SC 45A - Instrumentation, control and electrical power systems of nuclear facilities

IEC TR 62918:2014 describes the state of wireless technology for industrial applications in fossil and chemical plants and discusses the specific issues to be addressed in order to apply wireless technologies to nuclear power plants.

IEC TR 63400:2021 is intended to augment that description to enable users of individual IEC SC 45A standards to obtain a more comprehensive understanding of the overall structure of the series and its relationship with other standards bodies and standards. This document outlines the scope of the IEC SC 45A standards series and describes the basic structure of the IEC SC 45A standards series, with particular reference to a hierarchy of levels and subdivision into a set of broad topic areas. it presents the structure of the IEC SC 45A standards series in diagrammatic form.

IEC 63186:2021 specifies the minimum requirements for the design of the seismic trip system, and the components thereof, used in a nuclear power plant to mitigate seismic effects. This system is intended to shut down the reactor in operation automatically before it is significantly impacted by the vibratory ground motion incurred by strong earthquakes. This document is applicable to both the design of new built plants and the upgrading of plants in operation. It may be used for the design of other types of nuclear facilities where normal operation shall be stopped in case of strong seismic motions.

IEC 61468:2021 applies to in-core neutron detectors, viz. self-powered neutron detectors (SPNDs), which are intended for application in systems important for nuclear reactor safety: protection, instrumentation and control. This document contains SPND characteristics and test methods. In this document, the main sources of errors, and the possibilities for their minimization are also considered. This document contains requirements, recommendations and instructions concerning selection of SPND type and characteristics for various possible applications.
This document about SPNDs uses the basic requirements of IEC 61513 and IEC 60568 and complements them with more specific provisions in compliance with IAEA Safety Guides.
This second edition cancels and replaces the first edition, published in 2000, and its Amendment 1, published in 2003.
This edition includes the following significant technical changes with respect to the previous edition:
a. Title modified.
b. Justify the requirements for SPND characteristics in terms of influencing factors.
c. Align the terminology with the current state of the regulatory framework.

IEC/IEEE 63113:2021 provides criteria for spent fuel pool instrumentation for nuclear power generating stations and other nuclear facilities. The document applies to water filled spent fuel pools where the water volume is necessary to prevent a release of fission products that exceeds allowed operational limits. The purpose of this document is to establish design, performance, qualification, and display criteria for spent fuel pool instrumentation for normal operation, anticipated operational occurrences, design basis events, and design extension conditions (including severe accident conditions).

IEC TR 63335:2021 identifies a number of issues of particular importance to light water Small Modular Reactors (SMRs), which are not currently adequately addressed by existing IEC SC 45A standards, and that could be considered when revising existing publications or that could be the object of new work item proposals. Whether each of these issues will indeed be addressed, and if so in which publication, will be the decision of each SC 45A working group. Though there are a number of advanced Generation IV SMR projects underway, their specific needs are not covered by this document.

IEC 60987:2021 provides requirements and recommendations for the hardware aspects of I&C systems whatever the technology and applies for all safety classes in a graded manner (as defined by IEC 61513). The requirements defined within this document guide, in particular, the selection of pre-existing components, hardware aspects of system detailed design and implementation and equipment manufacturing.
This third edition cancels and replaces the second edition published in 2007. This edition includes the following significant technical changes with respect to the previous edition:
a) Title modified;
b) Take account of the fact that hardware requirements apply to all I&C technologies, including conventional hardwired equipment, programmable digital equipment or by using a combination of both types of equipment;
c) Align the standard with the new revisions of IAEA documents SSR-2/1, which include as far as possible an adaptation of the definitions;
d) Replace, as far as possible, the requirements associated with standards published since the edition 2.1, especially IEC 61513, IEC 60880, IEC 62138, IEC 62566 and IEC 62566‑2;
e) Review the existing requirements and update the terminology and definitions;
f) Extend the scope of the standard to all hardware (computerized and non-computerized) and to all safety classes 1, 2 and 3;
g) Complete, update the IEC and IAEA references and vocabulary;
h) Check possible impact of other IAEA requirements and recommendations considering extension of the scope of SC 45A;
i) Highlight the use of IEC 62566 and IEC 62566-2 for HPD development;
j) Introduce specific activities for pre-existing items (selection, acceptability and/or mitigation);
k) Introduce clearer requirements for electronic module-level design, manufacturing and control;
l) Complete reliability assessment methods;
m) Introduce requirements when using automated tests or control activities;
n) Complete description of manufacturing control activities (control process, assessment of manufactured equipment, preservation of products);
o) Define and ensure the inclusion of a graded approach for dealing with the 3 different classes of equipment and related requirements.

