Recently, the Belgian government gave the green light to the Belgian Nuclear Research Centre to start constructing MYRRHA, the first high power accelerator driven research reactor in the world. One of the primary objectives of MYRRHA is to demonstrate transmutation of spent nuclear fuel. Transmutation can help solve problems posed by the management of radioactive waste by strongly reducing its volume and the proportion of long-lived isotopes it contains.
In MYRRHA, liquid lead-bismuth eutectic (LBE) will be used as a primary coolant. During operation of MYRRHA, the coolant will be contaminated by radionuclides. Quantitative understanding of the evaporation of these radionuclide impurities from the LBE is required for the safety assessment of MYRRHA. The so-called source term of evaporated radionuclides must be known as accurately as possible in order to predict the short and long-term health and environmental effects of the release during various postulated accidents.
The main objective of this project to determine the molecular composition of the vapor of key radionuclide impurities in MYRRHA using mass spectrometry methods. The molecular composition will depend on conditions such as temperature and the presence of contaminants such as water. Changes of the molecular composition of the vapor may strongly influence the radionuclide source term. In this project, the focus will be on the mobile fission products I, Cs and Te. The experimental research will make use of stable isotopes of these elements only, in order to have them in sufficient quantity to allow mass spectrometric determination of the vapor composition.