At CEA, you'll put your skills and enthusiasm to work on major societal projects.

As a post-doc, you will join the IRESNE team: the Institute for Research on Nuclear Systems for Low-Carbon Energy Production at CEA Cadarache.

The characterization of nuclear waste represents a major challenge for nuclear facilities, which must accurately measure a wide range of fission products and activation products in various matrices.

Long-lived radionuclides (LLRNs) are present in spent nuclear fuel as well as in waste from reprocessing. Unlike many other radioactive elements, these radionuclides decay very slowly, posing a major challenge for long-term containment. Deep geological disposal relies on a multi-barrier approach designed to prevent the migration of LLRNs into the biosphere. However, the geological evolution of the sites, the physicochemical interactions of the waste with its environment, and uncertainties over extremely long time scales make this containment complex. Thus, the accurate assessment of the LLRNs inventory is a key challenge for ensuring the long-term safety of deep geological waste disposal. Quantifying long-lived radionuclides generally involves chemical separation steps to remove interferents, separate the radionuclide of interest from the matrix, and preconcentrate it prior to measurement by radiometry or mass spectrometry (Aguerre and Frechou 2006; Comte et al. 2003). Among the available measurement techniques, inductively coupled plasma mass spectrometry (ICP-MS) has expanded the range of measurable radionuclides compared to radiometric techniques, while reducing measurement time and thereby improving sample throughput. Nevertheless, measuring RNVLs remains complex due to factors related to the intrinsic characteristics of these isotopes (primarily pure beta decay, low specific activity), their generally very low concentration levels in samples, and the spectral interferences (isobaric, polyatomic) that affect them during ICP-MS measurements (Diez-Fernández et al. 2020) .

LARC has developed methods for the chemical separation and quantification of several LLRNs (79Se, 93Zr, 126Sn) in Zircalloy cladding. The main objectives of this project are to adapt this method to other types of matrices (concrete, ash, etc.) and to develop a method for measuring 107Pd.

The candidate will be responsible for:

- Sample preparation

- Establishing protocols for the chemical separation of the elements of interest

- Developing ICP-MS/MS and/or MC-ICP-MS/MS measurement methods to eliminate interferences and achieve the highest possible sensitivity

- Interpreting the results obtained

- Presenting the results at scientific conferences and publishing them in peer-reviewed journals

- PhD in analytical chemistry or related field

- Laboratory skills in chemical analysis using ICP-MS.

- Skills in sample purification using preparative chromatography.

- Experience in isotope analysis, radionuclide analysis and ion chromatography are a plus.

- Ability to communicate effectively in English and/or French

You enjoy teamwork and know how to interact with a diversity of partners, putting the collective interest first, but you are also capable of working independently on your projects.

You have demonstrated your ability to manage a research program with the necessary scientific rigor. Your enthusiasm for innovation will enable you to make proposals and design new concepts.