1、BSI Standards PublicationBS ISO 13164-4:2015Water quality Radon-222Part 4: Test method using two-phase liquidscintillation countingBS ISO 13164-4:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 13164-4:2015.The UK participation in its preparation was entru
2、sted to TechnicalCommittee EH/3/8, Radioactivity measurements methods.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplicat
3、ion. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 81397 9ICS 13.060.60; 13.280; 17.240Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Str
4、ategy Committee on 30 June 2015.Amendments issued since publicationDate Text affectedBS ISO 13164-4:2015 ISO 2015Water quality Radon-222 Part 4: Test method using two-phase liquid scintillation countingQualit de leau Radon 222 Partie 4: Mthode dessai par comptage des scintillations en milieu liquide
5、 deux phasesINTERNATIONAL STANDARDISO13164-4First edition2015-06-15Reference numberISO 13164-4:2015(E)BS ISO 13164-4:2015ISO 13164-4:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this p
6、ublication 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 ISOs member body in the c
7、ountry of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 13164-4:2015ISO 13164-4:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions and
8、symbols 13.1 Terms and definitions . 13.2 Symbols and abbreviated terms. 14 Principle 25 Reagents and apparatus . 25.1 Reagents 25.2 Apparatus 36 Sampling 36.1 General . 36.2 Sampling with source preparation “on site” 36.3 Sampling without “on site” source preparation . 47 Instrument set up and cali
9、bration . 47.1 Preparation of calibration sources 47.2 Optimization of counting conditions . 47.3 Detection efficiency. 47.4 Blank sample preparation and measurement 58 Sample preparation and measurement 59 Expression of results 69.1 Calculation of activity per unit of mass 69.2 Standard uncertainty
10、 . 69.3 Decision threshold . 69.4 Detection limit . 79.5 Confidence limits. 79.6 Calculations using the activity concentration 710 Interference control 811 Quality control 812 Test report . 8Annex A (informative) Set-up parameters and validation data 9Bibliography .12 ISO 2015 All rights reserved ii
11、iContents PageBS ISO 13164-4:2015ISO 13164-4:2015(E)ForewordISO (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. Eac
12、h 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 Internation
13、al 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
14、types of ISO documents 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).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not
15、be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is infor
16、mation given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see t
17、he following URL: Foreword Supplementary information .The committee responsible for this document is ISO/TC 147, Water quality, Subcommittee SC 3, Radioactivity measurements.ISO 13164 consists of the following parts, under the general title Water quality Radon-222: Part 1: General principles Part 2:
18、 Test method using gamma-ray spectrometry Part 3: Test method using emanometry Part 4: Test method using two-phase liquid scintillation countingiv ISO 2015 All rights reservedBS ISO 13164-4:2015ISO 13164-4:2015(E)IntroductionRadioactivity from several naturally occurring and anthropogenic sources is
19、 present throughout the environment. Thus, water bodies (surface waters, ground waters, sea waters) can contain radionuclides of natural or human-made origin, or both. Natural radionuclides, including potassium-40, and those originating from the thorium and uranium decay series, in particular radium
20、-226, radium-228, uranium-234, uranium-238, and lead-210, can be found in water for natural reasons (e.g. desorption from the soil and wash-off by rain water) or can be released from technological processes involving naturally occurring radioactive materials (e.g. the mining and processing of minera
21、l sands or phosphate fertilizer production and use). Human-made radionuclides such as transuranium elements (americium, plutonium, neptunium, curium), tritium, carbon-14, strontium-90, and some gamma-emitting radionuclides can also be found in natural waters as a result of authorized routine release
22、s into the environment in small quantities in the effluent discharged from nuclear fuel cycle facilities. They are also released into the environment following their use in unsealed form in medicine or industrial applications. They are also found in the water as a result of past fallout resulting fr
23、om explosion in the atmosphere of nuclear devices and accidents such as those that occurred in Chernobyl and Fukushima.Drinking water can, thus, contain radionuclides at activity concentration which could present a risk to human health. In order to assess the quality of drinking water (including min
24、eral waters and spring waters) with respect to its radionuclide content and to provide guidance on reducing health risks by taking measures to decrease radionuclide activity concentrations, water resources (groundwater, river, lake, sea, etc.) and drinking water are monitored for their radioactivity
25、 content as recommended by the World Health Organization (WHO) and may be required by some national authorities.Standard test methods for radon-222 activity concentrations in water samples are needed by test laboratories carrying out such measurements in fulfilment of national authority requirements
26、.Laboratories may have to obtain a specific accreditation for radionuclide measurement in drinking water samples.The radon activity concentration in surface water is very low, usually below 1 Bq l1. In groundwater, the activity concentration varies from 1 Bq l1up to 50 Bq l1in sedimentary rock aquif
27、ers, from 10 Bq l1up to 300 Bq l1in wells, and from 100 Bq l1up to 1 000 Bq l1in crystalline rocks. The highest activity concentrations are normally measured in rocks with high concentration of uranium (see Reference 9).High variations in the activity concentrations of radon in aquifers have been ob
28、served. Even in a region with relatively uniform rock types, some well water can exhibit radon activity concentration greatly higher than the average value for the same region. Significant seasonal variations have also been recorded (see ISO 13164-1:2013, Annex A).Water can dissolve chemical substan