IEC/IEEE 60980-344:2020 describes methods for establishing seismic qualification procedures that will yield quantitative data to demonstrate that the equipment can meet its performance requirements. This document is applicable to electrical, mechanical, instrumentation and control equipment/components that are used in nuclear facilities. This document provides methods and documentation requirements for seismic qualification of equipment to verify the equipment’s ability to perform its specified performance requirements during and/or after specified seismic demands. This document does not specify seismic demand or performance requirements. Other aspects, relating to quality assurance, selection of equipment, and design and modification of systems, are not part of this document. As seismic qualification is only a part of equipment qualification, this document is used in conjunction with IEC/IEEE 60780-323.
The seismic qualification demonstrates equipment’s ability to perform its safety function(s) during and/or after the time it is subjected to the forces resulting from at least one safe shutdown earthquake (SSE/S2). This ability is demonstrated by taking into account, prior to the SSE/S2, the ageing of equipment and the postulated occurrences of a given number of lower intensity operating basis earthquake (OBE/S1). Ageing phenomena to be considered, if specified in the design specification, are those which could increase the vulnerability of equipment to vibrations caused by an SSE/S2.

IEC 63046:2020 provides requirements and recommendations for the overall Electrical Power System. In particular, it covers interruptible and uninterruptible Electrical Power Systems including the systems supplying the I&C systems; This document is consistent and coherent with IEC 61513. Like IEC 61513, this document also highlights the need for complete and precise requirements, derived from the plant safety goals. Those requirements are prerequisites for generating the comprehensive requirements for the overall Electrical Power System architecture, and for the electrical power supply sub-systems. This document establishes the high level specification and requirement to implement a suitable Electrical Power System in a NPP that supports reactor systems important to safety. It also enables electrical energy production providing the transmission grid with active and reactive power and electro-mechanical inertia.

IEC 61031:2020 applies to the design, location and application of installed equipment for monitoring local gamma radiation dose rates within nuclear facilities during normal operation and anticipated operational occurrences. High range area gamma radiation dose rate monitoring equipment for accident conditions currently addressed by IEC 60951-1 and IEC 60951-3 is not within the scope of this document. This document does not apply to the measurement of neutron dose rate. Additional equipment for neutron monitoring may be required, depending on the plant design, if the neutron dose rate makes a substantial contribution to the total dose equivalent to personnel.
This document provides guidelines for the design principles, the location, the application, the calibration, the operation, and the testing of installed equipment for continuously monitoring local gamma radiation dose rates in nuclear facilities under normal operation conditions and anticipated operational occurrences. These instruments are normally referred to as area radiation monitors. Portable instruments are also used for this purpose but are not covered by this document.

IEC 63260:2020 provides a structured framework for the incorporation of human reliability analysis (HRA) into probabilistic risk assessments (PRAs).
This document is to enhance the analysis of human-system interactions in PRAs, to help ensure reproducible conclusions, and to standardize the documentation of such assessments. To do this, a specific HRA framework is developed from standard practices to serve as a benchmark to assess alternative ways of incorporating HRA into PRA. This standard is an adoption of IEEE 1082-2017 by IEC.

IEC 62566-2:2020 provides requirements for achieving highly reliable HDL-Programmed Devices (HPDs), for use in I&C systems of nuclear power plants performing functions of safety category B or C as defined by IEC 61226.
The programming of HPDs relies on Hardware Description Languages (HDL) and related software tools. They are typically based on blank Field Programmable Gate Arrays (FPGAs) or similar micro-electronic technologies such as Programmable Logic Devices (PLD), Complex Programmable Logic Devices (CPLDs), etc. General purpose integrated circuits such as microprocessors are not HPDs.
This document provides requirements on:
a) a dedicated HPD life-cycle addressing each phase of the development of HPDs, including specification of requirements, design, implementation, integration and validation, as well as verification activities associated with each phase,
b) planning and complementary activities such as modification and production,
c) selection of pre-developed components. This includes micro-electronic technologies and Pre-Developed Blocks (PDBs),
d) tools used to design, implement and verify HPDs.

