SIST EN ISO 11665-1:2015
(Main)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 11665-1:2012)
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 11665-1:2012)
ISO 11665-1:2012 outlines guidance for measuring radon-222 activity concentration and the potential alpha energy concentration of its short-lived decay products in the air.
The measurement methods fall into three categories:
spot measurement methods;
continuous measurement methods;
integrated measurement methods.
ISO 11665-1:2012 provides several methods commonly used for measuring radon-222 and its short-lived decay products in air.
ISO 11665-1:2012 also provides guidance on the determination of the inherent uncertainty linked to the measurement methods described in its different parts.
Ermittlung der Radioaktivität in der Umwelt - Luft: Radon-222 - Teil 1: Radon und seine kurzlebigen Folgeprodukte: Quellen und Messverfahren (ISO 11665-1:2012)
Mesurage de la radioactivité dans l'environnement - Air: radon 222 - Partie 1: Origine du radon et de ses descendants à vie courte, et méthodes de mesure associées (ISO 11665-1:2012)
L'ISO 11665-1:2012 présente les lignes directrices pour le mesurage de l'activité volumique du radon 222 et de l'énergie alpha potentielle volumique de ses descendants à vie courte dans l'air.
Les méthodes de mesure se divisent en trois catégories:
méthodes de mesure ponctuelle;
méthodes de mesure en continu;
méthodes de mesure intégrée.
L'ISO 11665-1:2012 fournit plusieurs méthodes couramment utilisées pour le mesurage du radon 222 et de ses descendants à vie courte dans l'air.
L'ISO 11665-1:2012 fournit également des lignes directrices relatives à la détermination de l'incertitude relative aux méthodes de mesure décrites dans ses diverses parties.
Merjenje radioaktivnosti v okolju - Zrak: radon-222 - 1. del: Radon in njegovi kratkoživi razpadni produkti: izvori in merilne metode (ISO 11665-1:2012)
ISO 11665-1:2012 navaja smernice za merjenje koncentracije aktivnosti radona-222 in potencialne koncentracije alfa energije njegovih kratkoživih razpadnih produktov v zraku. Merilne metode so razdeljene v tri kategorije: – metode točkovnega merjenja; – metode neprekinjenega merjenja; – metode integriranega merjenja. ISO 11665-1:2012 določa več metod, ki se običajno uporabljajo za merjenje radona-222 in njegovih kratkoživih razpadnih produktov v zraku. ISO 11665-1:2012 določa tudi smernice za ugotavljanje temeljne negotovosti v povezavi z merilnimi metodami, opisanimi v različnih delih tega standarda.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 11665-1:2015
01-november-2015
Merjenje radioaktivnosti v okolju - Zrak: radon-222 - 1. del: Radon in njegovi
kratkoživi razpadni produkti: izvori in merilne metode (ISO 11665-1:2012)
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
11665-1:2012)
Ermittlung der Radioaktivität in der Umwelt - Luft: Radon-222 - Teil 1: Radon und seine
kurzlebigen Folgeprodukte: Quellen und Messverfahren (ISO 11665-1:2012)
Mesurage de la radioactivité dans l'environnement - Air: radon 222 - Partie 1: Origine du
radon et de ses descendants à vie courte, et méthodes de mesure associées (ISO
11665-1:2012)
Ta slovenski standard je istoveten z: EN ISO 11665-1:2015
ICS:
13.040.99 Drugi standardi v zvezi s Other standards related to air
kakovostjo zraka quality
17.240 Merjenje sevanja Radiation measurements
SIST EN ISO 11665-1:2015 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 11665-1:2015
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SIST EN ISO 11665-1:2015
EN ISO 11665-1
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2015
EUROPÄISCHE NORM
ICS 17.240
English Version
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 11665-1:2012)
Mesurage de la radioactivité dans l'environnement - Ermittlung der Radioaktivität in der Umwelt - Luft:
Air: radon 222 - Partie 1: Origine du radon et de ses Radon-222 - Teil 1: Radon und seine kurzlebigen
descendants à vie courte, et méthodes de mesure Folgeprodukte: Quellen und Messverfahren (ISO
associées (ISO 11665-1:2012) 11665-1:2012)
This European Standard was approved by CEN on 12 June 2015.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11665-1:2015 E
worldwide for CEN national Members.
