IEC 62705:2014

IEC 62705 ®
Edition 1.0 2014-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety –
Radiation monitoring systems (RMS): Characteristics and lifecycle

Centrales nucléaires de puissance – Instrumentation et contrôle-commande
importants pour la sûreté – Systèmes de surveillance des rayonnements (SSR):
Caractéristiques et cycle de vie

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IEC 62705 ®
Edition 1.0 2014-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety –

Radiation monitoring systems (RMS): Characteristics and lifecycle

Centrales nucléaires de puissance – Instrumentation et contrôle-commande

importants pour la sûreté – Systèmes de surveillance des rayonnements (SSR):

Caractéristiques et cycle de vie

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX S
ICS 27.120.20 ISBN 978-2-8322-1773-3

– 2 – IEC 62705:2014 © IEC 2014
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 11
4 Abbreviations . 13
5 RMS categorization and classification . 13
5.1 Function categorization for RMS . 13
5.2 System classification for RMS . 13
6 RMS detailed design and implementation . 14
6.1 General . 14
6.2 Radioactive noble gas off-line monitoring . 14
6.3 Radioactive aerosol off-line monitoring . 15
6.4 Radioactive iodine off-line monitoring . 15
6.5 Liquid off-line monitoring . 15
6.6 Tritium off-line monitoring . 15
6.7 On-line or in-line monitoring . 16
6.8 Area monitoring . 16
6.9 Centralized system . 16
6.10 Leak detection . 16
7 RMS integration and validation . 16
7.1 RMS integration . 16
7.2 RMS validation . 16
8 RMS installation . 16
9 RMS design modification . 17
10 RMS qualification . 17
10.1 General . 17
10.2 Environmental qualification . 17
10.3 Seismic qualification . 17
10.4 Electromagnetic interference. 18
11 Calibration . 18
11.1 General . 18
11.2 Periodical calibration and functional check . 18
11.2.1 General . 18
11.2.2 Calibration check after installation . 18
11.2.3 Functional check. 18
11.2.4 Countermeasures to loss of monitoring during calibration or functional
check . 18
11.3 Radiation calibration . 18
11.4 Calibration for other quantity . 18
11.5 Traceability . 19
Annex A (informative) Example of safety classification for RMS important to safety . 20
Annex B (informative) Relation between IEC 61513 system lifecycle and IEC 62705
requirements . 21

Table 1 – Overview of the standards covering the domain of radiation monitoring in
NPPs . 7
Table A.1 – Example of safety classification for RMS important to safety . 20
Table B.1 – Relation between IEC 61513 system lifecycle and IEC 62705
requirements . 21

