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French experience in management and research on
the protection of building with respect to radon
Bernard Collignan
Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
2
Table
Presentation of CSTB
Radon management in France
Information on building protection
Examples of research studies
Conclusion

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Radon Protection Conference, Dresden, 2
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and 3
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of December, 2013 | Bernard Collignan
3
Presentation of CSTB
Scientific and Technical Center for Building:
independent French public
institution dedicated to innovation in building, of around 900 employees
Public industrial and commercial establishment
(known as an EPIC)
It is placed under the joint supervision of
Ministry of Housing
and
the
Ministry of Ecology.
Complementary areas:
- Research and innovative technology,
- Evaluation (tests and certification on construction products and
processes)
- Knowledge dissemination towards professionals
Large range of disciplines in the field of construction:
acoustic, thermal engineering, lighting, environment, building structure,
safety, health, economy, sociology, virtual reality,...
contribution to the quality and safety of sustainable construction

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
4
Radon Management in France
French exposure:
Risk assessment:
excess risk of lung cancer
5-10% of lung cancers attributable to radon: between 1200 and 2900 deaths / year in France
Aggravating factor: tobacco -
source InVS
Public health issue

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
5
Mapping
> 150
101- 150
51- 100
0 - 50
Measurement campaign in around 12 000
dwellings (DGS/IRSN)
Definition of averaged departmental levels
(Bq/m
3
)
Definition of 31 priority departments for
current regulation

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
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Measurements
Example of Radon concentration evolution in a dwelling
Normalisation of screening methodology (NF ISO 11665-8)
Two months measurement with passive dosimeter in living room during heating season to
be representative of annual averaged measurement
Used in current regulation for screening and control of efficiency of building protection

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
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Current regulation
Existing Public buildings:
Decree of 22 July 2004: rules of risk management in some public buildings
Obligation of radon measurements:
In the 31 priority departments
Educational institutions, health and social institutions, jails and spas
By agencies approved by Nuclear Safety Authority (ASN) (NF ISO 11665-8)
Obligation of implementation of corrective measures
400 Bq/m
3
1000 Bq/m
3
No obligation of
corrective measures
Simple measures, technical diagnosis of
building, obligation of corrective
measures
Radon concentration
Short term corrective measures, technical
diagnostic of building, obligation of
corrective measures

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
8
Current regulation
Feed back on measurements in existing Public buildings (2005-2011):
11 079 establishments screened including:
6 735 educational institutions,
4 301 health and social institutions,
20 spas,
23 jails.

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
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Current regulation
Underground workplaces:
Decree of 7 August 2008: rules of risk management in some underground
workplaces
Obligation of radon measurements:
In the 31 priority departments
In the underground places for some professional activities, fixed by decree
By agencies approved by Nuclear Safety Authority (ASN) (NF ISO 11665-8)
Obligation of action
400 Bq/m
3
1000 Bq/m
3
Optimisation
Required corrective actions
(technical actions, organizational, ...)
Radon concentration
Technical actions, individual dosimetric
monitoring, atmosphere monitoring,
medical surveillance, ...)

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
10
Second National Action Plan (2011-2015)
Animated by The Nuclear Safety Authority (ASN)
In collaboration with the ministries involved:
Department of Housing, Urbanism and Landscape (DHUP)
General Direction of Health (DGS)
General Direction of Labour (DGT)
And partner organizations:
Institute for Radiological Protection and Nuclear Safety (IRSN)
Scientific and Technical Centre for Building (CSTB)
Health surveillance institute (InVS)
Regional relay:
Regional Health Agencies (ARS)
Local Technical centres (CETE)
Local communities

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
11
Second National Action Plan (2011-2015)
Developped in continuity of previous plan (2005-2008) and within the logic of:
The National Health and Environmental Plan (PNSE)
The second Cancer Plan (2009-2013),
The Health Work Plan (2010-2014)
Policy objectives:
New mapping
Exposure reduction in existing housing
New rules of construction in new buildings
Transposition of new Euratom Directive (action level: 300 Bq/m
3
, impact of building material)
Ensure a low level of human exposure.
Success of the plan:
Membership and collaboration of the various national and local actors,
Regional initiatives, in the context of Regional Health and Environmental Plan:
To strengthen the skill of local actors
To make new partners emerge
To promote the sharing of expertise

