Development of standard evaluation plan for survey and investigation of residual radioactivity on site

The development of decommissioning technologies, including those for evaluation of the radioactivity inventory and the radiation dose, and a site investigation plan are needed to ensure safe decommissioning. The residual radioactivity should be measured and analysed to release a site for unrestricted use. The methods used for measurement of residual radioactivity have an effect on the workers' manpower and the decommissioning cost. So the development of the measurement methods of residual radioactivity with guidelines for a radiation survey and site investigation is needed to prepare for the future decommissioning of commercial Nuclear Power plants. The major considerations and characteristics of the parameters related to the decision of measurements points have been reviewed. The methods for controlling uncertainty and techniques to determine whether the measurement results achieve the survey objectives have been established.