ISO/DIS 11665-10.2

Measurement of radioactivity in the environment -- Air: radon-222

Mesurage de la radioactivité dans l'environnement -- Air: radon 222

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD ISO/DIS 11665-10
ISO/TC 85/SC 2 Secretariat: AFNOR
Voting begins on Voting terminates on
2013-03-28 2013-06-28

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION

Measurement of radioactivity in the environment —
Air: radon-222 —
Part 10:
Determination of diffusion coefficient in waterproof materials
using activity concentration measurement
Mesurage de la radioactivité dans l'environnement — Air: radon 222 —

Partie 10: Détermination du coefficient de diffusion du radon des matériaux imperméables par mesurage de

l'activité volumique du radon
ICS 13.040.01; 17.240

To expedite distribution, this document is circulated as received from the committee

secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at

publication stage.

Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du

secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au

Secrétariat central de l'ISO au stade de publication.

THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE

REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.

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INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO

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RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH

THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION.
© International Organization for Standardization, 2013
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ISO/DIS 11665-10
COPYRIGHT PROTECTED DOCUMENT
© ISO 20##

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any

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ISO/DIS 11665-10
Contents Page

Foreword ............................................................................................................................................................. v

1 Scope ...................................................................................................................................................... 1

2 Normative references ............................................................................................................................ 1

3 Terms, definitions and symbols .......................................................................................................... 1

3.1 Terms and definitions ........................................................................................................................... 1

3.2 Symbols .................................................................................................................................................. 3

4 Principle of the test method ................................................................................................................. 4

5 Measuring system ................................................................................................................................. 5

5.1 Components of the measuring system ............................................................................................... 5

5.2 Configuration of the measuring system ............................................................................................. 5

6 Test methods ......................................................................................................................................... 7

6.1 General information .............................................................................................................................. 7

6.2 Method A – determining the radon diffusion coefficient during the phase of non-

stationary radon diffusion .................................................................................................................... 8

6.3 Method B – determining the radon diffusion coefficient during the phase of stationary

radon diffusion ...................................................................................................................................... 8

6.4 Method C – determining the radon diffusion coefficient during the phase of stationary

radon diffusion established during ventilation of the receiver container ....................................... 9

7 General application procedures .......................................................................................................... 9

7.1 Preparation of samples ......................................................................................................................... 9

7.2 Fixing the samples in the measuring device .................................................................................... 10

7.3 Test of air-tightness, assessment of the air exchange rate of the receiver container ................. 10

7.4 Determining the radon diffusion coefficient according to method A ............................................ 10

7.5 Determining the radon diffusion coefficient according to method B ............................................ 11

7.6 Determining the radon diffusion coefficient according to method C ............................................ 12

7.7 General requirements for performing the measurements .............................................................. 12

8 Influence quantities ............................................................................................................................. 14

9 Expression of results and standard uncertainty assessment ........................................................ 15

10 Quality management and calibration of the test device .................................................................. 15

11 Test report ............................................................................................................................................ 15

Annex A (informative) Determining the radon diffusion coefficient during the phase of stationary

radon diffusion according to method C ............................................................................................ 17

A.1 Scope .................................................................................................................................................... 17

A.2 Normative references .......................................................................................................................... 17

A.3 Terms and definitions ......................................................................................................................... 17

A.4 Equipment ............................................................................................................................................ 18

A.5 Measurement procedure ..................................................................................................................... 18

A.6 Expression of results .......................................................................................................................... 19

A.6.1 Radon concentration measurement using scintillation cells ......................................................... 19

A.6.2 Radon diffusion coefficient ................................................................................................................ 19

A.6.3 Standard uncertainty of radon concentration measurement .......................................................... 20

A.7 Example: Determination of the radon diffusion coefficient of the HDPE membrane with

the thickness 0,47 mm ........................................................................................................................ 20

Annex B (informative) Determining the radon diffusion coefficient during the phase of non-

stationary radon diffusion .................................................................................................................. 23

B.1 Scope .................................................................................................................................................... 23

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ISO/DIS 11665-10

B.2 Normative references ..........................................................................................................................23

B.3 Terms and definitions .........................................................................................................................23

B.4 Equipment ............................................................................................................................................24

B.5 Measurement procedure .....................................................................................................................25

B.6 Expression of results ..........................................................................................................................26

B.6.1 Radon concentration measurement using the current ionisation chamber .................................26

B.6.2 Radon diffusion coefficient determination using FEM ....................................................................26

B.6.3 Standard uncertainty ...........................................................................................................................29

B.7 Example: Determination of the radon diffusion coefficient of the HDPE membrane (of

different composition than assumed in the example A.7) with the thickness 1,63 mm ...............29

Bibliography ......................................................................................................................................................32

iv © ISO 2012 – All rights reserved
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ISO/DIS 11665-10
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.

