ENIQ Recommended Practice 1 Influential / Essential Parameters

Transcription

1 ENIQ Recommended Practice 1 Influential / Essential Parameters Issue 2 ENIQ Report nr. 24 EUR EN

2 Mission of the Institute for Energy The Institute for Energy provides scientific and technical support for the conception, development, implementation and monitoring of community policies related to energy. Special emphasis is given to the security of energy supply and to sustainable and safe energy production. European Commission Directorate General Joint Research Centre (DG JRC) Institute for Energy Contact: Arne Eriksson Tel.: +31 (0) 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. The use of trademarks in this publication does not constitute an endorsement by the European Commission. The views expressed in this publication are the sole responsibility of the author and do not necessarily reflect the views of the European Commission. A great deal of additional information of the European Union is available on the Internet. It can be accessed through the European server( Luxemburg; Office for Official Publications of the European Communities, 2005 EUR European Communities, 2005 Reproduction is authorised provided the source is acknowledged. Printed in The Netherlands, Institute for Energy JRC IE, PR & Communication COVER: JRC IE, R. Houghton No commercial use. Credit Audiovisual Library European Commission.

3 EUROPEAN COMMISSION Directorate General Joint Research Centre (DG JRC) Institute for Energy Petten The Netherlands ENIQ RECOMMENDED PRACTICE 1: INFLUENTIAL/ESSENTIAL PARAMETERS ISSUE 2 June 2005 ENIQ Report nr. 24 EUR EN Approved by the Steering Committee of ENIQ for publication Directorate General Joint Research Centre

4 CONTENTS 1. Introduction Concept of influential/essential parameters Application of the concept of influential/essential parameters in the overall qualification process References...12 Appendix 1: Checklist of parameters which can be influential for the case of an ultrasonic inspection of welds...13 Appendix 2: Checklist of parameters which can be influential for the case of an eddy current inspection of steam generator tubes...16 Appendix 3: Overview of published ENIQ Recommended Practices: Titles and Abstracts

5 1. Introduction The European Methodology Document [1] is intended to provide a general framework for development of qualifications for the inspection of specific components to ensure they are developed in a coherent and consistent way throughout Europe while still allowing qualification to be tailored in detail to meet different national requirements. In the European Methodology Document one will not find a detailed description of how the inspection of a specific component should be qualified. A recommended practice is a document produced by ENIQ to support the production of detailed qualification procedures by individual countries. A recommended practice is the next level of document below the methodology. A recommended practice is applicable in general to any qualification. This general scope means that valuable advice can be given by ENIQ to promote a uniform approach to qualification throughout Europe but the detail of how qualification is to be done is determined at the national level in line with the regulatory and technical requirements in that country. Organisations will be free to make use at national level of the existing recommended practices, as they see fit. This ENIQ recommended practice should assist those involved in inspection qualification in how to use and implement the concept of influential/essential parameters in agreement with the spirit of the European methodology. The main objectives of this recommended practice are: - to explain the proposed concept of influential/essential parameters, - to indicate how the concept could be used in inspection qualification according to the European methodology, - to give advice concerning the classification of influential parameters, - to give examples of parameters which can be influential as a function of the specific inspection to be qualified for 2 cases: an ultrasonic inspection of welds and an eddy current inspection of steam generator tubes. This recommended practice is relevant to any non-destructive testing method. Examples given are taken from ultrasonic and eddy current inspections. It is emphasised that the general principles given in this recommended practice can also be used for qualification of manufacturing inspections or of inspections performed in the non-nuclear field, although it was developed specifically for in-service inspection of nuclear power plant components. The definitions, as given in the second issue of the ENIQ glossary [2], apply to this recommended practice. 2