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SIST EN ISO 11665-1:2015
EN ISO 11665-1:2015 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 11665-1:2015
EN ISO 11665-1:2015 (E)
European foreword
The text of ISO 11665-1:2012 has been prepared by Technical Committee ISO/TC 85 “Nuclear energy,
nuclear technologies, and radiological protection” of the International Organization for Standardization
(ISO) and has been taken over as EN ISO 11665-1:2015 by Technical Committee CEN/TC 430 “Nuclear
energy, nuclear technologies, and radiological protection” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2016, and conflicting national standards shall
be withdrawn at the latest by March 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 11665-1:2012 has been approved by CEN as EN ISO 11665-1:2015 without any
modification.
3
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SIST EN ISO 11665-1:2015
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SIST EN ISO 11665-1:2015
INTERNATIONAL ISO
STANDARD 11665-1
First edition
2012-07-15
Measurement of radioactivity in the
environment — Air: radon-222 —
Part 1:
Origins of radon and its short-lived
decay products and associated
measurement methods
Mesurage de la radioactivité dans l’environnement — Air: radon 222 —
Partie 1: Origine du radon et de ses descendants à vie courte, et
méthodes de mesure associées
Reference number
ISO 11665-1:2012(E)
©
ISO 2012
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2012 – All rights reserved
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms and definitions . 1
3.2 Symbols . 8
4 Principle . 9
5 Equipment . 9
6 Sampling .10
6.1 General .10
6.2 Sampling objective .10
6.3 Sampling characteristics .10
6.4 Sampling conditions . 11
7 Detection .12
7.1 Silver-activated zinc sulphide ZnS(Ag) scintillation .12
7.2 Gamma-ray spectrometry .13
7.3 Liquid scintillation .13
7.4 Air ionization .13
7.5 Semi-conductor (alpha detection) .13
7.6 Solid-state nuclear track detectors (SSNTD) .13
7.7 Discharge of polarised surface inside an ionization chamber .13
8 Measurement .13
8.1 Methods .13
8.2 Influence quantities .14
8.3 Calibration .15
8.4 Quality control .15
9 Expression of results .15
10 Test report .15
Annex A (informative) Radon and its decay products — General information .17
Annex B (informative) Example of results of spot, integrated and continuous measurements of
radon-222 activity concentration .25
Annex C (informative) Example of a test report .27
Bibliography .28
© ISO 2012 – All rights reserved iii
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 11665-1 was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies, and
radiological protection, Subcommittee SC 2, Radiological protection.
ISO 11665 consists of the following parts, under the general title Measurement of radioactivity in the
environment — Air: radon-222:
— Part 1: Origins of radon and its short-lived decay products and associated measurement methods
— Part 2: Integrated measurement method for determining average potential alpha energy concentration of
its short-lived decay products
— Part 3: Spot measurement method of the potential alpha energy concentration of its short-lived decay products
— Part 4: Integrated measurement method for determining average activity concentration using passive
sampling and delayed analysis
— Part 5: Continuous measurement method of the activity concentration
— Part 6: Spot measurement method of the activity concentration
— Part 7: Accumulation method for estimating surface exhalation rate
— Part 8: Methodologies for initial and additional investigations in buildings
The following parts are under preparation:
— Part 9: Method for determining exhalation rate of dense building materials
— Part 10: Determination of diffusion coefficient in waterproof materials using activity concentration measurement
iv © ISO 2012 – All rights reserved
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
Introduction
Radon isotopes 222, 220 and 219 are radioactive gases produced by the disintegration of radium isotopes 226,
224 and 223, which are decay products of uranium-238, thorium-232 and uranium-235 respectively, and are
all found in the earth’s crust (see Annex A for further information). Solid elements, also radioactive, followed by
[1]
stable lead are produced by radon disintegration .
Radon is considered a noble gas in the periodic table of elements, along with helium, argon, neon, krypton and
xenon.
