1、BS ISO18589-5:2009ICS 13.080.01; 17.240NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMeasurement ofradioactivity in theenvironment SoilPart 5: Measurement of strontium 90This British Standardwas published under theauthority of the StandardsPolicy and StrategyC
2、ommittee on 30 April2009. BSI 2009ISBN 978 0 580 67404 4Amendments/corrigenda issued since publicationDate CommentsBS ISO 18589-5:2009National forewordThis British Standard is the UK implementation of ISO 18589-5:2009.The UK participation in its preparation was entrusted to TechnicalCommittee NCE/2,
3、 Radiation protection and measurement.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British S
4、tandard cannot confer immunityfrom legal obligations.BS ISO 18589-5:2009RECIPIENTS OF THIS DRAFT ARE INVITED TOSUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICHTHEY ARE AWARE AND TO PROVIDE SUPPORT-ING DOCUMENTATION. IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE
5、FOR INDUSTRIAL, TECHNO-LOGICAL, COMMERCIAL AND USER PURPOSES,DRAFT INTERNATIONAL STANDARDS MAY ONOCCASION HAVE TO BE CONSIDERED IN THELIGHT OF THEIR POTENTIAL TO BECOME STAN-DARDS TO WHICH REFERENCE MAY BE MADE INNATIONAL REGULATIONS. Reference numberISO 18589-5:2009(E)ISO 2009INTERNATIONAL STANDARD
6、 ISO18589-5First edition2009-03-01Measurement of radioactivity in the environment Soil Part 5: Measurement of strontium 90 Mesurage de la radioactivit dans lenvironnement Sol Partie 5: Mesurage du strontium 90 BS ISO 18589-5:2009ISO 18589-5:2009(E) PDF disclaimer This PDF file may contain embedded t
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9、ptimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 All rights reserved
10、. 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 ISOs member body in the country of the requester.
11、 ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 18589-5:2009ISO 18589-5:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv Introd
12、uction v 1 Scope . 1 2 Normative references . 1 3 Terms, definitions and symbols 2 4 Principle. 3 5 Chemical reagents and equipment . 4 6 Procedure 4 7 Expression of results . 7 8 Test report . 14 Annex A (informative) Test portion preparation . 15 Annex B (informative) Measurement of strontium by p
13、recipitation 17 Annex C (informative) Measurement of strontium 90 from its daughter product yttrium 90 at equilibrium by organic extraction. 23 Annex D (informative) Measurement of strontium after separation on a “crown ether”-specific resin 27 Bibliography . 30 BS ISO 18589-5:2009ISO 18589-5:2009(E
14、) iv ISO 2009 All rights reservedForeword 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 inte
15、rested 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 Electrotechnica
16、l 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 t
17、echnical 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. I
18、SO shall not be held responsible for identifying any or all such patent rights. ISO 18589-5 was prepared by Technical Committee ISO/TC 85, Nuclear energy, Subcommittee SC 2, Radiation protection. ISO 18589 consists of the following parts, under the general title Measurement of radioactivity in the e
19、nvironment Soil: Part 1: General guidelines and definitions Part 2 : Guidance for the selection of the sampling strategy, sampling and pre-treatment of samples Part 3: Measurements of gamma-emitting radionuclides Part 4: Measurement of plutonium isotopes (plutonium 238 and plutonium 239 + 240) by al
20、pha spectrometry Part 5: Measurement of strontium 90 Part 6: Measurement of gross alpha and gross beta activities BS ISO 18589-5:2009ISO 18589-5:2009(E) ISO 2009 All rights reserved vIntroduction ISO 18589 is published in several parts for use jointly or separately according to needs. Parts 1 to 6 c
21、oncerning the measurements of radioactivity in the soil have been prepared simultaneously. These parts are complementary and are addressed to those responsible for determining the radioactivity present in soil. The first two parts are general in nature. Parts 3 to 5 deal with nuclide-specific measur
