Численная спектрометрия нейтронного излучения ОЯТ ВВЭР-1200: моделирование в MCNP6.2, WIMS-D5B, Sources-4C

Abstract

One of the ways to improve the properties of the reactor core is the use of modified fuel. In this study, it was found that the use of elements of low and medium atomic mass as alloying additives is inappropriate, since they are targeted for the (α, n)-reaction, reduce the uranium content of fuel pellets and complicate the technological process of their manufacture. The UO2+Gd2O3 fuel has a low thermal conductivity, alternative burnable absorbers are being sought. It was found that the most optimal composition of the modified fuel for VVER-1200 is UO2+0.2 at.% AmO2. Such fuel is placed in fuel elements without changing the enrichment, AmO2 does not worsen the thermal conductivity of the fuel. The performed neutron-physical calculation using WIMS-D5B and MCNP6.2 confirms the efficiency of using AmO2 as a burnable absorber. The results of calculating the activity using MCNP6.2 and the neutron component of the SNF radiation characteristics using Sources-4C show that the dose rate when using fuel with AmO2 remains within acceptable limits