GIFT-1.0: Advanced light water reactor fuel performance code

In response to emerging fuel technologies, such as Accident Tolerant Fuels (ATF), Small Modular Reactor (SMR) fuels, and extended spent fuel storage in the nuclear power industry, GIFT-1.0 was developed to enable full life-cycle simulations of Light Water Reactor (LWR) nuclear fuel, from steady-state operation to extended spent fuel storage. GIFT-1.0 is equipped with state-of-the-art models tailored to meet these new requirements. This paper introduces GIFT-1.0, presenting its structure, models, key features, validation, and performance. The code employs a high-fidelity 2-D axisymmetric (r, z) model for cladding mechanical analyses, allowing mechanistic modeling of multi-layered claddings, such as Cr-coated cladding and SiC cladding. GIFT-1.0 achieves highly accurate steady-state fuel behavior at affordable computational costs, making it suitable for full-core scale simulations.