Changes in ambient dose equivalent rates around roads at Kawamata town after the Fukushima accident

福島事故後の川俣町における道路周辺の周辺線量当量率変化

木名瀬 栄   ; 佐藤 仁士; 坂本 隆一*; 山本 英明; 斎藤 公明  

Kinase, Sakae; Sato, Satoshi; Sakamoto, Ryuichi*; Yamamoto, Hideaki; Saito, Kimiaki

Changes in ambient dose equivalent rates through the vehicle-borne surveys have elucidated ecological half-lives of radioactive caesium in the environment. To confirm that the ecological half-lives are appropriate for predicting ambient dose equivalent rates within living areas, it is important to ascertain ambient dose equivalent rates on/around roads. In this present study, radiation monitoring on/around roads at Kawamata town located about 37km northwest of the Fukushima Daiichi Nuclear Power Plant was performed using monitoring vehicles and survey meters. It was found that the ambient dose equivalent rates around roads were higher than those on roads as of October of 2012. And withal the ecological half-lives on roads were essentially consistent with those around roads. As basis of dose predictions using ecological half-lives on roads, it is necessary to make corrections to ambient dose equivalent rates through the vehicle-borne surveys against those within living areas.