Multi-element ultra-trace detection of radionuclides in environmental samples

A ‘hot particle’ is a microscopic fragment deriving from nuclear material. The detection of these particles is in some cases the first marker of the release of nuclear material. Its history is contained in its isotopic composition, characteristic of its origin and interaction with the environment. This work focuses on environmental samples derived from the accident sites in Chornobyl and Fukushima, studied through resonant ionisation mass spectrometry, RIMS. The principle of RIMS relies on the universality of atomic structure to selectively analyse isotope ratios in a target element. This work discusses the design and operation of different instruments. Individual hot particles were analysed in the SIRIUS RIMS instrument at the Institute for Radiation Protection and Radioecology (IRS) in Hannover, Germany. A comparison study was done on eight Chornobyl Exclusion Zone (CEZ) particles with the LION at Lawrence Livermore National Laboratory (LLNL) in Livermore, USA. Comparable results across instruments show a range of burnup dependent isotope ratios for U and Pu and Cs, characteristic of RBMK-type reactors. Isotopic analysis therefore provides vital information about sample origin and degradation. In most mass spectrometric techniques without laser ionisation, the removal of isobaric interference requires chemical pre-treatment, thereby destroying the sample. This limits their application for isotopic analysis, necessitating a focus on one or two elements only, as allowed by small sample size. The versatility offered by multi-element RIMS makes it uniquely suited to the study of individual hot particles. In this work, isotope ratio analysis has been expanded to the actinides U, Pu, Np, and Am, and the fission products Rb, Sr, Zr, Cs and Ba. Isotope ratio analysis is interpreted in the contexts of nuclear forensics, radioecology, and reactor physics. A collection of samples can be grouped by analysing the time-dependent Sr, show how flux changes the U, Pu, and Cs composition across a reactor, and show through Ba that Cs has been lost to the environment

Production and characterization of standard particles for rL-SNMS

In this work, uranium-and plutonium-baring particles were produced by fast iron co-precipitation for the purpose of creating homogeneous multi-element standards. A set of single isolated particles showing no inhomogeneities in the element distribution were selected. These particles were used to determine the maximal achievable suppression ratios for uranium in Resonant Laser Secondary Neutral Mass Spectrometry (rL-SNMS) measurements of plutonium. It was shown for the first time directly that suppression-ratios in the order of three magnitudes are achievable with a resonant two-step excitation scheme for non-destructive measurements

Multi-element isotopic analysis of hot particles from Chornobyl

Microscopic fuel fragments, so-called “hot particles”, were released during the 1986 accident at the Chornobyl nuclear powerplant and continue to contaminate the exclusion zone in northern Ukraine. Isotopic analysis can provide vital information about sample origin, history and contamination of the environment, though it has been underutilized due to the destructive nature of most mass spectrometric techniques, and inability to remove isobaric interference. Recent developments have diversified the range of elements that can be investigated through resonance ionization mass spectrometry (RIMS), notably in the fission products. The purpose of this study is to demonstrate the application of multi-element analysis on hot particles as relates to their burnup, particle formation in the accident, and weathering. The particles were analysed with two RIMS instruments: resonant-laser secondary neutral mass spectrometry (rL-SNMS) at the Institute for Radiation Protection and Radioecology (IRS) in Hannover, Germany, and laser ionization of neutrals (LION) at Lawrence Livermore National Laboratory (LLNL) in Livermore, USA. Comparable results across instruments show a range of burnup dependent isotope ratios for U and Pu and Cs, characteristic of RBMK-type reactors. Results for Rb, Ba and Sr show the influence of the environment, retention of Cs in the particles and time passed since fuel discharge

innovative technologies for chemical security

AbstractAdvances across the chemical and biological (life) sciences are increasingly enabled by ideas and tools from sectors outside these disciplines, with information and communication technologies playing a key role across 21st century scientific development. In the face of rapid technological change, the Organisation for the Prohibition of Chemical Weapons (OPCW), the implementing body of the Chemical Weapons Convention ("the Convention"), seeks technological opportunities to strengthen capabilities in the field of chemical disarmament. The OPCW Scientific Advisory Board (SAB) in its review of developments in science and technology examined the potential uses of emerging technologies for the implementation of the Convention at a workshop entitled "Innovative Technologies for Chemical Security", held from 3 to 5 July 2017, in Rio de Janeiro, Brazil. The event, organized in cooperation with the International Union of Pure and Applied Chemistry (IUPAC), the National Academies of Science, Engineering and Medicine of the United States of America, the Brazilian Academy of Sciences, and the Brazilian Chemical Society, was attended by 45 scientists and engineers from 22 countries. Their insights into the use of innovative technological tools and how they might benefit chemical disarmament and non-proliferation informed the SAB's report on developments in science and technology for the Fourth Review Conference of the Convention (to be held in November 2018), and are described herein, as are recommendations that the SAB submitted to the OPCW Director-General and the States Parties of the Convention. It is concluded that technologies exist or are under development that could be used for investigations, contingency, assistance and protection, reducing risks to inspectors, and enhancing sampling and analysis

ESARDA Bulletin n. 60

ESARDA is an association initially formed to advance and harmonize research and development for nuclear safeguards whose scope has in recent year expanded as the number and type of its working groups’ activities below indicates. Esarda is currently composed of about 30 laboratories, private and governmental institutions worldwide. Within Esarda (http://esarda.jrc.ec.europa.eu/), a number working groups have been over the years established and active namely: Techniques and Standards for Destructive Analysis, Techniques and Standards for Non-Destructive Analysis, Containment and Surveillance, Novel Approaches / Novel Technologies, Implementation of Safeguards, Verification Technologies and Methodologies, Training and Knowledge Management, Editorial Committee. ESARDA publishes a Bulletin containing peer reviewed scientific related to nuclear Safeguards, verification and non-proliferation. This publication appears generally twice a year. In addition, thematic special issues are published as proposed by the ESARDA community. The Bulletin Editorial Board is composed of about 10 experts in the various technical and scientific fields related to safeguards. They are all actively engaged in safeguards R&D or in safeguards implementation and other fields. The Editorial Board decides the contents of the Bulletin, selects the papers to be published and reviews them before publication. All ESARDA editorial activities are carried out at JRC in Ispra. Scientific papers submitted for publication are reviewed by independent authors and by members of the Editorial Committee. The Bulletin is currently submitted to Scopus for evaluation in view of citation. ESARDA Bulletin is published jointly by ESARDA and the Joint Research Centre of the European Commission and distributed free of charge to over 1000 registered members, libraries and institutions worldwide.JRC.G.II.7-Nuclear securit