ANALISIS KRITIKALITAS PROSES HYDRIDING SERTA PENYIMPANAN PADUAN UMo DAN UZr SEBAGAI KANDIDAT BAHAN BAKAR REAKTOR RISET MENGGUNAKAN OPENMC

Abstract

Current research on research reactor fuel is focused at increasing uranium density to produce higher neutron flux in order to increase radioisotope production as well as efficiency and accuracy in various material tests. Research and developments of nuclear fuel in Indonesia in order to increase uranium density is the development of UMo and UZr. One of the processes for making UMo and UZr powder is through a hydriding-dehydriding process which involves enriched uranium, and high pressure hydrogen gas. This combination presents the potential for criticality accidents that must be anticipated. Criticality calculations were carried out using OpenMC software, which is a nuclear physics simulation that uses the Monte Carlo method. In this simulation, two types of alloys are used, namely U7Mo and U6Zr. Simulations were carried out using 10,000 particles and 44 batches as parameter settings. From the simulation results, the k_eff value for the U7Mo and U6Zr alloy are 0.0297 and 0.0314, respectively. Both values are far below the critical value, indicating that the potential for criticality accidents is very low. In the storage simulation of hydriding products, there is the potential for criticality accidents if the storage bottles are placed close together without any distance. To anticipate this risk, each bottle must be given a safe distance and there needs to be a limit on the permitted mass of uranium per unit volume.