IEC 61226:2009
Nuclear power plants - Instrumentation and control important to safety - Classification of instrumentation and control functions

Standard No.

IEC 61226:2009

Release Date

2009

Published By

International Electrotechnical Commission (IEC)

Status

Be replaced

Replace By

IEC 61226:2020

Latest

IEC 61226:2020

Replace

IEC 45A/745/FDIS:2009 IEC 61226:2005

Scope

This International Standard establishes a method of classification of the information and command functions for nuclear power plants@ and the IC systems and equipment that provide those functions@ into categories that designate the importance to safety of the function. The resulting classification then determines relevant design criteria. The design criteria are the measures of quality by which the adequacy of each function in relation to its importance to plant safety is ensured. In this standard@ the criteria are those of functionality@ reliability@ performance@ environmental durability (including seismic) and quality assurance (QA). This standard is applicable to all the information and command functions and the instrumentation and control (IC) systems and equipment that provide those functions. The functions@ systems and equipment under consideration provide automated protection@ closed or open loop control and information to the operating staff. They keep the NPP conditions inside the safe operating envelope and provide automatic actions@ or enable manual actions@ that prevent or mitigate accidents@ or that prevent or minimize radioactive releases to the site or wider environment. The IC functions that fulfil these roles safeguard the health and safety of the NPP operators and the public. This standard follows the general principles given in IAEA safety code NS-R-1 and safety guide NS-G-1.3@ and it defines a structured method of applying the guidance contained in those codes and standards to the IC systems that perform functions important to safety in a NPP. This standard should be read in association with the IAEA guides and IEC 61513 in implementing the requirements of IEC 61508 series.

IEC 61226:2009 history

• 2020 IEC 61226:2020 Nuclear power plants - Instrumentation, control and electrical power systems important to safety - Categorization of functions and classification of systems
• 2009 IEC 61226:2009 Nuclear power plants - Instrumentation and control important to safety - Classification of instrumentation and control functions
• 2005 IEC 61226:2005 Nuclear power plants - Instrumentation and control systems important to safety - Classification of instrumentation and control functions
• 1993 IEC 61226:1993 Nuclear power plants; instrumentation and control systems important for safety; classification