oSIST prEN 17637:2021

Construction products: Assessment of release of dangerous substances - Dose assessment of emitted gamma radiation

This document specifies a methodology to determine indoor gamma dose from building materials and to help classify such a product as required in the Construction Products Regulation (EU 305/2011). With this methodology, the relation between the actual release of radiation and the dose to which inhabitants of a buidling are exposed can be assessed. The method takes into account also the Basic Safety Standards Directive (2013/59/EURATOM).

Bauprodukte - Bewertung der Freisetzung von gefährlichen Stoffen - Verfahren zur Beurteilung von emittierter Gammastrahlung

Dieses Dokument beschreibt ein Berechnungsverfahren zur Bestimmung der Gamma-Dosen aus Baupro-dukten in Innenräumen. Dieses Verfahren beinhaltet die Berechnung der Gamma-Dosis aus dem einzelnen Bauprodukt während seines bestimmungsgemäßen Gebrauchs sowie der Dosis aus dem Gebäude unter Berücksichtigung mehrerer Baumaterialien, wo dies als notwendig angesehen wird, und jeder Abschirmung vor dem terrestrischen Hintergrund.
Das Berechnungsverfahren basiert auf bestehenden Modellierungsgrundsätzen für die Photonenemission und  absorption. Parameter der Modellierung, die nicht produktspezifisch sind, wie etwa die Raumgeo-metrie, Expositions-Koeffizienten und Umrechnungsfaktoren sind vordefiniert und bilden die Grundlage für das Verfahren in diesem Dokument. Die Entscheidung für vordefinierte Modellparameter ist wesentlich aus Sicht der Harmonisierung, auch wenn solche Parameter je nach Hauseigentümer, Gebäudetyp, Region oder Land erheblich variieren können. Übliche Beispiele sind die Expositionsdauer, die Gebäudegeometrie, die Lage der Exposition im Gebäude und die terrestrische Hintergrundstrahlung. Die Parameter werden auf der Grundlage eines internationalen Konsenses ausgewählt, wie in den ICRP, UNSCEAR, EU RP-Richtlinien und anderen anerkannten Publikationen festgelegt. Produktspezifische Parameter wie Dichte und Dicke werden entsprechend dem bestimmungsgemäßen Gebrauch des Produkts festgelegt. Darüber hinaus werden die massebezogenen Aktivitäten von 226Ra, 232Th und 40K festgelegt und nach prEN 17216 [3] ermittelt. Das Verfahren bietet einen stufenweisen Ansatz mit einem grundlegenden Ansatz für die Bewertung einzelner Bauprodukte, gefolgt von einem verfeinerten Ansatz zur Bewertung einer kompletten Gebäudegestaltung. Der erste Ansatz geht von einer identischen Struktur der Baustoffe auf allen sechs Oberflächen des Modellraums und gegebenenfalls anderen Baustoffen, die intrinsischer Teil des bestimmungsgemäßen Gebrauchs des Produkts sind, aus. Der letztere Ansatz ermöglicht die Bewertung einer bekannten Gebäudegestaltung. Hier kann der Anwender die angewendeten Bauprodukte auf Wänden, Böden und Decken separat entsprechend dem bestimmungsgemäßen Gebrauch des Produkts festlegen.
Die Gamma-Dosis in Innenräumen aus einzelnen Bauprodukten sowie des Gebäudes wird als effektive Jahresdosis aus Gammastrahlung in Innenraumumgebung angegeben. Die Formulierung der Innenraum-Gamma-Dosis im Gebäude ist mit der Dosis der externen Exposition in Innenräumen nach Artikel 75 der Sicherheits-Grundnormenrichtlinie konsistent. Aus diesem Grund ermöglicht das beschriebene Verfahren die Bewertung der berechneten Jahresdosis des Gebäudes im Vergleich zu dem Referenzwert, wie in der Sicherheits-Grundnormenrichtlinie definiert.
Das Verfahren ist für die Bewertung mineralbasierter Baustoffe ausgelegt, die als Schüttgut oder auf Oberflächen und als Bauprodukt in Gebäuden eingesetzt werden. Dies umfasst alle Baustoffe, die von den EU-Mitgliedsstaaten als aus Strahlenschutzsicht bedenklich eingestuft wurden. Dieses Verfahren ist für die Anwendung durch Hersteller von Baustoffen, Architekten und Bauausführern sowie Behörden vorgesehen.
Es ist wichtig, darauf hinzuweisen, dass über die Berechnung der Dosis hinaus jegliche anschließende regulatorische Klassifizierung ausdrücklich nicht im Anwendungsbereich dieses Verfahrens liegt und der Verantwortung der zuständigen Behörden unterliegt.

