1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Dosimetry for exposures to cosmic radiation in civilian aircraftPart 1: Conceptual basis for measurements (ISO 20785-1:2012)BS EN ISO 20785-1:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 20785-1 October
2、2017 ICS 13.280; 49.020 English Version Dosimetry for exposures to cosmic radiation in civilian aircraft - Part 1: Conceptual basis for measurements (ISO 20785-1:2012) Dosimtrie pour lexposition au rayonnement cosmique bord dun avion civil - Partie 1: Fondement thorique des mesurages (ISO 20785-1:20
3、12) This European Standard was approved by CEN on 13 September 2017. 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 bibliographic
4、al 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
5、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 M
6、acedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMAL
7、ISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 20785-1:2017 ENational forewordThis British Standard is the UK impleme
8、ntation of EN ISO 207851:2017. It is identical to ISO 207851:2012. It supersedes BS ISO 207851:2012, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee NCE/2, Radiation protection and measurement.A list of organizations represented on this committee can b
9、e obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2018 Published by BSI Standards Limited 2018ISBN 978 0 580 96937 9ICS 49.020; 13.280Com
10、pliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2018.Amendments/corrigenda issued since publicationDate Text affected31 January 2018 This corrigendum ren
11、umbers BS ISO 207851:2012 as BS EN ISO 207851:2017BRITISH STANDARDBS EN ISO 207851:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 20785-1 October 2017 ICS 13.280; 49.020 English Version Dosimetry for exposures to cosmic radiation in civilian aircraft - Part 1: Conceptual basis for meas
12、urements (ISO 20785-1:2012) Dosimtrie pour lexposition au rayonnement cosmique bord dun avion civil - Partie 1: Fondement thorique des mesurages (ISO 20785-1:2012) This European Standard was approved by CEN on 13 September 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulatio
13、ns 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. T
14、his 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 me
15、mbers 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, Port
16、ugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation
17、in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 20785-1:2017 EBS EN ISO 207851:2017EN ISO 20785-1:2017 (E) 3 European foreword The text of ISO 20785-1:2012 has been prepared by Technical Committee ISO/TC 85 “Nuclear energy, nuclear technologies, and radiolog
18、ical protection” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 20785-1:2017 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
19、 given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 2018, and conflicting national standards shall be withdrawn at the latest by April 2018. Attention is drawn to the possibility that some of the elements of this document may
20、 be the subject of patent rights. CEN 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, Bulga
21、ria, 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerl
22、and, Turkey and the United Kingdom. Endorsement notice The text of ISO 20785-1:2012 has been approved by CEN as EN ISO 20785-1:2017 without any modification. BS EN ISO 207851:2017ISO 20785-1:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Terms and definiti
23、ons . 12.1 General . 12.2 Quantities and units . 22.3 Atmospheric radiation field . 83 General considerations .103.1 General description of the cosmic radiation field in the atmosphere 103.2 General calibration considerations for the dosimetry of cosmic radiation fields in aircraft . 113.3 Conversio
24、n coefficients . 134 Dosimetric devices 134.1 Introduction . 134.2 Active devices 144.3 Passive devices . 17Annex A (informative) Representative particle fluence rate energy distributions for the cosmic radiation field at flight altitudes for solar minimum and maximum conditions and for minimum and
25、maximum vertical cut-off rigidity 80.20Bibliography .24BS EN ISO 207851:2017ISO 20785-1:2012(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 carrie
26、d 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. IS
27、O 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 Internationa
28、l 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 elemen
29、ts 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 20785-1 was prepared by Technical Committee ISO/TC 85, Nuclear energy, nuclear technologies, and radiological protection, Subcommittee SC 2, Radiological prote
30、ction.This second edition cancels and replaces the first edition (ISO 20785-1:2006), which has been technically revised.ISO 20785 consists of the following parts, under the general title Dosimetry for exposures to cosmic radiation in civilian aircraft: Part 1: Conceptual basis for measurements Part
31、2: Characterization of instrument responseMeasurements at aviation altitudes is to form the subject of a future Part 3.iv ISO 2012 All rights reservedBS EN ISO 207851:2017ISO 20785-1:2012(E)IntroductionAircraft crews are exposed to elevated levels of cosmic radiation of galactic and solar origin and
32、 secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60,1confirmed by Publication 103,2the European Union (EU) introduced a revised Basic Safety Standards Directiv