ISO 11665-10 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: Origin 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
⎯ Part 9:Method for determining exhalation rate of dense building materials

⎯ Part 10: Determination of the diffusion coefficient in waterproof materials using activity concentration

measurement
⎯ Part 11: Method for soil gas
© ISO 2012 – All rights reserved v
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DRAFT INTERNATIONAL STANDARD ISO/DIS 11665-10
Measurement of radioactivity in the environment — Air: radon
222 — Part 10: Determination of the diffusion coefficient in
waterproof materials using activity concentration measurement
1 Scope

This standard specifies assumptions and boundary conditions that shall be met by methods intended for

determining the radon diffusion coefficient in waterproofing materials such as bitumen or polymeric

membranes, coatings or paints.

This standard is not applicable for porous materials, where radon diffusion depends on porosity and moisture

content.
2 Normative references

Les documents ci-après, dans leur intégralité ou non, sont des références normatives indispensables à

l’application du présent document. Pour les références datées, seule l'édition citée s'applique. Pour les

références non datées, la dernière édition du document de référence s'applique (y compris les éventuels

amendements).
ISO 921, Nuclear energy — Vocabulary
ISO 80000-10, Quantities and units – Part 10: Atomic and nuclear physics

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

measuring 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 11929, Determination of the characteristic limits (decision threshold, detection limit and limits of the

confidence interval) for measurements of ionizing radiation — Fundamentals and applications

ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in

measurement (GUM:1995)
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, ISO 921 and ISO 80000-

10 and the following apply.
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ISO/DIS 11665-10
3.1.1
diffusion length l
distance crossed by an atom due to diffusion forces before decaying

Note1 to entry Diffusion length, l, is expressed by the relationship given in Formula (1)

1/2
l = (D/λ) (1)
where
D is the diffusion coefficient, in square metres per second;
λ is the decay constant per second.
3.1.2
diffusive radon exhalation rate E

value of the activity concentration of radon atoms that leave a material per unit time

Note 1 to entry For the purpose of this standard only the diffusion transport through the sample is taken into account.

The diffusive radon exhalation rate is given by Formula (2) (Fick's law)
E = −D (2)
where
D is the diffusion coefficient, in square metres per second;
C is the activity concentration of 222Rn, in becquerels per cubic metre;
x is the distance in matter.
3.1.3
non-stationary radon diffusion

time dependent radon diffusion through the sample when the radon concentration within the sample is

changing (in dependence on time, distance from the surface exposed to radon and the radon concentration in

the source container) and the radon exhalation rate from the sample into the receiver container is also

changing; this occurs during the time when radon concentration in the source container is not steady and in

the time interval that immediately follows the moment when the steady concentration in the source container is

established; one-dimensional non-stationary radon diffusion is described by the partial differential equation:

∂ C ∂C
D ⋅ − λ ⋅ C =
(3)
where
D is the diffusion coefficient, in square metres per second;
C is the activity concentration of 222Rn, in becquerels per cubic metre;
x is the distance in matter in metres;
λ is the decay constant per second.
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ISO/DIS 11665-10
3.1.4
stationary radon diffusion

time independent radon diffusion through the sample; stationary radon diffusion is characterized by a stable