Produits de construction : Évaluation de l’émission de substances dangereuses — Évaluation de la dose de rayonnement gamma émis

Le présent document décrit une méthode de calcul permettant de déterminer la dose due aux rayonnements gamma émise par les produits de construction à l’intérieur des bâtiments. La méthode comprend le calcul de la dose due aux rayonnements gamma à l’intérieur du bâtiment émise par le produit de construction individuel dans le cadre de son usage prévu, ainsi que le calcul de la dose provenant du bâtiment, en prenant en considération plusieurs matériaux de construction lorsque cela est jugé nécessaire et toute protection éventuelle contre le bruit de fond terrestre.
La méthode de calcul s’appuie sur des principes de modélisation existants pour l’émission et l’absorption des photons. Les paramètres de modélisation qui ne sont pas spécifiques du produit, tels que la géométrie de la pièce, les coefficients d’exposition et les facteurs de conversion, sont prédéfinis et servent de base à la méthode décrite dans le présent document. Le choix de paramètres de modélisation prédéfinis est essentiel dans une perspective d’harmonisation, bien que ces paramètres puissent varier considérablement pour chaque propriétaire occupant, et selon le type de bâtiment, la région ou le pays. La durée d’exposition, la géométrie du bâtiment, l’emplacement d’exposition dans le bâtiment et le bruit de fond terrestre en sont des exemples types. Les paramètres sont sélectionnés sur la base du consensus international, indiqué dans les lignes directrices de la CIPR, de l’UNSCEAR et de la collection « Radiation Protection » de l’Union européenne et dans d’autres publications renommées. Les paramètres spécifiques du produit, tels que la masse volumique et l’épaisseur, sont spécifiés en fonction de l’usage prévu du produit. De plus, les activités massiques du 226Ra, du 232Th et du 40K des produits sont spécifiées et obtenues conformément au prEN 17216 [3]. La méthode fournit une approche fondamentale par étape destinée à évaluer des produits de construction individuels, suivie d’une approche plus approfondie permettant d’évaluer une conception de bâtiment complète. La première approche suppose une structure identique des matériaux de construction sur les six surfaces de la pièce modèle et ceux-ci sont complétés, si nécessaire, par d’autres matériaux de construction qui font partie intégrante de l’usage prévu du produit. La seconde approche permet d’évaluer une conception de bâtiment connue. Ici, l’utilisateur peut spécifier le produit de construction appliqué sur les murs, le plancher ou le plafond séparément en fonction de l’usage prévu du produit.
La dose due aux rayonnements gamma à l’intérieur du bâtiment émise par le produit de construction individuel ainsi que par le bâtiment lui-même est exprimée en termes de dose efficace annuelle due aux rayonnements gamma dans l’environnement intérieur. La formulation de la dose due aux rayonnements gamma à l’intérieur du bâtiment est cohérente avec la dose correspondant à une exposition externe à l’intérieur du bâtiment telle qu’indiquée à l’Article 75 de la Directive « Normes de base relatives à la protection sanitaire ». Par conséquent, la méthode décrite permet d’évaluer la dose annuelle calculée pour le bâtiment par rapport au niveau de référence tel que défini dans la Directive « Normes de base relatives à la protection sanitaire ».
La méthode est conçue pour l’évaluation des matériaux de construction de nature minérale, massifs ou superficiels, et utilisés comme produits de construction dans les bâtiments. Cela inclut tout matériau de construction ayant été identifié par les états membres de l’UE comme étant préoccupant du point de vue de la radioprotection. ...

