EUROPEAN COMMISSION DG-JRC Institute for Advanced Materials Joint Research Centre DG Environment Direction C, Safety of Nuclear Installations ENIQ GLOSSARY ISSUE 2 December 1999 ENIQ Report nr. 12 EUR 18102 EN Directorates-General Environment/Joint Research Centre
Published by the EUROPEAN COMMISSION Directorate-General Telecommunications, Information, Industries and Innovation L-2920 LUXEMBOURG LEGAL NOTICE Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information. Catalogue number: CD-NA-18102-EN-C ECSC-EEC-EAEC, Brussels Luxembourg, 1999 Printed in the Netherlands
CONTENTS Contents... 1 1. Introduction... 2 2. Glossary... 3 3. Relevant documents... 9 1
1. Introduction This glossary has been produced to define the terms used in the qualification of nondestructive tests. Such qualifications are being required increasingly by regulatory bodies to give confidence that NDT is capable of providing the information required by structural integrity assessment in a reliable and reproducible way. The European Network for Inspection Qualification (ENIQ) is developing methods for inspection qualification on a European-wide basis. In addition, bodies such as the European Nuclear Regulators Working Group have turned their attention to the subject. Qualification systems are being developed under Tacis and Phare for Eastern Europe and individual Western European utilities are introducing qualification. It is timely, therefore, as the subject develops, to have a glossary of terms so that they are used in a common way and ambiguities and confusion are avoided. In compiling this glossary, all relevant European Standards have been consulted and, where definitions of pertinent terms already exist, such definitions have been adopted. Also, account has been taken of an earlier glossary of terms used in PISC where these are relevant to the present subject. In addition, drafts of the glossary have been circulated widely for comment and the views received have also been taken into account in the present version. It should be emphasised that the present document is simply a definition of relevant terms as they are used within ENIQ and in the different ENIQ documents on inspection qualification. It does not describe how qualification is to be carried out. That is the purpose of the European Methodology for inspection qualification of NDT, the recommended practices written by ENIQ and documents produced at national level based on the European Methodology. The work to produce the first issue of this glossary was financed by Directorate General XI (Direction C, Safety of Nuclear Installations) of the European Commission through contract ETNU/CT/94/0132-UK with AEA Technology. The first issue was finalised in 1996. Since then the European Methodology has been applied more and more widely in several countries. Within ENIQ a pilot study was conducted. Furthermore several recommended practices have been prepared on technical justification, the issue of influential/essential parameters, input information, test piece trials and the use of modelling in inspection qualification. As a result some of the definitions given in previous ENIQ documents have changed and therefore it was decided by ENIQ to issue a second issue of the glossary. It is anticipated that future issues of the European Methodology and/or recommended practices will reference the glossary rather than contain, as at present, a limited list of definitions. Other organisations involved in inspection qualification at both European and national level are encouraged to use this glossary in the same way. 2
2. Glossary Artificial Defect A defect deliberately introduced into a test piece which may not metallurgically resemble a real defect in appearance. Ease and reproducibility are major factors in selection of such defects. Defects such as electro discharge machined (EDM) notches or saw cuts might be used as artificial defects. The most useful types of artificial defects for qualification purposes are those whose non-destructive testing (NDT) responses resemble, or can be related to, those of the real defects of interest, for the NDT techniques being considered. Blind Trial A trial in which a inspection technique is applied to a test piece and those applying the NDT have no specific and detailed knowledge of the numbers, sizes, orientations and positions of defects which the test piece may contain. It is normally part of a formal qualification exercise supervised by the qualification body. Essential Parameters Essential Variables Those parameters, among the influential parameters, which have a significant influence on the outcome of a particular inspection. Further information can be found in ENIQ Recommended Practice 1. Experimental Evidence Could be part of the technical justification. It could include the following: a) results from relevant round robin exercises b) results from relevant experimental studies, whether conducted on representative or simplified test pieces c) results from previous relevant inspection qualification exercises and results from field experience. This can cite previous work or contain an account of work carried out specifically for the component in question. 3
