Study on the radiological effect of the tritium gas released from fussion reactor

Abstract

BackgroundThe amount of gaseous tritium stored and released in fusion reactor is higher than that in current fission reactors, so that tritium is an important source of potential radioactivity in fusion reactor.PurposeThis study aims to investigate the environmental impact of gas tritium emission from fusion reactor for achieving the safety and environmental friendliness of fusion reactor in the future.MethodsTypical factory sites along the eastern coast of China with the highest frequency east wind direction was selected as the research object, and the Gauss model was employed to predict the atmospheric dispersion of gaseous tritium release and the dry deposition of tritium gas (HT), soil oxidation and re-evaporation of HTO. The radiation dose of 1 g HT in the case of short-term released from fusion reactor to the public in the surrounding environment was calculated.ResultsCalculation results show that the effective dose of inhalation internal irradiation of HT released at 10 m height for adults at 500~3 000 m west of the release point ranges from 0.38 mSv to 0.1 mSv. The dose caused by the re-evaporation effect of HTO at different distances is the main source of the dose of gaseous tritium. The proportion of the HT deposited to soil being oxidized to HTO and the atmosphere condition are the key parameter determining the effective dose of the tritium gas.ConclusionsThe study shows that the effective dose of HT released from fusion reactor to public is higher than which released from fission reactor, hence further attention to the environmental impact of the tritium is needed in the research on the fusion reactor subsequently.

Keywords

• fusion reactor
• tritium gas
• atmosphere dispersion
• revaporization
• effective dose