Gradbeni proizvodi - Ocenjevanje sproščanja nevarnih snovi - Ocenjevanje doze emitiranega gama sevanja

General Information

• Status: Not Published
• Public Enquiry End Date: 01-Feb-2021
• ICS: 13.020.99 - Other standards related to environmental protection
• ICS: 13.280 - Radiation protection
• ICS: 91.100.01 - Construction materials in general
• Technical Committee: NES - Dangerous substances
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 23-Nov-2020
• Due Date: 12-Apr-2021
• Completion Date: 23-Apr-2021
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Mandate: M/366 - Concerning the execution of standardisation work for the development of horizontal standardised assessment methods for harmonized approcaches relating to dangerous substances under the construction products directive (CPD)
• Ref Project: prEN 17637 - Construction products: Assessment of release of dangerous substances - Dose assessment of emitted gamma radiation

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 17637:2021
01-januar-2021
Gradbeni proizvodi - Ocenjevanje sproščanja nevarnih snovi - Ocenjevanje doze
emitiranega gama sevanja
Construction products: Assessment of release of dangerous substances - Dose
assessment of emitted gamma radiation
Bauprodukte - Bewertung der Freisetzung von gefährlichen Stoffen - Verfahren zur
Beurteilung von emittierter Gammastrahlung
Ta slovenski standard je istoveten z: prEN 17637
ICS:
13.020.99 Drugi standardi v zvezi z Other standards related to
varstvom okolja environmental protection
13.280 Varstvo pred sevanjem Radiation protection
91.100.01 Gradbeni materiali na Construction materials in
splošno general
oSIST prEN 17637:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 17637:2021
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oSIST prEN 17637:2021
DRAFT
EUROPEAN STANDARD
prEN 17637
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2021
ICS 91.100.01
English Version
Construction products: Assessment of release of
dangerous substances - Dose assessment of emitted
gamma radiation
Bauprodukte - Bewertung der Freisetzung von
gefährlichen Stoffen - Verfahren zur Beurteilung von
emittierter Gammastrahlung

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 351.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

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.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17637:2021 E

worldwide for CEN national Members.
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Contents Page

European foreword ..................................................................................................................................... 3

Introduction .................................................................................................................................................. 4

1 Scope .................................................................................................................................................. 5

2 Normative references .................................................................................................................. 5

3 Terms and definitions ................................................................................................................. 6

4 Symbols and abbreviated terms .............................................................................................. 8

5 Method for dose assessment ..................................................................................................... 8

5.1 General .............................................................................................................................................. 8

5.2 Assessment for evaluation of a construction product ...................................................10

5.2.1 Product information...................................................................................................................10

5.2.2 Dose assessment of the construction product ..................................................................11

5.2.3 Dose assessment of the model building ..............................................................................14

5.3 Assessment for evaluation of a building design ...............................................................14

5.3.1 Product information...................................................................................................................14

5.3.2 Dose assessment of the construction product ..................................................................15

6 Reporting ........................................................................................................................................18

Annex A (informative) Description of the dose assessment model .......................................19

A.1 General ............................................................................................................................................19

A.2 Method description ....................................................................................................................19

A.3 Dimensions of the model room ..............................................................................................19

A.4 Model assumptions .....................................................................................................................19

Annex B (informative) Examples of dose assessment .................................................................21

B.1 Assessment for evaluation of the construction product ...............................................21

B.1.1 General ............................................................................................................................................21

B.1.2 Example 1: Concrete with elevated massic activities .....................................................21

B.1.3 Example 2a: Superficial material ...........................................................................................22

B.1.4 Example 2b: Superficial material used in combination with another bulk

material ...........................................................................................................................................22

B.1.5 Example 3: Ceramic brick for an intended use as outer wall ......................................23

B.2 Assessment for evaluation of the building design ...........................................................24

B.2.1 General ............................................................................................................................................24

B.2.2 Example 1: Room with concrete walls with elevated concentrations and typical

concrete floor and ceiling .........................................................................................................24

B.2.3 Example 2: Room with cavity walls and concrete floor and ceiling ..........................25

Bibliography ................................................................................................................................................26

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European foreword

This document (prEN 17637:2021) has been prepared by Technical Committee CEN/TC 351

“Construction products: Assessment of release of dangerous substances”, the secretariat of which is

held by NEN.
This document is currently submitted to the CEN Enquiry.

