It is the principal constituent of the fuel rods in a nuclear reactor. By far the most important one is uranium-235 (U-235). Research has been conducted by several different countries into segregating the rare isotopes in fission waste including the 'fission platinoids' (Ru. At TU Delft we investigate in the radioactive laboratories of the Reactor Institute Delft the complex chemistry of the JOG combining structure studies by X-ray and neutron diffraction, X-ray Absorption Spectroscopy (XAS), thermodynamic measurements by Differential Scanning Calorimetry (DSC) and solution calorimetry, as well as thermodynamic modelling assessments using the CALPHAD method. Principles of Nuclear Fission In Table 12-1 we listed examples of radioactive nuclei that are important in nuclear fission. Many of the fission products are either non-radioactive or only short-lived radioisotopes, but a considerable number are medium to long-lived radioisotopes such as 90 Sr, 137 Cs, 99 Tc and 129 I. The chemistry of cesium compounds forming in the JOG is particularly relevant since the potential release of 135Cs and 137 Cs (the isotopes which are the main cause for the radiological consequences of an accident) into the environment is a subject of primary concern for the public. Cesium molybdate Cs2MoO4 is the main component of the JOG, which shows a high and anisotropic thermal expansion, which is detrimental to the mechanical properties, and a thermal conductivity one order of magnitude lower than the fuel, which can lead to the creation of hot spots. They accumulate in the space between fuel and cladding, forming a multi-component phase, the so called “Joint-Oxide Gain” (JOG), in the form of a layer of 150-200 μm. Fission products created by neutron irradiation of natural uranium in a nuclear reactor show in the initial stage approximately the same nuclide distribution as. SFR or LFR) from the centre of the fuel pin towards the pellet edge due to their high volatility, and to the strong temperature gradient (~450 mm-1). Easy money Nuclear Fission Reactors of the Future (Generation IV) The Uranium 235 Chain Reaction - Physics Made Fun Nuclear Power Plant Safety. They migrate in a fast neutron reactor (e.g.

Cs, Mo, I and Te in particular are volatile fission products that are generated with a high fission yield.

Nuclear fission products