Integrated Approach to Nuclear Safety at NPCIL

The main objective of Nuclear Power Plant (NPP) safety is to ensure and demonstrate that safety is met at all states of the reactor operation and the related risks from nuclear power plant to plant personnel, public and environment are acceptably low. The safety philosophy is based on deterministic approach, which includes various layers in line with defence-in-depth principle. To complement the traditional deterministic approach, use of Probabilistic Safety Assessment (PSA) methodology is gaining importance as a tool for Risk Informed Decision-Making (RIDM). PSA is a standard tool in safety evaluation of NPPs. It provides a useful, consistent and structured framework for safety evaluation. It is an integrated model addressing overall safety of the plant. It puts the safety issues in perspective and helps in taking safety related decisions considering design, operations and maintenance characteristics. At NPCIL, areas where PSA supports deterministic approach, include, events categorization using Defence in Depth, development of the Symptom Based Event Handling and Accident Management Guidelines (AMG). Inline with these applications of PSA, it also gives Point-in-time risk by the Risk Monitor application which is an operator aid in decision making to plan the maintenance and the configuration control. Thus, an integrated approach in assessing and maintaining the NPP safety is followed at all stages of the NPP at NPCIL including regulatory requirements.