Experimental analysis of nuclear fuel depletion : method development, validation and uncertainty assessment

High-quality experimental data of nuclide inventories in spent nuclear fuel are critical for validation of computational tools and associated nuclear data that are used to simulate the nuclide transmutations and decay in nuclear fuel during and post irradiation. They provide the basis for evaluating the bias and uncertainty in code predictions of key metrics of importance to back-end fuel cycle applications as well as reactor safety analyses. This validation basis must be continuously reassessed and expanded to address changes in validation needs and to keep pace with changes in operation and fuel designs and characteristics for current and future commercial reactors. High-accuracy measurements of nuclide inventories can be obtained by destructive radiochemical assay (RCA) experiments. This type of experiment requires complex analytical methods (i.e., for sample preparation, chemical separation, spectrometry), specialized instruments and expertise, state-of-the-art experimental laboratories and facilities for handling and measuring irradiated nuclear fuel.

SCK CEN is recognized worldwide for its expertise in the field. Both through bilateral projects and in international collaborative projects initiated and led by SCK CEN, we contribute to validation and expansion of experimental nuclide inventory data for irradiated nuclear fuel. With the continued advancement of computational tools, three direct challenges are encountered:

• improved experimental precision is required on the nuclides used for burnup determination
• local, microscopic techniques are to be validated for burnup determination in heterogeneous fuels
• nuclide inventory of several key nuclides of importance for the back-end and final disposal which are currently not measured due to lack of (qualified) analysis methods (e.g. ¹⁴C, ³⁶Cl, ¹²⁹I, ⁷⁹Se, ⁴¹Ca)

The PhD candidate opts to tackle these challenges in order to enhance the quality of spent nuclear fuel characterization using diverse destructive analytical techniques.

The minimum diploma level of the candidate needs to be

• Academic bachelor
• Master of sciences in engineering

The candidate needs to have a background in

• Chemistry

Estimated duration

Expert group