This document has been prepared under a mandate given to CEN by the European Commission and

the European Free Trade Association.
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Introduction

In January 2014 the Basic Safety Standards Directive (2013/59/Euratom) [1], also named EU-BSS,

was issued laying down basic safety standards for the protection against the danger arising from

exposure to ionising radiation. The directive also sets requirements on the gamma radiation dose

226 232 40

from the naturally occurring radionuclides ( Ra, Th and K) in building materials and must be

taken into account along with the 2011 EU regulation laying down harmonized conditions for the

marketing of construction products (EU no 305/2011) [2], the so called CPR. Both EU regulatory

documents constitute a new basis for radiation protection regulation of building materials and are

intended to be complemented by EU guidance and standards of which this document is part.

Pivotal in the regulatory system of the EU-BSS and CPR is the dose assessment of building materials

and its compliance against a reference level as defined under Article 75 of the EU-BSS. For this

purpose an activity concentration index is provided in the directive under Annex VIII. The index

226 232 40

value is determined using the material’s massic activity Ra, Th and K. As the index is proposed

as a conservative screening tool provisions are put in place under Annex VIII to allow for more

precise assessment of the dose if needed. This includes consideration of the material’s density,

thickness and other factors relating to the type of construction and the intended use. However, no

method for a more refined dose assessment is provided in the directive, despite the fact that various

EU member states allow for such refined assessment. This document serves as a harmonized

assessment method that can support harmonized standards under the CPR, and is meant to address

the provisions in the EU-BSS for a more refined assessment.

This document is an addition to the activity concentration index as formulated in the Annex VIII of

the EU-BSS. The method describes a state-of-the-art dose assessment that takes account of all factors

stipulated under Annex VIII of the directive. In the method, important consideration is given to

differentiate between the dose from the individual construction product and the assembly of

products that result in the dose from the model building. In the EU-BSS dose requirements are

expressed in terms of a dose from the building, while the CPR is intended to set product specific

requirements. For this reason the method provides for a calculation of dose from the individual

product, followed by a calculation of the product assembly with subtraction of background to enable

assessment against the reference level defined in Article 75 of the EU-BSS.
This document has the following structure:

— A normative instruction on the use of the assessment method with description of the equations

and parameters to be used, followed by a list of information to be reported;

— An informative Annex A with a description of the dose assessment model, including explanation

of the modelling principles, main assumptions, coefficients and conversion factors;

— An informative Annex B containing a series of examples on the use of the assessment method.

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1 Scope

This document describes a calculation method to determine the indoor gamma dose from

construction products. The method includes calculation of the indoor gamma dose from the

individual construction product under its intended use, as well as the dose from the building taking

consideration of multiple building materials where this is deemed necessary and any shielding from

the terrestrial background.

The calculation method builds on existing modelling principles for photon emission and absorption.

Parameters of the modelling that are not product specific, such as room geometry, exposure

coefficients and conversion factors are predefined and form the underlying basis for the method in

this document. The choice for pre-defined model parameters is essential from a harmonization

perspective, despite the fact that such parameters can vary considerably for every homeowner,

building type, region or country. Typical examples are the exposure time, building geometry, the

location of exposure in the building and the terrestrial background radiation. The parameters are

selected on the basis of international consensus, as laid down in ICRP, UNSCEAR, EU RP guidelines

and other renowned publications. Product specific parameters such as density and thickness are

specified in accordance with the product’s intended use. In addition the products’ massic activities

226 232 40

of Ra, Th and K are specified and obtained according to prEN 17216 [3]. The method provides

a tiered approach with a basic approach intended for assessing individual construction products,

followed by a more refined approach to assess a complete building design. The former approach

assumes an identical structure of building materials on all six surfaces of the model room, and where

needed complemented with other building materials that form an intrinsic part of the product’s

intended use. The latter approach enables evaluation of a known building design. Here the user can

specify the applied construction product to walls, floor or ceiling separately in accordance with the

product’s intended use.