IEC 61226:2020 establishes, for nuclear power plants , a method of assignment of the functions specified for the plant into categories according to their importance to safety. Subsequent classification of the I&C and electrical power systems performing or supporting these functions, based on the assigned category, then determines relevant design criteria.
The design criteria, when applied, ensure the achievement of each function in accordance to its importance to safety. In this document, the criteria are those of functionality, reliability, performance, environmental qualification (e.g. seismic) and quality assurance (QA).
This edition includes the following significant technical changes with respect to the previous edition:
- to align on IAEA requirements, recommendations and terminology, particularly to take into account the replacement of NS-R-1 by SSR 2/1 and publication of SSG 30;
- to extend the scope to electrical power systems;
- to move the detailed requirements applying to functions and I&C systems to a normative annex, which will be removed after updating IEC 61513.

IEC 62003:2020 establishes requirements for electromagnetic compatibility testing of instrumentation, control, and electrical equipment supplied for use in systems important to safety at nuclear power plants and other nuclear facilities. The document lists the applicable IEC standards (principally the IEC 61000 series) which define the general test methods, and provides the necessary application-specific parameters and criteria to ensure that nuclear safety requirements are met.
This second edition cancels and replaces the first edition published in 2009. This edition includes the following significant technical changes with respect to the previous edition:
a) title modified.
b) expand the scope to encompass Electromagnetic Magnetic Compatibility (EMC) considerations for electrical equipment.
c) provide guidance for addressing the use of wireless technology.
d) enhance the description of the electromagnetic environment to provide clarification when selecting custom test levels or for test exemptions.
e) include example information to be contained within an EMC test plan.
f) provide guidance for characterization of the electromagnetic environment at the point of installation within a nuclear facility.

IEC 62645:2019 establishes requirements and provides guidance for the development and management of effective computer security programmes for I&C programmable digital systems. Inherent to these requirements and guidance is the criterion that the power plant I&C programmable digital system security programme complies with the applicable country’s requirements.
This document defines adequate measures for the prevention of, detection of and reaction to malicious acts by digital means (cyberattacks) on I&C programmable digital systems. This includes any unsafe situation, equipment damage or plant performance degradation.
This second edition cancels and replaces the first edition published in 2014. This edition includes the following significant technical changes with respect to the previous edition:
a) to align the standard with the new revisions of ISO/IEC 27001;
b) to review the existing requirements and to update the terminology and definitions;
c) to take account of, as far as possible, requirements associated with standards published since the first edition;
d) to take into account the fact that cybersecurity techniques, but also national practices evolve.

IEC TR 63214:2019 provides a summary of arguments and a technical basis for the development of a new Human Factors Engineering IEC standard and the alignment of IEC 60964. Based on the provided argumentation, the participating members will vote for such an approach. The proposed content of the new standard provides the basis for fruitful discussion within IEC SC 45A WG 8 and raises interest in the development of the new standard.
The scope of the new HFE IEC standard will follow a holistic approach towards the design of the plant-wide control rooms and all HMI, including e.g. the local control stations located throughout the plant. The general principle is to consider the complete nuclear installation design as a sociotechnical system, in a holistic and integrated way.

IEC/IEEE 62582-6:2019 contains methods for condition monitoring of organic and polymeric materials in instrumentation and control cables using insulation resistance measurements in the detail necessary to produce accurate and reproducible results during simulated accident conditions. It includes the requirements for the measurement system and measurement procedure, and the reporting of the measurement results.
NOTE Measurement of insulation resistance during simulated accident conditions with the aim of determining the lowest value during the accident in order to assess cable performance involves special requirements given in this document. Methods for measurement under stable (non-accident) conditions are available in other international standards, e.g. IEC 62631-3-3.
The different parts of the IEC/IEEE 62582 series are measurement standards, primarily for use in the management of ageing in initial qualification and after installation. IEC/IEEE 62582-1 includes requirements for the application of the other parts of the IEC/IEEE 62582 series and some elements which are common to all methods. Information on the role of condition monitoring in qualification of equipment important to safety is found in IEC/IEEE 60780-323.

