1、BRITISH STANDARD BS EN 60761-2:2004 Incorporating Amendment No. 1 to BS IEC 60761-2:2002 (renumbers the BS IEC as BS EN 60761-2:2004) Equipment for continuous monitoring radioactivity in gaseous effluents Part 2: Specific requirements for aerosol monitors including transuranic aerosols The European
2、Standard EN 60761-2:2004 has the status of a British Standard ICS 13.280 BS EN 60761-2:2004 This British Standard, having been prepared under the direction of the Engineering Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 4 D
3、ecember 2002 BSI 10 March 2005 ISBN 0 580 40885 X National foreword This British Standard is the official English language version of EN 60761-2:2004. The CENELEC common modifications have been implemented at the appropriate places in the text. The start and finish of each common modification is ind
4、icated in the text by tags . Where a common modification has been introduced by amendment, the tags carry the number of the amendment. For example, the common modifications introduced by CENELEC amendment A11 are indicated by . The UK participation in its preparation was entrusted to Technical Commi
5、ttee NCE/2, Health physics instrumentation, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document m
6、ay be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users
7、 are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change,
8、and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 21, the Annex ZA page, an inside back cover and a back cover. The BS
9、I copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments 15426 10 March 2005 Implementation of the European StandardEUROPEAN STANDARD EN 60761-2 NORME EUROPENNE EUROPISCHE NORM December 2004 CENELEC European
10、 Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CE
11、NELEC members. Ref. No. EN 60761-2:2004 E ICS 13.280 English version Equipment for continuous monitoring radioactivity in gaseous effluents Part 2: Specific requirements for aerosols monitors including transuranic aerosols (IEC 60761-2:2002, modified) Equipements de surveillance en continu de la rad
12、ioactivit dans les effluents gazeux Partie 2: Exigences particulires aux moniteurs darosols radioactifs, y compris les arosols transuraniens (CEI 60761-2:2002, modifie) Einrichtungen zur kontinuierlichen berwachung von Radioaktivitt in gasfrmigen Ableitungen Teil 2: Besondere Anforderungen an Monito
13、re fr radioaktive Aerosole einschlielich Transuranaerosole (IEC 60761-2:2002, modifiziert) This European Standard was approved by CENELEC on 2004-11-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the
14、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 Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, Germ
15、an). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus,
16、Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. NE 067-162:2004 2 Foreword The text of the Internation
17、al Standard IEC 60761-2:2002, prepared by SC 45B, Radiation protection instrumentation, of IEC TC 45, Nuclear instrumentation, together with the common modifications prepared by the CENELEC BTTF 111-3 Instrumentation for ionizing radiation measurement and protection, was submitted to the formal vote
18、 and was approved by CENELEC as EN 60761-2 on 2004-11-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2005-11-01 latest date by which the national standards conflicting wi
19、th the EN have to be withdrawn (dow) 2007-11-01 Annex ZA has been added by CENELEC. _ Page2 EN607612:2004-167062 2002:CEI 6 EQUIPMENT FOR CONTINUOUS MONITORING OF RADIOACTIVITY IN GASEOUS EFFLUENTS Part 2: Specific requirements for radioactive aerosol monitors including transuranic aerosols 1 Scope
20、and object This part of IEC 60761 is applicable to equipment intended for simultaneous, delayed or discrete sequential measurement of aerosols in gaseous effluents discharged into the environment. It is applicable to equipment designed to fulfill the following functions: the measurement of the volum
21、ic activity (Bq/m 3 ) of the aerosols in gaseous effluents and/or the released total activity of aerosols (Bq); the actuation of an alarm signal when either a predetermined volumic activity or a predetermined total released activity of aerosols is exceeded. This equipment is intended for measurement
22、 over a wide range of activity, including very small quantities in the presence of a much larger natural background. The daughters of 222 Rn (radon) and 220 Rn (thoron) are naturally occurring aerosols contributing to the natural background. The discrimination against natural activity can be an impo
23、rtant problem in monitoring low level activity. In order to provide more and better information, complementary or retrospective laboratory analysis of the filters after collection may be performed. The object of this standard is to establish specific standard requirements, including technical charac
24、teristics and general test conditions, and to give examples of acceptable methods for aerosol effluent monitors. The general requirements, technical characteristics, test procedures, radiation characteristics, electrical, mechanical, safety and environmental characteristics are given in IEC 60761-1.
