Ventilation Systems Operating Experience Review for Fusion Applications

Abstract

This report is a collection and review of system operation and failure experiences for air ventilation systems in nuclear facilities. These experiences are applicable for magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. The report contains descriptions of ventilation system components, operating experiences with these systems, component failure rates, and component repair times. Since ventilation systems have a role in mitigating accident releases in nuclear facilities, these data are useful in safety analysis and risk assessment of public safety. An effort has also been given to identifying any safety issues with personnel operating or maintaining ventilation systems. Finally, the recommended failure data were compared to an independent data set to determine the accuracy of individual values. This comparison is useful for the International Energy Agency task on fusion component failure rate data collection.v SUMMARY This report is a collection of design and reliability information on ventilation systems applicable to magnetic and laser fusion experiments. Ventilation is an important plant system since it can control concentrations of radioactive particulate and gases, and also concentrations of toxicological materials. General ventilation system components are discussed, and typical equipment operating parameters are given. Design issues, such as air flow rates and ventilation zone pressures, are given from Department of Energy guidance and direction. Operating experiences with ventilation systems in nuclear facilities have been outlined to show the types of events that could occur. Sometimes, ventilation systems do not respond as desired in off-normal events. These experiences are applicable to magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. Personnel safety issues for operators and maintainers have been addressed as well. Ventilation system component failure rates and representative average repair times have been selected from the literature. The chosen failure rate values have been compared to independent data from non-nuclear applications to determine how general the data values are between industries. Generally, military equipment data are the most rigorously collected and analyzed data after nuclear power plant data, and these values were used for comparison. Most of the comparison values were fair, and some values were poor. Nonetheless, the data presented are the most applicable for nuclear facility ventilation systems and can be used for safety or risk analyses of general ventilation systems at fusion facilities.