22、ements and Part 6 with non-specific measurements of gross alpha or gross beta activities. Additional parts can be added to ISO 18589 in the future if the standardization of the measurement of other radionuclides becomes necessary. BS ISO 18589-5:2009BS ISO 18589-5:2009INTERNATIONAL STANDARD ISO 1858
23、9-5:2009(E) ISO 2009 All rights reserved 1Measurement of radioactivity in the environment Soil Part 5: Measurement of strontium 90 1 Scope This part of ISO 18589 describes the principles for the measurement of the activity of 90Sr in equilibrium with 90Y, and 89Sr, pure beta-emitting radionuclides,
24、in soil samples. Different chemical separation methods are presented to produce strontium and yttrium sources, the activity of which is determined using proportional counter (PC) or liquid scintillation counter (LSC). The selection of the measuring method depends on the origin of the contamination,
25、the characteristics of the soil being analysed, the required accuracy of measurement and the resources of the available laboratories. These methods are used for soil monitoring following past or present, accidental or routine, liquid or gaseous discharges. It also covers the monitoring of contaminat
26、ion caused by global fallout. In the case of recent fallout immediately following a nuclear accident, the contribution of 89Sr to the total amount of strontium activity is not negligible. This part of ISO 18589 provides the measurement method to determine the activity of 90Sr in the presence of 89Sr
27、. 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 31-9, Quantities and
28、 units Part 9: Atomic and nuclear physics ISO 11074, Soil quality Vocabulary ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories ISO 18589-1, Measurement of radioactivity in the environment Soil Part 1: General guidelines and definitions ISO 18589-2, Measur
29、ement of radioactivity in the environment Soil Part 2: Guidance for the selection of the sampling strategy, sampling and pre-treatment of samples BS ISO 18589-5:2009ISO 18589-5:2009(E) 2 ISO 2009 All rights reserved3 Terms, definitions and symbols For the purposes of this document, the terms, defini
30、tions and symbols given in ISO 18589-1, ISO 11074 and ISO 31-9 and the following symbols apply. m Mass of the test portion, expressed in kilograms aiActivity per unit of mass, of radionuclide i, expressed in becquerel per kilogram Ai,sCalibration source activity of radionuclide i, at the calibration
31、 time, expressed in becquerel AiSample source activity of radionuclide i, at time t = 0, expressed in becquerel tgSample counting time, expressed in seconds t0Background counting time, expressed in seconds, tsCalibration source counting time rgGross count rate per second r0Background count rate per
32、second rsCalibration source count rate per second Rc,iChemical yield of the extraction of radionuclide i iCounting efficiency of radionuclide i iDecay constant of radionuclide i td, tfStart and finish time respectively of the measurement referred to t = 0, expressed in seconds rgjGross count rate pe
33、r second, for measurement j r0jBackground count rate per second, for measurement j rjNet count rate per second, for measurement j tjStart time of measurement j, referred to t = 0 u(ai) Standard uncertainty associated with the measurement result, expressed in becquerel per kilogram U Expanded uncerta
34、inty, calculated by ( )iUkua= with k = 1, 2, , expressed in becquerel per kilogram *ia Decision threshold of radionuclide i, expressed in becquerel per kilogram #ia Detection limit of radionuclide i, expressed in becquerel per kilogram ,iaiaLower and upper limits respectively of the confidence inter
35、val of radionuclide i, expressed in becquerel per kilogram BS ISO 18589-5:2009ISO 18589-5:2009(E) ISO 2009 All rights reserved 34 Principle 90Sr, 90Y and 89Sr are pure beta-emitter radionuclides. Their beta-emission energies and half-lives are given in Table 11). Table 1 Average beta-emission energi
36、es and half-lives of 90Sr, 90Y and 89Sr 90Sr 90Y 89Sr Beta energy, keV 196 926,7 584,6 Half-life 28,8 a 2,67 d 50,6 d Strontium can be measured directly or estimated through the measurement of its daughter product, yttrium. All the measurements are based on a chemical separation step followed by bet