– 4 – IEC 62705:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NUCLEAR POWER PLANTS – INSTRUMENTATION
AND CONTROL IMPORTANT TO SAFETY –
RADIATION MONITORING SYSTEMS (RMS):
CHARACTERISTICS AND LIFECYCLE
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62705 has been prepared by subcommittee 45A: Instrumentation,
control and electrical systems of nuclear facilities, of IEC technical committee 45: Nuclear
instrumentation.
The text of this standard is based on the following documents:
FDIS Report on voting
45A/960/FDIS 45A/973/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 62705:2014 © IEC 2014
INTRODUCTION
a) Technical background, main issues and organisation of the Standard
This IEC standard sets out the requirements for the lifecycle management of radiation
monitoring system (RMS) installed in the nuclear power plants (NPPs). This standard is
applicable to the equipment of RMS and intended to be used during normal operations and
anticipated operational occurrences, as well as, for certain monitors, in accident
conditions. This standard may be applicable to other nuclear facilities (e.g. nuclear fuel
storage and processing sites) by evaluating the differences from NPPs.
It is intended that the Standard be used by operators of NPPs (utilities), systems
evaluators and by licensors.
b) Situation of the current Standard in the structure of the IEC SC 45A standard series
IEC 62705 is the third level in the hierarchy of SC 45A standards. This standard provides
guidance on the application of existing IEC/ISO standards covering design and
qualification of system and equipment for RMS. This standard is an application
supplement of IEC 61513 as shown in Annex B, and it is not intended that this standard
limits the application of other IEC 61513 requirements to RMS lifecycle.
For general requirements and guidance, the following standards provide requirements and
guidance for RMS. IEC 61513 is the first level standard of SC 45A standards, and
provides general requirements for I&C systems and equipment that are used to perform
functions important to safety in NPPs. IEC 61226 provides the criteria for classification of
instrumentation and control functions. Most modern RMSs contain computer-based
equipment. Hence RMS should often be treated as computer-based system. So following
standards required for computer-based system are generally applicable to RMS.
IEC 60880 provides the software requirements for category A functions and IEC 62138
provides the software requirements for Category B or C functions. IEC 60987 provides
hardware design requirements for computer-based systems. IEC 62566 provides the
requirements for HDL-Programmed Device (HPD) for systems performing category A
functions. IEC 62645 provides security requirements for computer based I&C systems. For
qualification testing, the following SC 45A standards are applicable. IEC 60780 provides
guidance for the environmental qualification and IEC 60980 provides guidance for seismic
qualification for equipment performing category A or B functions. IEC 62003 provides the
requirements for electromagnetic compatibility testing. In addition, IEC 61250 specifies the
leak detection requirements by using RMS.
For radiation monitoring specific requirements, the following standards provide
requirements and guidance for RMS. The IEC 60951 series provides guidance on the
design and testing of radiation monitoring equipment used for accident and post-accident
conditions. The IEC 60761 series provide requirements for equipment for continuous off-
line monitoring of radioactivity in gaseous effluent in normal conditions. Some of the
SC 45B standards (e.g. Gas offline: IEC 62302, Tritium: IEC 62303) are now replacing the
IEC 60761 series. IEC 60861 provides requirements for equipment continuous off-line
monitoring of radioactivity in liquid effluent in normal conditions. IEC 60768 provides
requirements for equipment for continuous in-line and on-line monitoring of radioactivity in
process stream in normal and incident conditions. IEC 61031 provides requirements for
equipment for area radiation monitor in normal conditions in conjunction with IEC 60532.
IEC 61504 provides requirements for centralized system for plant-wide radiation
monitoring in conjunction with the IEC 61559 series which specifies the requirements for
centralized system. If the centralized system is a part of the safety parameter display
system, IEC 60960 provides the functional design criteria. ISO 2889 gives guidance on
gas and particulate sampling. The ISO 4037 series provides calibration methodology for
radiation monitors.
The relationship between these various standards is given in Table 1.

