The complicated severe accident phenomena in typical Pressurized Water Reactor (PWR) Generation III may have a strong influence on source term release into environment and radiological consequence. The study on sensitivity analysis is beneficial to the identification of important factors in severe accident source term analysis and the quantification of their impact.
ASTEC, the integral code of severe accident analysis developed by IRSN, is used to analyze the sensitivity of key parameters of severe accident source term for typical PWR Generation III, with the simulation of safety systems and source term phenomena, in the representative sequence with fast accident progression, Large Break Loss of Coolant Accident (LBLOCA). With the consideration of the design features of typical PWR Generation III and research status of severe accident source term, the key parameters for sensitivity analysis are identified and selected based on the whole process of radionuclides release, including gaseous iodine mass release fraction from primary circuit to containment, silver iodide reaction, dose rate and pH value in sump, washing effect, etc.
The sensitivity is quantified by iodine release mass to containment, which is one of the most dangerous radionuclides due to its threat to environment and human thyroid after inhalation and ingestion. The gaseous iodine mass release fraction from primary circuit to containment, silver iodide reaction and washing effect are presented in results as the major contributors to the variation of severe accident source term evaluation.
With the rapid development of nuclear power, its safety has attracted more and more attention. In the event of a nuclear accident, once the leakage of radioactive material occurs, it will pose a huge threat to the surrounding environment and the economy and safety of human. In this case, the rapid and accurate evaluation of pollutant dispersion and radiation dose of offsite consequences can guide the decision of nuclear emergency, including the public emergency response and rescue operations. It can also provide the best solution of routes for public evacuation and rescue entrance. The limitation of radioactive accident consequences is essential to protect property security and public safety.
In this paper, a real-time evaluation program for offsite dose for nuclear emergency system is developed. The selected for atmospheric dispersion model is the segmented Gaussian model (SGM). Diffusion, advection, plume rise, dry deposition, wet deposition, decay, etc. are considered and FORTRAN language is used for the development.
For code-to-code comparison, C3X, the French general offsite dose evaluation program, is chosen as the reference. In the release of changing weather conditions, the simulation results are consistent with C3X, which demonstrates the validity and reliability of program. This paper makes also a nuclear emergency simulation for the changing weather conditions. The results show that the program can precisely calculate the plume nuclides concentration, ground concentration and dose in different time and space. It can also accurately divide the dose area for public emergency guide and rescue operations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.