Levels and behavior of environmental tritium in East Asia

Abstract

For a more systematic understanding of the levels of environmental tritium and its behavior in East Asia, a database on environmental tritium was established based on the literature published in the past 30 years. Subsequently, the levels and behavior of the environmental tritium were further studied by statistical analyses. The results indicate that the distribution of environmental tritium is inhomogeneous and complex. In areas without nuclear facilities, the level of environmental tritium has decreased to its background level, even though a certain number of atmospheric nuclear tests were performed before 1980. In general, the level of atmospheric tritium was marginally higher than the levels in precipitation and surface water; the levels in shallow groundwater and seawater were considerably lower. Furthermore, the levels of tritium in the atmosphere, precipitation, and inland surface water were strongly correlated with latitude and distance from the coastline. In soil and living organisms, the level of tissue-free water tritium (TFWT) was comparable to the tritium levels in local rainfall, whereas the persistence of organically bound tritium (OBT) in the majority of organisms resulted in an OBT/TFWT ratio greater than one. Conversely, extremely high levels of environmental tritium were observed near certain nuclear power plants and the Fukushima accident sites. These results highlight the requirement to know the tritium baseline level and its behavior in the environment beforehand to better assess the impact of tritium discharge. Further investigations of environmental tritium in East Asia using more efficient and adequate monitoring methods are also required.

Research and Application of Digital Emergency Decontamination System

“…As a result, the concentration of tritium in the environment around the nuclear-related sites is relatively high. For instance, HTO concentrations in the atmosphere and soil reach 3822 mBq/m 3 and 5838 Bq/L, respectively [9]~ [10] . Since China lacks industrialized tail gas purification technology currently, it is urgent to develop a corresponding tritiated tail gas treatment system to guarantee the optimal principle of radiation protection.…”

Development of a Novel Passive Monitoring Technique to Showcase the 3D Distribution of Tritiated Water (HTO) Vapor in Indoor Air of a Nuclear Facility

“…Releases of radionuclides from nuclear facilities may cause negative health effects but are even more likely to trigger public concern and hence cause socioeconomic damage. , Comprehensive and reliable monitoring of anthropogenic radionuclides in the environment, therefore, is essential for nuclear safety and risk assessment of occupational exposure. − Among various anthropogenic radionuclides, tritium ( 3 H) is noteworthy due to its relatively long half-life ( T 1/2 = 12.33 years) and high migration capacity. − As a radioactive isotope of hydrogen, 3 H is omnipresent as tritiated water (HTO) vapor in air, leading to widespread distribution through the water cycle and food chain. − Despite analytical challenges due to tritium’s volatility and low-energy beta decay, radiation regulatory authorities have extensively documented airborne HTO dynamics in many countries over the past decades. − Concerning the indoor atmosphere of nuclear facilities, HTO monitoring primarily serves for surveillance monitoring to diagnose reactor status and assess occupational exposure. − Although online tritium monitoring instruments (e.g., ionization chambers) provide timely information in case of accidental leakage, the high instrument costs, high detection limits, and single-point radiation measurement limit their ability to characterize the spatiotemporal heterogeneity of HTO in large volumes of indoor air, such as reactor halls. , Without exact and quantitative knowledge on HTO in air, small leakages from nuclear installations cannot be pinpointed accurately, and the development of proper strategies for nuclear facility decommissioning may also influenced. Therefore, a supplementary method for the comprehensive characterization of HTO vapor in nuclear facilities is desired to meet future challenges resulting from nuclear power expansion based on both fission and fusion.…”