IEC 62118 pdf download – Pressurized water reactor (PWR) of VVER design – Monitoring adequate cooling within the core during shutdown
1 Scope and object
This International Standard applies to pressurized water reactors (PWRs) of VVER design with configurations similar to those shown in figures 1 and 2, and presents the requirements for monitoring adequate cooling within the core during hot and cold shutdown conditions. Annex B provides more information on VVER operating states. Good international practices to be used when designing new or upgrading existing core cooling monitors for VVER systems are summarized in this standard.
This standard does not consider the design details of the different VVER technological systems designs, except to the extent that the design affects the monitoring of core cooling. Requirements are given for core cooling monitoring instrumentation to ensure the safe operation of VVERs during abnormal operation and during and after design basis accidents (DBA). Requirements for core cooling monitoring during conditions beyond a DBA, which could be a specific national requirement or consideration, are not covered here.
The core cooling monitoring instrumentation has to function under widely different conditions.
The circumstances under which this instrumentation needs to function are described. Descriptions of diverse measuring principles and suitable devices are given along with requirements for the following:
• operational conditions;
• installation;
• operator displays;
• testing, calibration and maintenance;
• equipment qualification;
• documentation;
• redundancy.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards
IEC 60050(393):1 996, International Electrotechnical Vocabulary (IEV) – Chapter 393: Nuclear Instrumentation – Physical phenomena and basic concepts
IEC 60737:1 982, In-core temperature or primary envelope temperature measurements in nuclear power reactors – Characteristics and test methods
IEC 60770-1:1999，Transmitters for use in industrial-process control systems – Part 1:Methods for performance evaluation
IEC 60780:1998,Nuclear power plants – Electrical equipment of the safety system -Qualification
IEC 60880:1986,Software for computers in the safety systems of nuclear power stations
IEC 60911:1987,Measurements for monitoring adequate cooling within the core ofpressurized light water reactors
IEC 60964:1989,Design for control rooms of nuclear power plants
IEC 60980:1989，Recommended practices for seismic qualification of electrical equipment ofthe safety system for nuclcar generating stations
IEC 60987:1989,Programmed digital computers important to safety for nuclear power stationsIEC 61225:1993，Nuclear power plants – Instrumentation and control systems important forsafety – Requiremenfs for electrical supplies
IEC 61226:1993，Nuclear power plants – Instrumentation and control systems important forsafety – Classification
IEC 61227:1993,Nuclear power plants – Control rooms – Operator controls
IEC 61343:1996，Nuclear reactor instrumentation – Boiling light water reactors (BWR)-Measurements in the reactor vessel for monitoring adequate cooling within the core
IAEA Safety Guide 50-SG-D8:1984,Safety related instrumentation and control systems fornuclear power plants
3Definitions and abbreviations
For the purpose of this International Standard，the following definitions apply. For termsdefined elsewhere, the source is given in square brackets.
3.1
ALARA
as low as reasonably achievable
3.2
coolant
water andior steam for heat removal from the core
3.3
DBA
design basis accident
3.4
diversity
the existence of redundant components or systems to perform an identified function，wheresuch components or systems collectively incorporate one or more different attributes
[IAEA 50-SG-D8]
3.5
downcomer
annular volume between reactor vessel wall and internals that directs coolant flow to thebottom of the core
3.6
ECCS
emergency core cooling system
3.7
LOCA
loss of coolant accident
3.8
monitoring
means provided to indicate continuously the state or condition of a system, sub-system,
equipment or assembly
[IEV 393-08-48]
3.9
PAMS
post-accident monitoring system
3.1 0
pressurized water reactor (PWR)
a nuclear steam supply system in which the pressurized coolant is heated by the reactor core, and process steam is generated in the steam generator by heat transfer from the coolant
IEC 62118 pdf download – Pressurized water reactor (PWR) of VVER design – Monitoring adequate cooling within the core during shutdown
