SIST EN ISO 11665-7:2015

SLOVENSKI STANDARD
SIST EN ISO 11665-7:2015
01-november-2015
Merjenje radioaktivnosti v okolju - Zrak: radon-222 - 7. del: Akumulacijska metoda
za ocenjevanje hitrosti površinskega izhajanja (ISO 11665-7:2012)
Measurement of radioactivity in the environment - Air: radon-222 - Part 7: Accumulation
method for estimating surface exhalation rate (ISO 11665-7:2012)
Ermittlung der Radioaktivität in der Umwelt - Luft: Radon-222 - Teil 7:
Anreicherungsverfahren zur Abschätzung der Oberflächenexhalationsrate (ISO 11665-
7:2012)
Mesurage de la radioactivité dans l'environnement - Air: radon 222 - Partie 7: Méthode
d'estimation du flux surfacique d'exhalation par la méthode d'accumulation (ISO 11665-
7:2012)
Ta slovenski standard je istoveten z: EN ISO 11665-7:2015
ICS:
13.040.99 Drugi standardi v zvezi s Other standards related to air
kakovostjo zraka quality
17.240 Merjenje sevanja Radiation measurements
SIST EN ISO 11665-7:2015 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 11665-7:2015

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SIST EN ISO 11665-7:2015


EN ISO 11665-7
EUROPEAN STANDARD

NORME EUROPÉENNE

September 2015
EUROPÄISCHE NORM
ICS 17.240
English Version

Measurement of radioactivity in the environment - Air:
radon-222 - Part 7: Accumulation method for estimating
surface exhalation rate (ISO 11665-7:2012)
Mesurage de la radioactivité dans l'environnement - Ermittlung der Radioaktivität in der Umwelt - Luft:
Air: radon 222 - Partie 7: Méthode d'estimation du flux Radon-222 - Teil 7: Anreicherungsverfahren zur
surfacique d'exhalation par la méthode d'accumulation Abschätzung der Oberflächenexhalationsrate (ISO
(ISO 11665-7:2012) 11665-7:2012)
This European Standard was approved by CEN on 12 June 2015.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11665-7:2015 E
worldwide for CEN national Members.

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SIST EN ISO 11665-7:2015
EN ISO 11665-7:2015 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 11665-7:2015
EN ISO 11665-7:2015 (E)
European foreword
The text of ISO 11665-7:2012 has been prepared by Technical Committee ISO/TC 85 “Nuclear energy,
nuclear technologies, and radiological protection” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 11665-7:2015 by Technical Committee CEN/TC 430 “Nuclear
energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2016, and conflicting national standards shall
be withdrawn at the latest by March 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 11665-7:2012 has been approved by CEN as EN ISO 11665-7:2015 without any
modification.
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SIST EN ISO 11665-7:2015

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SIST EN ISO 11665-7:2015
INTERNATIONAL ISO
STANDARD 11665-7
First edition
2012-07-15
Measurement of radioactivity in the
environment — Air: radon-222 —
Part 7:
Accumulation method for estimating
surface exhalation rate
Mesurage de la radioactivité dans l’environnement — Air: radon 222 —
Partie 7:
Méthode d’estimation du flux surfacique d’exhalation par la méthode
d’accumulation
Reference number
ISO 11665-7:2012(E)
©
ISO 2012

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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved

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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms and definitions . 1
3.2 Symbols . 2
4 Principle of the measurement method for estimating surface exhalation rate . 2
5 Equipment . 4
6 Accumulation of radon in a container . 5
6.1 Accumulation characteristics . 5
6.2 Accumulation duration . 5
7 Sampling . 5
7.1 Sampling objective . 5
7.2 Sampling characteristics . 5
7.3 Sampling duration . 6
7.4 Volume of air sampled . 6
8 Detection method . 6
9 Measurement . 6
9.1 Procedure . 6
9.2 Influence quantities . 7
10 Expression of results . 7
10.1 Radon surface exhalation rate . 7
10.2 Standard uncertainty . 7
10.3 Decision threshold and detection limit . 7
10.4 Limits of the confidence interval . 8
11 Test report . 8
Annex A (informative) Example of a sample results sheet .10
Annex B (informative) Estimation of radon surface exhalation rate using a continuous
measurement method .12
Annex C (informative) Estimation of radon surface exhalation rate using a spot measurement method 18
Bibliography .23
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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 11665-7 was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies, and
radiological protection, Subcommittee SC 2, Radiological protection.
ISO 11665 consists of the following parts, under the general title Measurement of radioactivity in the
environment — Air: radon-222:
— Part 1: Origins of radon and its short-lived decay products and associated measurement methods
— Part 2: Integrated measurement method for determining average potential alpha energy concentration of
its short-lived decay products
— Part 3: Spot measurement method of the potential alpha energy concentration of its short-lived decay products
— Part 4: Integrated measurement method for determining average activity concentration using passive
sampling and delayed analysis
— Part 5: Continuous measurement method of the activity concentration
— Part 6: Spot measurement method of the activity concentration
— Part 7: Accumulation method for estimating surface exhalation rate
— Part 8: Methodologies for initial and additional investigations in buildings
The following parts are under preparation:
— Part 9: Method for determining exhalation rate of dense building materials
— Part 10: Determination of diffusion coefficient in waterproof materials using activity concentration measurement
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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
Introduction
Radon isotopes 222, 220 and 219 are radioactive gases produced by the disintegration of radium isotopes 226,
224 and 223, which are decay products of uranium-238, thorium-232 and uranium-235 respectively, and are
all found in the earth’s crust. Solid elements, also radioactive, followed by stable lead are produced by radon
[1]
disintegration .
Radon is today considered to be the main source of human exposure to natural radiation. The UNSCEAR (2006)
[2]
report suggests that, at the worldwide level, radon accounts for around 52 % of global average exposure to
natural radiation. The radiological impact of isotope 222 (48 %) is far more significant than isotope 220 (4 %),
while isotope 219 is considered negligible. For this reason, references to radon in this part of ISO 11665 refer
only to radon-222.
The radon-222 half-life (3,8 days) is long enough for it to migrate from the rock producing it, through the soil,
[3]
to the air . The radon atoms in the soil are produced by the disintegration of the radium-226 contained in the
mineral grains in the medium. Some of these atoms reach the interstitial spaces between the grains: this is the
phenomenon of emanation. Some of the atoms produced by emanation reach the soil’s surface by diffusion
[3][4][5]
and convection: this is the phenomenon of exhalation . These mechanisms are also brought into play in
materials (building materials, walls, etc.).
The quantity of radon-222 reaching the open air per unit of time and per unit of surface is called the radon-222
surface exhalation rate and depends on the physical characteristics of the soil and weather conditions. When the
ground is covered in snow or a layer of water, or is frozen, this surface exhalation rate can become very weak.
2
Values of the radon-222 surface exhalation rate observed in France, for example, vary between 1 mBq/m /s
2 [6][7]
and about 100 mBq/m /s . In uranium-bearing ground, radon-222 surface exhalation rates in the order of
2
50 000 mBq/m /s can be observed. By way of comparison, the United Nations Scientific Committee estimates
2 [8]
the average surface exhalation rate on the surface of the globe at 20 mBq/m /s .
NOTE The origin of radon-222 and its short-lived decay products in the atmospheric environment and other
measurement methods are described generally in ISO 11665-1.
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SIST EN ISO 11665-7:2015