(time independent) radon distribution within the sample and consequently by a stable radon exhalation rate

from the sample into the receiver container; one-dimensional stationary radon diffusion is described by the

differential equation:
∂ C
D ⋅ − λ.C = 0 (4)
where
D is the diffusion coefficient, in square metres per second;
C is the activity concentration of 222Rn, in becquerels per cubic metre;
x is the distance in matter in metres;
λ is the decay constant per second.
3.1.5
decisive measurement of radon concentrations

the measurement of the time courses of radon concentrations in the source and receiver containers that is

used for calculating the radon diffusion coefficient; the duration of the decisive measurement can be shorter or

the same as the duration of the test
3.1.6
minimum duration of the decisive measurement for non-stationary radon diffusion

such period of time in the frame of the decisive measurement of radon concentrations in the source and

receiver containers taken during the phase of non-stationary diffusion ensuring the uncertainty of the radon

diffusion coefficient assessment lower than ± 20 %
3.1.7
minimum duration of the decisive measurement for stationary radon diffusion

such period of time in the frame of the decisive measurement of radon concentrations in the source and

receiver containers taken during the phase of stationary diffusion ensuring the uncertainty of the radon

diffusion coefficient assessment lower than ± 20 %
3.1.8
minimum radon concentration in the source container

such concentration of radon in the source container which for the particular sample characterised by the d/l

ratio ensures values of radon concentration in the receiver container measurable with uncertainty lower than

10 %
3.2 Symbols

For the purposes of this document, the symbols given in ISO 11665-1 and the following apply.

Radon decay constant, in per second

Air exchange rate characterising the ventilation of the receiver container, in per second

C Activity concentration, in becquerel per cubic metre

C Activity concentration in a particular container of the measuring device, in becquerels per cubic

metre
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ISO/DIS 11665-10

C Activity concentration on the surface of the sample, in becquerels per cubic metre

C Activity concentration in the receiver container, in becquerels per cubic metre

C Activity concentration in the source container, in becquerels per cubic metre
D Radon diffusion coefficient, in square metre per second
d Thickness of the sample, in metre
E Diffusive radon exhalation rate, in becquerels per square metre per second

E Diffusive radon exhalation rate from the sample to the receiver container, in becquerels per

square metre per second
h Radon transfer coefficient, in metre per second
i Index
l Diffusion length, in metre
S Area of the sample, in square metres
t Time, in seconds
∆t Duration of the considered time step between time t and t , in seconds
i-1 i
V Volume of the receiver container, in cubic metres
Distance from the surface of the sample exposed to radon, in metre
4 Principle of the test method

The sample of the tested material is placed between the air-tight source and the receiver containers, and the

joint is carefully sealed.

Radon activity concentration in both containers can be measured using continuous or spot measurement

methods as described in ISO 11665-5 and 11665-6.

By means of the certified artificial radon source, the radon concentration in the source container is kept on a

-3 -3

high level (usually within the range 1 MBq m to 100 MBq m ). The radon that diffuses through the sample is

monitored using calibrated radon monitor in the receiver container.

Using an appropriate mathematical process (either analytical or numerical), the radon diffusion coefficient is

afterwards calculated from the time-dependent courses of the radon activity concentrations measured in the

source and receiver containers, and the area and thickness of the tested sample.
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ISO/DIS 11665-10
5 Measuring system
5.1 Components of the measuring system

The measuring system for determining the radon diffusion coefficient in the radon barrier materials shall

comprise the following components:

a) at least two air-tight containers (source and receiver), each with a minimum air volume of 0,5 dm and

made from metal materials (for example aluminium, rustless steel, etc.) of a thickness that effectively

eliminates radon transport between the air inside and outside the containers; each container shall be

equipped with a test area of at least 0,5 dm surrounded by flanges for fixing the tested material; the

minimum width of the flanges shall be 10 mm and their arrangement shall eliminate the transport of radon

from the source container to the receiver container; each container shall be further equipped with an

appropriate number of valves intended for ventilating the containers, for measuring the pressure

differences between the containers, for extracting air samples for control measurements of radon

concentration and for connecting to an artificial radon source;

b) a measuring instrument capable of determining the thickness of the tested sample with accuracy

± 0,01 mm (maximum standard relative uncertainty of measurement 5 %);

c) a certified artificial source of radon capable of creating a radon concentration in the source container

-3 -3
within the range 1 MBq m to 100 MBq m ;
3 3

d) an air-tight flow pump with the range of air flow rates 0,1 dm /min to 0,5 dm /min that is used in some

measurement methods in a closed circuit with an artificial radon source and a source container;

e) a calibrated measuring device for monitoring the radon activity concentration in the receiver container

