Lithium borohydride (LiBH۴): An innovative material for neutron radiation shielding

Radiation shielding plays a crucial role in various industries, including nuclear and space exploration. Among the most abundant elements and isotopes found in nature, B-۱۰ has one of the highest neutron absorption cross-sections, closely followed by Li-۶. It is worth noting that hydrogen, with its light nucleus, serves as an excellent neutron reflector. Surprisingly, the potential of the lithium borohydride molecule (LiBH۴), which consists exclusively of these elements, as a shield against neutron radiation has not yet been explored. This study investigates various materials that can potentially be used as shields. First, we assessed traditional shields and previous optimizations for shielding. The findings showed that concrete containing ۱۰% B۴C yielded the best results. High-performance concrete (HPC) replaced regular concrete. By gradually incorporating lithium borohydride into the shield, along with the appropriate level of boron carbide, further optimization was achieved. Calculations were performed using the MCNPX ۲.۷E code. The introduction of the new shield resulted in a significant ۴۰% reduction in volume compared with the previous sample. The study findings showed that a ۳۰ cm thick shield effectively blocked ۹۵% of the total neutrons and ۹۲% of the total gamma radiation. Additionally, it was noted that the shielding effects of lithium borohydride against fast neutrons are greater than those of boron carbide. Various parameters and data of the designed shield were calculated and compared with those of the previous sample.

کلیدواژه ها:

high performance concrete ، MCNPX code ، radioactive protection ، MET ۱۰۰۰ reactor ، Lithium borohydride ، Neutron radiation shielding