BS IEC 61504:2017

This standard BS IEC 61504:2017 Nuclear facilities. Instrumentation and control systems important to safety. Centralized systems for continuous monitoring of radiation and/or levels of radioactivity is classified in these ICS categories:

• 27.120.20 Nuclear power plants. Safety

This document supplements IEC 61559-1 to include radiation monitoring functions important to safety that are not within the scope of IEC 61559-1. It applies to centralized systems having a direct role in the achievement or maintenance of radiation protection in nuclear facilities. These systems perform functions such as:

• radiation protection of plant discharge;

• interlock of control functions to prevent or to mitigate accidental release of radioactive material;

• radiation and environmental monitoring functions to support monitoring of and response to accidents;

• provide information to process control or safety systems for use in control or interlock functions.

This document defines the communication criteria to link distributed radiation monitoring equipment in the facility, integrates data processing, storage, optimization, and correlation of data flow and displays, and provides criteria for the interface between monitors of different safety classes.

It will not directly apply to the design and testing of detection and measurement assemblies except as necessary to define the interface with the central computer. Requirements for these assemblies are contained in existing standards.

This document describes the integration of functions including equipment such as those described in IEC 60761-1, IEC 60761-2, IEC 60761-3, IEC 60761-4, IEC 60761-5, IEC 60768, IEC 60861, IEC 60910, IEC 60951-1 IEC 60951-2, IEC 60951-3, IEC 60951-4, IEC 60951-5, IEC 61031, IEC 61250, IEC 62302 and IEC 62303, into a centralized system. The requirements of system-level components (central computer, subsystem computers, operator consoles, and interconnections) are discussed. For detector assemblies, processing assemblies and alarm assemblies, this document contains only the requirements needed to allow connection into the central computer. The standards referenced above contain the specific requirements for these components.

This document identifies requirements pertinent to the integration of the above functions into a centralized system. Requirements for general and design characteristics, electrical performance requirements and tests, mechanical performance and tests, software performance requirements and tests, environmental characteristics performance requirements and tests and documentation are considered by referring to IEC 62705.

Certain complete centralized systems for radiation monitoring may be entirely implemented with direct-connected analogue/relay technology. This document does not apply to such systems.