-3 -3

with standard relative uncertainty 10 % and a dynamic measuring range from 500 Bq m to 1,0 MBq m ;

f) a calibrated measuring device for monitoring the radon activity concentration in the source container with

-3 -3

standard relative uncertainty 10 % and a dynamic measuring range from 10 kBq m to 100,0 MBq m ;

g) a measuring instrument for determining the relative pressure difference between the air volume in the

source container and the air volume in the receiver container with standard relative uncertainty 10 % and

a dynamic measuring range from 1 Pa to 150 Pa;

h) suitable sensors and a data storage system capable of continuously monitoring the temperature and

relative humidity of air, atmospheric pressure and radon activity concentration in the place where the

measuring device is positioned.
5.2 Configuration of the measuring system

In the simplest case, the measuring system can comprise one source container, one receiver container and a

radon source connected to the source container (Figure 1). If more than one sample is to be measured under

equal conditions, it is convenient to use a measuring system comprising more than one receiver container

assembled on one source container (Figure 2), or a set of pair containers (source + receiver) connected to the

radon source in a parallel circuit (Figure 3) or connected to each other and to the radon source through the

source containers in a serial circuit.
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ISO/DIS 11665-10
Key
1 receiver container
2 radon detector
3 tested sample
4 source container
5 pump
6 radon source

Figure 1 — Measuring system comprising one source container and one receiver container

Key
1 receiver container
2 radon detector
3 tested sample
4 source container
5 pump
6 radon source

Figure 2 — Measuring system comprising two receiver containers assembled on one source container

6 © ISO 2012 – All rights reserved
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ISO/DIS 11665-10
Key
1 receiver container
2 radon detector
3 tested sample
4 source container
5 pump
6 radon source

Figure 3 — Measuring system comprising two pair containers (source + receiver) connected to the

radon source in a parallel circuit

The artificial radon source shall be connected to the source container and the source containers shall be

interconnected by flexible pipes that are as radon-tight as possible.

Radon can be transported from the radon source to the source container only by diffusion or with the help of a

flow pump. If a flow pump is used, the radon source, the source container and the flow pump shall be in a

single closed circuit. A flow pump shall not be applied if the radon diffusion through the tested sample is

influenced by the pressure difference between the source and receiver containers (this can be seen as rapid

drop or rise of radon concentration in the receiver container after applying the pump).

If the measuring system is made up of a set of pair containers, the maximum number of pairs that can be

connected to one radon source in a single closed circuit is 4. A flow pump shall be an indispensable part of

the circuit. Only samples of one material can be tested in a single circuit at the same time.

If the measuring system is made up of more than one receiver container assembled on a single source

container, only samples of one material can be tested in this system at the same time.

6 Test methods
6.1 General information

A suitable test method is selected from the following options in dependence on the properties of the tested

material, especially its thickness and the assumed radon diffusion coefficient value. The method A is the only

method that can be used when we do not succeed in creating the stationary radon diffusion or when we

cannot wait for establishing the stationary radon diffusion. The method B is usually preceded by the method A.

The method C gives the highest radon exhalation rates and therefore it should be applied every time when

very low radon diffusion coefficient is expected. Methods A and B are convenient for continuous monitoring of

radon concentrations and the method C for grab sampling measurements.
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ISO/DIS 11665-10

6.2 Method A – determining the radon diffusion coefficient during the phase of non-

stationary radon diffusion

After placing the sample between the source and receiver containers, both containers are closed and radon is

admitted into the source container. The decisive measurement of radon concentrations in both containers

begins at this moment (Figure 4).

Figure 4 — Principle of determining the radon diffusion coefficient according to method A

6.3 Method B – determining the radon diffusion coefficient during the phase of stationary

radon diffusion

After placing the sample between the source and receiver containers, both containers are closed and radon is

admitted into the source container. The time dependent increase in radon concentrations in both containers is

monitored. After establishing stationary radon diffusion through the sample, the receiver container is flushed

with radon-poor ambient air. Flushing is stopped when the radon concentration in the receiver container

decreases below the operational threshold (at least below 1 kBq m ). The decisive measurement of radon

concentrations in both containers begins at this moment (Figure 5).

