Post-doc : Quantification of Selenium 79 in Nuclear Waste

Position description

**Category**:

- Chemistry

**Contract**:

- Postdoc

**Job title**:

- Post-doc : Quantification of Selenium 79 in nuclear waste

**Subject**:

- This post-doc aim to develop an analytical method for the quantification of the long-lived radionuclide Selenium 79 in nuclear waste. More specifically, this will be done using preparative chromatography and ICP-MS/MS.

**Contract duration (months)**:

- 12

**Job description**:

- 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 sites, which must accurately measure a diverse range of fission products, activation products and naturally occurring radionuclides in various matrices.

**Long-lived radionuclides**(LLRN) are present in both spent nuclear fuel and reprocessed waste. Accurate assessment of the inventory of LLRNs is therefore a key issue in guaranteeing 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 pre-concentrate it prior to measurement by radiometry or mass spectrometry.

**ICP-MS** has expanded the number of radionuclides that can be measured compared with radiometric techniques. Nevertheless, the measurement of RNVL remains complex, due to the generally very low concentrations in samples and to spectral interferences during ICP-MS measurements.

**Selenium 79** (79Se) is one of the seven main long-lived fission products, but very few actual quantifications of 79Se in real samples are reported in the literature (less than 20 publications). For direct quantification in fuel cladding dissolutions, a detection limit of less than ng/L is required.

**The main goal** of this post-doctoral project is to develop a method for quantifying 79Se in nuclear waste, and more specifically in zircaloy cladding from spent fuel.

**You will be responsible for**:

- Preparing samples.
- Setting up protocols for the separation of selenium by ion exchange chromatography.
- Development of an ICP-MS/MS measurement method (choice of reaction/collision gas, optimization of measurement parameters, correction of mass bias, etc.) to eliminate interferents and achieve the best possible detection limit.
- Interpretation of the results obtained.
- Presentation of results at scientific conferences and publication in peer-reviewed journals.

Depending on the progress of the project, the missions may be extended for a further year to include the quantification of 107Pd and 126Sn.

**Applicant Profile**:
**You have a PhD in analytical chemistry.**

You have:

- 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.

You enjoy teamwork and know how to interact with a diversity of partners, putting the collective interest first.

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.

You are able to work independently on your projects, but you are also capable of working as part of a team and collaborating with different profiles.

**Why join the CEA?**
- Give meaning to your career by working on tomorrow's major societal challenges.
- Have career prospects with over 60 job families, training courses...
- Our benefits: RTT (reduced working hours), a network of bus routes at certain centers (free of charge), collective catering, CSE...
- In line with CEA's commitment to the integration of disabled people, this job is open to all. The CEA offers accommodations and/or organizational possibilities for the inclusion of disabled workers._

Position location

**Site**:

- Cadarache

**Job location**:

- France, Provence-Côte d'Azur, Bouches du Rhône (13)

**Location**:

- Saint-Paul-lez-Durance

**Languages**:

- English (Fluent)

**Recommended training**:

- PhD

Requester

**Position start date**:

- 01/07/2025

General information

**Organisation**:
The French Alternative Energies and Atomic Energy Commission (CEA) is a key player in research, development and innovation in four main areas:

- defence and security,
- nuclear energy (fission and fusion),
- technological research for industry,
- fundamental research in the physical sciences and life sciences.

Drawing on its widely acknowledged expertise, and thanks to its 16000 technicians, engineers, researchers and staff, the CEA actively participates in collaborative projects with a large number of academic and industrial partners.

The CEA is established in ten centers spread throughout France

**Refer