scholarly journals Severe Accidents in Sodium-Cooled Fast Reactors: CFD Sensitivity Studies on the Thermal Ablation of Core-Catcher

2021 ◽  
Author(s):  
Olivier A. Czarny ◽  
Adrien Collin de l'Hortet ◽  
Nicolas Goreaud
Keyword(s):  
Thermal Ablation ◽  
Solid Material ◽  
Ablation Process ◽  
Fast Reactors ◽  
Severe Accidents ◽  
Core Catcher ◽  
Show Evidence ◽  
Internal Core ◽  
Sensitivity Studies

Abstract The present work aims at testing the CFD capabilities to simulate erosion of materials which interact with a corium mass. The main foreseen applications are the design of external/internal core catchers or in-vessel retentions devices used to mitigate severe accidents for Sodium-cooled Fast Reactors (SFR). 2D axisymmetric simulations of a corium jet impinging a sacrificial solid material show evidence of a pool-effect, previously observed in experiments, which contributes to limit the ablation process. Complementary sensitivities assess the influence of jet diameter, temperature and velocity.

A multi layer core catcher concept for future sodium cooled fast reactors

2014 ◽  
Vol 65 ◽  
pp. 253-261 ◽  
Author(s):  
A. Jasmin Sudha ◽  
K. Velusamy ◽  
P. Chellapandi
Keyword(s):  
Fast Reactors ◽  
Core Catcher

Development Work for a Borax Internal Core-Catcher for a Gas-Cooled Fast Reactor

1978 ◽  
Vol 39 (2) ◽  
pp. 138-154 ◽  
Author(s):  
M. Dalle Donne ◽  
S. Dorner ◽  
G. Schumacher
Keyword(s):  
Fast Reactor ◽  
Development Work ◽  
Core Catcher ◽  
Internal Core

scholarly journals The heuristically-based generalized perturbation theory

2021 ◽  
Vol 7 ◽  
pp. 7
Author(s):  
Augusto Gandini
Keyword(s):  
Perturbation Theory ◽  
Perturbation Method ◽  
Linear Analysis ◽  
Linear Functionals ◽  
Fast Reactors ◽  
The Real ◽  
Generalized Perturbation Theory ◽  
Sensitivity Studies

The generalized perturbation method is described relevant to ratios of bi-linear functionals of the real and adjoint neutron fluxes of critical multiplying systems. Simple linear analysis for optimization and sensitivity studies are then feasible relative to spectrum and space-dependent quantities, such as Doppler and coolant void reactivity effects in fast reactors.

Numerical and Experimental Model Studies on Thermal Hydraulic Behavior of FBR Internal Core Catcher Assembly

2006 ◽  
Author(s):  
Sanjay Kumar Das ◽  
Anil Kumar Sharma ◽  
A. Jasmin Sudha ◽  
G. Punitha ◽  
G. Lydia ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Maximum Temperature ◽  
Model Studies ◽  
The Core ◽  
Core Catcher ◽  
Internal Core ◽  
Series Of Experiments ◽  
Retention Device ◽  
Good Agreement

Core Catcher is provided as an in-vessel core debris retention device to collect, support, cool and maintain in sub-critical configuration, the generated core debris from fuel melting due to certain postulated Beyond Design Basis Events (BDBE) for Fast Breeder Reactor (FBR). This also acts as a barrier to prevent settling of debris on main vessel and keeps its maximum temperature within acceptable creep range. Heat transfer by natural convection in the core catcher assembly has been assessed numerically and through water experiments using geometrically similar configuration. Resistive heating elements are used in experiment as heat source to simulate debris decay heat on core catcher. Series of experiments were carried out for two configurations referred as geometry A and geometry B. The later configuration showed enhanced natural convective heat transfer from the lower plenum of the vessel. Temperatures were monitored at critical positions and compared with numerical evaluation. Numerically evaluated flow fields and isotherms are compared with experimental data for specific steady state temperatures on heat source plate. Numerical results are found to be in good agreement with that obtained from experiments. The combined efforts of numerical and experimental work conclude core catcher assembly with geometry B to be more suitable.

scholarly journals Study on Non-Thermal Ablation Process of Silica Glass Using Laser Plasma Soft X-rays toward Nanomachining

2009 ◽  
Vol 129 (7) ◽  
pp. 1186-1191
Author(s):  
Shuichi Torii ◽  
Takashige Fujimori ◽  
Tetsuya Makimura ◽  
Hiroyuki Niino ◽  
Kouichi Murakami
Keyword(s):  
Laser Plasma ◽  
Silica Glass ◽  
Thermal Ablation ◽  
X Rays ◽  
Ablation Process

scholarly journals Numerical simulation of melt relocation and heat transfer during severe accidents in the fast reactors

2018 ◽  
Vol 1105 ◽  
pp. 012106
Author(s):  
E V Usov ◽  
A A Butov ◽  
I A Klimonov ◽  
V I Chuhno ◽  
N A Pribaturin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fast Reactors ◽  
Severe Accidents

Discussion About Sodium-Concrete Reaction in Presence of Internal Heater

2018 ◽  
Author(s):  
Munemichi Kawaguchi ◽  
Shinya Miyahara ◽  
Masayoshi Uno
Keyword(s):  
Chemical Reaction ◽  
Reaction Front ◽  
Ablation Depth ◽  
The Self ◽  
Past Study ◽  
Heating Effect ◽  
Fast Reactors ◽  
Containment Vessel ◽  
Severe Accidents ◽  
Concentration Condition

Sodium-concrete reaction (SCR) is one of the important phenomena during severe accidents in sodium-cooled fast reactors (SFRs) owing to the generation of large sources of hydrogen and aerosols in the containment vessel [1–3]. In this study, SCR experiments were performed to investigate the chemical reaction beneath the internal heater (800 °C), which was used to simulate the obstacle and heating effect for SCR. Furthermore, the effects of the internal heater on the self-termination mechanism were discussed. The internal heater on the concrete seemed to hinder the transport of Na into the concrete. Therefore, Na could react with the concrete at the periphery of the internal heater. The concrete ablation depth at the periphery was larger than under the internal heater. However, the Na concentration around the reaction front was about 30 wt.% despite the position of the internal heater. The Na concentration was similar to that of Na2SiO3, which was almost same as that in our past study [4–5]. It was found that the Na concentration condition was one of the dominant parameters for the self-termination of SCR, even in the presence of the internal heater.

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