Table 1 – Overview of the standards covering
the domain of radiation monitoring in NPPs
IEC
Developer ISO
SC 45A SC 45B
Accident and
Scope Sampling Calibration post accident Normal conditions
conditions
IEC 62302 /
Radioactive noble gas
ISO 4037-1, IEC 60951-1,
ISO 2889 N/A IEC 60761-1,
off-line monitoring ISO 4037-3 IEC 60951-2
IEC 60761-3
Radioactive aerosol ISO 4037-1, IEC 60951-1, IEC 60761-1,
ISO 2889 N/A
off-line monitoring ISO 4037-3 IEC 60951-2 IEC 60761-2
Radioactive iodine off- ISO 4037-1, IEC 60951-1, IEC 60761-1,
ISO 2889 N/A
line monitoring ISO 4037-3 IEC 60951-2 IEC 60761-4
Liquid off-line
N/A N/A N/A N/A IEC 60861
monitoring
IEC 62303 /
Tritium off-line
N/A N/A N/A N/A
IEC 60761-1,
monitoring
IEC 60761-5
On-line or in-line ISO 4037-1, IEC 60951-1,
N/A IEC 60768 N/A
monitoring ISO 4037-3 IEC 60951-4
ISO 4037-1, IEC 60951-1,
Area monitoring N/A IEC 61031 IEC 60532
ISO 4037-3 IEC 60951-3
Centralized system
N/A N/A IEC 61504, IEC 60960 IEC 61559-1
IEC 61513, IEC 60880,
Classification/basic
IEC 60987, IEC 61226,
N/A N/A N/A
requirements IEC 62138, IEC 62566,
IEC 62645, IEC 61250
IEC 60780, IEC 60980,
Qualification N/A N/A IEC 62706
IEC 62003
For more details on the structure of the IEC SC 45A standard series, see item d) of this
introduction.
c) Recommendations and limitations regarding the application of this Standard
It is important to note that this standard establishes no additional functional requirements
for safety systems. Where requirements are given in this standard, they refer generally to
the need to apply other IEC and ISO Standards and specific functional and technical
requirements contained in these standards.
To ensure that the standard will continue to be relevant in future years, the emphasis has
been placed on issues of principle, rather than specific technologies.
d) Description of the structure of the IEC SC 45A standard series and relationships
with other IEC documents and other bodies documents (IAEA, ISO)
The top-level document of the IEC SC 45A standard series is IEC 61513. It provides
general requirements for I&C systems and equipment that are used to perform functions
important to safety in NPPs. IEC 61513 structures the IEC SC 45A standard series.
IEC 61513 refers directly to other IEC SC 45A standards for general topics related to
categorization of functions and classification of systems, qualification, separation of
systems, defence against common cause failure, software aspects of computer-based
systems, hardware aspects of computer-based systems, and control room design. The
standards referenced directly at this second level should be considered together with
IEC 61513 as a consistent document set.
At a third level, IEC SC 45A standards not directly referenced by IEC 61513 are standards
related to specific equipment, technical methods, or specific activities. Usually these
documents, which make reference to second-level documents for general topics, can be
used on their own.
– 8 – IEC 62705:2014 © IEC 2014
A fourth level extending the IEC SC 45A standard series, corresponds to the Technical
Reports which are not normative.
IEC 61513 has adopted a presentation format similar to the basic safety publication
IEC 61508 with an overall safety life-cycle framework and a system life-cycle framework.
Regarding nuclear safety, it provides the interpretation of the general requirements of
IEC 61508-1, IEC 61508-2 and IEC 61508-4, for the nuclear application sector, regarding
nuclear safety. In this framework IEC 60880 and IEC 62138 correspond to IEC 61508-3 for
the nuclear application sector. IEC 61513 refers to ISO as well as to IAEA GS-R-3 and
IAEA GS-G-3.1 and IAEA GS-G-3.5 for topics related to quality assurance (QA).
The IEC SC 45A standards series consistently implements and details the principles and
basic safety aspects provided in the IAEA code on the safety of NPPs and in the IAEA
safety series, in particular the Requirements NS-R-1, establishing safety requirements
related to the design of Nuclear Power Plants, and the Safety Guide NS-G-1.3 dealing with
instrumentation and control systems important to safety in Nuclear Power Plants. The
terminology and definitions used by SC 45A standards are consistent with those used by
the IAEA.
NOTE It is assumed that for the design of I&C systems in NPPs that implement conventional safety functions
(e.g. to address worker safety, asset protection, chemical hazards, process energy hazards) international or
national standards would be applied, that are based on the requirements of a standard such as IEC 61508.