6 The first issue of ENIQ Recommended Practice 1 was produced by the ENIQ Task Group 2.2 and was approved by the Steering Committee of ENIQ for publication in September The present document is Issue 2 and builds upon the experience gained in the use of Issue 1 since then. This RP1 on Influential/Essential Parameters, Issue 2, has been developed as a consensus document amongst the members of TGQ. The contributors include (in alphabetical order): J-A Berglund R Chapman O J V Chapman D Couplet A Eriksson L Horácek A Jonsson P Kelsey P Krebs B Neundorf T Seldis H Söderstrand C Waites A Walker J Whittle H Wirdelius Ringhals NPP, Sweden British Energy, United Kingdom OJVC Associates, United Kingdom Tractebel, Belgium Directorate General JRC, European Commission NRI-REZ, Czech Republic Forsmark NPP, Sweden Rolls-Royce Marine Power, United Kingdom Engineer Consulting, Switzerland Vattenfall Europe Nuclear Energy, Germany Directorate General JRC, European Commission, Co-chairman of Task Group Qualification SQC, Sweden Serco, United Kingdom Rolls-Royce Marine Power, United Kingdom John Whittle & Associates, United Kingdom, Chairman of Task Group Qualification SQC, Sweden The Steering Committee of ENIQ has formally approved this RP 1, Issue 2, for publication during the 28 th Steering Committee meeting held at Řež, Czech Republic on June The voting members of the Steering Committee of ENIQ are (in alphabetical order): R Chapman British Energy plc, United Kingdom, ENIQ Chairman D Couplet Tractebel, Belgium C Faidy EDF-Septen, France K Hukkanen Teollisuuden Voima OY, Finland P Krebs Engineer Consulting, Switzerland B Neundorf Vattenfall Europe Nuclear Energy, Germany, ENIQ Vice-Chairman J Neupauer Slovenské Elektrárne, Slovakia U Sandberg Forsmark NPP, Sweden J Shejbal Dukovany NPP, Czech Republic D Szabó Paks NPP, Hungary R Van Beusekom EPZ, The Netherlands European Commission representatives in the SC: A Eriksson. T Seldis J Guinovart Directorate General JRC, ENIQ Network Manager Directorate General JRC, Scientific Secretary to ENIQ Directorate General Transport and Energy, Luxemburg 3

7 2. Concept of influential/essential parameters 2.1 Influential and Essential Parameters There are many parameters which can potentially influence the outcome of an inspection. These are the influential parameters. The list of influential parameters to be considered will depend upon the specific inspection to be qualified. Those influential parameters whose change in value would actually affect a particular inspection in such a way that the inspection could no longer meet its defined objectives are defined as the essential parameters and are the parameters (together with a tolerance where appropriate) which need to be considered for the qualification. A caseby-case analysis has to be performed for each particular qualification in order to identify the essential parameters for a specific inspection. In Appendix 1, one finds examples of parameters which can be influential for the case of an ultrasonic inspection of welds. In Appendix 2, examples of parameters are given which can be influential for the case of an eddy current inspection of steam generator tubes. The above appendices are not intended to be exhaustive but they can be used as check lists by those developing and justifying inspections to help identify the essential parameters. They can also be used by qualification bodies in the same way to check that all essential parameters have been identified and treated in the technical justification. Consideration of the influential parameters for any particular inspection shows that they can be divided into two distinct groups (see Figure 1): - input (component characteristics, characteristics of defects to be detected and sized, environment etc.), - NDT inspection system. This includes procedure parameters (for example probe frequency, beam angles, recording level, personnel requirements etc) and equipment parameters (for example digitisation rate, horizontal linearity, etc). 2.2 Input Parameters The first group contains parameters which define the particular inspection problem. Their values and the range over which they can vary determine the inspection approach which is appropriate to the problem. Details of the component such as its dimensions, material and geometry are included in this group along with the parameters of the defects which need to be detected and assessed. The particular defect parameters which have to be considered depend on the NDT method being used. This group of parameters is referred to as the Input Group. 4

