IEC 62694:2014

IEC 62694 ®
Edition 1.0 2014-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Radiation protection instrumentation – Backpack-type radiation detector (BRD)
for the detection of illicit trafficking of radioactive material

Instrumentation pour la radioprotection – Détecteur de rayonnement de type
sac-à-dos (BRD) pour la détection du trafic illicite des matières radioactives

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IEC 62694 ®
Edition 1.0 2014-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Radiation protection instrumentation – Backpack-type radiation detector (BRD)

for the detection of illicit trafficking of radioactive material

Instrumentation pour la radioprotection – Détecteur de rayonnement de type

sac-à-dos (BRD) pour la détection du trafic illicite des matières radioactives

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XB
ICS 13.280 ISBN 978-2-8322-1486-2

– 2 – IEC 62694:2014 © IEC 2014
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions, abbreviations, quantities and units . 8
3.1 Terms and definitions . 8
3.2 Abbreviations . 10
3.3 Quantities and units . 11
4 General test procedure . 11
4.1 Nature of test . 11
4.2 Standard test conditions . 11
4.3 Tests performed under standard test conditions . 11
4.4 Test performed with variation of influence quantities . 11
4.5 Statistical fluctuations . 11
4.6 Uncertainties in the measurements . 12
4.7 Background radiation during testing . 12
4.8 BRD set up . 12
4.9 Speed of moving sources and integration time for radionuclide
identification . 13
4.10 Radiation sources . 13
4.11 Functionality tests . 14
5 General requirements . 15
5.1 Mass . 15
5.1.1 Requirements . 15
5.1.2 Method of test. 16
5.2 Design requirements . 16
5.2.1 Requirements . 16
5.2.2 Method of test. 16
5.3 Marking . 16
5.3.1 Requirements . 16
5.3.2 Method of test. 16
5.4 Switches . 16
5.4.1 Requirements . 16
5.4.2 Method of test. 16
5.5 Effective range of measurement – Energy . 17
5.5.1 Requirements . 17
5.5.2 Method of test. 17
5.6 Effective range of measurement – Count rate . 17
5.6.1 Requirements . 17
5.6.2 Method of test. 17
5.7 Operating parameters . 17
5.7.1 Requirements . 17
5.7.2 Method of test. 17
5.8 Explosive atmospheres . 17
5.8.1 Requirements . 17
5.8.2 Method of test. 18
5.9 Diagnostics . 18
5.9.1 Requirements . 18

5.9.2 Method of test. 18
5.10 Power supply . 18
5.10.1 Requirements . 18
5.10.2 Method of test. 18
5.11 Data format . 19
5.11.1 Requirements . 19
5.11.2 Method of test. 20
5.12 Data storage . 21
5.12.1 Requirements . 21
5.12.2 Method of test. 21
5.13 Communication interface. 21
5.13.1 Requirements . 21
5.13.2 Method of test. 21
5.14 User interface . 21
5.14.1 Display . 21
5.14.2 Basic indications . 22
5.14.3 Additional indications . 22
5.14.4 Indications for BRDs with radionuclide identification
capabilities . 23
5.14.5 Indications for BRDs with radionuclide directionality
capabilities . 23
5.14.6 Basic functions and controls . 23
5.14.7 Restricted functions and controls . 24
6 Radiation detection requirements . 24
6.1 False alarm test . 24
6.1.1 Requirements . 24
6.1.2 Method of test. 24
6.2 Alarm response to photon radiation . 25
6.2.1 Requirements . 25
6.2.2 Method of test. 25
6.3 Alarm response to neutron radiation . 26
6.3.1 Requirements . 26
6.3.2 Method of test. 26
6.4 Personal radiation protection alarm and response time . 27
6.4.1 Requirements . 27
6.4.2 Method of test. 27
6.5 Gamma-ray ambient dose equivalent rate indication . 28
6.5.1 Requirements . 28
6.5.2 Method of test. 28
6.6 Angular dependence and verification of directional indication. 28
6.6.1 Requirements . 28
6.6.2 Method of test. 28
6.7 Over range test . 29
6.7.1 Requirements . 29
6.7.2 Method of test. 29
6.8 Neutron indication in the presence of photons . 30
6.8.1 Requirements . 30
6.8.2 Method of test. 30
6.9 Detection of gradually increasing radiation levels . 31