IEC 61225:2019 specifies the performance and the functional characteristics of the low voltage static uninterruptible power supply (SUPS) systems in a nuclear power plant and, for applicable parts, in general for nuclear facilities. An uninterruptible power supply is an electrical equipment which draws electrical energy from a source, stores it and maintains supply in a specified form by means inside the equipment to output terminals. A static uninterruptible power supply (SUPS) has no rotating parts to perform its functions.
This third edition cancels and replaces the second edition published in 2005. This edition includes the following significant technical changes with respect to the previous edition:
a) the principal objective of this edition is to address the requirements on the static uninterruptible power supplies in nuclear power plants;
b) in addition to Instrumentation and Control (I&C) power supplies include all static uninterruptible power supplies;
c) emphasize that the static uninterruptible power supplies shall protect the connected equipment (loads) from transients on the on-site AC distribution system (the immunity concept);
d) in accordance with the defence-in-depth concept, this standard applies to static uninterruptible power supplies for all equipment, not only for equipment important to safety, with a graded approach to verification and validation;
e) addition of the requirement that, when batteries are connected in parallel under abnormal operating conditions, they shall be properly protected with isolation devices to avoid any failure that may impair more than one division of the uninterruptible power supply.

IEC TR 63192:2019 provides the comparison of the hazard analysis requirements between IAEA framework and NRC-IEEE framework of standards and guidance. The hazard analysis requirements in the different standards were compared with a set of comparison criteria, including the safety principle, the safety process, the definitions, the hazard analysis process, etc. This document includes the comparison results of the HA requirements of the safety control systems of other safety industries in Annex C.
For a nuclear power plant, the design safety and operation safety shall be analyzed, for example, to meet the IAEA Safety Requirements for Design (SSR-2/1) and Operation (SSR‑2/2). The scope of this document is to survey the state of the art in the hazard analysis for the design of I&C system of NPPs.

IEC 62765-2:2019 identifies minimum requirements and applicable practices for correcting and preventing any potential impacts on nuclear power plant (NPP) safety due to the ageing of temperature sensors, such as NPP resistance temperature detectors (RTDs) and thermocouples (TCs).
This document provides strategies, technical requirements, and recommended practices for the management of the ageing of temperature sensors important to safety in nuclear power plants (NPPs) to ensure that ageing can be identified and that suitable remedial actions are undertaken as necessary to demonstrate that the safety of the plant will not be impaired. This document is aligned with IEC 62342, which provides guidance on ageing management for instrumentation and control (I&C) systems important to safety in NPPs

IEC 62954:2019 presents the requirements for the on-site emergency response facilities (referred to hereinafter as the “ERF”) which are to be used in case of incidents or accidents occurring on the associated Nuclear Power Plant (NPP).
The ERF consists of the Emergency Response Centre (ERC), the Technical Support Centre (TSC) and the Operational Support Centre (OSC).
It establishes requirements for the ERF features and ERF I&C equipment to:
· coordinate on-site operational efforts with respect to safety and radioprotection;
· optimize the design in terms of environment control, lighting, power supplies and access control of the ERF;
· enhance the identification and resolution of potential conflicts between the traditional operational means and emergency means (MCR/SCR and ERF, operating staff and emergency teams, operational procedures and emergency procedures);
· aid the identification and the enhancement of the potential synergies between the traditional operational means and emergency means.

IEC 60964:2018 is available as IEC 60964:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60964:2018 establishes requirements for the human-machine interface in the main control rooms of nuclear power plants. The document also establishes requirements for the selection of functions, design consideration and organization of the human-machine interface and procedures which are used systematically to verify and validate the functional design. These requirements reflect the application of human factors engineering principles as they apply to the human-machine interface during plant operational states and accident conditions (including design basis and design extension conditions), as defined in IAEA SSR-2/1 and IAEA NP-T-3.16. This third edition cancels and replaces the second edition published in 2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) to review the usage of the term “task” ensuring consistency between IEC 60964 and IEC 61839;
b) to clarify the role, functional capability, robustness and integrity of supporting services for the MCR to promote its continued use at the time of a severe accident or extreme external hazard;
c) to review the relevance of the standard to the IAEA safety guides and IEC SC 45A standards that have been published since IEC 60964:2009 was developed;
d) to clarify the role and meaning of “task analysis”,
e) to further delineate the relationships with derivative standards (i.e. IEC 61227, IEC 61771, IEC 61772, IEC 61839, IEC 62241 and others of relevance to the control room design);
f) to consider its alignment with the Human Factors Engineering principles, specifically with the ones of IAEA safety guide on Human Factors (DS-492) to be issued.

