On the use of a dedicated ballast pellet for a prompt self-ejection mechanism after a temperature transient in lead-cooled fast reactors

The potential use of changes in buoyancy as a reactivity feedback mechanism during temperature transients in heavy liquid metal fast reactors (HLMFRs) is discussed. It is shown that with the use of ballast pellets (~15% volume fraction) introduced in combination with fuel pellets, fuel rods will be...

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Detalles Bibliográficos
Autor: Arias Montenegro, Francisco Javier|||0000-0002-0779-9754
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/107743
Acceso en línea:https://hdl.handle.net/2117/107743
https://dx.doi.org/10.1016/j.nucengdes.2017.07.023
Access Level:acceso abierto
Palabra clave:Fluid dynamics
Nuclear reactors
Heavy liquid metal fast reactors
Buoyancy
Temperature transient compensation
Generation IV reactors
Dinàmica de fluids
Reactors nuclears
Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids
Àrees temàtiques de la UPC::Energies::Energia nuclear
Descripción
Sumario:The potential use of changes in buoyancy as a reactivity feedback mechanism during temperature transients in heavy liquid metal fast reactors (HLMFRs) is discussed. It is shown that with the use of ballast pellets (~15% volume fraction) introduced in combination with fuel pellets, fuel rods will be endowed with a reliable self-ejection mechanism that is able to compensate temperature transients. Utilizing a simplified model, an estimate of the negative reactivity insertion expected from this mechanism is derived. The use of ballast pellets opens up the possibility of introducing greater amounts of actinides into the core, as well as providing a solution to the classical problem of positive coolant temperature reactivity coefficients in fast reactors.