[en] The composition of two stable isotopes ¹⁰B(- 20%) and ¹¹B (- 80%) can vary significantly on the earth and provides important information on the global geochemical cycle. Art Spivack has proposed a simple and elegant idea called 'palaeo-pH', that boron isotopes in foraminifera might indicate past oceanic pH values. The mean oceanic residence time of boron is calculated at 1.6 x 10⁷ years. Therefore, the boron concentration (4.5 ppm) and isotopic composition (δ¹¹B = 39-40 per mille) in seawater are quite uniform throughout the world's oceans (Table 1). The dominant boron species in seawater is B(OH)₃ and B(OH)₄^-. There is about 2% difference between the isotopic composition of B(OH)₃ and B(OH)₄^-, as a result of the isotope fractionation. The ¹¹B isotope is concentrated into B(OH)₃ in seawater. The relative proportion of the two species is controlled by pH. Boron isotopic composition of B(OH)₃ and B(OH)₄^- in seawater is shown as a function of pH. If one of each species is incorporated into marine carbonates, the boron isotopes should reflect seawater records of pH in which they have grown. Using the boron isotope 'palaeo-pH' method, the Lamont group attempted to estimate surface oceanic pH differences between the last glacial period and the Holocene. Studies on boron isotopes from coral samples clarify some issues on the 'palaeo-pH' in aquatic environments. More detailed studies will make progress on the boron isotope pH-meter. (author)

[en] A key topic in international safeguards is the work in preventing the further spread of nuclear weapon technology and nuclear materials. High performance analyses play an important role in enabling the detection of undeclared nuclear activities. Such analyses require comparison between different producers of analytical results. Within the European Commission Support Programme, the JRC Karlsruhe has been demonstrating that the technical competences in safeguards laboratories are to the benefit to IAEA. It will be shown that direct contact between inspectors and applied nuclear scientists brings scientific excellence at the working level. Furthermore, frequent and informal contacts between inspectors and R&D staff are essential to enhance scientific/technical capabilities for the IAEA and the safeguards community. Specific examples include:  Participation in inter-laboratory exercises, provided by the IAEA, allowing the safeguards community to gain confidence in the results produced by different laboratories.  Reference materials produced by the IAEA, known as Large Size Dried (LSD) spikes, are verified by JRC Karlsruhe and other laboratories to offer assurance for U and Pu content analyses.  The experience gained from operating the Euratom safeguards on-site laboratories OSL/LSS since 1999. This activity has provided sustainable information and experience, which fed into the on-site laboratory at the Rokkasho Reprocessing Plant in Japan.  The COMPUCEA technique, which was developed in Karlsruhe for in-field measurement in support of inspections, was transferred to the IAEA and is now a Class A method used in international safeguards. Furthermore, such collaborations facilitate non-conventional combinations of measurement techniques, used in safeguards and nuclear forensics to obtain more comprehensive safeguards information. (author)

[en] The Joint Research Centre (JRC) and the International Atomic Energy Agency (IAEA) organized a workshop on the Hybrid K-Edge/K-XRF (HKED) technique in Karlsruhe, Germany, from 23 - 25 April 2018. The HKED technique is a key method for safeguards nuclear material accountancy at bulk-handling facilities. It allows one to measure uranium and plutonium concentration in liquid samples with uncertainties down to about 0.2% and 0.7%, respectively. The workshop brought together users of the Hybrid K-Edge / K-XRF (HKED) technique to discuss topics of common interest, such as performance and maintainability of HKED hardware and software, analytical performance of HKED, specific HKED applications and future developments. Particular focus was given to possible future collaborations. The workshop consisted of presentations and discussions on the above topics and also included a live demonstration of the HKED setup installed at JRC-Karlsruhe. To facilitate discussions, each participant was asked to present the HKED hardware and software used in their laboratory, the types and numbers of samples they analyse by HKED, their uncertainty requirements for HKED and any current or anticipated challenges/problems. A set of HKED spectra was distributed to the registered participants for independent analysis. The results of these analyses were shared during the workshop so that participants could benefit from each other’s experiences. The paper presents the outcomes of the workshop. The workshop will contribute to a common understanding of the current status of the HKED technique worldwide, and to addressing current and future challenges of the HKED technique. (author)

[en] Since the beginning of the 1990s when the first seizures of nuclear material were reported, the IAEA has recorded over 200 cases of illicit trafficking of nuclear materials. Despite the decreasing frequency of nuclear material seizures, particularly the ones involving weapons-grade material, the issue continues to attract public attention and is a reason for concern due to the hazard associated with such materials. Once illicitly trafficked nuclear material has been intercepted, the questions of its intended use and origin are to be addressed. Especially the origin is of prime importance in order to close the gaps and improve the physical protection at the sites where the theft or diversion occurred. To answer these questions, a dedicated nuclear forensics methodology has been developed. In this paper an overview is given on the methodologies used, on the past and on-going developments and on the experience gathered. Some selected examples shall illustrate the challenges and the complexity associated with this work