IEC 62855-2016 PDF

Full title and description

St IEC 62855-2016 — Nuclear power plants - Electrical power systems - Electrical power systems analysis. Provides electrotechnical engineering guidelines for analysis of AC and DC electrical power systems in nuclear power plants to demonstrate that power sources and distribution systems can ensure safe operation, shutdown and transition to a controlled/safe state following anticipated operational occurrences or accident conditions.

Abstract

IEC 62855:2016 defines recommended analyses and acceptance criteria (transient stability, load-flow, short-circuit, protection coordination, DC and uninterruptible AC systems, etc.) to verify design of new NPP electrical systems, evaluate major modifications of existing plants, and establish operating limits and constraints for safe plant operation. Informative annexes cover establishment of design bases, analytical study guidelines, verification of design bases and example plant-specific acceptance criteria.

General information

• Status: Published / Current (active standard).
• Publication date: 30 August 2016.
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 27.120.20 (Nuclear power plants. Safety).
• Edition / version: Edition 1.0 (2016).
• Number of pages: 123 pages (base IEC publication).

Scope

Sets out recommended methods and studies for electrical power system analysis in nuclear power plants, including off‑site power transient stability, AC on‑site system studies, DC and uninterruptible AC system analyses, short‑circuit and protection coordination studies, and other miscellaneous analyses needed to demonstrate capability for safe operation and shutdown and to define design and operating limits. Intended for design verification, assessment of major modifications, and where plant operating limits need to be established.

Key topics and requirements

• Transient stability and dynamic studies for off‑site and on‑site power systems.
• Load‑flow (steady‑state) analyses to verify power distribution under normal and contingency conditions.
• Short‑circuit studies and fault level assessments for equipment specification and protection design.
• Electrical protection coordination and selectivity to ensure correct fault clearing and minimal impact on safety functions.
• DC system and uninterruptible AC system analyses (including battery and inverter performance).
• Guidance for establishing design bases, verification of design bases, and example plant‑specific acceptance criteria (informative annexes).

Typical use and users

Used by nuclear electrical engineers, plant designers, system analysts, safety and licensing authorities, regulatory assessors, consultants performing plant modifications, and organizations responsible for establishing operating limits and technical specifications for nuclear power plant electrical systems. The standard supports design verification, licensing submissions, and post‑modification safety assessments.

Related standards

References and relations include other IEC and national standards relevant to voltages, switchgear, protection and I&C for nuclear plants (examples noted in the IEC bibliographic listing: IEC 60038, IEC 62271‑200 and IEC 62342 among others). Regional/adopted variants include EN IEC / BS EN adoptions where applicable.

Keywords

nuclear power plants, electrical power systems, power system analysis, transient stability, load flow, short‑circuit, protection coordination, DC systems, uninterruptible power, design bases, acceptance criteria.

FAQ

Q: What is this standard?

A: IEC 62855:2016 is an international standard giving guidelines for electrical power systems analysis in nuclear power plants to demonstrate safe operation, shutdown capability and to establish design/operational limits.

Q: What does it cover?

A: It covers recommended studies (transient stability, load‑flow, short‑circuit, protection coordination, DC/uninterruptible AC systems), methods for establishing design bases, verification practices and example acceptance criteria in informative annexes.

Q: Who typically uses it?

A: Nuclear electrical engineers, system analysts, plant designers, safety assessors, regulators and consultants involved in design verification, licensing, modification assessment and establishing operating constraints for NPP electrical systems.

Q: Is it current or superseded?

A: As published on 30 August 2016 (Edition 1.0) the IEC bibliographic record lists it as the current base publication; the IEC record also shows a stability date and continued validity in national/adopted editions. Users should confirm any later amendments or revisions with their national body or the IEC webstore if they need absolute up‑to‑date confirmation.

Q: Is it part of a series?

A: IEC 62855 is a standalone international standard produced by TC 45/SC 45A addressing instrumentation, control and electrical power systems of nuclear facilities; it is related by subject matter to other IEC TC45 publications but is not a sequential part number series. Regional/adopted versions (EN IEC, BS IEC, etc.) exist.

Q: What are the key keywords?

A: Nuclear power plants, electrical power systems, transient stability, load flow, short circuit, protection coordination, DC systems, design bases, acceptance criteria.