Dr. Yasutaka Omori (the Department of Radiation Measurement and Physical Dosimetry) attended “The 5th National Conference on Radiation Awareness and Detection in Natural Environment” held on October 7-9, 2024 in Dehradun, India to give an invited lecture. This conference is held every two years in India on the topics of radiation measurement, environmental radioactivity, and radiation shielding, and Dr. Omori was invited to give a lecture following the previous one. In his invited lecture, he shared his knowledge with the participants on the importance of assessing the ground radiation in nuclear disasters, based on the examples of the assessment of additional exposure doses in the Fukushima Dai-ichi Nuclear Power Plant accident. In the plenary session, 22 invited lectures, 34 oral presentations, and 81 poster presentations were given, and active discussions took place.