– 4 – IEC 62694:2014 © IEC 2014
6.9.1 Requirements . 31
6.9.2 Method of test. 31
6.10 Networked area monitors . 31
6.10.1 Requirements . 31
6.10.2 Method of test. 32
6.11 Radionuclide identification, when provided . 32
6.11.1 General Requirements . 32
6.11.2 Radionuclide identification library . 33
6.11.3 Single radionuclide identification . 33
6.11.4 Identification of shielded radionuclides . 35
6.11.5 Simultaneous and masked radionuclide identification . 35
6.11.6 Radionuclide not in library . 36
6.11.7 Low-exposure rate identification . 37
6.11.8 Over range characteristics for identification . 37
6.11.9 Rejection of natural background variations . 38
7 Environmental requirements . 39
8 Mechanical requirements . 39
9 Electromagnetic requirements . 40
10 Documentation . 40
10.1 Type test report . 40
10.2 Certificate . 40
10.3 Operation and maintenance manual . 40
Annex A (informative) Statistical considerations . 46
A.1 Poisson distribution . 46
A.2 Confidence intervals for Poisson distribution . 46
A.3 False alarm testing . 46
A.4 Binomial distribution. 48
Annex B (informative) List of expected progeny and expected impurities . 50
Annex C (informative) Summary of fluence rate calculations . 52
Annex D (normative) Calculation ambient dose equivalent rate . 54
Bibliography . 59

Figure 1 – Diagram of testing angles when source passes at an angle of 0° in the
horizontal plane (top view). The displayed source movement represents the test
configuration at an angle of 0°. . 44
Figure 2 – Diagram of the two orthogonal planes (horizontal and vertical planes), the
BRD reference point and testing angles . 45
Figure 3 – BRD setup and testing source positions for network area monitoring . 45

Table 1 – Standard test conditions . 42
Table 2 – Occurrence of functionality tests for environmental testing . 42
Table 3 – Occurrence of functionality tests for mechanical testing . 43
Table 4 – Emission frequency range . 43
Table 5 – Occurrence of functionality tests for electromagnetic testing . 44
Table A.1 – One-sided 95 % upper confidence bounds for the false alarm rate for a
given number of false alarms observed over a given time period . 47

Table A.2 – Necessary sample sizes (n) for different levels (p ) and number of failures
o
(k) . 49
Table B.1 – List of expected progeny and expected impurities . 51
Table C.1 – Examples of fluence rate calculations . 53
*
Table D.1 – Conversion coefficient h (10) from air kerma, K, to ambient dose
K
equivalent, H*(10), for mono-energetic and parallel photon beams . 55
232 226
Table D.2 – Probabilities per disintegration for Th and Ra (in equilibrium) as a
function of photon energy . 56
Table D.3 – Values of the mass energy-transfer, mass energy-absorption, and mass
attenuation coefficients for air . 58

– 6 – IEC 62694:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RADIATION PROTECTION INSTRUMENTATION – BACKPACK-TYPE
RADIATION DETECTOR (BRD) FOR THE DETECTION OF ILLICIT
TRAFFICKING OF RADIOACTIVE MATERIAL

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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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 62694 has been prepared by subcommittee 45B: Radiation protection
instrumentation, of IEC technical committee 45: Nuclear instrumentation.
The text of this standard is based on the following documents:
FDIS Report on voting
45B/781/FDIS 45B/790/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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 8 – IEC 62694:2014 © IEC 2014
RADIATION PROTECTION INSTRUMENTATION – BACKPACK-TYPE
RADIATION DETECTOR (BRD) FOR THE DETECTION OF ILLICIT
TRAFFICKING OF RADIOACTIVE MATERIAL

