Public Acceptance (PA) had been introduced as a means of citizens' participation in the early stage of strategy in nuclear safety in Japan. PA and risk communication have common aspect that aim is promotion of public understanding by means of correct information. When PA is performed, the government is considered to be responsible for decision making of policy in nuclear safety. Therefore, another aim of PA is that public can accept the policy of government. PA has a characteristic of publicity. On the other hand, in concept of the risk communication public have some involvement with policy making so that it does not have a characteristic of publicity in principle. In risk communication, construction of confidence between stakeholders with exchange of opinions is focused. PA has been replaced by risk-communication in the field of nuclear safety as well as that of safety of chemicals.
National Institute of Radiological Sciences (NIRS) has started a study on investigation of risk perception in 1983. Contents and significance of studies on risk perception and risk communication in NIRS have been varied with circumstances of PA and risk communication described above in these 25 years. In this seminar, historical change and current results in these studies in NIRS are introduced and significance of risk communication is discussed.