Chapter 4: Safety Assessment

Introduction

The safety assessment of an NPP should demonstrate that there is no undue risk caused by plant operation. Safety assessment is the systematic process that is carried out throughout the lifetime of the facility or activity to ensure that all the relevant safety requirements are met by the proposed (or actual) design, including:

• Showing that the design of the plant has sufficient implementation of the defence in depth, accounting for the operating experience and safety research;
• Plant equipment design requirements (equipment qualification and consideration of the ageing and reliability of systems through redundancy, physical separation and diversity);
• Plant systems design requirements (e.g. specific requirements on the reactor core, reactor coolant system, containment and engineered safety features).

Safety assessment includes, but is not limited to, the formal safety analysis (cf. Fig 2.3).

More generally, safety assessment can cover all aspects regarding siting, design, construction, operation and decommissioning of an NPP that are relevant to safety.

Figure 2-3: Safety assessment.