The indoor gamma dose from the individual construction product as well as the building is expressed

in terms of an annual effective dose from gamma radiation in the indoor environment. The

formulation of the indoor gamma dose in the building is consistent with the dose for indoor external

exposure as stated under Article 75 of the Basic Safety Standards Directive. As a result the described

method enables assessment of the calculated annual dose of the building against the reference level

as defined in the Basic Safety Standards Directive.

The method is designed for assessment of mineral based building materials applied in bulk or

superficially and used as a construction product in buildings. This includes any building materials

that have been identified by EU member states as being of concern from a radiation protection point

of view. The method is envisaged for use by producers of building materials, architects and building

constructors as well as authorities.

It is important to state that following the calculation of dose, any subsequent regulatory classification

falls explicitly outside the scope of this method and is the responsibility of the relevant authorities.

2 Normative references
There are no normative references in this document.
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3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
building material

any construction product for incorporation in a permanent manner in a building or parts thereof and

the performance of which has an effect on the performance of the building with regard to exposure

of its occupants to ionizing radiation
[SOURCE: 2013/59/EURATOM, chapter II, Article 4, (9) [1]]
3.2
building structure

structure consisting of one or more building materials with either vertical or horizontal orientation

or a combination of both, that separate the indoor space from the outdoor space or one space from

another space in the building
3.3
bulk material
building material not being a superficial material
3.4
default material
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building material with an assumed massic activity of 40 Bq/kg Ra, 30 Bq/kg Th and 400 Bq/kg

3.5
effective dose E

sum of the weighted equivalent doses in all the tissues and organs of the body from internal and

external exposure
Note 1 to entry: The effective dose is defined by Formula (1):
E Σ w H ΣΣw w D (1)
TT T TT R R T,R
where
E is the effective dose;
w is the tissue weighting factor for tissue or organ T;
HT is the equivalent dose absorbed by tissue or organ T;
w is the radiation weighting factor;
D is the absorbed dose averaged over tissue or organ T, due to radiation R.
T,R

Note 2 to entry: The values for w and w are specified in Annex II of the EU-BSS [1].

T R
Note 3 to entry: The unit for effective dose is the sievert (Sv).
[SOURCE: 2013/59/EURATOM, chapter II, Article 4, (25) [1]]
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3.6
radionuclide potassium-40
3.7
massic activity
quotient of the activity A of a sample and the mass m of that sample
[SOURCE: EN ISO 80000-10:2019, 10-28 [4]]
3.8
mass per unit area
quotient of mass and area
3.9
226
radionuclide radium-226 and its progenies in secular equilibrium
3.10
reference level

level of effective dose or equivalent dose or massic activity above which it is judged inappropriate to

allow exposures to occur, even though it is not a limit that may not be exceeded
[SOURCE: 2013/59/EURATOM, chapter II, Article 4, (84) [1]]
3.11
sievert
special name of the unit of equivalent or effective dose

Note 1 to entry: One sievert is equivalent to one joule per kilogram: 1 Sv = 1 J/kg. Further details are

provided under 3.4.
[SOURCE: 2013/59/EURATOM, chapter II, Article 4, (91) [1]]
Note 2 to entry: 1 Gy is also 1 J/kg.
3.12
superficial material

building material located on the interior side of the building structure, applied as a protective layer

and/or for decorative purposes, and characterised by a low mass per unit area

Note 1 to entry: Superficial material may also include any other building material with a restricted use

within the building structure, such as joint-filler, insulation material, sanitary ware, etc.

