Modeling and Experiment of Fission Products Release and Interaction with Coolant for Defective Fuel in Light Water Reactor (LWR) PDF Download

Author: Sha Xue
Publisher:
ISBN:
Category : Light water reactors
Languages : en
Pages : 102

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Book Description
During the normal operation of light water reactor, fuel defects can reside on fuel cladding from various reason such as fuel-pellet mechanical interaction, the hydriding of the Zr clad, the grid fritting from the assembly support, the warp wire fritting with the clad and also the stress corrosion cracking (SCC). The formation of defects on fuel cladding will result water ingression to the gap and react with nuclear fuel and the cladding inner surface. The interaction of water and nuclear fuel will affect the fuel thermal properties and deteriorate the cladding by hydriding and change of oxygen potential in the fuel. The change of fuel thermal properties will decrease the thermal conductivity, lead the decrease of heat transfer coefficient which may increase the fuel melting risk. The volatile fission products and fission gas will release to the coolant through cladding defects and increase the coolant activity and the defective nuclear fuel becomes a fission product source term when reactor is under normal operation. Experimental and modeling are applied to understand the behavior of a defective fuel pin. The experimental part focuses on the dissolution test of rare earth fission products in simulated LWR coolant chemistry and the diffusion coefficient measurement of cesium iodide in simulated LWR coolant chemistry using Nuclear Magnetic Resonance (NMR) technique. Rare earth fission products significantly contribute the residual heat and large quantity of radioactivity after the core shut down or in severe accident, therefore, their dissolution kinetic parameters in LWR are important to reactor safety and the understanding the source terms.