False Call An erroneous reporting of a defect indication from a part of a test object which is, in fact, free of defects. Human Factors The influences on the outcome of a non-destructive test arising from the fallibilities, which humans can exhibit when working under the actual conditions of the test. Influential Parameters Influential Variables Those parameters, relevant for the particular inspection, which can potentially influence the outcome of the inspection. Further information can be found in ENIQ Recommended Practice 1. Input Information Information (including essential parameters describing the component, material, defects, etc.), which has to be made available prior to the start of the process of inspection qualification. Further information can be found in ENIQ Recommended Practice 4. Inspection Inspection is a process of verifying conformity with a written requirement, which can be carried out at a number of levels: a) at the highest level, inspection can mean formal third party inspection to satisfy a legal requirement for independent endorsement. b) at the intermediate level, inspection can mean verifying by a variety of means that a specification has been met e.g. with regard to the overall size and shape of a component. c) the most specialised use of the word is synonymous with NDT e.g. in-service inspection of nuclear components Because the word inspection is in widespread use throughout the world in each of the three senses given above, no single meaning is given here. The applicable meaning must be deduced from the context. 4
Inspection Method Inspection Procedure Discipline applying a physical principle in non-destructive testing e.g.: ultrasonic testing method. A definition of how an inspection is implemented for a specific test situation. A written description specifying all essential parameters and setting out the precautions to be observed when applying an inspection technique, following an established standard, code or specification. Inspection Qualification The systematic assessment, by all those methods that are needed to provide reliable confirmation, of an inspection system to ensure it is capable of achieving the required performance under real inspection conditions. Inspection Reliability The degree to which an inspection system achieves its purpose regarding detection, characterisation, sizing at an acceptable false call rate. Inspection System All parts of the non-destructive test including equipment, inspection procedure and personnel which can influence the outcome and quality of the inspection. Inspection Technique A specific way of utilising an inspection method (e.g. ultrasonic immersion technique). Modelling The use of mathematical models of NDT to predict quantitatively the outcome of tests. Further information can be found in ENIQ Recommended Practice 6. Non-Essential Parameters Non-Essential Variables Parameters, which do not have any significant influence on the outcome of a particular inspection. Further information can be found in ENIQ Recommended Practice 1 Open Trial A trial of an inspection in which those applying the inspection to test pieces have specific knowledge of the 5
defects in the test pieces. It is part of a formal qualification exercise supervised by the qualification body. Parametric Studies Experimental laboratory studies to establish the separate influence of the various essential parameters such as defect characteristics, equipment characteristics etc. which can affect the outcome of a test. Pass/Fail Criteria The criteria relating to the number of defects detected in test pieces, number of false calls, size and positional accuracy and so on reported in an inspection qualification which determine success or failure of the NDT inspection. Physical Reasoning Part of the technical justification, containing a compilation of the detailed reasons for selection of a particular NDT approach expressed in qualitative terms. If early design of test pieces is needed, the input can be based on physical reasoning which is usually available at the start of compiling the technical justification. Practical Assessment Practical Trials The assessment of a non-destructive test by applying it to test pieces containing defects. More information can be found in ENIQ Recommended Practice 5. Qualification Body Body that conducts inspection qualification. Qualification Certificate A document issued under the rules of an inspection qualification system. It indicates that adequate confidence is provided that inspection procedures, equipment and personnel or any combination of these are capable, for a specific test, of achieving the stated objectives of the test. Qualification Certification Administrative procedure used to document the evidence arising from the inspection qualification of the inspection system according to a defined system. It leads to the issue 6
