Design and Mechanical Analysis of Gadolinium-containing Neutron Absorbing Material

A new type of neutron absorbing material with good neutron absorbing capacity, high strength and high toughness was designed to absorb thermal neutron radiation in the nuclear power plant spent fuel storage grid and spent fuel transportation. The material was designed by MCNP which was the Monte Carlo particle transport software, and the plate was prepared by spark plasma sintering equipment and hot rolling. The results of MCNP simulation and thermal neutron absorbing test show that the thermal neutron absorbing performance of Gd₂O₃/6061Al composite material is comparable to that of B₄C/6061Al composite material. After the different ball mill time, the microstructure of Gd₂O₃ particles is analyzed as micron level, and even some particles reach nanometer scale. The material strength increases with ball mill time. The phase of Gd-Al was detected by X-ray diffraction. The TEM analysis result shows that the strengthening mechanism of the materials is mainly dislocation strengthening and dispersion strengthening of Gd₂O₃ particle at nanometer level. The tensile strength and elongation reach 240 MPa and 16% respectively, and the fracture is mainly ductile fracture.