EN ISO 6980-1:2025

SLOVENSKI STANDARD
01-december-2025
Jedrska energija - Referenčno sevanje delcev beta - 1. del: Metode izdelave (ISO
6980-1:2023)
Nuclear energy - Reference beta-particle radiation - Part 1: Methods of production (ISO
6980-1:2023)
Énergie nucléaire - Rayonnement bêta de référence - Partie 1: Méthodes de production
(ISO 6980-1:2023)
Ta slovenski standard je istoveten z: EN ISO 6980-1:2025
ICS:
17.240 Merjenje sevanja Radiation measurements
27.120.01 Jedrska energija na splošno Nuclear energy in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 6980-1
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2025
EUROPÄISCHE NORM
ICS 17.240
English Version
Nuclear energy - Reference beta-particle radiation - Part 1:
Methods of production (ISO 6980-1:2023)
Énergie nucléaire - Rayonnement bêta de référence -
Partie 1: Méthodes de production (ISO 6980-1:2023)
This European Standard was approved by CEN on 22 September 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, 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, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6980-1:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 6980-1:2023 has been prepared by Technical Committee ISO/TC 85 "Nuclear energy,
nuclear technologies, and radiological protection” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 6980-1:2025 by Technical Committee CEN/TC 430 “Nuclear
energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2026, and conflicting national standards shall
be withdrawn at the latest by March 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, 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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 6980-1:2023 has been approved by CEN as EN ISO 6980-1:2025 without any
modification.
INTERNATIONAL ISO
STANDARD 6980-1
Third edition
2023-11
Nuclear energy — Reference beta-
particle radiation —
Part 1:
Methods of production
Énergie nucléaire — Rayonnement bêta de référence —
Partie 1: Méthodes de production
Reference number
ISO 6980-1:2023(E)
ISO 6980-1:2023(E)
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 6980-1:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Requirements for reference beta-particle radiation fields at the calibration distance .2
4.1 Standard test conditions . 2
4.2 Energy of the reference radiation fields . 2
4.3 Shape of the beta-particle spectrum . 2
4.4 Uniformity of the dose rate . 3
4.5 Photon contamination . 3
4.6 Variation of the beta-particle emission with time . 3
5 Radionuclides suitable for reference beta-particle radiation fields .3
6 Source characteristics and their measurement . 4
6.1 Fundamental characteristics of reference sources . 4
6.1.1 Construction of reference sources . 4
6.1.2 Measurement and/or simulation of characteristics of the reference
radiation fields . 4
6.1.3 Beta particle contamination . 13
6.1.4 Photon contamination . 13
6.2 Characteristics of the two series of reference beta-particle radiation fields .13
6.2.1 General .13
6.2.2 Series 1 reference beta-particle radiation fields .13
6.2.3 Series 2 reference beta-particle radiation fields . 14
7 Source calibration .15
Annex A (normative) Tissue substitutes .17
Annex B (normative) Reference conditions and standard test conditions .18
Annex C (informative) Characteristics of the recommended sources —Examples of source
construction .20
Bibliography .21
iii
ISO 6980-1:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies,
and radiological protection, Subcommittee SC 2, Radiological protection.
This third edition of ISO 6980-1 cancels and replaces ISO 6980-1:2022, of which it constitutes a minor
revision.
The main changes are as follows:
— editorial changes throughout the document.
A list of all the parts in the ISO 6980 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO 6980-1:2023(E)
Introduction
ISO 6980 series covers the production, calibration, and use of reference beta-particle radiation fields for
the calibration of dosemeters and dose-rate meters for protection purposes. This document describes
the methods of production and characterization of the reference radiation. ISO 6980-2 describes
procedures for the determination of absorbed dose rate to a reference depth of tissue from beta particle
reference radiation fields. ISO 6980-3 describes procedures for the calibration of dosemeters and dose-
rate meters and the determination of their response as a function of beta-particle energy and angle of
beta-particle incidence.
