Importance of quality assurance to safety and reliability of nuclear power plants

Quality assurance can make a very valuable contribution to the safety and reliability of nuclear power plants by prevention of component failures through planned and systematic approach to all activities affecting quality. In fact it can be regarded as the best defense against common cause failures occurring due to errors in design, manufacturing, installation, operation and maintenance. It is also an effective tool in the hands of management for assuring correct performance of all activities involved in building nuclear power plants. In this paper the important elements that constitute a quality assurance programme are briefly described. Some practical aspects of the implementation of a quality assurance programme with reference to a pressurized heavy water reactor system are highlighted. As an illustration, some of the activities which are considered to have a significant effect on quality, like raw materials, weld quality and non-destructive examination are discussed. The role of inservice inspection in the timely detection of any unacceptable degradation in component quality, thus providing assurance towards continued safe and reliable operation of the plant, is briefly dealt with