NUCLEAR POWER PLANTS – INSTRUMENTATION
AND CONTROL IMPORTANT TO SAFETY –
RADIATION MONITORING SYSTEMS (RMS):
CHARACTERISTICS AND LIFECYCLE
1 Scope
This International Standard applies to radiation monitoring system (RMS) installed in the
nuclear power plants (NPPs). This standard gives requirements for the lifecycle management
of RMSs and gives guidance on the application of existing IEC standards covering the design
and qualification of systems and equipment.
This International Standard is applicable to RMSs intended to be used during normal
operations and anticipated operational occurrences, and to be used during and/or after
accident conditions. The technical guidance contained in this Standard applies to NPPs,
although the specific functions of individual facilities shall be considered during the design
and operational lifecycle of RMS. This standard is intended to be consistent with the latest
versions of International Standards dealing with radiation monitors, sampling of radioactive
materials, instruments calibration, hardware and software design, classification, and
qualification. Unless otherwise specified in this International Standard, top level IEC SC 45A
standard, IEC 61513, and the second level IEC SC 45A standards apply to RMSs.
This standard may be applicable to other nuclear facilities (e.g. nuclear fuel storage and
processing sites) by evaluating the differences from NPPs.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60532, Radiation protection instrumentation – Installed dose rate meters, warning
assemblies and monitors – X and gamma radiation of energy between 50 keV and 7 MeV
IEC 60761-1, Equipment for continuous monitoring of radioactivity in gaseous effluents –
Part 1: General requirements
IEC 60761-2, Equipment for continuous monitoring of radioactivity in gaseous effluents –
Part 2: Specific requirements for radioactive aerosol monitors including transuranic aerosols
IEC 60761-3, Equipment for continuous monitoring of radioactivity in gaseous effluents –
Part 3: Specific requirements for radioactive noble gas monitors
IEC 60761-4, Equipment for continuous monitoring of radioactivity in gaseous effluents –
Part 4: Specific requirements for radioactive iodine monitors
IEC 60761-5, Equipment for continuous monitoring of radioactivity in gaseous effluents –
Part 5: Specific requirements for tritium monitors
IEC 60768, Nuclear power plants – Instrumentation important to safety – Equipment for
continuous in-line or on-line monitoring of radioactivity in process streams for normal and
incident conditions
– 10 – IEC 62705:2014 © IEC 2014
IEC 60780:1998, Nuclear power plants – Electrical equipment of the safety system –
Qualification
IEC 60861, Equipment for monitoring of radionuclides in liquid effluents and surface waters
IEC 60880, Nuclear power plants – Instrumentation and control systems important to safety –
Software aspects for computer-based systems performing category A functions
IEC 60951-1, Nuclear power plants – Instrumentation important to safety – Radiation
monitoring for accident and post-accident conditions – Part 1: General requirements
IEC 60951-2, Nuclear power plants – Instrumentation important to safety – Radiation
monitoring for accident and post-accident conditions – Part 2: Equipment for continuous off-
line monitoring of radioactivity in gaseous effluents and ventilation air
IEC 60951-3, Nuclear power plants – Instrumentation important to safety – Radiation
monitoring for accident and post-accident conditions – Part 3: Equipment for continuous high
range area gamma monitoring
IEC 60951-4, Nuclear power plants – Instrumentation important to safety – Radiation
monitoring for accident and post-accident conditions – Part 4: Equipment for continuous in-
line or on-line monitoring of radioactivity in process streams
IEC 60960, Functional design criteria for a safety parameter display system for nuclear power
stations
IEC 60980, Recommended practices for seismic qualification of electrical equipment of the
safety system for nuclear generating stations
IEC 60987, Nuclear power plants – Instrumentation and control important to safety –
Hardware design requirements for computer-based systems
IEC 61031, Design, location and application criteria for installed area gamma radiation dose
rate monitoring equipment for use in nuclear power plants during normal operation and
anticipated operational occurrences
IEC 61226:2009, Nuclear power plants – Instrumentation and control important to safety –
Classification of instrumentation and control functions
IEC 61250, Nuclear reactors – Instrumentation and control systems important for safety –
Detection of leakage in coolant systems
IEC 61504, Nuclear power plants – Instrumentation and control systems important to safety –
Plant-wide radiation monitoring
IEC 61513:2011, Nuclear power plants – Instrumentation and control important to safety –
General requirements for systems
IEC 61559 (all parts), Radiation protection instrumentation in nuclear facilities – Centralized
systems for continuous monitoring of radiation and/or levels of radioactivity
IEC 62003, Nuclear power plants – Instrumentation and control important to safety –
Requirements for electromagnetic compatibility testing
IEC 62302, Radiation protection instrumentation – Equipment for sampling and monitoring
radioactive noble gases
IEC 62303, Radiation protection instrumentation – Equipment for monitoring airborne tritium
IEC 62138, Nuclear power plants – Instrumentation and control important for safety –
Software aspects for computer-based systems performing category B or C functions
IEC 62566, Nuclear power plants – Instrumentation and control important to safety –
Development of HDL-programmed integrated circuits for systems performing category A
functions
ISO 2889, Sampling airborne radioactive materials from the stacks and ducts of nuclear
facilities
ISO 4037-1, X and gamma reference radiation for calibrating dosemeters and doserate meters
and for determining their response as a function of photon energy – Part 1: Radiation
characteristics and production methods
ISO 4037-3, X and gamma reference radiation for calibrating dosemeters and doserate meters
and for determining their response as a function of photon energy – Part 3: Calibration of area
and personal dosemeters and the measurement of their response as a function of energy and
angle of incidence
ISO/IEC 17025, General requirements for the competence of testing and calibration
laboratories
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
alarm assembly
assembly which is initiated by the processing assembly, and provides audible and/or visual
alarms, normally local to detector assembly
3.2
calibration
set of operations that establish, under specified conditions the relationship between values of
quantities indicated by a measuring instrument or a measuring system, or values represented
by a material measure or a reference material, and the corresponding values realized by
standards
[SOURCE: IEC 62397:2007, 3.2]
3.3
category of an I&C function
one of three possible safety assignments (A, B, C) of I&C functions resulting from
considerations of the safety relevance of the function to be performed. An unclassified
assignment may be made if the function has no importance to safety
[SOURCE: IEC 61513:2011, 3.4]
3.4
centralized system
centralizer
central processing and control system for the calculation, display, and storage of data from
the processing assembly
– 12 – IEC 62705:2014 © IEC 2014
3.5
class of an I&C system
one of three possible assignments (1, 2, 3) of I&C systems important to safety resulting from
consideration of their requirement to implement I&C functions of different safety importance.
An unclassified assignment is made if the I&C system does not implement functions important
to safety
[SOURCE: IEC 61513:2011, 3.6]
3.6
detector assembly
detector and associated electronics (amplifier, discriminator, output pulse shaper), and can
also include hydraulic and programmable electronic circuits.
3.7
HDL-Programmed Device
HPD
integrated circuit configured (for NPP I&C systems), with Hardware Description Languages
and related software tools
Note 1 to entry: HPDs are typically based on blank FPGAs, PLDs or similar micro-electronic technologies.
[SOURCE: IEC 62566:2012, 3.7]
3.8
in-line monitoring
monitoring of the radioactivity in fluid by the detector located directly in the process stream
(pipe, stack, duct, etc.)
3.9
monitoring assembly
combinations of processing, alarm, and detector assemblies
3.10
network equipment
equipment supporting communication among assemblies of RMS and external equipment
3.11
off-line monitoring
monitoring of the radioactivity in fluid by sample drawn from the process stream to the
detector located at some distance
3.12
on-line monitoring
monitoring of the radioactivity in fluid by the detector directly facing the process stream
3.13
processing assembly
assembly which converts the output signal from the detector assemblies into a form, generally
digital, suitable for transmission down a data link to the central computer, centralized system,
and/or which generates alarm outputs to the alarm units at present signal levels
3.14
radiation monitor
device designed to measure the level of ionizing radiation and able to emit a warning signal
Note 1 to entry: A radiation monitor may also provide quantitative information.