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SIST EN ISO 11665-7:2015
INTERNATIONAL STANDARD ISO 11665-7:2012(E)
Measurement of radioactivity in the environment — Air:
radon-222 —
Part 7:
Accumulation method for estimating surface exhalation rate
1 Scope
This part of ISO 11665 gives guidelines for estimating the radon-222 surface exhalation rate over a short period
(a few hours), at a given place, at the interface of the medium (soil, rock, laid building material, walls, etc.) and
the atmosphere. This estimation is based on measuring the radon activity concentration emanating from the
surface under investigation and accumulated in a container of a known volume for a known duration.
This method is estimative only, as it is difficult to quantify the influence of many parameters in environmental
conditions. This part of ISO 11665 is particularly applicable, however, in case of an investigation, a search for
sources or a comparative study of exhalation rates at the same site. This part of ISO 11665 does not cover
calibration conditions for the rate estimation devices.
2
The measurement method described is applicable for radon exhalation rates greater than 5 mBq/m /s.
NOTE The uncertainty relating to the estimation of the result obtained by applying this part of ISO 11665 cannot
guarantee that the true flux value is included in the uncertainty domain.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 11665-1, Measurement of radioactivity in the environment — Air: radon-222 — Part 1: Origins of radon and
its short-lived decay products and associated measurement methods
ISO 11665-5, Measurement of radioactivity in the environment — Air: radon-222 — Part 5: Continuous
measurement method of the activity concentration
ISO 11665-6, Measurement of radioactivity in the environment — Air: radon-222 — Part 6: Spot measurement
method of the activity concentration
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
IEC 61577-1, Radiation protection instrumentation — Radon and radon decay product measuring instruments —
Part 1: General principles
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11665-1 and the following apply.
3.1.1
accumulation container
recipient with known geometric characteristics used to accumulate the radon, with one open face in contact
with the surface under investigation
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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
3.1.2
accumulation duration
time elapsed between installation of the container after air tightness is achieved and the end of sampling
3.1.3
back diffusion
mechanism responsible for the transport of radon from the accumulation container atmosphere into the material
under investigation
3.1.4
effective surface
internal surface of the open face of the container that is in contact with the surface under investigation
3.1.5
effective volume
available internal volume for radon accumulation after the container is installed
3.2 Symbols
For the purposes of this document, the symbols given in ISO 11665-1 and the following apply.
C
activity concentration in the accumulation container at time t, in becquerels per cubic metre
S
effective surface, in square metres
t
elapsed time since the start of the accumulation process, in seconds
U
expanded uncertainty calculated by Uk=⋅u with k = 2
()
u()
standard uncertainty associated with the measurement result
u
()
relative standard uncertainty
rel
V effective volume, in cubic metres
λ time constant of back diffusion, per second
B
λ decay constant of the nuclide i, per second
i
λ time constant of leakage, per second
V
φ surface exhalation rate, in becquerels per square metre per second
∗
φ
decision threshold of the surface exhalation rate, in becquerels per square metre per second
#
φ
detection limit of the surface exhalation rate, in becquerels per square metre per second

lower limit of the confidence interval of the surface exhalation rate, in becquerels per square metre
φ
per second

