ICONE23-1579 RAVONSICS-CHALLENGING FOR ASSURING SOFTWARE RELIABILITY OF NUCLEAR I&C SYSTEM

Abstract

As the "central nerve system", the highly reliable Instrumentation & Control (I&C) systems, which provide the right functions and functions correctly, are always desirable not only for the end users of NPPs but also the suppliers of I&C systems. The Digitalization of nuclear I&C system happened in recent years brought a lot of new features for nuclear I&C system. On one side digital technology provides more functionalities, and it should be more reliable and robust; on the other side, digital technology brings new challenge for nuclear I&C system, especially the software running in the hardware component. The software provides flexible functionalities for nuclear I&C system, but it also brings the difficulties to evaluate the reliability and safety of it because of the complexity of software. The reliability of software, which is indispensable part of I&C system, will have essential impact on the reliability of the whole system, and people definitely want to know what the reliability of this intangible part is. The methods used for the evaluation of reliability of system and hardware hardly work for software, because the inherent difference of failure mechanism exists between software and hardware. Failure in software is systematically induced by design error, but failure in hardware is randomly induced by material and production. To continue the effort on this hot topic and to try to achieve consensus on the potential methodology for software reliability evaluation, a cooperative research project called RAVONSICS (Reliability and Verification and Validation of Nuclear Safety I&C Software) is being carried on by 7 Chinese partners, which includes University, research institute, utility, vendor, and safety regulatory body. The objective of RAVONSICS is to bring forwards the methodology for the software reliability evaluation, and the software verification technique. RAVONSICS works cooperatively with its European sister project HARMONICS, both will target the software reliability evaluation and testing methodologies and techniques.