Model-Checking Detailed Fault-Tolerant Nuclear Power Plant Safety Functions

Loading...
Thumbnail Image

Access rights

openAccess
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2019

Major/Subject

Mcode

Degree programme

Language

en

Pages

18

Series

IEEE Access, Volume 7, pp. 162139-162156

Abstract

Model checking has been successfully used for detailed formal verification of instrumentation and control (IC) systems, as long as the focus has been on the application logic alone. In safety-critical applications, fault tolerance is also an important aspect, but introducing IC hardware failure modes to the formal models comes at a significant computational cost. Previous attempts have led to state space explosion and prohibitively long processing times. In this paper, we present an approach to model and formally verify protection functions allocated to one or several IC systems, accounting for hardware component failures and delays in communication within and between the systems. Formal verification is done with model checking, whose feasibility on such complex systems is achieved by utilizing the symmetry of IC systems: The components of the overall model that do not influence the checked requirements are eliminated, and the failing components are fixed. Generation of such abstracted models, as well as subsequent verification of their requirements and symmetry with the NuSMV symbolic model checker, is handled by a software tool. In addition, we explore how to specify formal requirements for systems of the considered class. Based on a case study built around a semi-fictitious nuclear power plant protection system that achieves reliability by means of redundancy, we demonstrate how failure tolerance of even detailed system designs can be formally verified.

Description

Keywords

Fault tolerance, Formal verification, Model checking, Nuclear IC systems

Other note

Citation

Buzhinsky, I & Pakonen, A 2019, ' Model-Checking Detailed Fault-Tolerant Nuclear Power Plant Safety Functions ', IEEE Access, vol. 7, 8892461, pp. 162139-162156 . https://doi.org/10.1109/ACCESS.2019.2951938