A THERMAL-HYDRAULIC ANALYSIS OF THE INL BOILING WATER REACTOR TEST FACILITY USING RELAP5-3D©

The closing and decommissioning of Halden Boiling Water Reactor in Norway resulted in the loss of a unique nuclear irradiation testing capability: irradiation in conditions approximating boiling water reactor environments. To ameliorate the loss of such a strategic asset, research and development efforts are currently underway to utilize the Advanced Test Reactor to replace this lost capacity. This effort seeks to develop a new type of in-core testing facility, the I-Loop Tube, inserted in the I-position of the core’s reflector, allowing for materials to be exposed to a radiation field that approximates prototypic plant conditions while remaining within a separate, contained pressure boundary. This paper will present estimations of void fraction, temperature, and pressure profiles within the fuel housing using the RELAP5-3D thermal-hydraulic system code. The thermal-hydraulic model will consider information inputs of dimensional data extracted from computer aided design models, expected steady state and transient fluidic environmental conditions that fuel experiments will be exposed to over their irradiation window, and projected facility operating limits as a metric of determining a standard operating window.