8 2.3 NDT Inspection System Parameters The second group of parameters includes firstly those which are chosen to ensure that the NDT to be used is matched to the component, the defects to be sought (and/or sized) and the performance required. Logically, they should follow from the value of the parameters in the Input Group, although code requirements or previous practice are sometimes the basis of the initial choice. Examples of such parameters are, in the case of ultrasonic inspection, the wave modes, frequencies, beam angles chosen and analysis criteria. The parameters are specified in the inspection procedure and one of the purposes of the technical justification is to justify the choices made and determine the resulting performance to be expected from the inspection. Some of the parameters in this group can often vary within their specified tolerance without affecting the outcome of the inspection. Examples are the beam angles and the frequency for ultrasonics. A function of the technical justification may be to determine and justify the tolerance allowed for the variation of parameters where the outcome of the inspection is particularly affected by variations of the particular parameter. The requirements of the inspection procedure in turn determine the kind of equipment which is to be used to implement the inspection. Some of the parameters in the Input Group can also be important. For example, a hostile environment or the need for precision in size measurement may dictate the use of automated rather than manual scanning. The need to operate the equipment remotely from the ultrasonic transducers may require the use of long cable lengths and these can influence the performance of the equipment and so on. As above, there will often be a tolerance within which the parameter will not affect a specific inspection. The need to ensure that the equipment parameters remain within such tolerances requires regular calibration. Those parameters which can change most rapidly require most frequent calibration. The parameters relating to the inspection procedure and the equipment used are included in the NDT Inspection System Group. 2.4 Summary All influential parameters of the two groups discussed above whose change in value actually affects the outcome of the inspection in such a way that it can no longer meet its objectives (and hence be qualified) will be considered as essential parameters and those from the second group must be specified in the inspection procedure. The values chosen for the NDT Inspection System Group parameters must be justified in the technical justification (TJ). The influential parameters which do not affect the qualification of the particular inspection considered are non-essential parameters and need not be considered in the TJ. 5

9 However, identifying those parameters in the TJ and justifying why they are not essential might provide even greater confidence for the end user if needed but at the expense of greater complexity in producing the TJ Many NDT inspection system parameters can vary within a tolerance. One of the purposes of the technical justification is to show that such variations do not affect the outcome of the inspection. The calibration requirements of the inspection procedure need to ensure that such parameters are checked at appropriate intervals to ensure that they remain within the specified tolerance The role of the different participants in inspection design and qualification in relation to the essential parameters is summarised in Table 1 below: Table 1: The role of different participants in relation to essential parameters Participant Parameter INPUT parameters (related to real on site conditions for implementation of the NDT system) NDT inspection system parameters (related to the instructions of the procedure, to the characteristics and settings of the equipment and to the personnel) Vendor (Developer of the NDT) Input to the Vendor for correct design of the inspection system Defined by the Vendor to fit the input parameters range of values (to be demonstrated) Qualification Body (Manager of the qualification process) Input to the QB for correct design of the qualification procedure (verification of the performance for all specified conditions) The QB verifies that the whole qualification process is performed with the defined values of the NDT system Owner of the plant (Buyer of the qualified examination) Defined by the Owner according to ISI objectives, component characteristics and other site conditions The Owner verifies that the on site implementation is done with the defined values of the NDT system 6

10 Input Parameters Procedure Parameters NDT Inspection System Parameters Equipment Parameters Figure 1: Different categories of influential/essential parameters 7

11 3. Application of the concept of influential/essential parameters in the overall qualification process 3.1 Use of Essential Parameters in the Technical Justification The second issue of the ENIQ European Methodology Document [1] describes inspection qualification as the sum of the following items: a. practical assessment (blind or non-blind), conducted on simplified or representative test pieces resembling the component to be inspected; b. technical justification, which involves assembling all evidence on the effectiveness of the test, including previous experience of its application, experimental studies, mathematical modelling, physical reasoning (qualitative assessment) and so on. The aim is that the practical assessment and technical justification should together provide convincing evidence that the proposed inspection will achieve the desired performance targets, in terms of defect detection and sizing capability. Technical justification (TJ) forms a key part of the ENIQ approach to qualification. Two recommended practices have been published on technical justification: one on the recommended contents of a TJ and one on a strategy of how to use a TJ [5-6]. The document dealing with the contents of a TJ recommends that it contain a section identifying the essential parameters for the inspection. An analysis of the specific inspection to be qualified has to be done in order to determine which are the essential parameters. The TJ can have a number of purposes and the precise function of the TJ determines what must be included in it. In most cases the TJ will contain a list of essential input and NDT inspection system parameters for the inspections of the components in question and will describe how they will be dealt with in the TJ. This involves demonstrating that the NDT inspection system parameters are appropriate to the different values that input parameters can assume. 3.2 Choice of Essential Parameters Usually it will be clear which of the parameters in the lists given in the Appendices (or similar lists for other inspection techniques) are essential for a specific inspection. Some of the parameters will clearly be inappropriate to the particular inspection e.g. pipe diameter for plate inspection but many of them have the potential to change the outcome of the inspection if they are changed sufficiently and so are essential. 8