upper limit of the confidence interval of the surface exhalation rate, in becquerels per square metre
φ
per second
4 Principle of the measurement method for estimating surface exhalation rate
The measurement method for estimating the radon surface exhalation rate is based on the following elements:
a) accumulating radon in a radon-free accumulation container applied to the surface under investigation for
a known duration;
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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
b) sampling a volume of air representative of the air contained in the accumulation container;
c) measuring the radon activity concentration in this air sample;
d) calculating the surface exhalation rate.
An estimate of the surface exhalation rate is calculated from the following elements:
— the variation in the radon activity concentration inside the accumulation container between two given moments;
— the effective surface of the accumulation container in contact with the surface under investigation;
— the effective volume of the accumulation container.
The radon activity concentration in the accumulation container increases over time depending on the surface-
related exhalation rate, the volume of the accumulation container and influencing factors such as inadequate
air tightness (leakage) and back diffusion.
The increase of radon activity concentration can be fitted with an exponential function:
φ ⋅S
−λt
Ct = ⋅−1e (1)
()
()
V ⋅λ
where
λλ=+λλ+ (2)
Rn222 BV
Since the background radon activity concentration in the container is close to zero at the beginning of the
[9][10]
accumulation process, the initial slope of the curve is independent of back diffusion . Assuming that radon
loss by leakage is negligible, the accumulation phase can be approximated by a linear increase of radon
activity concentration in the accumulation container (see the example in Figure 1) as described by Formula (3):
φ ⋅S
Ct = ⋅t (3)
()
V
Figure 1 — Example of changes in radon activity concentration in the accumulation container
For outdoor measurements, the analysis of the measurement results can require detailed knowledge of climatic
conditions. For example, the radon surface exhalation rate measurements carried out during snow or rain are
only representative of these weather conditions.
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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
For soil investigations, the surface area, topography, geology, pedology, vegetation, etc. all need to be taken
into account. The humidity content of the ground at the time of sampling may be determined (see ISO 11465).
Several measurement methods meet the requirements of this part of ISO 11665. They can be distinguished by
the way the air is sampled from the accumulation container.
5 Equipment
The apparatus shall include the following components.
a) An accumulation container with known geometric characteristics (see Figure 2): The accumulation
container characteristics shall be chosen so that any irregularities of the surface under investigation do
not introduce an uncertainty of more than 10 % into the effective volume of the accumulation container.
The effective surface of the accumulation container shall be selected to ensure that measurements are
the most representative possible of the surface under investigation (i.e. the effective surface shall be
appropriate for the surface area under investigation). The effective volume of the accumulation container
shall be at least 10 times greater than the volume of air sampled from the accumulation container by the
radon measuring device. The material used in the accumulation container shall not allow the radon to be
diffused towards the outside of the container during the accumulation period. Neither the accumulation
container material nor colour shall encourage a rise in temperature in the effective volume in the event of
exposure to sunlight. The accumulation container shall have one or two orifices with a closing system for
sampling purposes. When the accumulation container is placed on the material under investigation these
orifices shall be open to prevent overpressure in the container.
b) A homogenization system in the accumulation container: Depending on its dimensions, the container may
have a system to homogenize the entire volume of the container.
c) An air sampling device.
d) A measuring device adapted to the physical quantity to be measured.
The necessary equipment for specific measurement methods is specified in Annexes B and C.
Key
1 measuring device
2 accumulation container
3 effective volume
4 contact surface
5 effective surface
Figure 2 — Example set-up of apparatus
A single model of accumulation container shall be used when investigating a site in order to find the zones with
the highest exhalation rates.
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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
6 Accumulation of radon in a container
6.1 Accumulation characteristics
The open face of the accumulation container shall be positioned on the surface of the material under
investigation (soil, rock, building material, etc.). The accumulation container geometry shall suit the surface
under investigation. The contact surface shall be arranged so as to ensure uniform contact between the base
of the accumulation container and the surface under investigation (weeds, pebbles, roots removed) (see
Figure 2). Any alteration to the surface under investigation shall be recorded on the results sheet (see Annex A).
Whenever possible, the surface under investigation shall be chosen so that its irregularities do not introduce an
uncertainty of more than 10 % into the effective volume of the accumulation container.
After installing and before making the accumulation container air tight on the surface under investigation, the
container shall be purged with radon-free air to ensure that the radon activity concentration is close to zero at
the beginning of the accumulation process.
6.2 Accumulation duration
The experimental results show that accumulation takes between 1 h and 3 h depending on the volume of the
accumulation container.
7 Sampling
7.1 Sampling objective
The sampling objective is to place an air sample representative of the air contained in the accumulation
container in contact with the detector of the radon measuring device.
7.2 Sampling characteristics
7.2.1 General
Sampling may be either active via pumping or passive via natural diffusion. It shall not disturb the
accumulation phenomenon.
Sampling characteristics depend on the measuring device used (see ISO 11665-5, ISO 11665-6 and
Annexes B and C).
7.2.2 Grab sampling
When grab sampling is used, the sampling shall be carried out at the beginning and before the end of the
accumulation phase. Sampling shall be carried out as specified in ISO 11665-6.
7.2.3 Continuous sampling
Continuous sampling may be
a) active, whereby the pump integrated in the radon activity concentration measuring device provides
continuous air circulation between the measuring device and the accumulation container, or
b) passive by diffusion.
Sampling shall be carried out as specified in ISO 11665-5.
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SIST EN ISO 11665-7:2015
ISO 11665-7:2012(E)
7.3 Sampling duration
The sampling duration depends on the measuring method used (see ISO 11665-5, ISO 11665-6 and
Annexes B and C).
7.4 Volume of air sampled
The volume of air sampled depends on the measuring method used (see ISO 11665-5, ISO 11665-6 and
Annexes B and C). It shall be determined accurately. To avoid alteration of the exhalation process in the case
of grab sampling, the total volume of sampled air shall not exceed 10 % of the effective volume of the container.
8 Detection method
Various detection methods may be used to measure the radon activity concentration of the sampled air from
the accumulation container.
For grab sampling, detection methods shall be in accordance with ISO 11665-6.
For continuous sampling, detection methods shall be in accordance with ISO 11665-5.
9 Measurement
9.1 Procedure
Measurement shall be carried out as follows.
a) Select and locate the measuring place.
b) Record the location of the measuring place.
c) Prepare the surface under investigation b
...