Abstract
With the continuous advance of the mass construction of nuclear power in China, it has become an irresistible trend to use mature commercial-off-the-shelf (COTS) to perform safety functions in the safety important instrumentation and control (I&C) systems to reduce the construction cost of nuclear power plants (NPPs). The quality of pre-developed items especially the pre-developed software (PDS) has been paid more and more attention by stakeholders. By combining with the specific requirements of international mainstream guidelines and standards related to nuclear safety I&C systems or equipment PDS qualification, a set of strong commonality, operational PDS qualification scheme has been proposed. The scheme includes qualification process, activities, tasks and methods. The main qualification activities are suitability evaluation, quality evaluation, operating experience evaluation, and additional test. According to the software requirements of implementing different safety function categories, the corresponding software integrity level qualification tasks are matched to the activities. In addition, according to the characteristics of each task, the recommended execution methods are given, which mainly include document review, traceability analysis, FMEA, code review, code static analysis, code dynamic test and so on. Finally, the application effect of the PDS qualification scheme for safety I&C systems of NPP is introduced, and the concerns in the qualification process are expounded, so as to provide reference for the safety items software qualification of NPPs.