of a certificate attesting to the ability of the NDT to meet laid down requirements. Qualification Dossier An assembly of all the information relevant to the definition and execution of the inspection qualification. It includes information on defects, components to be inspected, the inspection procedure and NDT conditions. It also includes the qualification procedure and its final part contains the result of the inspection qualification. Qualification Procedure An orderly sequence of rules, which describe how, a specific non-destructive test on a specific component, is to be qualified. Real Defect A defect, which has developed in a component during its manufacture or in service, without any steps having been taken to deliberately encourage its development. Realistic Defect A defect deliberately inserted into a test piece which simulates the metallurgical appearance of a real defect. The most useful types of realistic defects for qualification purposes are those whose NDT responses resemble, or can be related to, those of the real defects of interest, for the NDT techniques being considered. Recommended Practice Documents produced by ENIQ to support individual countries in how to implement in practice the European methodology for inspection qualification of NDT. A recommended practice is the next level of document below the methodology. Synthetic Defect Defect made in a synthetic way referring to either artificial defects or realistic defects. Technical Justification Most commonly used for a collection of all the necessary information which provides evidence that the inspection 7
ENIQ Glossary: second issue system can meet its stated objectives. Technical justification may, however, be used for a number of other purposes such as for example to justify the defects or test pieces to be used during test piece trials or to justify an upgrade in inspection equipment without the need to repeat the whole qualification. Further information can be found in ENIQ Recommended Practices 2 and 3. Test Assembly Test Block Test Piece Test Specimen A structure, which may or may not simulate geometrically an engineering component or part of a component for use, for example, in test piece or round robin trials. Type A, B, C defects Terms used in the Programme for Inspection of Steel Components (PISC) to describe three types of defects. a) type A defects are smooth cracks with sharp tips. These can be used as realistic defects. b) type B defects are rough cracks affected by the implantation process so that they have unrealistic tips, which produce abnormal large ultrasonic responses. c) type C defects are volumetric defects such as slag and porosity. Worst Case (Defects) Defined as those cases of defects, component geometry, etc. which are likely to present the greatest challenges for detection and/or accurate sizing within the framework of the specific situation considered for inspection qualification, as defined in the input information, and considering also the specific inspection system used. 8
ENIQ Glossary: second issue 3. Relevant documents 1. European Methodology for Qualification of Non-Destructive Testing, ENIQ Report No. 2, EUR 17299 EN, published by the European Commission, Brussels-Luxembourg, 1997 2. Common position of the European regulators on qualification of NDT systems for preand in-service inspection of light water reactor components, EUR 16802 EN/FR, published by the European Commission, Brussels-Luxembourg, 1996 3. ENIQ Recommended Practice 1: Influential/essential parameters, Issue 1, ENIQ Report 6, EUR 18101 EN, published by the European Commission, Brussels-Luxembourg, 1998. 4. ENIQ Recommended Practice 2: Recommended contents for a technical justification, Issue 1, ENIQ report 4, EUR 18099 EN, published by the European Commission, Brussels-Luxembourg, 1998. 5. ENIQ Recommended Practice 3: Strategy document for technical justification, Issue 1, ENIQ Report 5, EUR 18100 EN, published by the European Commission, Brussels- Luxembourg, 1998. 6. ENIQ Recommended Practice 4: Recommended contents for the qualification dossier, ENIQ Report 13, EUR 18685 EN, published by the European Commission, Brussels- Luxembourg, 1999. 7. ENIQ Recommended Practice 5: Guidelines for the design of test pieces and the conduct of test piece trials, ENIQ Report 14, EUR 18686 EN, published by the European Commission, Brussels-Luxembourg, 1999 8. ENIQ Recommended Practice 6: The use of modelling in inspection qualification, ENIQ Report 15, EUR 19017 EN, published by the European Commission, Brussels- Luxembourg, 1999. 9
EUROPEAN COMMISSION EUR 18102 EN 9 pages Editors: P. Lemaitre/B. Eriksen Luxembourg: Office for Official Publications of the European Communities 1999 9 pag. 21.0 x 29.7 cm Physical sciences EN Catalogue number: CD-NA-18102-EN-C Copies of this ENIQ report can be obtained by writing to the following address: JRC Petten Institute for Advanced Materials P.O. Box 2 NL 1755 ZG Petten The Netherlands ABSTRACT This document is the second issue of the ENIQ glossary. It was approved by the Steering Committee of ENIQ for publication in December 1999. This is a living document and, if necessary, a second issue will be published in the future taking into account the experience gained from using this recommended practice.
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