37、a counting of the element using PC or LSC. (See Table 2 and References 1, 2 and 3.) 4.1 Chemical separation Following the desorption step of the soil test portion, isolate the strontium from the soil solution using precipitation or specific chromatographic resin separation such as a “crown ether” re
38、sin. Yttrium can be isolated by precipitation or liquid-liquid extraction. The separation step should maximize the extraction of the pure element. Choose the method that is selective with a high chemical yield. As thorium, lead, and bismuth radioisotopes are present in soil, it is necessary that the
39、y be removed from the sample because they can interfere with 90Sr or 90Y or 89Sr emissions during the detection step. It is necessary that other matrix constituents that can interfere, such as the alkaline earth elements, calcium for strontium, or the transuranic and lanthanide elements for yttrium,
40、 also be removed as they reduce the chemical yield of the extraction. The radiochemical separation yield is calculated using a carrier such as stable Sr or Y, or a radioactive tracer such as 85Sr. Techniques, such atomic absorption spectroscopy (AAS) or inductively coupled plasma atomic emission spe
41、ctroscopy (ICP-AES) or inductively coupled plasma mass spectrometry (ICP-MS) to measure the carrier, and gamma spectrometry to measure 85Sr, are recommended. A carrier can also be measured by gravimetric methods, but the presence of inactive elements, essentially alkaline earth elements, in the leac
42、hing solutions can lead to an overestimation of the radiochemical separation yields, particularly for the measurement of Sr. When stable strontium is added as a carrier, it is necessary that its original concentration in the test sample be known to avoid the overestimation of the radiochemical separ
43、ation yield. 4.2 Detection The use of LSC, which provides spectra and permits the detection of interference from unwanted radionuclides, is recommended in preference to PC, which does not distinguish between emissions from different beta emitters. When PC is used, it is recommended that the purity o
44、f the precipitate is checked by following the change over an appropriate time of the 90Y or 89Sr activity, even though this method is time consuming. A method of Sr/Y desorption of the soil test portion is given in Annex A. Three measurement methods are presented in Annexes B, C and D. 1) Source: BI
45、PM (Bureau International des Poids et Mesures). BS ISO 18589-5:2009ISO 18589-5:2009(E) 4 ISO 2009 All rights reservedTable 2 Determination procedures for strontium depending on its origin Origin Old fallout Fresh fallout Radionuclide contents 90Sr+90Y 90Sr+90Y 89Sr Element Sr YaSr Method Chromatogra
46、phybPrecipitation Extraction Precipitation ChromatographybPrecipitationProduct 90Sr 90Y 90Sr+89Sr Separation Carrier or tracerc85Sr or stable Sr Stable Y 85Sr or stable Sr Equilibrium 90Sr+90Y Yes 15 to 20 days (recommended) No No Yes 15 to 20 days (recommended) No Number One One Two or more Emissio
47、ns 90Sr 90Y 90Y 90Sr 90Y 89Sr Equipment PC or LSC (total) PC or LSC (total or Cerenkov) PC or LSC (total) Measurement(s) Calibration of sources 90Sr+90Y 90Sr 90Y 90Y 90Sr+90Y 89Sr 90Sr 90Y 89Sr aY separation is performed following the 90Sr 90Y equilibrium in the test sample. bSpecific chromatography
48、 using crown-ether resin. cCarrier or tracer measurements are done using gamma spectrometry for 85Sr and gravimetry, atomic absorption (AAS) or mass spectrometry (MS) for Sr and Y. 5 Chemical reagents and equipment The necessary chemical reagents and equipment for each strontium measurement method a
49、re specified in Annexes A, B, C and D. All the chemical reagents required to carry out this procedure shall be of analytical grade. 6 Procedure 6.1 Strontium desorption Strontium is desorbed from the soil test portion by acid treatment and remains in solution in the leachate fraction. The tracer or carrier is added at the start of this step of the procedure; time is allowed, usually up to one day, to obtain equilibrium before starting the strontium desorption. If stable strontium is added as
