Synthesis of the VERCORS experimental programme: Separate-effect experiments on Fission Product release, in support of the PHEBUS-FP programme

Insights on fission products behaviour in nuclear severe accident conditions by X-ray absorption spectroscopy

“…The absence of palladium after the test would imply a nearly complete release of this element out of the sample. Pd has been classified as a semi-volatile FP [15]. It was observed during the VERCORS tests that oxidizing atmospheres favoured the release of this FP, in a similar way to the other noble metals, Tc and Ru, present in the white inclusions.…”

BISON Theory Manual The Equations behind Nuclear Fuel Analysis

“…The rapid kinetics of the process cannot be interpreted as purely diffusion-controlled. From the available experimental evidence (e.g., [96,97,98,99]), the following main aspects of transient fission gas behaviour emerge:…”

SARNET benchmark on Phébus FPT3 integral experiment on core degradation and fission product behaviour

“…The FP release from intact fuel and control rods followed by the release from the in-core molten pool, depends mainly on temperature and oxygen potential but also on various physical and chemical processes that occur within the fuel matrix and in the surrounding gaseous atmosphere. In the FPT3 test, the main fission products were basically classified according to the results of the VERCORS programme (Ducros et al, 2013) in where the results of VERCORS and Phébus FP were mainly consistent. The consequent classification is the following:  Noble gases: Xe, Kr;…”

“…In order to gain more understanding about severe accident phenomena and to improve code models, international experimental programs have been/are being carried out. For the effects studied in FPT3, and more generally in Phébus FP, the most relevant are: experiments (2005-2010) performed by IRSN (Dominguez and Drouan, 2014) in the framework of the International Source Term Program (ISTP) (Clément and Zeyen, 2005), devoted to boron carbide effects on core degradation, as well as corresponding tests carried out at Karlsruhe Institute of Technology (BOX, LAVA, QUENCH-SR) under the German national programme (Steinbrück, 2010);  VERDON series (Ducros et al, 2013), being performed by CEA under ISTP, and the completed VERCORS series (Pontillon et al, 2010) also by CEA, which study/studied FP release and transport;  CHIP program being performed by IRSN (Haste et al, 2012b) under ISTP, to provide data on the physico-chemical transformations of iodine in the primary circuit, including kinetics, for example considering the systems {Mo, Cs, I, O, H} and {B, Cs, I, O, H};…”