The INE Beamlines  (INE-Beamline and the ACT station at the CAT-ACT Beamline) at the KIT-synchrotron are dedicated to actinide research with X-ray spectroscopic techniques. Both are operated by the Institute for Nuclear Waste Disposal (INE).

Schematic sketch visualizing some of the actinide mobilization / retention processes possibly following actinide release from corroded HAW.

Research and development at INE are largely aimed at long term safety assessment of proposed deep geological repositories for high-level, heat producing nuclear waste (HAW) disposal. To ensure sound safety assessment, a molecular understanding of processes determinant in the fate of radionuclides, notably the actinides, and thermodynamic quantification is essential. Of central importance in such investigations is determination of actinide speciation (i.e., their chemical and physical form). X-ray spectroscopic methods have proved to be valuable tools for actinide speciation research. Investigations on non-fissile radioisotopes up to 106 times the legal exemption limit and fissile radioisotopes (Pu-239, U-235) up to 200mg, contained within two layers of protection, are possible. The synchrotron-based activities at the INE-Beamline are embedded in INE’s in-house research, thereby allowing a combination of analytical and instrumental methods, notably laser techniques and microscopic methods.

In situ X-ray spectroscopic investigations on radioactive samples are routinely performed at the INE Beamlines for studying, e.g., actinide containing solid-water interface chemical reactions, not possible at other facilities. A special protocol for working with radioactive samples at both INE beamlines exists and is supervised by INE’s own radiation protection officers. The unique aspect of the INE Beamlines is its close proximity to INE’s active laboratories on-site KIT north campus. The design is for a multi-purpose beamline, where a number of methods are possible on one and the same sample.

Detectors

Sample holder (HUBER goniometer):

                   
                   Setup for confocal measurements with a µ-focused beam at the INE-Beamline.

XYZ Sample positioner (IBG-2 design):

Alternative sample positioner with larger travel ranges designed by KIT-IBG-2 using Phytron controllers.

Sample environment

• Standard holder for transmission and fluorescence measurements of radioactive and non-radioactive samples, e.g., 400 µl and 2 ml PE-tubes, pellets.

• Special sample chambers for grazing incidence measurements of flat samples (up to 3 inch diameter)

• Liquid sample cell for the investigation of redox labile systems under electrochemically controlled conditions

• High T / pressure cell setup

• Environment: atmosphere, inert gas (existing supplies: He, N_², Ar)

• Liquid N_² cryostat (OI OptistatDN) for low temperature measurements

• setup for tender X-ray measurements* (currently applicable down to the phosphorus K-edge at ∼2.14 keV)
 

* see Dardenne, K. et al. Inorg. Chem. 2021, 60, 12285−12298

                                                  Tender X-ray setup (Inorg. Chem. 2021, 60, 16, 12285-12298).