1 Scope
This International Standard applies to backpack-type radiation detectors (BRDs) that are used
for the detection of illicit trafficking of radioactive material. This standard establishes the
operational and performance requirements for BRDs. BRDs are portable instruments
designed to be worn during use. They may also be used as temporary area monitors in a
stand-alone mode.
BRDs detect gamma radiation and may include neutron detection and/or the identification of
gamma-ray emitting radionuclides. This standard establishes performance and testing
requirements associated with radiation measurements and the expected electrical,
mechanical, and environmental conditions while in use.
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 60050 (all parts): International Electrotechnical Vocabulary (available at
http://www.electropedia.org)
IEC 60050-393:2003, International Electrotechnical Vocabulary – Part 393: Nuclear
instrumentation – Physical phenomena and basic concepts
IEC 60050-394:2007, International Electrotechnical Vocabulary – Part 394: Nuclear
instrumentation – Instruments, systems, equipment and detectors
IEC 62706, Radiation protection instrumentation – Environmental, electromagnetic and
mechanical performance requirements
IEC 62755, Radiation protection instrumentation – Data format for radiation instruments used
in the detection of illicit trafficking of radioactive materials
3 Terms and definitions, abbreviations, quantities and units
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-393 and
IEC 60050-394 apply, as well as the following.
3.1.1
accuracy
closeness of the agreement between the result of a measurement and the conventionally true
value of the measurand
3.1.2
alarm
audible, visual, or other signal activated when the instrument reading exceeds a preset value,
falls outside of a preset range, or when the instrument detects the presence of the source of
radiation according to a preset condition
[SOURCE: IEC 60050-393:2003, 393-18-03, modified]
3.1.3
background level
radiation field in which there are no external sources present other than those in the natural
background at the location of the measurements
3.1.4
backpack-type radiation detector
instrument composed of several radiation detection components that are placed inside a
backpack or other similar enclosure with an external user interface or control device
3.1.5
centre line
horizontal or vertical line that describes the geometrical centre of an object
3.1.6
coefficient of variation
V
ratio of the standard deviation s to the arithmetic mean 𝑥̅ of a set of n measurements x given
i
by the following formula:
𝑛
𝑠 1 1
𝑉 = = � �(𝑥 −𝑥̅)
𝑖
𝑥̅𝑥̅𝑛− 1
[SOURCE: IEC 60050-394:2007, 394-40-14]
3.1.7
energy window
part of the energy spectrum within an upper and lower energy limit
[SOURCE: IEC 60050-394:2007, 394-38-70]
3.1.8
keyhole markup language
KML
is a file format used to display geographic data
Note 1 to entry: For example, see http://www.opengeospatial.org/standards/kml/.
3.1.9
fluence
Φ
the quotient of dN by da, where dN is the number of particles incident on a sphere of cross-
sectional area da: Φ = dN/da
[SOURCE: IEC 60050-881:1983, 881-04-18]

– 10 – IEC 62694:2014 © IEC 2014
3.1.10
fluence rate
the fluence rate, 𝜙̇, is the quotient of dΦ by dt, where dΦ is the increment of the fluence in the
𝑑𝜙
−2 −1
time interval dt, thus 𝜙̇= . The unit of fluence rate is m s
𝑑𝑡
[SOURCE: ICRU Report 60:1998]
3.1.11
type test
conformity test made on one or more items representative of the production
[SOURCE: IEC 60050-394:2007, 394-40-02]
3.1.12
user interface
software and/or hardware that manages interactions between a user and equipment
3.1.13
variance
σ
measure of dispersion, which is the sum of the squared deviation of observations from their
mean divided by one less than the number of observations
n
2 2
σ = (x x)
∑
i
n −1
i =1
3.2 Abbreviations
AC alternating current
BRD backpack-type radiation detector
cps counts per second
DC direct current
DU depleted uranium
ESD electrostatic discharge
FIFO first in first out
GPS global positioning system
HDPE high density polyethylene
HEU highly enriched uranium
HPGe high purity germanium
KML keyhole markup language
NORM naturally occurring radioactive material
PMMA polymethyl methacrylate
RGPu reactor grade plutonium
WGPu weapons grade plutonium
XML eXtensible Markup Language