12 3.3 Treatment of Essential Parameters in the TJ Review of the essential parameters of the NDT inspection system group will reveal that the outcome of the inspection would be particularly affected by changes in the values chosen for certain of them. When this is the case, it must be demonstrated in detail in the TJ that appropriate values have been chosen and specified in the IP in relation to the input parameters and the values the input parameters can assume and that, where appropriate, the inspection will not be degraded if the inspection system parameters vary over their full allowable tolerance. Those compiling the TJ should determine which system parameters fall into this category for the particular inspection. In the case of ultrasonic inspection, these might include scanning areas, scanning and recording sensitivity, sizing method and so on. The precise choice for a particular inspection must be determined from analysis of that inspection. The values chosen for these parameters and their tolerances where appropriate must be justified in some detail in the TJ. In ultrasonic testing, the beam angle is a key parameter and must be chosen according to the orientation of the defects being sought. If component geometry is complex, the angles of incidence on the defects in relation to the beam angles selected may require detailed calculation and this should be included in the TJ. Justification of the beam angles selected for the inspection will usually be a key part of the TJ of an ultrasonic inspection. However, the inspection would usually not be significantly affected if each angle were to differ by a few degrees from its nominal value and so the effect of tolerance in beam angle is often insignificant. Beam angle is an example of a parameter that must be justified in detail in the TJ even though its tolerance is usually of little consequence, In many other cases, general experience and recognised theoretical or empirical knowledge provide clear evidence that the outcome of the inspection is not particularly affected by changes in the value of an essential parameter within its defined range/tolerance and there is no need to treat it in detail in the TJ. An example of such a parameter is probe centre frequency in ultrasonics. The parameter is essential because if it is increased by an order of magnitude or more from its specified value the inspection can be affected by material noise whereas if frequency is too low, the inspection resolution and sensitivity to defects will diminish. Because it is essential, it must be specified in the inspection procedure (IP) together with its tolerance. However, the tolerance will usually be ±25% of nominal centre frequency or lower. This means that variation within its specified tolerance will not normally affect the inspection. Because the exact choice of frequency within a fairly broad range and also tolerance in frequency will not affect the inspection critically, all the TJ needs to contain is a brief statement justifying the choice of frequency e.g. 2MHz chosen to give reasonable resolution and sensitivity to defects. The QB should check the IP to ensure the tolerance and calibration requirements are suitable but these need not be justified in detail in the TJ. 9