33、e3which included exposure to natural sources of ionizing radiation, including cosmic radiation, as occupational exposure. The Directive requires account to be taken of the exposure of aircraft crews liable to receive more than 1 mSv per year. It then identifies the following four protection measures
34、: (i) to assess the exposure of the crew concerned; (ii) to take into account the assessed exposure when organizing working schedules with a view to reducing the doses of highly exposed crews; (iii) to inform the workers concerned of the health risks their work involves; and (iv) to apply the same s
35、pecial protection during pregnancy to female crews in respect of the “child to be born” as to other female workers. The EU Council Directive has already been incorporated into laws and regulations of EU Member States and is being included in the aviation safety standards and procedures of the Joint
36、Aviation Authorities and the European Air Safety Agency. Other countries such as Canada and Japan have issued advisories to their airline industries to manage aircraft crew exposure.For regulatory and legislative purposes, the radiation protection quantities of interest are the equivalent dose (to t
37、he foetus) and the effective dose. The cosmic radiation exposure of the body is essentially uniform and the maternal abdomen provides no effective shielding to the foetus. As a result, the magnitude of equivalent dose to the foetus can be put equal to that of the effective dose received by the mothe
38、r. Doses on board aircraft are generally predictable, and events comparable to unplanned exposure in other radiological workplaces cannot normally occur (with the rare exceptions of extremely intense and energetic solar particle events). Personal dosemeters for routine use are not considered necessa
39、ry. The preferred approach for the assessment of doses of aircraft crews, where necessary, is to calculate directly the effective dose per unit time, as a function of geographic location, altitude and solar cycle phase, and to fold these values with flight and staff roster information to obtain esti
40、mates of effective doses for individuals. This approach is supported by guidance from the European Commission and the ICRP in Publication 75.4The role of calculations in this procedure is unique in routine radiation protection and it is widely accepted that the calculated doses should be validated b
41、y measurement. The effective dose is not directly measurable. The operational quantity of interest is ambient dose equivalent, H*(10). In order to validate the assessed doses obtained in terms of effective dose, calculations can be made of ambient dose equivalent rates or route doses in terms of amb
42、ient dose equivalent, and values of this quantity determined by measurements traceable to national standards. The validation of calculations of ambient dose equivalent for a particular calculation method may be taken as a validation of the calculation of the effective dose by the same computer code,
43、 but this step in the process may need to be confirmed. The alternative is to establish a priori that the operational quantity ambient dose equivalent is a good estimator of effective dose and equivalent dose to the foetus for the radiation fields being considered, in the same way that the use of th
44、e operational quantity personal dose equivalent is justified for the estimation of effective dose for radiation workers. Ambient dose equivalent rate as a function of geographic location, altitude and solar cycle phase is then calculated and folded with flight and staff roster information.The radiat
45、ion field in aircraft at altitude is complex, with many types of ionizing radiation present, with energies ranging up to many GeV. The determination of ambient dose equivalent for such a complex radiation field is difficult. In many cases, the methods used for the determination of ambient dose equiv
46、alent in aircraft are similar to those used at high-energy accelerators in research laboratories. Therefore, it is possible to recommend dosimetric methods and methods for the calibration of dosimetric devices, as well as the techniques for maintaining the traceability of dosimetric measurements to
47、national standards. Dosimetric measurements made to evaluate ambient dose equivalent must be performed using accurate and reliable methods that ensure the quality of readings provided to workers and regulatory authorities. This part of ISO 20785 gives a conceptual basis for the characterization of t
48、he response of instruments for the determination of ambient dose equivalent in aircraft. ISO 2012 All rights reserved vBS EN ISO 207851:2017ISO 20785-1:2012(E)Requirements for the determination and recording of the cosmic radiation exposure of aircraft crews have been introduced into the national le
49、gislation of EU Member States and other countries. Harmonization of methods used for determining ambient dose equivalent and for calibrating instruments is desirable to ensure the compatibility of measurements performed with such instruments.This part of ISO 20785 is intended for the use of primary and secondary calibration laboratories for ionizing radiation, by radiation protection personnel employed by governmental agencies, and by industrial corporations concerned with the determination of ambient dose equivalent for aircraft
