As a result of the Fukushima accident in 2011, not only is radionuclides released into the atmosphere, but also large amount of contaminated water are accumulated from cooling water, ground water and rainwater at Fukushima Daiichi Nuclear Power Plant. Over 1 million metric tons of waste water has been contained in steel tanks crammed onto the Fukushima campus 10 years later. The storage capacity will be reached in late 2022. There is no other choice, Japan by TEPCO announced in April 2021 that it planned to release 1.25 million tons of treated wastewater contaminated from the Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean. The announcement raised many concerns from many countries and NGOs. What’s about Thailand? What we should know and do if Japan will go on with its plan to dump contaminated water with long half-life Cs-137 and H-3 into the ocean in another two years from now on. This will take decades to complete the task and we need a long-term plan in accordance with the TEPCO plan.