3.15
sampling assembly
set of interconnected instruments (devices) for collecting a representative sample
[SOURCE: IEC 60951-1:2009, 3.23]
3.16
volumetric activity
activity per unit volume of the sample
Note 1 to entry: For a gas, it is necessary to indicate the temperature and pressure conditions for which the
volumetric activity, expressed in becquerels per cubic metre, is measured, for example standard temperature and
pressure.
Note 2 to entry: This quantity is expressed in becquerels per cubic metre (Bq/m ).
[SOURCE: IEC 60050-395:2014, 395-01-09]
4 Abbreviations
BWR: Boiling Water Reactor
FPGA: Field-Programmable Gate Array
HPD: HDL (Hardware Description Language) -Programmed Device
I&C: Instrumentation and Control
IAEA: International Atomic Energy Agency
IEC: International Electrotechnical Commission
ISO: International Organization for Standardization
MRA: Multi Recognition Agreement
NPP: Nuclear Power Plant
NSLR: National Standardizing Laboratory of a country for Radioactivity measurement
PLD: Programmable Logic Device
PWR: Pressurized Water Reactor
RMS: Radiation Monitoring System
5 RMS categorization and classification
5.1 Function categorization for RMS
RMS in nuclear power plants provides continuous information about the radiological
conditions in NPP by measuring the radiation levels in specific areas, on certain process lines
and at gaseous and liquid release points. It provides alarms and can initiate automatic actions
when the monitored radioactivity reaches levels that have been determined to be abnormal.
The plant safety design base assigns the individual RMS functions important to safety into
one of three categories A, B or C, considering the relationships to other systems to be
connected. The main design requirements for the systems and equipment associated with
these categories are consistent with those of Clause 7 of IEC 61226:2009. The category shall
be assigned during system requirement specification phase.
5.2 System classification for RMS
RMS shall be classified according to its suitability to implement I&C functions up to a defined
category during the system specification phase as shown in 6.2.3 of IEC 61513:2011.
Examples of the classification for RMS installed in PWR and BWR plants are shown in
Annex A.
– 14 – IEC 62705:2014 © IEC 2014
According to the category of the function, the following standards shall be applied to each
system and equipment.
a) System and equipment performing category A functions
Any software in RMS performing category A function shall be designed and maintained in
accordance with IEC 60880. Any HDL-Programmed Device (HPD) in the equipment of
RMS performing category A function shall be designed and maintained in accordance with
IEC 62566. Any hardware in RMS performing category A function and including software
or HPD shall be designed and maintained in accordance with IEC 60987.
b) System and equipment performing category B or C functions
Any software in RMS performing category B or C function shall be designed and
maintained in accordance with IEC 62138. Any hardware in RMS performing category B
function and including software shall be designed and maintained in accordance with
IEC 60987. Hardware performing category C function shall be designed, selected and
maintained according to the supplier's requirements which can meet the application
specific qualification requirements.
6 RMS detailed design and implementation
6.1 General
RMS generally consists of a combination of following equipment:
• detector assembly
• sampling assembly
• monitoring assembly
• processing assembly
• alarm assembly
• centralized system
• network equipment
• cable
The above equipment may have resident software.
The RMS shall be designed and implemented in accordance with appropriate requirements
shown in the following standards.
6.2 Radioactive noble gas off-line monitoring
RMS for radioactive noble gas off-line monitoring is used for the following purposes:
– to measure the volumetric activity of radioactive noble gases in gaseous effluents at the
discharge point and the variation of volumetric activity. The monitor may also be used for
the determination of the total discharge of radioactive noble gas over a given period;
– to measure the volumetric activity in air or gas systems (control room ventilation, reactor
leakage collection, drywell ventilation exhaust, fuel handling building ventilation exhaust,
reactor building ventilation purge exhaust) and detect any significant increase of
radioactivity.
For RMS designed only for normal operation condition, the design and testing of RMS shall be
performed in accordance with IEC 60761-1 and IEC 60761-3. Instead of the set of
IEC 60761-1 and IEC 60761-3, IEC 62302 may be used alternatively.
For RMS designed for accident conditions, the design and testing of RMS shall be performed
in accordance with IEC 60951-1 and IEC 60951-2. Sampling assembly for RMS used for this
monitoring shall be designed and tested in accordance with ISO 2889.

