Tritium Concentration in Monthly Precipitation Near the Fusion Test Facility in Japan Before and After the Deuterium Plasma Experiment

Abstract

In Japan, the deuterium plasma experiment using the Large Helical Device was started at the National Institute for Fusion Science (NIFS) in March 2017 to investigate high-temperature plasma physics and hydrogen isotope effects in research leading towards the realisation of fusion energy. The deuterium plasma experiment produces small amount of tritium by fusion reactions. To understand any impacts by the experiment to the surrounding environment, monthly precipitation samples have been collected at the NIFS site since November 2013 to assess the relationship between isotope composition and chemical species in precipitation including tritium. By comparing data before and after the deuterium plasma experiment start, it was found that tritium released from the main stack of the fusion test facility had no impact on the environment surrounding NIFS.

Tritium Concentration in Natural Spring Water Collected at Hirosaki, Japan

“…Hasegawa et al [20] reported that tritium concentrations in surface and shallow groundwater from Rokkasho Village located on the Pacific Ocean side of Aomori Prefecture in 2009 -2012 ranged from 0.03 to 0.57 Bq/L. Outside of Aomori Prefecture, the tritium concentrations in rain samples from Sapporo City located on the large northern island of the Japanese archipelago during 2015 to 2019 and Toki City located in the central part of the main island during 2014 to 2020 ranged from 0.24 to 1.59 and 0.1 to 0.86 Bq/L, respectively [21,22]. On the other hand, tritium concentration in rain samples from Chiba City located Fig.…”