IEC 61504:2000 pdf download

IEC 61504:2000 pdf download.Nuclear power plants – Instrumentation and control systems important to safety – Plant-wide radiation monitoring.
3.3
category C FSE
those FSE that play an auxiliary or indirect role in the achievement or maintenance of nuclear power plant safety. Category C Includes FSE that have some safety significance, but are not category A or B. They can be part of the total response to an accident, but not directly involved in mitigating the physical consequences of the accident (see IEC 61226).
RMS functions that might be assigned to category C include, for example, area radiation monitoring functions.
3.4
FSE Important to safety
the instrumentation and control FSE that comprise:
• FSE whose malfunction or failure could lead to undue radiation exposure of the site personnel or members of the public:
• FSE that prevent anticipated operational occurrences from leading to a set of events that would result in unacceptable safety consequences;
• FSE that mitigate the safety consequences of malfunction or failure of structures, systems. or components (see IEC 61226).
FSE important to safety include both safety systems and safety-related systems.
3.5
FSE
functions and the associated systems and equipment. Functions are carried out for a purpose or to achieve a goal. The associated systems and equipment are the collections of components and the components themselves that are employed to achieve the functions (see lEG 61226)
3.6
Interlocks
equipment used to prevent unsafe operation, protect personnel, and prevent hazards (see
IEC 61497)
3.7
supplier
the designer and fabricator of the equipment. For some systems the term supplier may refer to several organizations, each of which has some role in the production of the equipment
3.8
multiplexed data transmission
the transmission from one location to another of two or more signals or messages over a
single data channel by use of time division, frequency division, pulse code techniques or the
like (lEG 61500, 3.11
3.9
purchaser
the user of the equipment
3.10
PItS
radiation monitoring system
3.11
safety systems
those systems important to safety provided to ensure, In any condition, the sale shutdown of the reactor and heat removal from the core, or to limit the consequences of anticipated operational occurrences and accident conditions (see IAEA 50-SG-D8 and 5O-SG-D3)
3.12
salety.related systems
those systems important to safety which are not included in safety systems (see IAEA 50•SG.D8). Category B and C FSE are safety’ related systems
4 Functions
4.1 Introduction
Nuclear plant instrumentation and control systems such as the safety system, Integrated control system. post accident monitoring system, and radiation monitoring system (RMS) are designed to provide the plant operator with timely Information as well as actuation of plant features during various plant conditions Including normal, anticipated operational occurrence. and accident conditions. A plant.wide radiation monitoring system performs one or more of the following functions:
• During normal plant conditions, the RMS allows operations personnel to monitor various processes and areas within the plant to ensure that radiation levels are within acceptable ranges. Specific process systems, effluent paths, and areas are monitored for that purpose. Departure from normal radiation levels in these selected locations may be an indication of an abnormal or approach to abnormal plant condition and potential degradation of plant operation.
• During accident conditions, the RMS provides information to the plant operator to assist in the evaluation of potential releases to the environment, impact on plant personnel. or equipment performance.
• During and following an accident, the RMS provides information to assist the operator in determining the lype of accident, evaluate the potential releases to the environment, and initiate appropriate emergency procedures.
• During and following an accident, the RMS provides release information to emergency response personnel. In some cases, this may include meteorological data to support prediction of release transport or calculation of estimates of activity cloud dispersion.
• The RMS initiates control and protection functions to support normal operation of systems. respond to anticipated operational occurrences, and prevent or mitigate releases during and following accidents.
• The RMS provides information to control and protection systems for interlock or activation functions.
• The RMS provides facility radiation levels and tracks personnel dose during normal and accident conditions for use by plant health physics staff.
• The RMS stores the relevant data for the analysis of normal, abnormal, or accident conditions, their Initiation and their sequence.
• The RMS supplies Information to the station data processing and display system on essential alarms and Information for use In the control room, and possibly In the ECC (emergency control centre).