3.13
232
radionuclide thorium-232 and its progenies in secular equilibrium
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4 Symbols and abbreviated terms

This document uses the symbols and names of quantities as mentioned below; the units in which the

quantities shall be expressed are also given.
Symbol Name of quantity Unit
A activity Bq
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a massic activity of Ra, Th or K Bq/kg
d thickness of the construction product m
normalised nuclide specific effective dose rate mSv/h per Bq/kg
E annual effective dose from the building without subtraction of mSv per year
background

EB2 annual effective dose from the building with subtraction of background mSv per year

E European annual average terrestrial background from gamma mSv per year
radiation
E annual effective dose from the construction product mSv per year
i ordinal for the construction product(s) starting with i = 1 for the –
construction product located on the inside of the building structure
j,k,l ordinal –
n number of construction products in the building structure –
ρ density of the construction product kg/m
ρ mass per unit area kg/m
ρ combined mass per unit area of the construction product i plus the kg/m
constructions products that are located in front of construction product
ρ combined mass per unit area of the constructions products that are kg/m
located in front of the construction product i
5 Method for dose assessment
5.1 General

The dose assessment comprises of two approaches to calculate the dose from a single construction

product or an assembly of construction products that make up a building or room. In addition it

calculates the dose of the building by summing the dose from each of the construction products that

make up the building. Subsequently a subtraction of background gamma radiation is applied to

obtain the annual indoor effective dose from gamma radiation.

The method builds on a room geometry with a cuboid shape and six surfaces (Figure 1), not including

any doors or windows. Here the front and back wall (W ) have dimensions of 4 m × 2,5 m, the two

side walls (W ) have dimensions of 3 m × 2,5 m, and the ceiling and floor have dimensions of

3 m × 4 m. The dose is determined for the centre of the room.

Calculation of the dose within the proposed procedure is based on the concept of mass per unit area

, which is the product’s density multiplied with the product’s thickness in its intended use. To

determine the dose from each construction product applied either at all six surfaces or only one,

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shielding effects from the products located in front are considered. For this purpose the parameters

ρ and ρ are introduced. ρ represents the mass per unit area of the construction product of

A1 A2 A1

interest plus all products located in front. ρ represents the mass per unit area of all construction

products located in front of the product that is considered and excludes the mass per unit area of the

product itself. An example is shown in Figure 1. The difference between ρ and ρ is the mass per

A1 A2

unit area of the considered construction product. For this reason it is essential in the assessment to

consider the appropriate order of the construction products, starting from the inside of the building

structure. Where the assessment only considers one construction product, ρ is the product’s mass

per unit area and ρ is 0.

The dose assessment is designed for building structures with a mass per unit area of up to 500 kg/m .

Any part of the building structure located on the outside that exceeds 500 kg/m will have a

negligible effect on the dose and shall be ignored in the calculation.
Key
C Ceiling b = 3 m
F Floor h = 2,5 m
W1 Wall W1 i = ordinal
W2 Wall W2 l = 4 m

NOTE The numbering (i) of the products runs from the inside to the outside of the building structure.

Figure 1 — Sketch of the model room together with a building structure containing three

construction products

The main difference between both assessment approaches described under 5.2 and 5.3 are the

following. The first assessment method for evaluation of a construction product is intended to assess

the dose from an individual product and assumes its application on all six surfaces of the building.

The second assessment method for evaluation of the building design is more refined and enables

specifying multiple construction products for each of the building surfaces, which include the front

and back wall, the two side walls, and the floor and ceiling separately.

Assessment of a single construction product does require that consideration should be given to a

intended use that is intrinsically combined with other bulk products. In that case the adjacent

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construction product shall be considered in the assessment in the form of a default material. For

these circumstances provisions are included to specify appropriate material properties for these

additional materials. Typical scenarios include superficial materials or products intended for

construction as an inner or outer wall.

For both assessment methods the calculated dose from the construction product considers the

properties of the product itself and takes account of any self-attenuation in the product, but it also

takes account of any shielding from the adjacent product(s) located on the inside of the product. It is

therefore important to stress that the calculated dose of the construction product is not an intrinsic

property of the product, but is specific to the composition of the building structure specified in the

assessment.
5.2 Assessment for evaluation of a construction product
5.2.1 Product information
The following information of the construction product should be specified.
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a) Massic activity a of Ra, Th and K expressed in Bq/kg of the construction product obtained

according to prEN 17216.

b) The thickness d and density ρ of the construction product under its intended use expressed in m

3 2

and kg/m respectively, with a minimum mass per unit area ρ of 25 kg/m . In cases where the

mass per unit area is lower, a value of 25 kg/m shall be assumed.