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
12
New mapping
Existing mapping risk management:
Definition of main radon areas but not enough precise for efficient management
IRSN built a new mapping for risk management linking:
Geological nature with cofactors facilitating the transport of radon in rocks and soils (faults,
underground mine workings, hydrothermal sites)
Radon potential map of geological formations
Map of municipalities affected by radon potential
Future Risk management map?
Under discussions

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
13
Radon entry into building
Influence factors
2
3
5
6
7
1
2
3
4
cracks
joints between components
pipes, cables, ...
cavities on wall
from the ground
5
6
7
building materials
use of water
external air
3
4
1
2
1
Source CSTB
1
Radium (solid)
Radon (Gaz)
P+
P-
P+
T
ext
<
T
int
Diffusion
Convection
Source CSTB
Main process: convection generated by
depression due to stack effect and wind
Indoor radon concentration:
- Underlying soil characteristics:
Nature of the soil, air permeability, presence of cracks or fractures
- Specific building features:
Nature and state of the basement, air permeability of the building, ventilation level, heating, number of
floors of the building, etc..
- Behavior of the occupant.
Airing (+), heating (-).

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
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Building protection
Principles:
Restrict the entry of radon
Dilute the presence of radon in the building.
Solution Types:
Sealing the building interface with ground
Building ventilation
Treatment of the basement (ventilation, Soil Depressurization System)

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
15
New building protection
Systematic approach using Soil Depressurization System (S.D.S.)
Principle of S.D.S.:
Initial state
S.D.S.
To generate a slight depressurization of basement compared to indoor environment with
low extract flow
Associated with basement sealing
P++
P+
P-
P++
P--
P-

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
16
New building protection
Systematic approach using Soil Depressurization System (S.D.S.)
Principle of preparation of basement:
Réservation extérieure
pour une dépressurisation ultérieure éventuelle
Gravier
Membrane
d'étanchéité éventuelle
Puisard
Vide sanitaire
Réservation extérieure
pour une dépressurisation ultérieure éventuelle
Membrane
d'étanchéité éventuelle
Dallage
Raccord d'étanchéité
Etanchéité
Joint d'étanchéité
Dallage
Membrane anti radon avec raccord
Tube PVC
Mastic d'étanchéité
Platine métallique ou PVC
Examples of treatments for penetrations networks:
Easy to activate S.D.S. if necessary

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
17
Existing building protection
Disparity of situations
Solution protections to implement depend on:
Level screening measures (NF ISO 11665-8)
Building characteristics
solutions defined on a case by case basis, could be an iterative process
Appropriate combination:
Sealing basement interface,
Building ventilation,
Treatment of basement
Importance of proper identification of the structure and building systems

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
18
Remediation efficiency in existing building
Feedback on the efficiency of solutions implemented in public buildings:
Number of cases %age
Below 400 Bq/m
3
49
40
Above 400 Bq/m
3
73
60
with:
Between 400 and 1 000 Bq/m
3
57
47
Above 1 000 Bq/m
3
16
13
Control
measurement
Levels of measurement controls obtained after remediation compared to the
two action thresholds 400 Bq/m
3
and 1000 Bq/m
3
(122 cases, ASN data)

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Radon Protection Conference, Dresden, 2
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and 3
rd
of December, 2013 | Bernard Collignan
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Remediation efficiency in existing building
Feedback on the efficiency of solutions implemented in public buildings:
Very variable and
not always satisfactory
Radon pathways not
always easy to identify.
Building characterization
should be undertaken in a
relevant way
Knowledge of actors not
sufficient