13 Such a treatment is acceptable as long as the brief statement is sufficient to provide the required confidence (depending on the qualification level) that the qualification conclusion is correct. It is suggested that the section of the TJ which deals with essential parameters contains a table listing all the essential parameters identified for the inspection. For those parameters whose precise values particularly affect the inspection, the table should contain a reference to the part of the TJ in which they are treated in detail. For other, less critical essential parameters, the table itself should contain a brief justification of the value chosen. Some judgement by the TJ compiler is needed to determine which parameters are treated in detail and which are not. This decision should be taken with great care because, in some cases, the influence of the parameter may not be obvious. For example, tolerance in beam angle may not affect detection capability but may affect the correct sizing and positioning of the defect which may determine whether the defect is classified as acceptable or not. A decision not to treat an essential parameter in detail may be briefly justified in the TJ to strengthen the case and give higher confidence. The QB will need to be satisfied with whatever treatment is given to each parameter and early discussions between the QB and TJ compiler have the potential to save unnecessary effort. In many cases, for logistical reasons, the TJ is produced following experimental trials. If the trials are successful, the TJ will need to show that they would still have been successful over the full range of input parameter values. Most NDT inspection system parameters whose variation does not affect the outcome of the inspection until they vary by considerable margins from their specified value are effectively qualified by the trials. In this situation, the table should simply record which parameters are qualified by the successful trials. Where the value or range for an essential parameter is not defined, this should generally be stated in the TJ together with the reason for this, e.g. no information on the value of the parameter is available or there is no way currently known to predict the effect of varying the parameter. This makes a potential weakness in the justification apparent. The values of the essential parameters of the NDT inspection system group may be based on previous practice, on the requirements of codes or standards or on an assessment of the requirements following from the input parameters. The TJ will usually involve assessing the proposed inspection system through the identified essential parameters to determine whether its performance matches the requirements. 10

14 This assessment may reveal deficiencies, which then lead to a process of iteration to produce a satisfactory inspection system or to a decision to limit the application of the inspection system. 3.4 Summary In summary, the analysis of the influential/essential parameters can be done in successive phases and the TJ compiler should follow the steps below: - Determine the value and the tolerance/range for the essential parameters of the input group related to the component and the defects, - Determine which of the influential NDT inspection system parameters are essential for a particular inspection - Determine the value of the essential parameters of the NDT inspection system group and ensure the IP includes values for all of them together with allowable tolerances - Divide the essential NDT inspection system parameters into two sets Those which particularly affect the outcome of the inspection taking into account the selected values for the input essential parameters related to the component and the defects. (Set 1) Those which affect the outcome of the inspection but only if they differ by a substantial margin from their chosen values (Set 2) - List all essential parameters, including input parameters, in the appropriate section of the TJ in a table. For input parameters, identify in the table where evidence is given in the TJ that the NDT system will meet its objectives for all values in the range of each essential parameter. For each Set 1 system parameter, identify in the table where it is treated in detail in the TJ. Include a brief justification in the table for the value (and tolerance where applicable) chosen for each of the Set 2 system parameters. - Demonstrate in detail in the TJ that Set 1 parameter values are correctly chosen in relation to input parameter values and that allowable tolerances for any of the Set 1 parameters does not lead to an unacceptable value for that parameter. This situation is unlikely to arise for Set 2 parameters because, by definition, the outcome of the inspection will not be affected unless their value changes by very large amounts. - Check that calibration requirements are included in the inspection procedure to ensure that all parameters are and remain within their specified tolerance and include a statement in the TJ to this effect 11

15 4. References 1. The European methodology for qualification of non-destructive testing, Second Issue, EUR EN, published by the European Commission, Brussels- Luxembourg, ENIQ glossary of terms, second issue, ENIQ Report 12, EUR EN. 3. Technical Justification: Pre-Trials, (first ENIQ pilot study), ENIQ Report 10, EUR EN, published by the European Commission, Brussels-Luxembourg, Inspection procedure for the first ENIQ pilot study, ENIQ Report 11, EUR EN, published by the European Commission, Brussels-Luxembourg, ENIQ Recommended Practice 2: Recommended contents for a technical justification, Issue 1, ENIQ Report 4, EUR EN, published by the European Commission, Brussels-Luxembourg, ENIQ Recommended Practice 3: Strategy document for technical justification, Issue 1, ENIQ Report 5, EUR EN, published by the European Commission, Brussels-Luxembourg,