IEC 62138:2018 is also available as IEC 62138:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62138:2018 specifies requirements for the software of computer-based instrumentation and control (I&C) systems performing functions of safety category B or C as defined by IEC 61226. It complements IEC 60880 which provides requirements for the software of computer-based I&C systems performing functions of safety category A. It is consistent with, and complementary to, IEC 61513. Requirements that are not specific to software are deferred to IEC 61513. This new edition includes the following significant technical changes with respect to the previous edition:
- align the standard with standards published or revised since the first edition, in particular IEC 61513, IEC 60880, IEC 62645 and IEC 62671;
- merge two clauses in order to avoid repetitions of text;
- introduce requirements on traceability in consistency with IEC 61513;
- introduce new annexes.

IEC 62887:2018 lays down specific requirements for nuclear applications of pressure transmitters including design, materials, manufacturing, testing, calibration and inspection. This document is applicable to general aspects of design, manufacturing and test methods for pressure transmitters used in instrumentation systems important to safety in all nuclear power plants (PWR, BWR, FBR, etc.). The consequences of nuclear conditions for pressure transmitters lead to onerous requirements regarding qualification.

IEC 60772:2018 applies to electrical penetration assemblies (EPAs) in containment structures of nuclear power plants. It covers the engineering safety requirements to be met in the design, calculation, qualification, fabrication, assembly, testing, and installation of EPAs. EPAs provide gas-tight and pressure-resistant penetrations through the containment for one or more electrical circuits. EPA requirements are divided into mechanical (e.g. containment integrity), and electrical or optical aspects regarding safety. The mechanical requirements are valid for all EPAs.
This new edition includes the following significant technical changes with respect to the previous edition:
a) Adaptation of terminology and definitions to current available IAEA and IEC glossaries.
b) Inclusion of various new definitions and requirements.

IEC 60744:2018 provides requirements and recommendations for the design, construction and test of safety logic assemblies used in safety systems to perform category A safety functions (in accordance with IEC 61226). Safety logic assemblies include logic such as the hardwired logic assembly interfacing computer-based systems to switchgear, actuators or contactors to provide trip or engineered safety feature actuations. Safety logic assemblies are significant parts of a safety system and may include voting logic between redundant channels. This document provides a general description of safety logic assemblies for safety actuators control. The principles to meet dependability objectives are presented. The main features relating to the design requirements are described and explained.
This new edition includes the following significant technical changes with respect to the previous edition:
a) update of the references to standards published or revised since the issue of the first edition of the current standard, including IEC 61513 and IEC 61226;
b) additional requirements for operational and maintenance bypass use; requirements of voting logic; and others.

IEC 62988:2018 establishes requirements relevant to the selection and use of wireless devices in instrumentation and control (I&C) systems important to safety used in nuclear power plants (NPPs). Those I&C systems may fully consist of wireless devices. This document applies to the I&C of new NPPs and to backfit of I&C in existing NPPs. Every wireless device or wireless system that is important to safety is in the scope of this document. Both fixed and mobile devices and all data types (voice, process data, etc.) are included within the scope if they provide a safety classified function. This document restricts the use of wireless devices to systems supporting category C functions according to IEC 61226, excluding explicitly their use for categories A and B. Non-safety devices and systems may use this document as guidelines, for example to ensure that important to safety devices are not disturbed.

IEC 61500:2018 is available as IEC 61500:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 61500:2018 establishes requirements for data communication which is used in systems performing category A functions in nuclear power plants. It covers also interface requirements for data communication of equipment performing category A functions with other systems including those performing category B and C functions and functions not important to safety. This document gives requirements for functions and properties of on-line plant data communication by reference to IEC 60880 and IEC 60987, produced within the framework of IEC 61513. It requires categorisation of the communication functions in accordance with IEC 61226. This new edition includes the following significant technical changes with respect to the previous edition:
- the changes introduced to previously referenced standards have been confirmed to apply;
- relevant newly published standards have been referenced;
- lessons learned from several industrial applications have been incorporated.

IEC 60709:2018 is applicable to nuclear power plant instrumentation and control (I&C) and electrical systems and equipment, whose functions are required to be independent due to their contribution to:
a redundant or diverse safety group;
different defence in depth levels;
different safety classes and also with non-classified (NC) systems.  This standard is also applicable to temporary installations which are part of those I&C and *electrical systems important to safety (for example, auxiliary equipment for commissioning tests and experiments or mobile power supply systems).
This new edition includes the following significant technical changes with respect to the previous edition:
include requirements referring to the separation principle in electrical systems important to safety;
define separation criteria for I&C and electrical systems in a generic way;
align with the new revisions of IAEA documents and broaden the scope to include other aspects of separation.