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
20
Complementary tool for existing buildings
to support the management process of radon reduction in existing buildings
French experimental norm (February 2011):
Referential for technical diagnosis related to the presence of radon in buildings
Mission and methodology (NF X 46-040)
Objectives :
to identify the causes of radon presence in the building
to provide the necessary building description for the choice of remediation techniques best suited to the case
encountered.
Technical content:
Undertaken after screening measurement (NF ISO 11665-8),
Qualitative analysis of building and basement structure, ventilation systems, occupant behaviour, …
Collect of information and building visit:
Geology, Site and building history, climatic conditions, building description, structure, basement, networks,
materials, systems (ventilation, heating, …)
Could be completed with:
Additional radon measurements (NF ISO 11665-8),
Ventilation measurements

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Radon Protection Conference, Dresden, 2
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and 3
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of December, 2013 | Bernard Collignan
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Applied research at CSTB
Aim of research:
To ameliorate building protection
To help authorities and building actors in risk management
Some topics:
• Test of faisability for S.D.S. in existing building
• Use of existing mechanical ventilation system for S.D.S.
• Experimental study on passive S.D.S and modeling
• Efficiency of mechanical insufflating ventilation
• Building characterisation related to radon entry and exposure
• Impact of thermal rehabilitation on radon exposure

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
22
Test of faisability for S.D.S. in existing building
Principle:
To manage a hole on slab,
To extract air flow from the ground,
To measure the air flow,
To measure pressure difference either side of the floor at
different points
Characterisation of air permeability of the ground
below the floor
Mechanical faisability of SDS
Associated with continuous radon measurement:
efficiency of SDS
Basement
Indoor environment
Pressure difference measurement
Air flow measurement
Variable velocity fan

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
23
Test of faisability for S.D.S. in existing building

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
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Test of faisability for S.D.S. in existing building

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
25
Test of faisability for S.D.S. in existing building
Installing real system:
3: starting point of S.D.S. running
Duct in a room
Fan below roof

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
26
Test of faisability for S.D.S. in existing building
Technical void
P1
P3
P2
Mechanical extraction
of technical void
Rn_1
Rn_2
Technical void
Depression measurement below slab
Mechanical extraction from technical void

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
27
Test of faisability for S.D.S. in existing building
Technical void
P1
P3
P2
Mechanical extraction
of technical void
Rn_1
Rn_2
10
100
1000
1
10
100
underfloor depressure(Pa)
Technical void
P1
P2
P3
Mechanical extract flow (m
3
/h)

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
28
Test of faisability for S.D.S. in existing building
Impact of S.D.S. running on indoor radon concentration
0
400
800
1200
1600
20:52
23:16
01:40
04:04
06:28
08:52
11:16
Bq/m
3
S.D.S. start
Hours
Radon measurement

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
29
Use of existing mechanical ventilation system for S.D.S.
Description of Mechanical Exhaust Ventilation Principle in a dwelling
5 living room
Self regulated registers to obtain required exhaust flow
Kitchen
45 m
3
/h
Kitchen, high flow, cooking activity
135 m
3
/h
Bathroom
30 m
3
/h
Toilet
30 m
3
/h
Optional other bathroom
30 m
3
/h
Optional other toilet
15 m
3
/h

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Radon Protection Conference, Dresden, 2
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and 3
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of December, 2013 | Bernard Collignan
30
Use of existing mechanical ventilation system for S.D.S.
S.D.S. connexion to the exhaust unit

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
31
Use of existing mechanical ventilation system for S.D.S.
S.D.S. connexion to the exhaust unit

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
32
Use of existing mechanical ventilation system for S.D.S.
Results
Kitchen, bathroom and toilet connexion configuration
Dwelling ventilation
S.D.S.
Kitchen
exhaust flow
(m
3
/h)
Bathroom
exhaust flow
(m
3
/h)
Toilet
exhaust flow
(m
3
/h)
basement
exhaust flow
(m
3
/h)
Basement
depressurization
(Pa)
Low
Only
velocity
55
35
34
mechanical
ventilation
High
velocity
149
30
30
Low
velocity
52
34
33
20
5.8
Sump with
15 m
3
/h
theoretical
register
High
velocity
131
29
28
17
4.8
Low
velocity
52
35
33
32
12
Sump with
30 m
3
/h
theoretical
register
High
velocity
140
31
30
28
9.9
Low
velocity
49
32
31
45
18.9
Sump
connexion
with no
register
High
velocity
123
29
29
40
14.9