6.3 Radioactive aerosol off-line monitoring
RMS for radioactive aerosol off-line monitoring is used for the following purposes:
– to measure the volumetric activity of radioactive aerosols in gaseous effluents at the
discharge point and the variation of volumetric activity. The monitor may also be used for
the determination of the total discharge of radioactive aerosol over a given period;
– to measure the volumetric activity in air or gas systems (control room ventilation, reactor
leakage collection, drywell ventilation exhaust, fuel handling building ventilation exhaust,
reactor building ventilation purge exhaust) and detect any significant increase of
radioactivity.
For RMS designed only for normal operation condition, the design and testing of RMS shall be
performed in accordance with IEC 60761-1 and IEC 60761-2. For RMS designed for accident
conditions, the design and testing of RMS shall be performed in accordance with IEC 60951-1
and IEC 60951-2. Sampling assembly for RMS used for this monitoring shall be designed and
tested in accordance with ISO 2889.
6.4 Radioactive iodine off-line monitoring
RMS for radioactive iodine off-line monitoring is used for the following purposes:
– to measure the volumetric activity of radioactive iodines in gaseous effluents at the
discharge point and the variation of volumetric activity. The monitor may also be used for
the determination of the total discharge of radioactive iodine over a given period;
– to measure the volumetric activity in air or gas systems (control room ventilation, reactor
leakage collection, drywell ventilation exhaust, fuel handling building ventilation exhaust,
reactor building ventilation purge exhaust) and detect any significant increase of
radioactivity.
For RMS designed only for normal operation condition, the design and testing of RMS shall be
performed in accordance with IEC 60761-1 and IEC 60761-4. For RMS designed for accident
conditions, the design and testing of RMS shall be performed in accordance with IEC 60951-1
and IEC 60951-2. Sampling assembly for RMS used for this monitoring shall be designed and
be tested in accordance with ISO 2889.
6.5 Liquid off-line monitoring
RMS for continuous liquid off-line monitoring is used for following purposes:
– to measure the volumetric activity in liquid at the discharge point or the surface water and
the variation of volumetric activity. The monitor may also be used for the determination of
the total discharge of radioactive materials in liquid over a given period.
The design and testing of RMS shall be performed in accordance with IEC 60861.
6.6 Tritium off-line monitoring
RMS for continuous radioactive tritium off-line monitoring is used for following purposes:
– to measure the volumetric activity of t
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