For beta particles, the calibration and the determination of the response of dosemeters and dose-rate
meters is essentially a three-step process. First, the basic field quantity, absorbed dose to tissue at
a depth of 0,07 mm (and optionally also at a depth of 3 mm) in a tissue-equivalent slab geometry is
measured at the point of test, using methods described in ISO 6980-2. Then, the appropriate operational
quantity is derived by the application of a conversion coefficient that relates the quantity measured
(reference absorbed dose) to the selected operational quantity for the selected irradiation geometry.
Finally, the reference point of the device under test is placed at the point of test for the calibration
and determination of the response of the dosemeter. Depending on the type of dosemeter under test,
the irradiation is either carried out on a phantom or free-in-air for personal and area dosemeters,
respectively. For individual and area monitoring, this document describes the methods and the
conversion coefficients to be used for the determination of the response of dosemeters and dose-rate
meters in terms of the ICRU operational quantities, i.e., directional dose equivalent, H′(0,07;Ω) and
H′(3;Ω), as well as personal dose equivalent, H (0,07) and H (3).
p p
v
INTERNATIONAL STANDARD ISO 6980-1:2023(E)
Nuclear energy — Reference beta-particle radiation —
Part 1:
Methods of production
1 Scope
This document specifies the requirements for reference beta radiation fields produced by radioactive
sources to be used for the calibration of personal and area dosemeters and dose-rate meters to be used
for the determination of the quantities H (0,07), H'(0,07;Ω), H (3) and H'(3;Ω), and for the determination
p p
of their response as a function of beta particle energy and angle of incidence. The basic quantity in beta
dosimetry is the absorbed-dose rate in a tissue-equivalent slab phantom. This document gives the
characteristics of radionuclides that have been used to produce reference beta radiation fields, gives
examples of suitable source constructions and describes methods for the measurement of the residual
maximum beta particle energy and the dose equivalent rate at a depth of 0,07 mm in the International
Commission on Radiation Units and Measurements (ICRU) sphere. The energy range involved lies
between 0,22 MeV and 3,6 MeV maximum beta energy corresponding to 0,07 MeV to 1,2 MeV mean beta
−1
-1
energy and the dose equivalent rates are in the range from about 10 µSv·h to at least 10 Svh·. In
addition, for some sources, variations of the dose equivalent rate as a function of the angle of incidence
[5]
are given. However, as noted in ICRU 56 , the ambient dose equivalent, H*(10), used for area
monitoring, and the personal dose equivalent, H (10), as used for individual monitoring, of strongly
p
penetrating radiation, are not appropriate quantities for any beta radiation, even that which penetrates
10 mm of tissue (E > 2 MeV).
max
This document is applicable to two series of reference beta radiation fields, from which the radiation
necessary for determining the characteristics (calibration and energy and angular dependence of
response) of an instrument can be selected.
Series 1 reference radiation fields are produced by radioactive sources used with beam-flattening
filters designed to give uniform dose equivalent rates over a large area at a specified distance. The
106 106 90 90 85 204 147
proposed sources of Ru/ Rh, Sr/ Y, Kr, Tl and Pm produce maximum dose equivalent
–1
rates of approximately 200 mSv·h .
Series 2 reference radiation fields are produced without the use of beam-flattening filters, which allows
large area planar sources and a range of source-to-calibration plane distances to be used. Close to the
sources, only relatively small areas of uniform dose rate are produced, but this series has the advantage
of extending the energy and dose rate ranges beyond those of series 1. The series also include radiation
fields using polymethylmethacrylate (PMMA) absorbers to reduce the maximum beta particle energy.
The radionuclides used are those of series 1; these sources produce dose equivalent rates of up
–1
to 10 Sv·h .
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 29661, Reference radiation fields for radiation protection — Definitions and fundamental concepts
ISO/IEC Guide 99, International vocabulary of metrology — Basic and general concepts and associated
terms (VIM)
ISO 6980-1:2023(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 29661, ISO/IEC Guide 99 and
the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
tissue equivalence
property of a material that approximates the radiation attenuation and scattering properties of ICRU
tissue
[4]
Note 1 to entry: See Annex A; more tissue substitutes are given by ICRU 44 .
