Accident analysis method for digital control diversity protection system of million-kilowatt nuclear power station

Abstract

The invention relates to an accident analysis method for a digital control diversity protection system of a million-kilowatt nuclear power station. The method analyzes that a pile main protection system of a 'digital control system (DCS)' in a million-kilowatt nuclear power project is in software common cause failure, and simultaneously, the method superposes the expected operation transient or design basis accident, in the case that an operator has no time to perform manual intervention, the method further researches on adding a diverse actuation system (DAS) in the DCS to ensure the safety of the pile. A DAS scheme is determined after rounded accident analysis of the nuclear power station, and the DAS scheme comprises corresponding automatic protection signals and setting values, so as to guarantee that the accident consequence meets the requirement of a 'diversity and defense in depth (3D)' acceptance criterion.

Description

Technical field [0001] The invention relates to an improved design method for a digital I&C system of a nuclear power plant, in particular to an accident analysis method for a digital I&C system of a million kilowatt nuclear power plant. Background technique [0002] At present, domestic nuclear power plants under construction have adopted the digital instrument control system (DCS) as the control system of the main control room, and its reliability and safety have become the most concerned issues of end users. The digital instrumentation and control system (DCS) of nuclear power plants is generally divided into two platforms, a safety-level main protection system platform and a non-safety-level system platform. The main reactor protection system (RPS: including the emergency shutdown function of the reactor and the function of special safety facilities) adopts digital instrument control. Compared with the traditional analog instrument control system, the value collection is more...

AI Technical Summary

Problems solved by technology

However, software common cause failure (SWCCF) may occur in the main protection system of the reactor based on digitalization, which will lead to the complete failure of the main protection system.

If a software common-mode failure occurs and a hypothetical expected transient or design basis accident (hereinafter referred to as: software common-mode superposition accident) occurs superimposed at the same time, the accident cannot be mitigated and will cause serious consequences

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