KSOME (kinetic simulations of microstructural evolution) is an object Kinetic Monte Carlo (OMKC) simulation code developed to simulate microstructural evolution in materials under irradiation. KSOME is developed from the ground up at PNNL. KSOME was developed because of the need for a flexible OKMC code to perform high fidelity simulations of microstructural evolution in materials under irradiation. During the development of KSOME, priority was given to the flexibility, ease of upgradability and computational Efficiency, in that order. Feature of KSOME, some of which will discussed in detail later are No Limit on the number of defect types or defect sub-types No Limit on the number of parameters that can used to capture atomistic details of a defect - Defects of same type with different characteristics can distinguished, allowing for the inclusion of corresponding diffusion-reaction events precisely - Eg.1: A vacancy loop or spherical vacancy clusters or void can be distinguished. Eg.2: (110) and (111) type interstitial defects can be distinguished Ability to incorporate a wide variety of diffusion-reaction properties of irradiation produced defects such as Vacancies (V), Interstitials (I), Transmutants (in case of neutron irradiation) Ability to incorporate pre-existing such as grain Boundaries and dislocations (also called extended defects), alloying and other Impurities Only the diffusion-reaction categories and data-management scheme for efficient execution of the KMC algorithm are hardwired. - Rules for the execution of individual diffusion-reaction processes are provided via input files. - Hence simulations are designed via input files for a particular set of conditions. Gives the user ability to perform high fidelity KMC simulations of radiation damage in materials. Ability to parse mathematical expression via a regular text file. - Eliminates the need for source code modification every time a new mathematical expression to calculate a defect property needs to incorporated into a simulation. - This ability also lets ability to include diffusion-reaction processes that are influenced by long-range interaction between defects