29、ces as it passes from the soil surface to an aquifer or spring waters. The water can pass through or remain for some time in rock, some formations of which can contain a high concentration of natural radionuclides. Under favourable geochemical conditions, the water can selectively dissolve some of t
30、hese natural radionuclides.Guidance on radon in drinking water supplies provided by WHO in 2008 suggests that controls should be implemented if the radon concentration of drinking water for public water supplies exceeds 100 Bq l1. It is also recommended that any new, especially public, drinking wate
31、r supply using groundwater should be tested prior to being used for general consumption and that if the radon concentration exceeds 100 Bq l1, treatment of the water source should be undertaken to reduce the radon levels to well below that level (see Reference 10).This part of ISO 13164 is one of th
32、e series dealing with the measurement of the activity concentration of radionuclides in water samples.The origin of radon-222 and its short-lived decay products in water and other measurement methods are described generally in ISO 13164-1. ISO 2015 All rights reserved vBS ISO 13164-4:2015BS ISO 1316
33、4-4:2015Water quality Radon-222 Part 4: Test method using two-phase liquid scintillation countingWARNING Persons using this part of ISO 13164 should be familiar with normal laboratory practice. This part of ISO 13164 does not purport to address all of the safety issues, if any, associated with its u
34、se. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.IMPORTANT It is absolutely essential that tests conducted in accordance with this part of ISO 13164 be carried out by suitably qualified staf
35、f.1 ScopeThis part of ISO 13164 describes a test method for the determination of radon-222 (222Rn) activity concentration in non-saline waters by extraction and liquid scintillation counting.The radon-222 activity concentrations, which can be measured by this test method utilizing currently availabl
36、e instruments, are at least above 0,5 Bq l1for a 10 ml test sample and a measuring time of 1 h.This test method can be used successfully with drinking water samples and it is the responsibility of the laboratory to ensure the validity of this test method for water samples of untested matrices.Annex
37、A gives indication on the necessary counting conditions to meet the required detection limits for drinking water monitoring.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references,
38、 only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3696, Water for analytical laboratory use Specification and test methodsISO 80000-10, Quantities and units Part 10: Atomic and nuclear physicsISO/IEC 17025, G
39、eneral requirements for the competence of testing and calibration laboratories3 Terms and definitions and symbols3.1 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 80000-10 apply.3.2 Symbols and abbreviated termsFor the purposes of this document, symbo
40、ls and abbreviations defined in ISO 80000-10, as well as the following symbols, apply.a massic activity of the sample, in becquerels per gramINTERNATIONAL STANDARD ISO 13164-4:2015(E) ISO 2015 All rights reserved 1BS ISO 13164-4:2015ISO 13164-4:2015(E)aSmassic activity of the standard solution at th
41、e measuring time, in becquerels per grama* decision threshold for the total massic activity, in becquerels per grama#detection limit for the total massic activity, in becquerels per grama, alower and upper limits of the confidence interval, in becquerels per gramcAactivity concentration, in becquere
42、ls per litrem mass of the test sample, in gramsmSmass of standard solution used for the preparation of the counting standard, in gramsr0blank sample count rate, in reciprocal secondsrgsample gross count rate, in reciprocal secondsrScount rate of the standard in the counting window (alpha + beta), in
43、 reciprocal secondst0blank sample counting time, in secondstgtest sample counting time, in secondstScalibration sample counting time, in secondsu(a) standard uncertainty associated with the measurement result; in becquerels per gramU expanded uncertainty, calculated using U = ku(a), with k = 2, in b
44、ecquerels per gramw coefficient equal to 1/( m), in reciprocal gram total efficiency density, in grams per litre4 Principle222Rn is extracted from aqueous solution by means of a scintillation cocktail not miscible with water (without emulsifier) inside the scintillation vial and counted as the equil
45、ibrium with its short lived decay products is reached.1 2 3 4The aqueous sample is drawn by the mean of a gas-tight syringe from inside the water volume (i.e. well below surface) to avoid radon losses during sampling and transferred into a scintillation vial containing the desired amount of scintill
46、ation cocktail. For the same reason, the water sample is injected below the cocktail surface. The vial is tightly capped, shaken and kept for 3 h preferably in the dark and at controlled temperature. The sample is then counted by a liquid scintillation counter. Either total counts (alpha + beta) or
47、alpha only counts are considered. In these conditions 222Rn and its short lived progeny (218Po, 214Pb, 214Bi, and 214Po) are measured.5 Reagents and apparatus5.1 ReagentsAll reagents shall be of recognized analytical grade and, except for 5.1.4, shall not contain any detectable alpha and beta activi
48、ty.2 ISO 2015 All rights reservedBS ISO 13164-4:2015ISO 13164-4:2015(E)5.1.1 Water, distilled or deionized, complying with ISO 3696, grade 3.Deionized water can contain detectable amounts of 222Rn and short lived daughters. It is, therefore, strongly recommended that water be boiled under vigorous s
49、tirring and allowed to stand for 1 day before use. Otherwise, purge it with nitrogen for about 1 h for 2 l.5.1.2 Scintillation cocktail, commercially available scintillation cocktails, not water miscible.5.1.3 Ethanol, 95 %.5.1.4 Radium standard solution.226Ra standard solutions shall be provided with calibration certificates containing at least the activity concentration, measurement uncertainty and/or statement of compliance with an identified metrological specification.5.2 Apparatus5.2.1 Balance.5.2.2
