Coated Nuclear Fuel Particles: The Coating Process and Its Model

TRISO coated fuel particles with enhanced SiC properties

“…2), it was observed that the particles in the multispout bed showed much better mixing and circulation from top to bottom than those in the single spout system. This enhanced mixing ensures that the particles spend considerably less time out of the spout where little or no deposition of SiC or PyC occurs [7]. Furthermore, considering that the temperature gradient inside the furnace could have an important effect on the type and properties of the PyC or SiC produced [30,31], an increased circulation would also ensure that the particles do not remain stationary for long periods of time, therefore producing coatings with more uniform characteristics.…”

“…Both pyrolytic carbon (PyC) and silicon carbide are produced by a process known as fluidized bed chemical vapor deposition (FBCVD) [6][7][8]. Most of the CVD equipment currently used for the production of coated fuel particles consist of a gas distributor of conical shape ( Fig.…”

Control of stoichiometry, microstructure, and mechanical properties in SiC coatings produced by fluidized bed chemical vapor deposition

“…2-4, the composition of SiC goes from Si + SiC to stoichiometric SiC and C + SiC as deposition temperature increases. (3) and (6)] 27-32 : Silicon carbide can be deposited by two separate reaction sequences, one involving hydrocarbons [Eqs.…”

“…3 Among these layers, the silicon carbide coating is considered the most important since it provides the mechanical strength and is responsible for retaining most of the solid fission products. The structural integrity and performance of the coated fuel is the most important safety aspect in this nuclear reactor, since it relies on the properties of the coatings surrounding the kernel fuel to stop the release of harmful radioactive material.…”

Thermal conductivity mapping of pyrolytic carbon and silicon carbide coatings on simulated fuel particles by time-domain thermoreflectance

“…Three different samples were prepared using fluidized bed chemical vapor deposition [4,19,20]. Two single layer PyC coatings and a triple layered particle consisting of a buffer, inner pyrolytic carbon (IPyC) and silicon carbide (SiC) were deposited on alumina particles 500 lm in diameter.…”