Published online by Cambridge University Press: 16 February 2017
In the framework of the Euratom FIRST-Nuclides program, SCK•CEN conducted leaching experiments on a PWR UOX fuel, taken from the Belgian Tihange 1 reactor, with an average rod burnup of 50 MWd/kgHM in order to determine the rapid release of some of the most critical radionuclides. Experiments were conducted with an intact and a declad spent fuel segment in contact with a reference carbonate solution. During one year, samplings were performed to determine the release of the most relevant radionuclides. The samples taken after six months of leaching were analysed by means of Thermal Ionisation Mass Spectrometry (TIMS). These results were compared to the total inventory measured with radiochemical burnup analyses, as well as with the calculated inventory profile along the pellet radius. The comparison gives information about the origin of the dissolved uranium.