IEC TR 63123:2017(E) gives guidance for the application in the IAEA / IEC framework of IEC 63147:2017/IEEE 497 corresponding to the adoption without modification of IEEE 497:2016.

IEC 63147:2017(E) contains the functional and design criteria for accident monitoring instrumentation for new plant designs and nuclear power generating stations desiring to perform design modifications. The purpose of this standard is to establish selection, design, performance, qualification, and display criteria for accident monitoring instrumentation for anticipated operational occurrences, design basis events, and severe accidents.
This standard applies to accident monitoring instrumentation intended for use during the following operations:
- As required for planned operator action related to accident mitigation,
- For assessing plant conditions, safety system performance, and making decisions related to plant response to abnormal events,
- For achieving and maintaining safe shutdown following an accident
This standard does not apply to the following:
- Accident monitoring instrumentation that is intended solely for historical recording or solely for maintenance purposes
- Other instrumentation that may be available during accident conditions.
This standard is an adoption of IEEE 497-2016 by IEC.
When applied in an IAEA / IEC environment this standard is to be used in conjunction with IEC TR 63123.

IEC TR 63084:2017(E) provides an assessment framework and activities for efficient and transparent qualification of I&C platforms for use in nuclear applications important to safety, according to nuclear standards and state of the art. The assessment aims at a pre-qualification of I&C platforms outside the framework of a specific plant design. Qualification is assumed to be pre-requisite for allowing the particular I&C platform to be used for implementation of the safety classified I&C system. It is to enable parties implementing particular plant specific I&C systems to concentrate on application functions, while for basic system functions to rely on platform qualification. Basic means of equipment qualification, as prescribed by the IEC/IEEE 60780-323, are through analysis, type testing and documented operational experience. Other documents applicable for qualification for nuclear use include IEC 61513, IEC 60880, IEC 62138, IEC 62566, IEC 62671 and IEC 61226.

IEC 61504:2017 supplements IEC 61559-1 and includes radiation monitoring functions important to safety that are outside 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 new edition includes the following significant technical changes with respect to the previous edition:
- it supplements IEC 61559-1 and integrates IEC 61559-2;
- it describes integration of functions including equipment covered by other IEC standards.

IEC 62859:2016 provides a framework to manage the interactions between safety and cybersecurity for nuclear power plant (NPP) systems, taking into account current IEC standards addressing these issues and the specifics of nuclear I&C programmable digital systems. This standard establishes requirements and guidance to:
- integrate cybersecurity provisions in nuclear I&C architectures and systems, which are fundamentally tailored for safety;
- avoid potential conflicts between safety and cybersecurity provisions;
- aid the identification and the leveraging of the potential synergies between safety and cybersecurity.

IEC 62646:2016 establishes requirements for the whole life cycle of operating procedures that the designer wishes to computerise. It also provides guidance for making decisions about which types of procedures should be computerised and to what extent. Once computerised, procedures are designated as "computer-based procedures" (CBP). This new edition includes the following significant technical changes with respect to the previous edition: clarification of the way in which the standard is to be used in conjunction with related standards.
This publication is to be read in conjunction with IEC 60964:2009 and IEC 61839:2000.

IEC 62855:2016 provides the electrotechnical engineering guidelines for analysis of AC and DC electrical power systems in nuclear power plants (NPPs) in order to demonstrate that the power sources and the distribution systems have the capability for safe operation and shut down of the NPP, bringing it to a controlled state after an anticipated operational occurrence or accident conditions and finally reaching a safe state. This standard is intended to be used:
- for verification of the design of new nuclear power plants;
- for demonstrating the adequacy and impact of major modifications of electrical power systems in operating nuclear power plants;
- and where there is a requirement to assess and establish operating limits and constraints for existing plants.

IEC 60965:2016 establishes requirements for the Supplementary Control Room provided to enable the operating staff of nuclear power plants to shut down the reactor, where previously operating, and maintain the plant in a safe shut-down state in the event that control of the safety functions can no longer be exercised from the Main Control Room, due to unavailability of the Main Control Room or its facilities. The design has to ensure that the Supplementary Control Room is protected against the hazards, including any localised extreme hazards, leading to the unavailability of the Main Control Room. This new edition includes the following significant technical changes with respect to the previous edition:
- requirements associated with regular testing of the supplementary control room (SCR);
- requirements to assess the time available during which the reactor will be safe but unattended, in order to move from the main control room (MCR) to the SCR and for the SCR to become operational;
- taking into account new requirements laid down by the IAEA.

