Evolution of thermo-physical properties and annealing of fast neutron irradiated boron carbide - Archive ouverte HAL Access content directly
Conference Papers Year : 2016

Evolution of thermo-physical properties and annealing of fast neutron irradiated boron carbide

(1) , (2) , (1) , (1) , (3)
1
2
3

Abstract

Boron carbide is widely used as a neutron absorber in most nuclear reactors, in particular in fast neutron ones. The irradiation leads to a large helium production (up to 10$^{22}$/cm$^3$) together with a strong decrease of the thermal conductivity. In this paper, we have performed thermal diffusivity measurements and X-ray diffraction analyses on boron carbide samples coming from control rods of the French Phenix LMFBR reactor. The burnups range from 10$^{21}$ to 8.10$^{21}$/cm$^3$. We first confirm the strong decrease of the thermal conductivity at the low burnup, together with high microstructural modifications: swelling, large micro strains, high defects density, and disordered-like material conductivity. We observe the microstructural parameters are highly anisotropic, with high micro-strains and flattened coherent diffracting domains along the (00l) direction of the hexagonal structure. Performing heat treatments up to high temperature (2200°C) allows us to observe the material thermal conductivity and microstructure restoration. It then appears the thermal conductivity healing is correlated to the micro-strain relaxation. We then assume the defects responsible for most of the damage are the helium bubbles and the associated stress fields.
Fichier principal
Vignette du fichier
201600003745.pdf (988.62 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

cea-02435072 , version 1 (10-01-2020)

Identifiers

  • HAL Id : cea-02435072 , version 1

Cite

D. Gosset, B. Kryger, J.-P. Bonal, C. Verdeau, K. Froment. Evolution of thermo-physical properties and annealing of fast neutron irradiated boron carbide. The Nuclear Materials Conference, 2016 – NUMAT 2016, Nov 2016, Montpellier, France. ⟨cea-02435072⟩
33 View
180 Download

Share

Gmail Facebook Twitter LinkedIn More