STATE OF A SUBCRITICAL NUCLEAR REACTOR DRIVEN BY AN EXTERNAL NEUTRON SOURCE

• Grant number: 24/10899-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2024
• End date: August 31, 2025
• Field of knowledge: Engineering - Nuclear Engineering - Reactor Technologies
• Principal Investigator: Cláudio de Conti
• Grantee: Beatriz Brioli Doll de Moraes
• Host Institution: Faculdade de Engenharia e Ciências (FEC). Universidade Estadual Paulista (UNESP). Campus de Rosana. Rosana , SP, Brazil

Abstract

A significant advance in the field of nuclear energy is the ADS reactor. This type of reactor combines a subcritical nuclear fission reactor driven by an external neutron source, which is an external particle accelerator, designed to transmute high-activity nuclear waste and reduce spent fuel storage problems. In addition, as the fission reactor depends on the accelerator's neutrons to maintain the chain reaction, if it is switched off, the reaction stops, thus reducing the risk of accidents. To numerically simulate the ADS reactor, several equations are used that describe neutron density, fuel and coolant temperature, reactivity and the decay of neutron poisons. These equations form a set of coupled non-linear differential equations. Monitoring and estimating the core parameters of a nuclear reactor is crucial for operational safety, but many of these parameters cannot be measured directly. The extended Kalman filter (EKF) model is an effective approach for estimating the parameters of an ADS reactor. In this project the core of an ADS reactor will be modeled with the point kinetic equations, the thermal-hydraulic model equations, the neutron poison decay equations and the reactivity feedback model. Three types of external neutron source and reactivity insertion varieties are simulated. Estimates of measurable and non-measurable parameters will be made using the EKF model.