「放射線施設廃止のための確認手順と測定法検討」専門委員会活動報告

抄録

Since December 2003, the Expert Group on Decommissioning of Radiation Facilities has been working under the Planning Committee of JRSM. In order to study the past cases, the first questionnaire was sent out to 92 facilities, which were closed between 2001 and 2003. We received 51 answers, according to which RI tracers were used in biological research in 86% facilities, and only two major isotopes of H-3 and C-14 in 33 facilities. Other conditions such as the opening year and the area of controlled region depend on each case.
It is necessary to confirm radiological safety after decommissioning by measuring the dose rate and the residual activity both in the control area and on the building. So, the second questionnaire was carried out to obtain more detail information about technical procedures. We recognized from the answers that most radiation protection supervisors desired a manual or instruction for decommissioning to be published. In the next step, our group will propose a typical procedure of decommissioning referring to the results of this survey.