The present report is a contribution to the “Numerical analysis of operational scenarios and incidental” activity. It consists in developing, applying and validating an approach and numerical models for the safety analysis of liquid metal Gen. IV reactors. The activity benefits of the International Coordinated Research Project (CRP) on EBR-II Shutdown Heat Removal tests promoted by IAEA. It is multi-physics and multi-scale and it will require the synergistic effort of different technical skills. The work is based on the availability of experimental tests carried out in EBR-II reactor. These tests are: protected (SHRT-17) ed unprotected (SHRT-45r) loss of flow. The documents presents the EBR-II and describes the SHRT-17 and the experimental data available. Then, the 3D thermal-hydraulic model of EBR-II by RELAP5-3D© system code is presented, together with the nodalization qualification carried out by means of the post-test analysis. Considering the highly detailed measurements of temperatures in the SA XX09, a CFD model with ANSYS CFX code was set up and employed for complex 3D simulations of the temperature filed and coolant flow paths. Steady state simulations (at starting of transient) and transient simulation of SHRT17 were also performed starting from the boundary conditions provided by the system code results. Finally, a methodology was also set-up to carry out neutronic core analysis based on 3D codes. Starting from the SHRT-45r test specifications, including the fuel composition data, an MCNP6 model of the overall core was developed. Every single pin was modeled, including the stainless steel of the reflector, according with the original geometry. The keff value was calculated as well as the power distribution, which can be used as reference for the 3D nodal model at reduced number of energy groups. Homogenized cross sections were calculated for 33 groups by means of SCALE code. Different 2D models were generated for the fuels, the CR and the reflector. These were used to derive a cross section library for all core, excluding the blanket zone. Then, this library was implemented in the core 3D neutron kinetic code model, PHISICS, which will be used for the coupled calculation of the unprotected transient.
Development and validation of an approach and numerical models for safety analysis of FBR / Del Nevo, A.; Di Piazza, I.; Parisi, C.; Martelli, Emanuela; Balestra, Paolo; Giannetti, Fabio; Caruso, Gianfranco; Naviglio, Antonio. - ELETTRONICO. - -:(2015), pp. ---.
Development and validation of an approach and numerical models for safety analysis of FBR
MARTELLI, EMANUELA;BALESTRA, PAOLO;GIANNETTI, FABIO;CARUSO, Gianfranco;NAVIGLIO, Antonio
2015
Abstract
The present report is a contribution to the “Numerical analysis of operational scenarios and incidental” activity. It consists in developing, applying and validating an approach and numerical models for the safety analysis of liquid metal Gen. IV reactors. The activity benefits of the International Coordinated Research Project (CRP) on EBR-II Shutdown Heat Removal tests promoted by IAEA. It is multi-physics and multi-scale and it will require the synergistic effort of different technical skills. The work is based on the availability of experimental tests carried out in EBR-II reactor. These tests are: protected (SHRT-17) ed unprotected (SHRT-45r) loss of flow. The documents presents the EBR-II and describes the SHRT-17 and the experimental data available. Then, the 3D thermal-hydraulic model of EBR-II by RELAP5-3D© system code is presented, together with the nodalization qualification carried out by means of the post-test analysis. Considering the highly detailed measurements of temperatures in the SA XX09, a CFD model with ANSYS CFX code was set up and employed for complex 3D simulations of the temperature filed and coolant flow paths. Steady state simulations (at starting of transient) and transient simulation of SHRT17 were also performed starting from the boundary conditions provided by the system code results. Finally, a methodology was also set-up to carry out neutronic core analysis based on 3D codes. Starting from the SHRT-45r test specifications, including the fuel composition data, an MCNP6 model of the overall core was developed. Every single pin was modeled, including the stainless steel of the reflector, according with the original geometry. The keff value was calculated as well as the power distribution, which can be used as reference for the 3D nodal model at reduced number of energy groups. Homogenized cross sections were calculated for 33 groups by means of SCALE code. Different 2D models were generated for the fuels, the CR and the reflector. These were used to derive a cross section library for all core, excluding the blanket zone. Then, this library was implemented in the core 3D neutron kinetic code model, PHISICS, which will be used for the coupled calculation of the unprotected transient.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