Figure 5 — Principle of determining the radon diffusion coefficient according to method B

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ISO/DIS 11665-10

6.4 Method C – determining the radon diffusion coefficient during the phase of stationary

radon diffusion established during ventilation of the receiver container

After placing the sample between the source and receiver containers, radon is admitted into the source

container and the time dependent increase in the radon concentrations in both containers is monitored. The

radon concentration in the receiver container is held at values below the operational threshold (at least below

1 kBq.m ) by means of continuous ventilation of the receiver container. After establishing the stationary radon

diffusion through the sample, the ventilation of the receiver container is stopped. The decisive measurement

of radon concentrations in both containers begins at this moment (Figure 6).
Figure
...

DRAFT INTERNATIONAL STANDARD
ISO/DIS 11665-10.2
ISO/TC 85/SC 2 Secretariat: AFNOR
Voting begins on: Voting terminates on:
2015-08-25 2015-10-25
Measurement of radioactivity in the environment — Air:
radon-222 —
Part 10:
Determination of diffusion coefficient in waterproof
materials using activity concentration measurement
Mesurage de la radioactivité dans l’environnement — Air: radon 222 —

Partie 10: Détermination du coefficient de diffusion du radon des matériaux imperméables par mesurage

de l’activité volumique du radon
ICS: 13.040.01; 17.240
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 11665-10.2:2015(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2015
---------------------- Page: 1 ----------------------
ISO/DIS 11665-10.2:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 11665-10
Contents Page

Foreword ............................................................................................................................................................. v

Introduction ........................................................................................................................................................ vi

1 Scope ...................................................................................................................................................... 1

2 Normative references ............................................................................................................................ 1

3 Terms, definitions and symbols .......................................................................................................... 1

3.1 Terms and definitions ........................................................................................................................... 1

3.2 Symbols .................................................................................................................................................. 4

4 Principle.................................................................................................................................................. 5

5 Preparation of samples – General consideration .............................................................................. 5

6 Rapid test method ................................................................................................................................. 6

6.1 Principle.................................................................................................................................................. 6

6.2 Equipment .............................................................................................................................................. 7

6.3 Sample preparation ............................................................................................................................... 9

6.3.1 Fixing the sample in the holder ........................................................................................................... 9

6.3.2 Connection of the holder (cap) with the chamber ........................................................................... 10

6.4 Control measurements ....................................................................................................................... 10

6.4.1 Verification of radon-tightness .......................................................................................................... 10

6.4.2 Calibration ............................................................................................................................................ 11

6.4.3 Detector background .......................................................................................................................... 11

6.4.4 Instrument statistical fluctuation ....................................................................................................... 12

6.5 Measurement of radon activity concentration ................................................................................. 12

6.6 Determination of the radon diffusion coefficient in the sample ..................................................... 14

6.7 Characteristics of measurement limits ............................................................................................. 14

6.8 Estimation of confidential interval and uncertainty ......................................................................... 16

6.9 Expression of the result ...................................................................................................................... 16

6.10 Requirements for the test ................................................................................................................... 16

6.11 Influencing factors .............................................................................................................................. 17

7 Long term test methods ...................................................................................................................... 19

7.1 Principle................................................................................................................................................ 19

7.1.1 Method A – determining the radon diffusion coefficient during the phase of non-

stationary radon diffusion .................................................................................................................. 19

7.1.2 Method B – determining the radon diffusion coefficient during the phase of stationary

radon diffusion .................................................................................................................................... 20

7.1.3 Method C – determining the radon diffusion coefficient during the phase of stationary

radon diffusion established during ventilation of the receiver container ..................................... 20

7.2 Equipment ............................................................................................................................................ 21

7.3 Fixing the samples in the measuring device .................................................................................... 23

7.4 Verification of radon-tightness .......................................................................................................... 24

7.5 Determination of the radon diffusion coefficient in the sample ..................................................... 24

7.5.1 Method A .............................................................................................................................................. 24

7.5.2 Method B .............................................................................................................................................. 25

7.5.3 Method C .............................................................................................................................................. 25

7.6 Requirements for the tests ................................................................................................................. 26

7.7 Influence quantities ............................................................................................................................. 28