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 decay products rather
than the gas itself. Whether or not they are attached to atmospheric aerosols, radon decay products can be
[2][3][4][5]
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
[6]
(2006) report suggests that, at the worldwide level, radon accounts for around 52 % of global average
exposure to natural radiation. The radiological impact of isotope 222 (48 %) is far more significant than isotope
220 (4 %), while isotope 219 is considered negligible (see Annex A). For this reason, references to radon in this
part of ISO 11665 refer only to radon-222.
Radon activity concentration can vary by one to multiple orders of magnitude over time and space. Exposure
to radon and its decay products varies tremendously from one area to another, as it depends firstly on the
amount of radon emitted by the soil and the building materials in each area and, secondly, on the degree of
containment and weather conditions in the areas where individuals are exposed.
The values usually found in the continental environment are normally between a few becquerels per cubic
metre and several thousand becquerels per cubic metre. Activity concentrations of less than one becquerel per
cubic metre may be observed in the oceanic environment. Radon activity concentrations vary inside houses
[7]
from several tens of becquerels per cubic metre to several hundreds of becquerels per cubic metre . Activity
concentration can reach several thousands of becquerels per cubic metre in very confined spaces. Variations
of a few nanojoules per cubic metre to several thousand nanojoules per cubic metre are observed for the
potential alpha energy concentration of short-lived radon decay products.
ISO 11665 consists of 10 parts (see Figure 1) dealing with:
— measurement methods for radon-222 and its short-lived decay products (see ISO 11665-2, ISO 11665-3,
ISO 11665-4, ISO 11665-5 and ISO 11665-6);
NOTE 1 There are many methods for measuring the radon-222 activity concentration and the potential alpha energy
concentration of its short-lived decay products. The choice of measurement method will depend on the expected level of
[8][9]
concentration and on the intended use of the data, such as scientific research and health-related assessments .
— measurement methods for the radon-222 exhalation rate (see ISO 11665-7 and ISO 11665-9);
NOTE 2 ISO 11665-7 refers back to ISO 11665-5 and ISO 11665-6.
— measurement methods for the radon-222 diffusion coefficient (see ISO 11665-10);
— methodologies for radon-222 measurements in buildings (see ISO 11665-8).
NOTE 3 ISO 11665-8 refers back to ISO 11665-4 for radon measurements for initial investigation purposes in a building
and to ISO 11665-5, ISO 11665-6 and ISO 11665-7 for measurements for any additional investigation.
© ISO 2012 – All rights reserved v
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
ISO 11665-1
Origins of radon and its
short-lived decay products
and associated
measurement methods
MEASUREMENT APPLICATION
ISO 11665-2 ISO 11665-4
ISO 11665-7
Integrated measurement Integrated measurement
Accumulation method
method for determining method for determining
for estimating surface
average potential alpha energy average activity concentration
exhalation rate
concentration of its short-lived using passive sampling and
delayed analysis
decay products
ISO 11665-3
ISO 11665-5 11665-8
Spot measurement method
Continuous measurement Methodologies for initial
of the potential alpha energy
method of the activity and additional investigations
concentration of its short-lived
concentration in buildings
decay products
ISO 11665-6 11665-9
Spot measurement Method for determining
method of the activity exhalation rate of
concentration dense building materials
ISO 11665-10
Determination of diffusion
coefficient in waterproof
materials using activity
concentration measurement
Figure 1 — Structure of the ISO 11665 series
vi © ISO 2012 – All rights reserved
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SIST EN ISO 11665-1:2015
INTERNATIONAL STANDARD ISO 11665-1:2012(E)
Measurement of radioactivity in the environment — Air:
radon-222 —
Part 1:
Origins of radon and its short-lived decay products and
associated measurement methods
1 Scope
This part of ISO 11665 outlines guidance for measuring radon-222 activity concentration and the potential
alpha energy concentration of its short-lived decay products in the air.
The measurement methods fall into three categories:
a) spot measurement methods;
b) continuous measurement methods;
c) integrated measurement methods.
This part of ISO 11665 provides several methods commonly used for measuring radon-222 and its short-lived
decay products in air.
