1、NORME INTERNATIONALE INTERNATIONAL STANDARD CE1 I EC 1250 Premire dition First edition 1 994-0 1 Racteurs nuclaires - Systmes dinstrumentation et de contrle-commande pour la sret - Dtection des fuites dans les systmes de refroidissement Nuclear reactors - Instrumentation and control systems importan
2、t for safety - Detection of leakage in coolant systems Numro de rfrence Reference number CEMEC 1250: 1994 Numros des publications Depuis le ler janvier 1997, les publications de la CE1 sont numrotes partir de 60000. Publications consolides Les versions consolides de certaines publications de la CE1
3、incorporant les amendements sont disponibles. Par exemple, les numros ddition 1.0, 1.1 et 1.2 indiquent respectivement la publication de base, la publication de base incorporant lamendement 1, et la publication de base incorporant les amendements 1 et 2. Validit de la prsente publication Le contenu
4、technique des publications de la CE1 est constamment revu par la CE1 afin quil reflte ltat actuel de la technique. Des renseignements relatifs la date de reconfirmation de la publication sont disponibles dans le Catalogue de la CEI. Les renseignements relatifs des questions ltude et des travaux en c
5、ours entrepris par le comit technique qui a tabli cette publication, ainsi que la liste des publications tablies, se trouvent dans les documents ci- d e s s o u s : Site web de la CEl* Catalogue des publications de la CE1 Publi annuellement et mis jour rgulirement (Catalogue en ligne) Disponible la
6、fois au 4te web de la CEI* et comme priodique imprim Bulletin de la CE1 Terminologie, symboles graphiques et littraux En ce qui concerne la terminologie gnrale, le lecteur se reportera la CE1 60050: Vocabulaire Electro- technique International (VE I). Pour les symboles graphiques, les symboles littr
7、aux et les signes dusage gnral approuvs par la CEI, le lecteur consultera la CE1 60027: Symboles littraux a utiliser en lectrotechnique, la CE1 6041 7: Symboles graphiques utilisables sur le matriel. Index, relev et compilation des feuilles individuelles, et la CE1 60617: Symboles graphiques pour sc
8、hmas. * Voir adresse site web sur la page de titre. Num ber i ng As from 1 January 1997 all IEC publications are issued with a designation in the 60000 series. Consolidated publications Consolidated versions of some IEC publications including amendments are available. For example, edition numbers 1.
9、0, 1.1 and 1.2 refer, respectively, to the base publication, the base publication incorporating amendment 1 and the base publication incorporating amendments 1 and 2. Validity of this publication The technical content of IEC publications is kept under constant review by the IEC, thus ensuring that t
10、he content reflects current technology. Information relating to the date of the reconfirmation of the publication is available in the IEC catalogue. Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication, as well
11、 as the list of publications issued, is to be found at the following IEC sources: IEC web site* Catalogue of IEC publications Published yearly with regular updates (On-line catalogue) Available both at the IEC web site and as a printed periodical IEC Bulletin Terminology, graphical and letter symbol
12、s For general terminology, readers are referred to I EC 60050: International Electrotechnical Vocabulary (IEV). For graphical symbols, and letter symbols and signs approved by the IEC for general use, readers are referred to publications IEC 60027: Letter symbols to be used in electrical technologys
13、 IEC 60417: Graphical symbols for use on equipment. Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols for diagrams. * See web site address on title page. NORME INTERNATIONALE INTERNATIONAL STANDARD CE1 IEC 1250 Premire dition First edition 1994-01 Racteurs nuclaires
14、 - Systmes dinstrumentation et de contrle-commande pour la sret - Dtection des fuites dans les systmes de refroidissement Nuclear reactors - Instrumentation and control systems important for safety - Detection of leakage in coolant systems 0 CE1 1994 Droits de reproduction rservs - Copyright - all r
15、ights reserved Aucune pariie de cette publication ne peul any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and nongovernmental organizations liaising with the IEC also participate in this preparation. The IEC collab
16、orates closely with the International Standardization Organization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on which all the National Committees h
17、aving a special interest therein are represented, express, as nearly as possible, an international consensus of opinion on the subject dealt with. 3) They have the form of recommendations for international use published in the form of standards, technical reports or guides and they are accepted by t
18、he National Committees in that sense. 4) In order to promote international unification, IEC National Committees undertake to apply IEC International Standards transparently to the maximum extent possible in their national and regional standards. Any divergence between the IEC Standard and the corres
19、ponding national or regional standard shall be clearly indicated in the latter. International Standard IEC 1250 has been prepared by sub-committee 45A: Reactor instrumentation, of IEC technical committee 45: Nuclear instrumentation. The text of this standard is based upon the following documents: I
20、DIS I Reportonvoting I I 45A(C0)137 I 45A(C0)140 I Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. -6- 1250 O CE1 :1994 Introduction Ladtection des fuites du rfrigrant du racteur et des systmes associs (RRSA) dans le
21、nceinte de confinement du racteur dune centrale nuclaire est prescrite, en appui du concept de fuite avant rupture-, et de dtection prcoce danomalies par rapport au fonctionnement normal. Les prescriptions internationales applicables pour la dtection des fuites du RRSA sont spcifies dans le guide de
22、 sret de IAIEA 50-SG-D13. Les dimensions, la capacit et la conception des centrales nuclaires peuvent varier considrablement dune centrale lautre. II est donc recommand que les mthodes existantes de dtection des fuites et les prescriptions spcifiques de dtection soient examines individuellement par
23、le concepteur pour dterminer si un systme de dtection de fuites convient pour une centrale particulire. La dtection des fuites dans les systmes sous pression est ncessaire car les petites fuites sont susceptibles de se transformer en fuites plus importantes ou en ruptures. Pendant le fonctionnement
24、du racteur, la dtection des fuites dans des parties non isolables du RRSA est importante pour permettre lidentification prcoce de dfauts mineurs avant que ceux-ci nvoluent en une rupture de canalisation ou de composant qui risquerait de provoquer un accident de perte de rfrigrant. II est recommand q
25、ue linstrumentation de dtection des fuites fasse la diffrence entre les fuites admissibles et les fuites anormales, et soit assez sensible pour faciliter la dtection de petites fuites et rpondre aux prescriptions de radioprotection pour le personnel dans lenceinte de confinement, de manire viter le
26、dclenchement dalarmes de fuites intempestives. 1250 O IEC:1994 -7- Introduction Detection of leakage from the reactor coolant and associated systems (RCAS) into the reactor containment of a nuclear power plant is required, in support of the concepts of “leak before break“, and early detection of dev
27、eloping deviation from normal operation. The applicable international requirement for RCAS leak detection is specified in the IAEA safety guide 50-SG-D13. Nuclear power plants vary widely in size, capacity, and design. Available leakage detection methods and specific plant leakage detection requirem
28、ents should be individually examined by the designer to determine the suitability of a leakage detection system for a particular plant. Leakage detection from pressurized systems is needed because small leaks may develop into larger leaks or ruptures. During reactor operation, detection of leakage f
29、rom non-isolable portions of the RCAS is important to allow early identification of minor flaws before they can develop into a pipe break or component rupture that could result in a loss of coolant accident. Leakage detection instrumentation should differentiate between allowable and abnormal leakages. It should be sensitive enough to facilitate detection of small leaks and it should meet health physics requirements for personnel within the containment. The sensitivity should be selected, however, to avoid spurious leakage alarms.