8 Expression of the results and assessment of the standard uncertainty for the material ........... 30

9 Quality management and calibration of the test device .................................................................. 30

10 Test report ............................................................................................................................................ 30

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ISO/DIS 11665-10

Annex A (informative) Rapid method for determination of radon diffusion coefficient of the

sample .................................................................................................................................................. 32

A.1 Scope ................................................................................................................................................... 32

A.2 Method of calculation of radon activity concentration in the source-detect chamber ............... 32

A.3 Example: Determination of radon diffusion coefficient of the sample from the waterproof

material (polyolefin) with the thickness of 0.60 mm ....................................................................... 34

A.4 Example: The statistical uncertainty of the test results of different materials based on the

rapid method ....................................................................................................................................... 36

Annex B (informative) Determining the radon diffusion coefficient during the phase of stationary

radon diffusion according to method C ........................................................................................... 39

B.1 Scope ................................................................................................................................................... 39

B.2 Normative references ......................................................................................................................... 39

B.3 Terms and definitions ........................................................................................................................ 39

B.4 Equipment ........................................................................................................................................... 40

B.5 Measurement procedure .................................................................................................................... 40

B.6 Expression of results ......................................................................................................................... 41

B.6.1 Radon activity concentration measurement using scintillation cells ........................................... 41

B.6.2 Radon diffusion coefficient in the sample ....................................................................................... 41

B.6.3 Standard uncertainty of radon activity concentration measurement ........................................... 42

B.7 Example: Determination of the radon diffusion coefficient of the HDPE membrane with

the thickness 0,47 mm ....................................................................................................................... 42

Annex C (informative) Determining the radon diffusion coefficient during the phase of non-

stationary radon diffusion according to method A ......................................................................... 45

C.1 Scope ................................................................................................................................................... 45

C.2 Normative references ......................................................................................................................... 45

C.3 Terms and definitions ........................................................................................................................ 45

C.4 Equipment ........................................................................................................................................... 46

C.5 Measurement procedure .................................................................................................................... 47

C.6 Expression of results ......................................................................................................................... 48

C.6.1 Radon activity concentration measurement using the current ionisation chamber ................... 48

C.6.2 Radon diffusion coefficient in the sample determination using finite element method

(FEM) .................................................................................................................................................... 48

C.6.3 Standard uncertainty .......................................................................................................................... 51

C.7 Example: Determination of the radon diffusion coefficient of an HDPE membrane ................... 51

Bibliography ..................................................................................................................................................... 54

iv © ISO 2015 – All rights reserved
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ISO/DIS 11665-10
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 11665-10 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
 Part 9:Test methods for determining exhalation rate of building materials

 Part 10: Determination of the diffusion coefficient in waterproof materials using activity concentration

measurement
 Part 11: Method for soil gas with sampling at depth
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ISO/DIS 11665-10
Introduction

Radon isotopes 222, 219 and 220 are radioactive gases produced by the disintegration of radium isotopes

226, and 224, which are decay products of uranium-238 and thorium-232 respectively, and are all found in the

earth's crust. Solid elements, also radioactive, followed by stable lead are produced by radon disintegration

[Nuclear Data Base issued from the Decay Data Evaluation Project.
http://www.nucleide.org/DDEP_WG/DDEPdata.htm].

When disintegrating, radon emits alpha particles and generates solid decay products, which are also

radioactive (polonium, bismuth, lead, etc.). The potential effects on human health of radon lie in its solid decay

products rather than the gas itself. Whether or not they are attached to atmospheric aerosols, radon decay

products can be inhaled and deposited in the bronchopulmonary tree to varying depths according to their size.

Radon is today considered to be the main source of human exposure to natural radiation. The UNSCEAR

(2006) report [UNSCEAR, Effects of ionizing radiation, Vol. 1, 2006, Report to the General Assembly, with

Scientific Annexes (New York : United Nations Publication 2008)] 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.