This part of ISO 11665 also provides guidance on the determination of the inherent uncertainty linked to the
measurement methods described in its different parts.
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/IEC 17025, General requirements for the competence of testing and calibration laboratories
IEC 61577-1, Radiation protection instrumentation — Radon and radon decay product measuring instruments —
Part 1: General principles
IEC 61577-2, Radiation protection instrumentation — Radon and radon decay product measuring instruments —
Part 2: Specific requirements for radon measuring instruments
IEC 61577-3, Radiation protection instrumentation — Radon and radon decay product measuring instruments —
Part 3: Specific requirements for radon decay product measuring instruments
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
active sampling
sampling using active devices like pumps for sampling the atmosphere
[IEC 61577-1:2006]
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
3.1.2
activity
disintegration rate
number of spontaneous nuclear disintegrations occurring in a given quantity of material during a suitably small
interval of time divided by that interval of time
[ISO 921:1997, term 23]
NOTE 1 Activity, A, is expressed by the relationship given in Formula (1):
AN=⋅λ (1)
where
λ is the decay constant per second;
N is the number of atoms.
NOTE 2 The decay constant is linked to the radioactive half-life by the relationship:
ln 2
λ = (2)
T
12/
where
T is the radioactive half-life, in seconds.
1/2
3.1.3
activity concentration
activity per unit volume
[IEC 61577-1:2006]
3.1.4
attached fraction
fraction of the potential alpha energy concentration of short-lived decay products that is attached to the
ambient aerosol
[IEC 61577-1:2006]
NOTE The sizes of the carrier aerosol to which most of the short-lived decay products are attached are generally in
the 0,1 μm to 0,3 μm range of median values.
3.1.5
average activity concentration
exposure to activity concentration divided by the sampling duration
3.1.6
average potential alpha energy concentration
exposure to potential alpha energy concentration divided by the sampling duration
3.1.7
background noise
signals caused by something other than the radiation to be detected
NOTE A distinction can be made between signals caused by radiation from sources inside or outside the detector
other than those targeted for the measurements and signals caused by defects in the detection system electronic circuits
and their electrical power supply.
2 © ISO 2012 – All rights reserved
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
3.1.8
continuous measurement
measurement obtained by taking a sample continuously (or at integration intervals typically in range of 1 min to
120 min) with simultaneous or slightly delayed analysis
NOTE 1 The sampling duration shall be adapted to the dynamics of the phenomenon studied to monitor the evolution
of radon activity concentration over time.
NOTE 2 See Annex B for further information.
3.1.9
diffusion length
distance crossed by an atom due to diffusion forces before decaying
NOTE Diffusion length, l, is expressed by the relationship given in Formula (3):
1
2
D
l = (3)
λ
where
D is the diffusion coefficient, in square metres per second;
λ is the decay constant per second.
3.1.10
equilibrium factor
ratio of the potential alpha energy concentration of short-lived radon decay products in a given volume of air
to the potential alpha energy concentration of these decay products if these are in radioactive equilibrium with
radon in the same volume of air
222
NOTE 1 The short-lived Rn decay products present in an atmosphere are very rarely in radioactive equilibrium with
their parent (through being trapped on the walls or eliminated by an air renewal system, for example) and the equilibrium
factor is used to qualify this state of “non-equilibrium”.
NOTE 2 The equilibrium factor is between 0 and 1. The equilibrium factor in buildings typically varies between 0,1 and
[4][6]
0,9, with an average value equal to 0,4 .
NOTE 3 The equilibrium factor, F , is expressed by Formula (4):
eq
E
PAEC,222
Rn
F = (4)
eq
−9
55, 71⋅×0 C
222
Rn
where
222
is the potential alpha energy concentration of Rn, in joules per cubic metre;
E
PAEC,222
Rn
222
−9
is the potential alpha energy concentration of the short-lived Rn decay products for 1 Bq of
55, 71× 0
222
Rn in equilibrium with its short-lived decay products, in joules per becquerel;
222
is the activity concentration of Rn, in becquerels per cubic metre.