3.3 Quantities and units
In the present standard, units of the International System (SI) are used . The definitions of
radiation quantities are given in IEC 60050-393 and IEC 60050-394.
Nevertheless, the following units may also be used:
–19
– for energy: electron-volt (symbol: eV), 1 eV = 1,602 × 10 J;
– for time: years (symbol: y), days (symbol: d), hours (symbol: h), minutes (symbol: min);
– for distance: centimetre (symbol: cm), millimetre (symbol: mm), kilometre (symbol: km);
Multiples and submultiples of SI units will be used, when practicable, according to the SI
system.
4 General test procedure
4.1 Nature of test
The tests in this standard are to be considered type tests, unless otherwise stated.
4.2 Standard test conditions
Except where otherwise specified, the tests in this standard shall be performed under the
standard test conditions given in Table 1.
4.3 Tests performed under standard test conditions
For these tests, the value of temperature, pressure, relative humidity and gamma and neutron
background at the time of the test shall be recorded. Values should be within the standard
test conditions given in Table 1.
4.4 Test performed with variation of influence quantities
For those tests intended to determine the effects of variations in an influence quantity (e.g.,
temperature, humidity), all other influence quantities should be maintained at the standard
test conditions given in Table 1 unless otherwise specified in the applicable test method.
4.5 Statistical fluctuations
For tests involving the use of radioactive sources to verify susceptibility to an environmental,
electromagnetic, or mechanical condition the ambient dose equivalent rate produced by the
sources to verify the BRD response shall be adjusted to reduce the magnitude of the
statistical fluctuations.
If the magnitude of the statistical fluctuations of the BRD indication arising from the random
nature of radiation alone is a significant fraction of the variation of the indication permitted in
the test, then the ambient dose equivalent rate should be increased to ensure that the mean
value of such readings may be estimated with sufficient accuracy to demonstrate compliance
with the test in question.
It is recommended that the coefficient of variation (V, expressed in percentage) for each
nominal mean reading be less than or equal to 12 %. For neutron or photon background
measurements, attaining a coefficient of variation to meet this requirement may not be
possible. Therefore, testing with neutrons or photons at background levels (i.e., testing
___________
th
International Bureau of Weights and Measures: The International System of Units, 8 edition, 2006.

– 12 – IEC 62694:2014 © IEC 2014
without radioactive source present) can be performed even when the coefficient of variation is
larger than 12 %.
12 % is from statistical analysis techniques for dosimeter testing and has proven to be a
simple way of determining when a group of readings are acceptable for compliance testing.
The time interval between readings needs be sufficiently long (i.e., larger than the integration
time of the instrument) to ensure that the readings are statistically independent.
4.6 Uncertainties in the measurements
Unless otherwise stated for a specific quantity, the uncertainties for any measurable quantity
(e.g., radiation field) should not exceed 15 % with a coverage factor of k = 1.
4.7 Background radiation during testing
Testing shall be performed in an area with a nominal natural radiation background that has
only natural variation as defined in Table 1.
The gamma-ray background intensity shall be measured using a pressurized ion chamber or
similar environmental radiation measurement device that is calibrated to provide the gamma-
∗
ray ambient dose equivalent rate, 𝐻̇(10). When testing spectrometric BRDs the gamma-ray
background shall be characterized using a high resolution gamma-ray spectrometer (e.g.,
high purity germanium (HPGe) detector). The measured spectra shall be recorded. If the BRD
is equipped with neutron detectors, the neutron background should be the natural background
and should not be artificially modified during testing. The neutron background at the test
location shall be measured and recorded.
The evaluation of the BRD shall be performed without the benefit of any radiation shielding
against the natural background, except for that shielding that is part of the instrument.
4.8 BRD set up
The BRD shall be set up based on the manufacturer’s specifications including background
update mode, if applicable. Once set up for testing, no changes shall be made that could
affect the overall response of the BRD. If more than one background update mode is
available, testing should be performed in all modes when indicated in the specific clauses
under the radiological tests.
When performing the radiological tests in Clause 6, the BRD shall be configured and oriented
as it would be used. This may be achieved by using a phantom that would represent the
human upper torso. The phantom shall be made of polymethyl methacrylate (PMMA).The
phantom dimensions shall be 40 cm wide, 60 cm high and 15 cm thick.
The BRD shall be mounted on a stand or fixture made out of a material that does not have a
large hydrogen content (e.g., foam, plastic). It is recommended to use materials such as
aluminium for mounting the BRD to prevent possible additional moderation of the neutron
source.
The reference point of the BRD should be marked by the manufacturer. If marking is not
provided by the manufacturer, the reference point is defined as the imaginary point where the
three mutually orthogonal lines that go through the center of the length, width and thickness
of the BRD intersect (see Figure 2).
For static and dynamic tests described in Clause 6, the reference point of the BRD shall be
positioned 1,5 m from the floor or ground surface. The centreline of the source shall be at the
same height as the reference point of the BRD, 1,5 m from the floor or ground surface.
For static tests, the distance between the source and the centreline of the BRD shall be
between 1 m and 3 m unless otherwise stated.

