 nuclear release of ruthenium that led to widespread detections of the radioisotope Ru in the Eurasian region, and whether it derives from a civilian or military source, is of major importance for society and future improvements in nuclear safety. Until now, the released nuclear material has merely been studied by analyzing short-lived radioisotopes. Here, we report precise measurements of the stable isotopic composition of ruthenium captured in air filters before, during, and after the nuclear release, and find that the ruthenium collected during the period of the 2017 nuclear release has a non-natural isotopic composition.

Separation of Ultratraces of Radiosilver from Radiocesium for Environmental Nuclear Forensics.

The presence of environmental radiosilver and the investigation of the Ag/Ag isotopic ratio in the aftermath of a nuclear power plant accident provide valuable information on the condition of the control rods of pressurized water reactors. However, the detection of minute amounts of the γ-emitting radiosilver isotopes is often thwarted by the presence of concomitant and dominating γ emitters, primarily Cs, which results in increased detection limits in the γ spectra. We developed a rapid and robust separation protocol for trace silver extraction in the presence of overwhelming activities of Cs via the autodepostion of silver on a copper plate.