Indicators of safety case for the disposal of radioactive waste

As the concept of safety case for the disposal of radioactive waste was put forward, in addition to the radiological safety indicators (i. e., dose and risk), complementary indicators are widely accepted as important components of the safety case. The developments in the application, the categories, and the criteria of indicators in safety cases for disposal were introduced. According to different evaluation objects, complementary indicators are usually divided into safety indicators and performance indicators, and some organizations have developed the concept of safety function indicator as well. The corresponding criteria for comparison with the indicators are reference values, indicator criteria and safety function indicator criteria, respectively. If the disposal system is regarded as several compartments, the indicators could also be divided into 3 main groups including 'content and concentration' related, 'flux' related and 'status of barriers' related. The suggestions for the disposal of radioactive waste in our country are to develop the safety cases as soon as possible, to establish a complete indicator system, to select appropriate indicators for assessment, and to determine relevant criteria based on the characteristics of radioactive waste disposal sites in China, in order to implement the optimization of safety and protection. (authors)