A new Certified Reference Material of CETAMA: its certification approach

To meet a need expressed by the French nuclear laboratories, the Commission for the Establishment of Analytical Methods (CETAMA) has provided a new reference material with high level in plutonium isotope 242Pu and certified in isotopic ratio. Based on the ISO guide 34, the production of this material by LAMMAN laboratory (Metrology Laboratory of Nuclear Material) in CEA Marcoule has been made from a solution of plutonium nitrate enriched in 242Pu. The certification process has been undertaken by interlaboratory comparison in collaboration with five French and European laboratories. The method of mass spectrometry thermal ionization (TIMS) was recommended as the analytical technique for certification. The statistical processing of the data provided by the laboratories has been done by four different approaches. The “excess-variance” approach has proved to be the best to process these data. After determining certified values and their associated uncertainties, a certificate has been established for this new reference material 242Pu

Molybdenum solubility in aluminium nitrate solutions

International audienceFor over 60 years, research reactors (RR or RTR for research testing reactors) have been used as neutron sources for research, radioisotope production ($^{99}$Mo/$^{99m}$Tc), nuclear medicine, materials characterization, etc… Currently, over 240 of these reactors are in operation in 56 countries. They are simpler than power reactors and operate at lower temperature (cooled to below 100°C). The fuel assemblies are typically plates or cylinders of uranium alloy and aluminium (U-Al) coated with pure aluminium. These fuels can be processed in AREVA La Hague plant after batch dissolution in concentrated nitric acid and mixing with UOX fuel streams. The aim of this study is to accurately measure the solubility of molybdenum in nitric acid solution containing high concentrations of aluminium. The higher the molybdenum solubility is, the more flexible reprocessing operations are, especially when the spent fuels contain high amounts of molybdenum. To be most representative of the dissolution process, uranium-molybdenum alloy and molybdenum metal powder were dissolved in solutions of aluminium nitrate at the nominal dissolution temperature. The experiments showed complete dissolution of metallic elements after 30minutes stirring, even if molybdenum metal was added in excess. After an induction period, a slow precipitation of molybdic acid occurs for about 15hours. The data obtained show the molybdenum solubility decreases with increasing aluminium concentration. The solubility law follows an exponential relation around 40g/L of aluminium with a high determination coefficient. Molybdenum solubility is not impacted by the presence of gadolinium, or by an increasing concentration of uranium

Results of recent counter-current tests on An(III)/Ln(III) separation using TODGA extractant

International audienceOne of the different options investigated at the CEA Marcoule to separate trivalent minor actinides (An(III) = Am(III) to Cf(III)) directly from PUREX raffinates by solvent extraction takes advantage of both the high efficiency of the diglycolamide, N,N,N',N'-tetraoctyldiglycolamide (TODGA), to extract trivalent 4f and 5f elements from nitrate containing aqueous solutions, and the selectivity of hydrophilic polyaminocarboxylic acids, which better complex trivalent 5f elements than 4f elements in buffered conditions, and hence allow the former elements (An(III)) to be selectively stripped, whereas the latter elements (Ln(III)) remain in the solvent and are further back-extracted in diluted nitric acid. The major difficulty of this separation process is to tune the pH in a very narrow range of operating conditions, at the An(III) selective stripping step, because of the high sensitivity of the performances of the flowsheet. The extraction system was optimized to meet the requirements of an efficient process flowsheet allowing recovery yields greater than 99.9% to be obtained for the An(III), with high decontamination factors vs Ln(III), in only one cycle after the PUREX process implementation. A cold test was successfully carried out in small scale mixer-settlers in the Marcel testing loop, using a surrogate feed composed of major fission products. A medium activity test was further implemented in similar laboratory contactors, in the glove boxes of the ATALANTE facility, on a surrogate feed spiked with Am-241, Cm-244, and Eu-152. This paper describes the results of these two counter-current tests

Implementation of Americium Separation from a PUREX Raffinate

AbstractRecovering of minor actinides from spent nuclear fuel is investigated for heterogeneous recycling in Generation-IV reactors. After plutonium, americium is the main contributor to residual heat of long term radioactive waste which determines waste density within geological repository. Selective americium separation (EXAm process) by liquid-liquid extraction from a PUREX raffinate was studied. Two experiments were performed in ATALANTE facilities. The first test, on surrogate solution, validated the americium extraction performance. The second trial was carried out in the high-level shielded process line from a genuine PUREX raffinate. Tools used to manage the process are introduced to show performance process achievement

Trends in Fatal Poisoning Among Drug Users in France From 2011 to 2021

Importance The DRAMES (Décès en Relation avec l’Abus de Médicaments Et de Substances) register is a database of drug-related deaths with the aim of identifying the psychoactive substances associated with and estimating the trends in these deaths. Our novel approach is based on the collection of data on all deaths for which toxicology experts have performed analyses. Objective To describe drug-related deaths in France and report trends over an 11-year period. Design, Setting, and Participants This case series used a national register to assess 4460 drug-related deaths that occurred from 2011 to 2021 in France. Data analyses were performed from January 1, 2012, to December 31, 2022. Main Outcomes and Measures Demographic characteristics; medical and substance abuse history; forensic autopsy findings; and toxicology reports. Results Among the 4460 deceased individuals (mean [SD] age, 37.8 [10.5] years), the mortality rate was highest among men (sex ratio, 4.4:1). Of the deaths involving a single or predominant drug, the legal substitution product, methadone, was the leading cause of death during the entire study period, ahead of heroin—44.7% and 35.9% for methadone vs 15.8% and 21.8% for heroin in 2011 and 2021, respectively. Between 2011 and 2021, most of the drug-related deaths shifted from licit to illicit drugs, and statistically significant variations were found for buprenorphine, cocaine, heroin, methadone, and other licit opioids. Deaths related to polydrug use increased from 23.2% in 2011 to 30.6% in 2021. In this context, opioids remained associated with most deaths, with at least 1 opioid being involved in approximately 9 of 10 cases (85.9%) in 2021. However, the main trend was the dramatic increase in drug combinations with cocaine, from less than one-third of cases in 2011 (30.8%) to more than half in 2021 (57.8%). Conclusions and Relevance This case series assessment of 4460 drug-related deaths found that opioids used alone or in combination were the main contributor to drug-related deaths, despite having a lower prevalence than other drugs. This finding is similar to that of other countries; however, in France licit methadone was the leading cause of opioid-related deaths (ahead of heroin) during the study period. Deaths associated with use of cannabis, new psychoactive substances, and stimulants (including amphetamine-type stimulants and cocaine, especially in combination) have increased and should be closely monitored