C
222
Rn
3.1.11
grab sampling
collection of a sample (i.e of air containing radon or aerosol particles) during a period considered short
compared with the fluctuations of the quantity under study (i.e volume activity of air)
[IEC 61577-1:2006]
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
3.1.12
guideline value
value which corresponds to scientific, legal or other requirements and which is intended to be assessed by the
measurement procedure
NOTE 1 The guideline value can be given, for example, as an activity, a specific activity or an activity concentration, a
surface activity, or a dose rate.
NOTE 2 The comparison of the detection limit with a guideline value allows a decision on whether or not the measurement
procedure satisfies the requirements set forth by the guideline value and is therefore suitable for the intended measurement
purpose. The measurement procedure satisfies the requirement if the detection limit is smaller than the guideline value.
[ISO 11929:2010, term 3.10]
3.1.13
integrated measurement
measurement performed by continuous sampling of a volume of air which, over time, is accumulating physical
quantities (number of nuclear tracks, number of electric charges, etc.) linked to the disintegration of radon
and/or its decay products, followed by analysis at the end of the accumulation period
NOTE See Annex B for further information.
3.1.14
long-term measurement
measurement based on an air sample collected within a period greater than one month
3.1.15
measurand
quantity intended to be measured
[ISO/IEC Guide 99:2007, term 2.3]
3.1.16
measuring system
set of one or more measuring instruments and often other devices, including any reagent and supply, assembled
and adapted to give information used to generate measured quantity values within specified intervals for
quantities of specified kinds
[ISO/IEC Guide 99:2007, term 3.2]
3.1.17
passive sampling
sampling using no active devices such as pumps for sampling the atmosphere, whereby in most instruments
sampling is performed mainly by diffusion
NOTE Adapted from IEC 61577-1:2006.
3.1.18
potential alpha energy of short-lived radon decay products
total alpha energy emitted during the decay of atoms of short-lived radon decay products along the decay chain
210 222
through to Pb for the decay chains of the Rn
222
NOTE 1 The potential alpha energy of short-lived Rn decay products, E , is expressed by Formula (5):
PAE,222
Rn
EE+ ⋅ N
()AE,218 AE,214 ()218
Po Po Po
E = (5)
PAE,222
Rn
+⋅EN ++NE+⋅ N
AE,214 ()214 214 AE,214 ()214
Po Pb Bi Po Po
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SIST EN ISO 11665-1:2015
ISO 11665-1:2012(E)
where
218
is the alpha particle energy produced by the disintegration of Po, in joules;
E
AE,218
Po
214
is the alpha particle energy produced by the disintegration of Po, in joules;
E
AE,214
Po
218
is the number of atoms of Po;
N
218
Po
214
is the number of atoms of Pb;
N
214
Pb
214
is the number of atoms of Bi;
N
214
Bi
214
is the number of atoms of Po.
N
214
Po
NOTE 2 The total alpha energy emitted during the decay of atoms of short-lived radon decay products along the decay
208 220
chain through to Pb for the decay chains of the Rn is expressed by Formula (6):
EE+⋅03,,60+⋅64 EN⋅
()AE,216 AE,212 AE,212 ()216
Po Bi Po Poo
E = (6)
PAE,220
Rn
+⋅03,,60EE+⋅64 ⋅+NN +E ⋅ N
() () ()
AE,212 AE,212 212 212 AE,2112 212
Bi Po Pb Bi Po Po
where
220
is the potential alpha energy of Rn, in joules;
E
PAE,220
Rn
216
E is the alpha particle energy produced by the disintegration of Po, in joules;
AE,216
Po
212
is the alpha particle energy produced by the disintegration of Bi, in joules;
E
AE,212
Bi
212
is the alpha particle energy produced by the disintegration of Po, in joules;
E
AE,212
Po
212
is the number of atoms of Pb;
N
212
Pb
212
N is the number of atoms of Bi;
212
Bi
212
is the number of atoms of Po.
N
212
Po
3.1.19
potential alpha energy concentration of short-lived radon decay products
concentration of any mixture of short-lived radon decay products in air in terms of the al
...
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