IEC 61839:2000 pdf free download – Nuclear power plants -Design of control rooms – Functional analysis and assignment
1 Scope and object
This International Standard specifies functional analysis and assignment procedures (FAand A, sometimes called allocation of functions) for the design of the control-room system fornuclear power plants and gives rules for developing criteria for the assignment of functions.
This standard supplements lEC 60964,which applies to the design of the control-room fornuclear power plants.
The purpose of this standard is to provide specific requirements for carrying out the functionalanalysis and assignment required in 3.1 and 3.2 of IEC 60964, and therefore supersedes theguidance given in A.3.1 and A.3.2 of lEC 60964.
This standard is applicable to the design of new control-rooms or to backfits (design renewaland design modifications) to existing control-rooms. In the latter case,particular caution is tobe exercised to identify areas indirectly affected as well as those directly affected.
2Normative references
The following normative documents contain provisions which,through reference in this text,constitute provisions of this International Standard. For dated references，subsequentamendments to, or revisions of, any of these publications do not apply. However，parties toagreements based on this International Standard are encouraged to investigate the possibilityof applying the most recent editions of the normative documents indicated below. For undatedreferences,the latest edition of the normative document referred to applies. Members of lECand lSo maintain registers of currently valid lnternational Standards.
IEC 60964:1989,Design for control rooms of nuclear power plants
IEC 61771:1995,Nuclear power plants – Main control-room – Verification and validation ofdesign
3.3 human machine interface, HMI
interface between operating staff and l and C system and computer systems linked with theplant.The interface includes displays，controls,and the Operator Support System interface(see man/machine interface in IEC 6o964)
3.4 probabilistic risk assessment(PRA)
methodological approach to identify accident sequences that can follow from a broad range ofinitiating events; it includes the systematic and realistic determination of accident frequenciesand consequences
3.5 control function
control actions performed by humans or machines for the accomplishment of a functional goalincluding the associated information acquisition and processing 1)
3.6 tasks
control actions performed by humans for the accomplishment of a functional goal 1)
4Process of functional analysis and assignment
4.1 General description
The process of functional analysis and assignment is required in clause 3 of lEC 60964 as afirst step for the design of a control-room (see figure 1). It aims initially to identify all of thefunctions required to operate the plant，then to assign the functions to humans or tomachines.
a) Two basic steps are required:a) functional analysis;
b) assignment of functions.
They are defined respectively in clauses 5 and 6 of this standard.
4.1.1 Functional analysis
The identification of the functions (see 5.2) is obtained initially by defining general orfundamental objectives of the plant operation， i.e. safe and effective generation of electricalpower, protection of the public from radiological hazards, then by breaking down the top-levelfunctions，allowing those objectives to be fulfilled, into a hierarchy of functions where thelowest set of functions are the control functions which must then be assigned to humans or tomachines.The general nuclear power plant functional analysis is a means to the identificationof all the functions achieved from the main control-room.
The static database of functions of different levels, obtained in the previous step, is completedby the determination of the basic operational information flow and processing requirements forplant operation (see 5.3.1).