IEC/IEEE 60780-323:2016 describes the basic requirements for qualifying electrical equipment important to safety and interfaces (electrical and mechanical) that are to be used in nuclear facilities. The principles, methods, and procedures described are intended to be used for qualifying equipment, maintaining and extending qualification, and updating qualification, as required, if the equipment is modified. The qualification requirements in this standard, when met, demonstrate and document the ability of equipment to perform safety function(s) under applicable service conditions, including design basis events and certain design extension conditions, and reduce the risk of environmentally induced common-cause equipment failure. This new edition includes the following main changes with respect to the previous edition IEC 60780:1998 harmonizes in a unique standard qualification practices formerly given by IEC 60780:1998 and IEEE 323:2003 on initial qualification, takes into account the need to reassess and extend the qualified life of electrical equipment regarding projects to extend the operating life of nuclear facilities.

IEC TR 62987:2015(E) provides guidance on nuclear-specific issues when applying failure modes and effects analysis (FMEA) and related methods to instrumentation and control systems important to safety in nuclear power plants. The information in this Technical Report complements, for nuclear power plant applications, the procedure for FMEA in IEC 60812.

IEC/IEEE 62582-5:2015 contains methods for monitoring the attenuation condition of optical fibres and cables in instrumentation and control systems using optical time domain reflectometer measurements in the detail necessary to produce accurate and reproducible measurements. It includes the requirements for the measurement system and conditions, and the reporting of the measurement results.

IEC 62808:2015 establishes requirements for the design, analysis and qualification of isolation devices used to ensure electrical independence of redundant safety system circuits, or between safety and lower class circuits, as specified in IEC 60709. This standard includes guidance on the determination of the maximum credible fault that is applied to the isolation devices. The maximum credible fault can be used as a basis for the test levels used in testing based on other standards (e.g. IEC TS 61000-6-5 or IEC 62003).

IEC 62765-1:2015 provides strategies, technical requirements, and recommended practices for the management of ageing to ensure that ageing of pressure transmitters important to safety in nuclear power plants (NPPs) can be identified and that suitable remedial actions are undertaken as necessary to demonstrate that the safety of the plant will not be impaired. This standard is aligned with IEC 62342, which provides guidance on ageing management for I&C systems important to safety in NPPs. This standard, IEC 62765-1, is the first part for pressure transmitters in the IEC 62765 sensor and transmitter series for pressure, temperature, neutron and other sensors.

IEC 62705:2014 applies to radiation monitoring system (RMS) installed in the nuclear power plants (NPPs). This standard gives requirements for the lifecycle management of RMSs and gives guidance on the application of existing IEC standards covering the design and qualification of systems and equipment. This standard may be applicable to other nuclear facilities (e.g. nuclear fuel storage and processing sites) by evaluating the differences from NPPs.

IEC 62651:2013 describes the requirements for thermocouples suitable for nuclear power plant (NPP) applications. Thermocouples are widely used in NPPs with other temperature measurement devices such as resistance temperature detectors. They are simple and robust and have some specific characteristics (range of measurement and maximum temperature) which make them uniquely suitable for some measurements. The requirements given in this standard for thermocouples include design, materials, manufacturing, testing, calibration, procurement, and inspection.

This second, updated edition deals with electrical, thermal and loading characteristics of rotating anode X-ray tubes and X-ray tube assemblies intended for use in medical diagnosis, concerning their behaviour during and after energization.

IEC 62671:2013 addresses certain devices that contain embedded software or electronically-configured digital circuits that have not been produced to other IEC Standards which apply to systems and equipment important to safety in nuclear power plants, but which are candidates for use in nuclear power plants. It provides requirements for the selection and evaluation of such devices where they have dedicated, limited, and specific functionality and limited configurability. The contents of the corrigendum of September 2016 have been included in this copy.

IEC/IEEE 62582-3:2012 contains methods for condition monitoring of organic and polymeric materials in instrumentation and control systems using tensile elongation techniques in the detail necessary to produce accurate and reproducible measurements. It includes the requirements for selection of samples, the measurement system and conditions, and the reporting of the measurement results.