Preface

the founder of ISORD played a very important role.In the beginning, this was a Korea-Japan international symposium, however, China Institute for Radiation Protection greatly contributed to the third symposium in 2005.Then in 2011, the sixth symposium was held in Malaysia.In this way, ISORD has broaden its impact and significance in radiation safety and detection technology among Asian countries.12th International Symposium on Radiation Safety and Detection Technology (ISORD-12) was held in the University of Tokyo, which is conveniently located in the center of Tokyo.We had 232 papers and more than 250 participants attended in person this time, which needed two large auditoria, Sanjo Hall for main symposium site and Koshiba Hall mainly for the student presentations.We very much appreciate that we could obtain such a large number of participants in this symposium.The symposium started on June 30 until July 3, 2025 including afternoon Riken tour on July 3.We also organized a satellite tutorial workshop on July 4.There were many interesting talks and poster presentations in the symposium.In order to share the recent progress in this field, we would like to publish proceedings as a collection of selected papers from the presented ones in this symposium.There were great efforts behind this proceeding.I would like to express my sincere gratitude to the editors, reviewers, authors,