Researchers have developed a set of neutronic benchmarks based on the extended phase of the China Experimental Fast Reactor (CEFR) start-up tests. This work relies on experimental data obtained during reactor operation, using the Monte Carlo code MCS for simulation and analysis. The primary goal is to provide a robust and validated dataset for the verification and improvement of fast reactor design codes, as well as for the optimization of their operational parameters.

The CEFR is a sodium-cooled fast reactor, designed for research and development of fast reactor technology in China. Start-up tests are crucial for characterizing the neutronic behavior of the reactor and ensuring its safe and efficient operation. The extended phase of these tests allowed for the collection of a significant amount of data on criticality, neutron flux distribution, and reactivity coefficients, which are essential for the validation of nuclear models.

The MCS code, a Monte Carlo simulation software developed by Tsinghua University, was used to model the CEFR. Simulations included a detailed representation of the core geometry, fuel composition, and structural materials. The simulation results were compared with experimental data from the start-up tests, showing good agreement. This cross-validation between experimental data and Monte Carlo simulations establishes a highly reliable set of neutronic benchmarks. These benchmarks will be fundamental for future fast reactor design and safety studies, contributing to the advancement of nuclear fission energy.