25、 Unless otherwise stated, these requirements apply to this standard. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of IEC 60761. For dated references, subsequent amendments to, or revisions of, an
26、y of these publications do not apply. However, parties to agreements based on this part of IEC 60761 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document ref
27、erred to applies. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 60068-2-27:1987, Environmental testing Part 2: Tests Test Ea and guidance Shock IEC 60761-1:2002, Equipment for continuous monitoring of radioactivity in gaseous effluents Part 1: General requ
28、irements IEC 61000 (all parts): Electromagnetic compatibility (EMC) Page3 EN607612:2004-167062 2002:CEI 7 IEC 61578:1997, Radiation protection instrumentation Calibration and verification of the effectiveness of radon compensation for alpha and/or beta aerosol measuring instruments Test methods EN 4
29、81:1993, Workplace Atmospheres: Size Fraction Definitions for Measurement of Airborne Particles EN 55022:1994, Limits and Methods of Measurement of Radio Disturbance Characteristics of Information Technology Equipment 3 Terms and definitions For the purpose of this part of IEC 60761, the following d
30、efinitions apply. 3.1 aerosols a suspension in air or gas of solid or liquid particles 3.2 aerodynamic equivalent diameter diameter of a unit-density sphere having the same gravitational-settling velocity as the particle in question 3.3 activity median aerodynamic diameter (AMAD) the aerodynamic par
31、ticle diameter for which 50 % of the aerosol activity is associated with sizes smaller than (or larger than) that particular size 3.4 aerosol monitor equipment designed for the continuous, delayed or sequential measurement of aerosol activity in gaseous effluents discharged into the environment 3.5
32、total equivalent window thickness the equivalent window thickness (or density thickness), generally expressed in mass per unit area (mg/cm 2 ), that a particle emitted normally from the surface of the aerosol collecting medium must traverse to reach the sensitive volume of the detector NOTE This thi
33、ckness includes the distance covered in air plus the thickness of the entry window of the detector, thickness which may include any coating over the detector for protection against radioactive contamination, noxious chemicals or water vapour. 3.6 high efficiency source source in which the efficiency
34、 for particles with an energy greater than 5 keV is greater than 0,25, including backscattered particles (this definition applies to beta emitters with maximum energy 150 keV) 3.7 source efficiency largest of the two quotients, of the surface emission rate by the number of particles of the same type
35、 created or released per unit time, either within the source thickness or within the source saturation layer Page4 EN607612:2004-167062 2002:CEI 8 4 Classification of aerosol effluent monitors The equipment may be classified according to the type of measuring method such as: gross gamma aerosol moni
36、tors; gross beta aerosol monitors; gross alpha aerosol monitors; gross alpha and gross beta aerosol monitors; alpha spectroscopy monitors; gamma spectroscopy monitors. It may also be classified according to the method of operation (see bibliography) such as: equipment with static filter sampler and
37、simultaneous measurement; equipment with moving filter sampler and simultaneous measurement; equipment with moving filter sampler and delayed measurement; equipment with moving filter sampler and simultaneous and delayed measurement; equipment with static filter sampler and simultaneous measurement
38、combined with a moving filter sampler and simultaneous and/or delayed measurement; equipment with impactor; equipment with electrostatic precipitator. 5 Sampling and detection assembly 5.1 Air delivery system including pump The requirement of clause 11 of IEC 60761-1 is applicable. Additionally, the
39、 air or gas pump shall be capable of holding the variation of pressure induced by normal operating conditions (maximum expected sampling time, collection media or back-up filter, atmospheric dust, mass concentration contributing to blockage, etc.), so that there shall not be a reduction from nominal
40、 air flow-rate of more than 10 % or an error in the value of total air volume sampled of more than 8 % at the end of the sampling. A back-up filter should be used to minimize contamination of the pump. In all cases, the instrument shall be designed to prevent flow blockage or malfunctioning of the c
41、ollection device in its ability to retain particles. An alarm shall be fitted to detect the absence, rupture or blockage of the collection medium, for example a filter or an impactor. NOTE The delivery line efficiency is not always constant and can change with the operation time of the system. There
42、fore, the efficiency should be verified after installation of the system and then periodically, for example every two years. 5.2 Aerosol collection device The collection surface may have different geometries according to the method of operation of the assembly (see clause 4): circular, for example,
43、for static filter assemblies or cassette systems where filter papers are moved under a detector or circular impactor; square or rectangular, for example, for moving filter assemblies, or rectangular impactor designs. NOTE For moving filters, square or rectangular geometry allows a simplification for
44、 calculations. Page5 EN607612:2004-167062 2002:CEI 9 For equipment measuring alpha radiation that uses a detector to view the collection medium, it is important to minimize, as much as possible, the absorption of alpha radiation by the collection medium. Significant non-uniformity of deposition of a
45、erosols collected on the filters shall be avoided. The design of the aerosol retention device shall minimize deposition on surfaces other than the collection media. The filter-holder design characteristics (dimensions, geometry, filter support, etc.) shall take account of the mechanical strength of
46、the filters used and the characteristics of the air (or gas) sampling pump. For simultaneous sampling and measuring assemblies, the measurement of aerosol volumic activity may be disturbed by radioactive gases, such as 41 Ar, 85 Kr, 133 Xe, etc., liable to be present in the sampled air (or gas). Thi
47、s shall be minimized by the special geometry of cavities located near the detector in front of and behind the filter and the corresponding reduction of dead volumes. The design shall minimize leaks, particularly internal leaks causing the flow to bypass the collection media. Access to the collection
48、 media shall be designed in such a manner as to permit fast and easy removal without risk of damage to the detection device and minimum risk to the operator when a high level of activity has been accumulated. To improve the accuracy and sensitivity of the measurements, the equipment should be design
49、ed so that complementary laboratory analyses of the media after collection can be performed. In addition, the collection media may provide a means of verification of the instrumental measurements. Also, in the case of a failure of the electronic part of the instrument, the medium analysis may serve as a back-up to the measurements. 5.3 Particle collection effici
