Delayed Heating Calculations Using the MCNP-ORIGEN Activation Automation Tool

An accurate assessment of the deposited energy across a reactor geometry allows for a better determination of the heat removal requirements and ensures effective cooling after shutdown. This work discusses several methods in detail that target the heat deposition in specific reactor regions, leading to a choice of a prevalent method for the calculation workflow. This paper introduces a delayed heating calculation workflow based on the formal three-step process. The workflow relies on the MCNP-ORIGEN Activation Automation tool for performing the first two steps of the process, while the third step is conducted via MCNP photon transport simulations. This paper showcases two applications to demonstrate the workflow and simulation outputs. These include an Advanced Test Reactor (ATR) experiment and the RA-6 reactor structures.