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
33
Experimental study on passive S.D.S and modeling
One year follow up to assess mechanical efficiency of passive SDS
- Wind (velocity and direction)
- External temperature
- Internal temperature
- Duct air velocity
- Duct temperature
Basement
depressurisation:
P
In situ experimental dwelling
Adaptation of initial sump

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Radon Protection Conference, Dresden, 2
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and 3
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of December, 2013 | Bernard Collignan
34
Experimental study on passive S.D.S and modeling
0
10
20
30
40
50
60
05/03/08
10/03/08
15/03/08
20/03/08
25/03/08
30/03/08
m
3
/h
0
5
10
15
20
25
30
Pa
basement extract flow
basement depressurisation
Evolution of basement extract flow (Q
SDS
) and basement depressurisation
Monthly percentage of running time of SDS above three thresholds

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
35
Experimental study on passive S.D.S and modeling
Modeling:
to develop an analytical model to determine the mechanical running characteristics of a
passive SDS (Q
SDS
and P
e
) as a function of building characteristics and meteorological
conditions
Q
SDS
= Q
ind
+ Q
soil
Qsoil: air flow from the soil
Qind: air flow from indoors
Gravel
Concrete
Soil
0
out
P
ug
P
us
P
e
P
P
s
ind
P
SDS
Q
H
slab
L
/2
mf
L
H
U: wind
out
P
slab
L
/2

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
36
Experimental study on passive S.D.S and modeling
Modeling: controntation with experimental data
Airflow trough SDS duct
Gravel depressurization

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
37
Experimental study on passive S.D.S and modeling
Modeling: sensitivity studies
Monthly percentage of running time of SDS above three thresholds
To test and to dimension passive SDS in a given configuration:
Building, climate

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
38
Efficiency of mechanical insufflating ventilation
Neutral plan
Use of mechanical
extraction
for ventilation:
enhance depressurisation at floor level
Use of mechanical
insufflation
for ventilation:
diminish depressurisation at floor level
P
P
gH
P
P
gH
ext
ext
H
ext
H
..
..
0
int
0
int
int
Indoor and outdoor hydrostatic pressures depending on heigh of building

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
39
Efficiency of mechanical insufflating ventilation
0
100
200
300
400
500
600
700
800
10:48
12:00
13:12
14:24
15:36
16:48
18:00
19:12
séjour RdC
Buanderie
Cuisine
Ch. 1
Radim RdC
Mechanical extraction
0.7 vol/h ; -4 Pa
Bq/m3
Mechanical insufflation
0.7 vol/h ; + 2 Pa

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
40
Efficiency of mechanical insufflating ventilation

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
41
Efficiency of mechanical insufflating ventilation
Very good efficiency against radon entry
Cost-effective solution
Potential condensation risk accentuation in walls depending on:
- water vapour production in building,
- meteorological conditions and
- building characteristics.

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Radon Protection Conference, Dresden, 2
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and 3
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of December, 2013 | Bernard Collignan
42
Building characterisation related to radon entry and
exposure
Context:
• High variability of indoor radon concentration along time.
• In France in current regulation, radon screening normalised: 2 months measurement
during heating period to assess annual averaged indoor radon concentration
• Difficult to use this protocol in existing dwelling (real estate transaction, occupant
behaviour, ...)
Objective:
To find an alternative or complementary technique to assess radon potential of a dwelling