Some construction products such as superficial materials or products intended for construction of

an inner or outer wall, which are by definition used in conjunction with an additional bulk material

and. In the case where the material properties of the additional construction product(s) are not

known, properties should be determined according to items c) and d).

NOTE 1 The additional construction products under consideration are only those that are intrinsically

required as part of the product that is to be assessed; materials such as superficial materials can be ignored.

226 232 40

c) Massic activity a of Ra, Th and K expressed in Bq/kg of the construction product(s) that

are part of the building structure are set to the European default values of respectively 40, 30

and 400.
226 232 40

NOTE 2 The European default massic activities for Ra, Th and K are obtained from the European

radiation protection publication RP 112 [5] and are typical values for concrete.

d) The thickness d and density ρ of the additional construction product(s) under its intended use

that are part of the building structure expressed in m and kg/m respectively, with a minimum

mass per unit area ρ of 25 kg/m per construction product.

The thickness and density should be selected realistically. A guideline for determining the

product properties is to assume a thickness of 0,2 m and a mass per unit area of 470 kg/m for

the whole building structure.

e) The mass per unit area ρ of the building structure shall not exceed 500 kg/m . Where needed

the mass per unit area of the construction product(s) shall be reduced or excluded starting with

the construction product located on the outside.

f) Set the ordinal i for the construction product(s) starting from the inside of the building structure

with i=1.
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oSIST prEN 17637:2021
prEN 17637:2021 (E)
5.2.2 Dose assessment of the construction product

a) Sum the mass per unit area of the construction products i selected for assessment together with

the constructions products that are located in front of the product i, according to Formula (2):

ρ =Σρ d (2)
A1,i j=1 jj
where
ρ is the combined mass per unit area of the construction product i plus the
A1,i

construction products that are located in front of the construction product i, in

kg/m ;
ρ is the density of the construction product, in kg/m ;
d is the thickness of the construction product, in m;
i is the ordinal for the construction product(s) starting with i = 1 for the
construction product located on the inside of the building structure;
j is the ordinal.

b) Sum the mass per unit area of the constructions product(s) that are located in front of the

according to Formula (3). Where i=1
product. Where i > 1 determine the mass per unit area ρA2
there ρ =0.
i−1
(3)
ρ =Σρ d
A2,i j=1 jj
where

ρ is the combined mass per unit area of the construction products that are located

A2,i
in front of the construction product i, in kg/m ;
ρ is the density of the construction product, in kg/m ;
d is the thickness of the construction product, in m;
i is the ordinal for the construction product(s) starting with i = 1 for the
construction product located on the inside of the building structure;
j is the ordinal.
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oSIST prEN 17637:2021
prEN 17637:2021 (E)

c) Calculate the annual effective dose E in mSv per year of the construction product selected for

assessment according to Formula (4). Select the specific dose rate Eρ in Table 1 with the mass

per unit area that is nearest to the calculated mass per unit area ρ or ρ .
A1 A2
 
a ×−E 226 ρ E 226 ρ +
 
226 ( Ra,i Ra,,i k )
A1,,iiA2
Ra,i
 
 
Ea × E 232 ρ− E 232 ρ+× 7000 (4)
( )
Cp,i 232 Th,i A1,,iiTh,,i k A2
Th,i
 
  
aE× 40 ρρ− E 40
40 ( Ki, Ki,,k )
A1,,iiA2
 
Ki,
 
where
E is the annual effective dose from the construction product i, in mSv per year;
Cp,i
a is the massic activity of the construction product, in Bq/kg;
is the normalized nuclide specific effective dose rate obtained from Table 1 in
mSv/h per Bq/kg and is a function of the mass per unit area ρ or ρ ;
A1 A2
ρ is the combined mass per unit area of the construction product i plus the
A1,i

construction products that are located in front of the construction product i, in

kg/m ;

ρ is the combined mass per unit area of the construction products located in front

A2,i
of the construction product i, in kg/m ;
i is the ordinal for the construction product(s) starting with i = 1 for the
construction product located on the inside of the building structure;

7 000 is the occupancy time as an average for the annual time spent indoors in Europe,

in h per year, according to the UNSCEAR 1988 report [6].
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oSIST prEN 176
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