Note 2 to entry: Further details are given in ISO 6980-2:2023, 6.2.
3.2
maximum beta energy
E
max
highest value of the energy of beta particles emitted by a particular radionuclide which can emit one or
several continuous spectra of beta particles with different maximum energies
3.3
mean beta energy
E
mean
fluence averaged energy of the beta particle spectrum at the calibration distance free in air
3.4
residual maximum beta energy
E
res
highest value of the energy of a beta-particle spectrum at the calibration distance after having been
modified by scattering and absorption
3.5
residual maximum beta particle range
R
res
range in an absorbing material of a beta-particle spectrum of residual maximum energy, E
res
4 Requirements for reference beta-particle radiation fields at the calibration
distance
4.1 Standard test conditions
All calibrations and measurements shall be conducted under standard test conditions in accordance
with Tables B.1 and B.2. The range of values of influence quantities within the standard test conditions
are given in Tables B.1 and B.2 for radiation-related and other parameters, respectively.
4.2 Energy of the reference radiation fields
The energy of the reference radiation field is defined to be equal to E (see 3.4 and 6.1.2).
res
4.3 Shape of the beta-particle spectrum
The beta-particle spectrum of the reference radiation should ideally result from one beta decay branch
from one radionuclide. In practice, the emission of more than one branch is acceptable provided that all
ISO 6980-1:2023(E)
the main branches have similar energies, E , within ±20 %. In other cases, the lower energy branches
max
shall be attenuated by the source encapsulation or by additional filtration to reduce their beta emission
rates to less than 10 % of the emission rate from the main branch.
4.4 Uniformity of the dose rate
The dose rate at the calibration distance should be as uniform as possible over the area of the detector.
Since available sources for series 1 reference radiation fields (see 6.2.2) cannot at present produce high
absorbed dose rates with satisfactory uniformity for large radiation field diameters, a further series
(series 2) of reference beta-particle radiation fields is proposed (see 6.2.3). A beta-particle radiation
field is considered to be uniform over a certain radiation field diameter if the dose rate does not vary by
more than ±5 % for E ≥ 300 keV and by not more than ±10 % for E < 300 keV (see 6.2.2).
res res
4.5 Photon contamination
The photon dose rate contributing to the total dose rate due to contamination of the reference radiation
by gamma, X-ray and bremsstrahlung radiation, H , should be less than 2 % of the beta particle
photon
dose rate, H , i.e. H /H < 0,02. This shall be valid for the considered quantity, i.e. for H (0,07),
beta photon beta p
H'(0,07;Ω), H (3) or H'(3;Ω).
p
Regarding the determination of the photon contribution and the indication of the instrument under test
see 6.1.4.
4.6 Variation of the beta-particle emission with time
The beta-particle emission rate decreases with time due to the radioactive decay of the beta emitting
radionuclide. The half-life of a radionuclide should be as long as possible, preferably longer than one
year. The half-lives of the recommended sources are given in Table 1.
5 Radionuclides suitable for reference beta-particle radiation fields
Table 1 gives the characteristics of beta-emitting radionuclides of a suitable energy range. Beta-emitters
should be selected from those listed in this table. These radionuclides emit a continuous spectrum
of beta particles with energies ranging from zero up to a maximum value, E , characteristic of the
max
particular nuclide.
A radionuclide normally requires encapsulation to be a source which may be handled. Such encapsulating
material produces bremsstrahlung and characteristic X-rays.