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
43
Building characterisation related to radon entry and
exposure
Protocol:
>
Depressurisation of dwelling using blower door
Principle:
For a given depressurisation and mechanical exhaust air (AR) flow of
dwelling, analysis of Indoor Rn concentration
(measured at the exhaust)
F
Rn
= C
Rn
asympt.
x AR for a given P
time
C
Rn
asympt.
P
F
Rn
Test at different depressurisation levels
convective flux of radon from ground:
F
Rn
= k x P
n

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Radon Protection Conference, Dresden, 2
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and 3
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of December, 2013 | Bernard Collignan
44
Building characterisation related to radon entry and
exposure
Potential for entry of radon building:
P
Rn4
: Convective flux of radon under 4 Pa depressurization per square meter of floor
(Bq/s/m²)
Protocol tested on 14 dwellings where classical screening had also been realized

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
45
Building characterisation related to radon entry and
exposure
Tentative of classification:
P
Rn4
< 0,25 Bq/s/m²
low exposure to radon
0,25 < P
Rn4
< 0,65 Bq/s/m²
Medium exposure to radon
P
Rn4
> 0,65 Bq/s/m²
High exposure to radon
Classification globaly in
accordance with measurements

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
46
Building characterisation related to radon entry and
exposure
Numerical assessment of averaged radon concentration:
Annual calculation using ventilation
model and Rn emission law characterised
experimentally
To rebuild annual averaged Rn
concentration
Conclusion:
Promising methodology, need to be tested in a larger number of building to be reinforced
could be considered as a complementary tool for radon management

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
47
Impact of thermal remediation on radon exposure
Often iterative process
Source Ademe
Data on thermal rehabilitation In France

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
48
Impact of thermal remediation on radon exposure
Data from Switzerland:
Difference in concentration of radon after retrofitting (undifferentiated)
for 163 dwellings
Averaged before retrofitting : 153 Bq/m
3
Averaged after retrofitting : 193 Bq/m
3
Increase of 40 Bq/m
3
(26 %)

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
49
Impact of thermal remediation on radon exposure
Data from Switzerland:
Difference in concentration of radon after retrofitting (changing windows)
for 70 dwellings
Averaged before retrofitting : 141 Bq/m
3
Averaged after retrofitting : 191 Bq/m
3
Increase of 50 Bq/m
3
(35 %)

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Radon Protection Conference, Dresden, 2
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and 3
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of December, 2013 | Bernard Collignan
50
Numerical study on impact of thermal remediation on
radon exposure
Sensitivity study using ventilation model and convective law for radon entry:
Airtightness of dwelling
I
4
= 1,6 m
3
/h/m²
I
4
= 1,2 m
3
/h/m²
Changing windows
I
4
= 1 m
3
/h/m²
+ internal insulation
I
4
= 0,8 m
3
/h/m²
+ external insulation
No ventilation
system
X
X
X
X
Natural
ventilation
system
Reference case
X
X
X
Exhaust
Mechanical
ventilation
X
X
X
X
Double flux
X
X
X
X

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Radon Protection Conference, Dresden, 2
nd
and 3
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of December, 2013 | Bernard Collignan
51
Numerical study on impact of thermal remediation on
radon exposure
Sensitivity study using ventilation model and convective law for radon entry:
Airtightness of dwelling
I
4
= 1,6 m
3
/h/m²
I
4
= 1,2 m
3
/h/m²
Changing windows
I
4
= 1 m
3
/h/m²
+ internal insulation
I
4
= 0,8 m
3
/h/m²
+ external insulation
No ventilation
system
313
418
503
628
Natural
ventilation
system
176
220
253
301
Exhaust
Mechanical
ventilation
153
169
178
191
Double flux
99
110
117
127
Radon annual averaged concentration (Bq/m
3
)

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
52
Conclusion
Future Challenges :
Development of professional practices for existing and new building to
ameliorate protection efficiency
Existing building:
Thermal remediation of building and radon exposure
New buildings:
Efficiency of ventilation systems and good maintenance along time

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Radon Protection Conference, Dresden, 2
nd
and 3
rd
of December, 2013 | Bernard Collignan
53
Thank you for your attention !
Examples of radon free buildings