Research on gaseous and liquid source term of tritium for pressurized water reactor

• Published in: Nuclear engineering and design 2024-09, Vol.426, p.113367, Article 113367
• Main Authors: Zhang, Junnan, Yang, Defeng, Li, Lu, Zuo, Qingning, Huang, Jingyun, Bai, Xiaoping, Qiu, Lin
• Format: Article
• Language: English
• Subjects: Discharge strategy; PWR; Source term; Tritium
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2024.113367

This study presents a comprehensive mathematical model developed to predict annual average tritium releases through gaseous and liquid effluents from pressurized water reactor (PWR) nuclear power plants (NPPs), serving as a critical component for Radiological Environmental Impact Assessments (REIA). Through an examination of tritium production, decay, migration, and emission processes, this research offers insights into the dynamics of tritium behavior within nuclear power plants. Notably, the study evaluates various emission strategies’ impact on tritium concentration in the Reactor Coolant System (RCS) and the subsequent environmental discharges. The analysis reveals a direct correlation between emission strategies and tritium concentration profiles, with implications for environmental safety and operational efficiency. Furthermore, a sensitivity analysis underscores the significant influence of the boron recycle system, radioactive waste liquid treatment system emissions, and uncontrolled primary circuit leakages on tritium discharges. The findings advocate for meticulous parameter selection in calculating the tritium source term and reflect a changing emission ratio (liquid/gas) to accommodate varying environmental and operational contexts, especially for inland NPPs with stringent water resource constraints. This study not only enhances understanding of tritium management in nuclear power plants but also guides the development of more sustainable and safety-oriented operational strategies. •A mathematical model of tritium emission from PWR to the environment is developed.•The effects of different emission strategies on tritium emissions are analyzed.•Emission ratio (liquid/gas) varies especially for inland NPPs with effluent reuse.•Tritium cumulates to a gradual equilibrium in the SFP and RWST across fuel cycles.