Radon activity concentration can vary from one to more orders of magnitude over time and space. Exposure

to radon and its decay products varies tremendously from one area to another, as it depends on the amount of

radon emitted by the soil, weather conditions, and on the degree of containment in the areas where individuals

are exposed [Kemski, J.; Klingel, R.; Siehl, A.; Neznal, M.; Neznal, M.; Matolín, M. (2012): Erarbeitung

fachlicher Grundlagen zur Beurteilung der Vergleichbarkeit unterschiedlicher Messmethoden zur Bestimmung

der Radonbodenluftkonzentration; Bd.2 Sachstandsbericht “Radonmessungen in der Bodenluft –

Einflussfaktoren, Messverfahren, Bewertung“, BfS Forchungsvorhaben 3609S10003, 2012, 122 pages].

As radon tends to concentrate in enclosed spaces like houses, the main part of the population exposure is

due to indoor radon. Soil gas is recognized as the most important source of residential radon through

infiltration pathways. Other sources are described in other parts of this standard (building materials) and ISO

13164 (water).

Radon enters into buildings mainly via convection mechanism, the so-called “stack effect” that is due to a

difference in air temperature between the inside and the outside of the building, which generates a difference

in pressure between the air in the building and the air contained in the underlying soil. Radon activity

concentration depends on the building structure, the equipment (chimney, ventilation systems, among others),

the environmental parameters of the building (temperature, pressure, etc.) and the occupants’ lifestyle.

To limit the risk to individuals, a national reference level of 100 Bq.m is recommended by the World Health

Organization [WHO Handbook on indoor radon [WHO, 2009. A public Health Perspective]. Wherever this is

not possible, the chosen level should not exceed 300 Bq.m . COUNCIL DIRECTIVE 2013/59/EURATOM of 5

December 2013 laying down basic safety standards for protection against the dangers arising from exposure

to ionising radiation, (and repealing Directives 89/618/Euratom, 90/641/Euratom, 96/29/Euratom,

97/43/Euratom and 2003/122/Euratom) sets that Member States shall establish national reference levels for

indoor radon concentrations. The reference levels for the annual average activity concentration in air shall not

be higher than 300 Bq.m .

To reduce the risk to the overall population, building codes should be implemented that require radon

prevention measures in buildings under construction and radon mitigating measures in existing buildings.

Radon measurements are needed because building codes alone cannot guarantee that radon concentrations

are below the reference level.

When a building requires protection against radon from the soil, radon-proof insulation (based on membranes,

coatings or paints) placed between the soil and the indoors may be used as a stand-alone radon

prevention/remediation strategy or in combination with other techniques such as passive or active soil

depressurization. Radon-proof insulation functions at the same time as the waterproof insulation [5], [6], [7].

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ISO/DIS 11665-10

Radon diffusion coefficient is a parameter that determines the barrier properties of waterproof materials

against the diffusive transport of radon. Applicability of the radon diffusion coefficient for the design of radon-

proof insulation is prescribed by national building standards and codes. Requirements for radon-proof

insulation as regards the durability, mechanical and physical properties and the maximum value of the radon

diffusion coefficient are also prescribed by national building standards and codes or independent certification

bodies.

Radon diffusion coefficient is a material property. In homogeneous (single-layered) materials its value does

not depend on the thickness of the tested material. Radon diffusion coefficient of layered materials produced

in several thicknesses shall be determined separately for each thickness.

The radon diffusion coefficient of these membranes is currently assessed with two types of methods based on

different assumptions:
 Rapid determination test method
 Long term test methods.

As no reference standards and reference materials are currently available for these types of materials and

related values of radon diffusion coefficient, the metrological requirement regarding the determination of the

performance of a method, as required by ISO 17025, cannot be directly met.

As it is the responsibility of the laboratory to carry out its testing in such a way as to meet the requirements of

this International Standard and to satisfy the needs of the customer, this part of ISO 11665 gives, for each

testing method described, assumptions and boundary conditions that shall be met.

NOTE The origin of radon-222 and its short-lived decay products in the atmospheric environment and the

measurement methods are described generally in ISO 11665-1.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 11665-10
Measurement of radioactivity in the environment — Air: radon
222 — Part 10: Determination of the diffusion coefficient in
waterproof materials using activity concentration measurement
1 Scope

This standard specifies the different methods intended for assessing the radon diffusion coefficient in

waterproofing materials such as bitumen or polymeric membranes, coatings or paints, as well as assumptions

and boundary conditions that shall be met during the test.

