Design of the Reactor Coolant System and Associated Systems for Nuclear Power Plants

Specific Safety Guide

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• Publisher: International Atomic Energy Agency
• Year: 2020
• eBook ISBN: 9789201064226
• Topic: Technology & Engineering
• Subtopic: Mechanical Engineering
• Index: Technology & Engineering

This Safety Guide provides recommendations on how to meet the requirements established in IAEA Safety Standards Series No. SSR-2/1 (Rev. 1) in relation to the reactor coolant system and associated systems for nuclear power plants. It is a revision of IAEA Safety Standards Series No. NS-G-1.9, which it supersedes. The publication takes into account developments, experience and practices in the design of nuclear power plants throughout their lifetime. It references and considers other IAEA safety standards that are relevant and related to the design of the reactor coolant system and associated systems for nuclear power plants. Recommendations to achieve the required reliability of the capabilities designed to transfer residual heat to the ultimate heat sink in the different plant states are also included. As those systems are dependent on specific reactor technologies, more appropriate recommendations have been developed respectively for pressurized light water reactors, boiling water reactors and pressurized heavy water reactors.

1. INTRODUCTION

Background

1.1. This Safety Guide on the design of the reactor coolant system and associated systems for nuclear power plants provides recommendations on how to meet the requirements of IAEA Safety Standards Series No. SSR-2/1 (Rev. 1), Safety of Nuclear Power Plants: Design [1], in relation to the cooling systems for nuclear power plants.

1.2. This Safety Guide is a revision of IAEA Safety Standards Series No. NS-G-1.9, Design of the Reactor Coolant System and Associated Systems in Nuclear Power Plants1, which it supersedes.

Objective

1.3. The objective of this Safety Guide is to provide recommendations for the design of the reactor coolant system and associated systems, as described in Section 2, to meet the requirements for these systems established in SSR-2/1 (Rev. 1) [1].

1.4. The recommendations provided in this Safety Guide are aimed at regulatory bodies, nuclear power plant designers and nuclear power plant licensees.

1.5. The terms used in this Safety Guide are to be understood as defined and explained in the IAEA Safety Glossary [2].

Scope

1.6. This Safety Guide applies primarily to land based stationary nuclear power plants with water cooled reactors, designed for electricity generation. It is recognized that for other reactor types, including innovative developments in future systems, some parts of the Safety Guide might not be applicable or might need some judgement to be applied in their interpretation.

1.7. The recommendations provided in this Safety Guide are targeted primarily at new nuclear power plants. For nuclear power plants designed in accordance with earlier standards, it is expected that in the safety assessments of such designs a comparison will be made with the current standards (e.g. as part of the periodic safety reassessment for the plant) to determine whether the safe operation of the plant could be further enhanced by means of reasonably practicable safety improvements (see para. 1.3 of SSR-2/1 (Rev. 1) [1]).

1.8. This Safety Guide covers the reactor coolant system and associated systems, including the ultimate heat sink, as described in Section 4. It covers design considerations for the reactor coolant system and associated systems that are common for the reactor types described in para. 1.6. The scope does not extend to the detailed design of specific components.

1.9. Section 2 describes the extent of the reactor coolant system and associated systems that are addressed in this Safety Guide. To be independent of individual designs to the extent practicable, design recommendations are given on the basis of the safety functions to be fulfilled by the systems.

1.10. Design limits and engineering criteria, together with the system parameters that should be used to verify these limits and criteria, are specific to individual designs for nuclear power plants and are therefore outside the scope of this Safety Guide. However, qualitative recommendations on these topics are provided.

1.11. Fuel elements and control rods for controlling the core reactivity and shutting down the reactor are not addressed in this Safety Guide.

Structure

1.12. Section 2 describes the extent of the reactor coolant system and associated systems that are addressed in this Safety Guide. Section 3 provides generic design recommendations for the reactor coolant system and associated systems, which apply to pressurized water reactor (PWR), boiling water reactor (BWR) and pressurized heavy water reactor (PHWR) technologies. Section 4 provides design recommendations for the different heat transfer chains and generic considerations for the ultimate heat sink. Section 5 provides supplementary design recommendations that are specific to reactor coolant systems for PWR, BWR and PHWR technologies. Sections 6–8 provide supplementary design recommendations that are specific to associated systems for PWR, BWR and PHWR technologies, respectively.

2. Extent of the reactor coolant system and associated systems

2.1. The recommendations provided in this Safety Guide apply to the reactor coolant system and associated systems designed to ...

Table of contents

• 1. INTRODUCTION
• CONTRIBUTORS TO DRAFTING AND REVIEW