ISO 6980-1:2023(E)
Table 1 — Beta-emitting radionuclide data
a ab ac
Radionuclide Half life Maximum energy emitted Photon radiation
E (approximate values) (approximate values)
days
max
MeV
Pm 958,18 (0,15) 0,224 γ: 0,121 MeV (0,002 7 %)
Sm X-rays:  5,0 to 7,5 keV
39,5 to 46,8 keV
Kr 3 922 (5) 0,687 γ: 0,514 MeV (0,44 %)
Rb X-rays: 13,3 to 15,2 keV
Tl 1 382 (4) 0,764 γ: none
Hg X-rays:  8,7 to 14,8 keV
68,9 to 83,0 keV
Pb X-rays:  72,8 to 87,9 keV
90 90 d
Sr/ Y 10 559 (11) 2,279 Negligible
106 106 106
Ru/ Rh 371,8 (1,8) 3,546 Rh γ:  0,512 MeV (21 %)
0,616 MeV (0,7 %)
0,622 MeV (10 %)
0,87 MeV (0,4 %)
1,05 MeV (1,5 %)
1,13 MeV (0,4 %)
1,56 MeV (0,16 %)
Pd X-rays: 2,5 to 24,3 keV
a
The values in this column are taken from the Nuclear Data Sheets (NDS); the values in brackets are the standard
[6][7][8][9][10]
uncertainties .
b
The values given in this column are for information purposes only.
c
The values in brackets are emission probabilities per decay.
d
"Negligible" indicates levels of emissions that do not affect the detection of beta radiation.
6 Source characteristics and their measurement
6.1 Fundamental characteristics of reference sources
6.1.1 Construction of reference sources
The construction of the reference sources should have the following characteristics to meet the
requirements of Clause 4.
a) The chemical form of the radionuclide should be stable with time over the range of temperatures
and humidities at which it is used and stored.
b) The construction and encapsulation constituting the source containment should be sufficiently
robust and stable to withstand normal use without damage to the source and leakage of the
radioactivity but shall allow E to exceed the minimum values recommended in Table 2.
res
c) The typical set of radionuclides shown in Table 2 can be complemented by two energy-reduced
90 90
radiation fields from Sr/ Y sources. Such fields can be obtained by placing 3 mm or 4 mm thick
polymethylmethacrylate (PMMA) absorbers in front of the source. The absorber shall be positioned
with its end face 4 cm from the source, i.e. with its front face 3,7 cm and 3,6 cm for the 3 mm and
[11][12]
4 mm plate, respectively, and its diameter shall be at least 20 cm .
6.1.2 Measurement and/or simulation of characteristics of the reference radiation fields
The values of the residual maximum beta energy, E , shall equal or exceed the values given in Table 2.
res
ISO 6980-1:2023(E)
Table 2 — Minimum value of the residual maximum beta energy, E , at the calibration
res,min
distance
E
res,min
Radionuclide
MeV
Pm 0,13
Kr 0,53
Tl 0,53
90 90
Sr/ Y 1,80
106 106
Ru/ Rh 2,50
The purpose in setting a lower limit to E is to prevent the use of sources that have excessive self and/
res
or window absorption.
[13]
The residual maximum beta energy, E , shall be calculated from Formula (1) :
res
 
ER=⋅()0,/009 11+ −1224, (1)
resres
 
where
E is expressed in MeV and R is the residual maximum beta particle range, expressed in milligrams
res res
-2
per square centimetre (mg·cm ).
R shall be measured by a suitable detector (extrapolation chamber, thin-window ionization chamber,
res
Geiger Müller counter, beta-sensitive phosphor, etc.) that shall be positioned at the calibration
distance with its entrance window facing the source. For the measurements, various thicknesses
of absorber shall be placed immediately in front of the detector. The absorber shall be made of a
tissue-equivalent substance, e.g. PMMA, polystyrene, polyethylene, polyethylene terephthalate
(PET) or an equivalent material. A list of tissue-equivalent substances is given in Annex A. The
thickness of the detector window used for these measurements shall be taken into account in
the measurement of R . If the source uses a beam-flattening filter, i.e. a series 1 reference ra-
res
diation is produced (see 6.2.2), then this filter shall be in position for the measurement of R .
res
The signal from the detector shall be determined as a function of absor
...