For dynamic tests, the line of source movement and detector centreline shall be kept parallel,
the distance of closest approach between the source and the reference point of the BRD shall
be between 1 m and 3 m unless otherwise stated, see Figure 1.
The phantom is not used when the BRD is evaluated for use as a stand-alone area radiation
monitor. Testing as an area radiation monitor is performed if such claim is made by the
manufacturer.
When performing the tests in Clauses 7, 8, and 9, the BRD shall not be mounted on a
phantom. The BRD-to-source distance and the relative orientation and position between the
BRD and the radiation source shall be adjusted to reduce the statistical fluctuations as
discussed in 4.5. The testing distance, orientation and position of the BRD with respect to
source shall be recorded for these tests. Due to the nature of the tests, there is no need for
this standard to specify the BRD-to-source distance, and relative orientation and position
between the BRD and the source.
4.9 Speed of moving sources and integration time for radionuclide identification
For static tests, the integration time required to perform a radionuclide identification shall be
as specified by the manufacturer or a maximum of 1 min (whichever is the shortest).
During the static tests, the source shall be removed and placed back in the same location
between trials. There shall be a 10 s minimum delay between each trial with the source either
positioned at a distance where it does not affect the background surrounding the BRD or
shielded during the delay.
For dynamic tests, the source or BRD shall be moved in a configuration that provides no
shielding around the source other than that required for the specific test. The source speed
–1
shall be 1,2 m·s (average walking speed) when tested at a distance of closest approach of
1,5 m, unless otherwise required in a test. If the distance of closest approach, d (expressed in
–1
m), is adjusted within 1 m and 3 m then the passage speed, v (expressed in m·s ), shall be
adjusted to 𝑣 =𝑣 ×𝑑/𝑑 ,
0 0
–1
where v = 1,2 m·s and d = 1,5 m.
0 0
During the dynamic tests, there shall be a 10 s minimum delay between each trial with the
source either positioned at a distance where it does not affect the background surrounding the
BRD or shielded during the delay.
NOTE For all dynamic tests, the source or the BRD can be moved relative to each other.
4.10 Radiation sources
Unless otherwise stated, tests involving the use of gamma radiation shall be carried out using
137 241 60
Cs for gross count measurements and Am together with Co for radionuclide
identification (see Table 1).
252 252
The reference source for neutron radiation is Cf. The neutron emission rate of the Cf
–1
source shall be 20 000 s (± 20 %) (see Table 1). The unmoderated reference neutron
source shall be encapsulated in 1 cm of steel and shielded with 0,5 cm-thick lead in order to
Cf source. The lead shall be placed
attenuate the possible gamma-ray emission from the
outside the steel encapsulation. The moderation of the Cf is achieved by surrounding the
source in the presence of the 1 cm of steel encapsulation and 0,5 cm-thick lead shielding with
4 cm-thick high density polyethylene (HDPE) container (e.g., sphere, cylinder, box).
The sources shall be mounted on a stand or fixture made out of a material that does not have
a large hydrogen content (e.g., foam, plastic). It is recommended to use materials such as
aluminium for mounting the sources to prevent possible additional scattering and moderation
of the neutron source.
– 14 – IEC 62694:2014 © IEC 2014
The isotopic composition and activity of different naturally occurring radioactive materials
(NORM), such as zircon, monazite and allanite, vary widely from sample to sample.
Therefore, point sources are used to ensure greater consistency and traceability in performing
measurements at different locations and at different times. The approximation of bulk NORM
226 232
sources is done by surrounding Ra and Th sources (in equilibrium with their progeny)
with 9 cm of polymethyl methacrylate (PMMA) each producing the same ambient dose
equivalent rate, see Annex D.
As the Am content in plutonium sources varies widely, when testing with WGPu the
emission rate of the 60 keV line from Am shall be no more than 10 times the emission rate
239 239 –1
of the 414 keV line for Pu (e.g., if the emission rate for Pu is 100 s then the emission
241 –1
rate for Am shall not exceed 1 000 s ), see Annex C. When needed, copper or cadmium
should be used to reduce the contribution from Am. The copper or cadmium shielded
WGPu source shall be considered the bare
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