The test methods described in this standard allows estimating the radon diffusion coefficient in the range of

-8 -12
10 to 10 m2/s with an associated uncertainty from 10 to 40 %.

This standard is not applicable for porous materials, where radon diffusion depends on porosity and moisture

content.
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 921, Nuclear energy — Vocabulary
ISO 80000-10, Quantities and units – Part 10: Atomic and nuclear physics

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

measuring 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 11929, Determination of the characteristic limits (decision threshold, detection limit and limits of the

confidence interval) for measurements of ionizing radiation — Fundamentals and applications

ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in

measurement (GUM:1995)

IEC 61577-2, Radiation Protection Instrumentation — Radon and radon decay product measuring instruments

222 220
— Part 2: Specific requirements for Rn and Rn measuring instruments
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, ISO 921 and ISO 80000-

10 and the following apply.
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ISO/DIS 11665-10
3.1.1
material

material produced according to a certain technical specifications which is the object of the test

3.1.2
sample (of material)

certain amount of material chosen from the production batch for determination of the material properties

3.1.3
radon diffusion coefficient (bulk) D

radon activity permeating due to molecular diffusion through unit area of a layer of material of unit thickness

per unit time at unit radon activity concentration gradient on the boundaries of this layer

3.1.4
radon diffusion length l

distance crossed by radon due to diffusion in which activity is reduced by "e" times because of decay (numeric

“е” is the natural logarithm, equal to about 2.72)

Note 1 to entry: Radon diffusion length is expressed by the relationship given in Formula (1)

1/2
l = (D/) (1)
where
l is the radon diffusion length, in metre
D is the radon diffusion coefficient of the sample, in square metre per second;
 is the radon decay constant, in per second.
3.1.5
diffusive radon surface exhalation rate E

value of the activity of radon atoms that leave a material per unit surface per unit time

Note 1 to entry: For the purpose of this standard only the diffusion transport through the sample is taken into account.

The diffusive radon exhalation rate in a homogeneous material is given by Formula (2) (Fick's law)

C(x)
E(x)D (2)
where

E(x) is the distribution function along the axis "x" the radon exhalation rate in the sample, in becquerel per square

metre per second
D is the radon diffusion coefficient of the sample, in square metre per second;

C(x) is the distribution function along the axis "x" the radon activity concentration in the sample, in becquerel per

cubic metre;

x is the coordinate on axis "x" (the axis is directed along radon transport and perpendicular to the sample surface),

in metre.
3.1.6
non-stationary radon diffusion

the process of radon diffusion through the sample characterized by a change in time of radon activity

concentration in the sample

one-dimensional non-stationary radon diffusion is described by the partial differential equation:

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ISO/DIS 11665-10
 C(x,t) C(x,t)
D C(x,t)
(3)
x t
where
D is the radon diffusion coefficient of the sample, in square metre per second;

C(x,t) is the function changing in time along the axis "x" of radon activity concentration in the sample,

in becquerel per cubic metre;

x is the coordinate on axis "x" (the axis is directed along radon transport and perpendicular to the

sample surface), in metre;
 is the radon decay constant, in per second.

Note 1 to entry: Non stationary radon diffusion occurs during the time when radon activity concentration in the source

container is not steady and in the time interval that immediately follows the moment when the steady concentration in the

source container is established (long term test methods).
3.1.7
stationary radon diffusion

time independent radon diffusion through the sample; stationary radon diffusion is characterized by a stable

(time independent) radon distribution within the sample and consequently by a stable radon surface exhalation

rate from the sample into the receiver container (long term test methods);

one-dimensional stationary radon diffusion is described by the differential equation:

 C(x)
(4)
D C(x) 0
where
D is the radon diffusion coefficient of the sample, in square metre per second;

C(x) is the distribution function along the axis "x" the radon activity concentration in the sample, in

becquerel per cubic metre;

x is the coordinate on axis "x" (the axis is directed along radon transport and perpendicular to the

sample surface), , in metre;
 is the radon decay constant, in per second.
3.1.8
decisive measurements
measurement results used to calculate the radon diffusion coefficient
3.1.9
decisive volume of the chamber (container)

volume of the chamber (container) used to calculate the radon diffusion coefficient

3.1.10
decisive sample area
material sample area used to calculate the radon diffusion coefficient
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