16 APPENDIX 1 Checklist of parameters which can be influential for the case of an ultrasonic inspection of welds 1. Input group 1.1 Component: geometry of the component access possibilities (including radiation, etc.) surface conditions weld crown configuration weld root configuration wall thickness of the straight pipe diameter of the pipe counterbore counterbore dimensions weld mismatch (misalignment) macrostructure of the base material macrostructure of the weld presence of buttering (in case of dissimilar metal welds) temperature. 1.2 Defects: type of defect degradation mechanism shape of the defect through-wall extent of the defect position of the defect through the thickness of the component position of the defect along the axis of the component tilt angle of the defect skew angle of the defect roughness/branching of the defect presence of residual stresses. 2. NDT inspection system group 2.1 Procedure parameters wave mode probe type probe configuration (pulse echo, tandem, pitch/catch etc.) probe size frequency 13

17 beam angle pulse length focal characteristics of (twin crystal) probes sensitivity for scanning and recording scanning pattern and step scanning speed scanned area on component surface personnel training, experience and qualification sizing method recording/identification criteria data analysis scheme. 2.2 Equipment parameters The influential parameters of the NDT equipment are classified in different categories: hardware pulser/receiver and data acquisition cable transducers scanner Hardware pulser/receiver and data acquisition: vertical linearity (screen height) horizontal linearity (time base) resolution of digitiser sampling rate averaging rate points per A-scan sampling pulse amplitude of the emitter pulse width of the emitter pulse fall time of the emitter pulse rise time of the emitter bandwidth of receiver available gain of receiver band pass filter of receiver time base setting for pulse echo probes time base setting for TOFD probes sampling gate. All of these parameters will in general be parameters to be fixed within a tolerance in the inspection procedure. Calibration requirements will be chosen to ensure that unacceptable variations have not occurred. 14

18 2.2.2 Cable: cable length impedance Probe: probe frequency probe index point beam shoe angle probe shoe angular deviations (squint angle) twin crystal probe shoe focal characteristics bandwidth Scanner: linearity of the scanner repeatability resolution. water path (for immersion inspection) The following procedure parameters concerning the scanner were already mentioned: scanning pattern and step scanning speed. scanned area on component surface 15

19 APPENDIX 2 Checklist of parameters which can be influential for the case of an eddy current inspection of steam generator tubes 1. Input group 1.1 Component: General geometry and environment: access restrictions channel head dimensions manway configuration temperature radiation structures (internals) Geometry of tubes: diameter wall thickness U-bend radius length expansion geometry nature of deposits (copper, sludge, etc.) presence of denting, etc. presence of tube supports or anti-vibration mounts 1.2 Defects: type of defect degradation mechanism origin of defects (inside or outside) through-wall extent of defects length of defects orientation of defects location of defects. 2. NDT inspection system group 2.1 Procedure parameters number of probes probe type probe dimensions frequencies 16

20 type of generation of frequencies (simultaneous or multiplexed) number of channels (number of probes /frequencies) sensitivity for scanning and recording scanning pattern scanning speed personnel training, experience and qualification detection method sizing method recording/identification criteria data analysis scheme. 2.2 Equipment parameters Transmitter: total harmonic distortion output impedance linearity of phase linearity of amplitude Receiver: input impedance amplifier linearity and stability bandwidth A/D converter: A/D resolution dynamic range sample rate Cable: type length impedance Probe: General: type of probe impedance frequency range resonance frequency Bobbin coil: effective scan field width fill factor coefficient depth coefficient 17

21 axial length coefficient transverse width coefficient phase to depth curve D.C. saturation strength Pancake coil: effective scan field width lift-off value depth coefficient axial width coefficient transverse width coefficient phase to depth curve Scan device: axial accuracy accuracy of scan speed speed range. 18

22 APPENDIX 3 Overview of Published ENIQ Recommended Practices (RP): Titles and Abstracts The RPs may be downloaded at: RP1 Influential/essential parameters, EUR EN ENIQ Recommended Practice 1 should assist those involved in inspection qualification how to use and implement the concept of influential/essential parameters in agreement with the spirit of the European methodology. This version of RP 1 Issue 2 builds upon the experience gained in the use of Issue 1since it was published in The main objectives of this recommended practice are: - to explain the proposed concept of influential/essential parameters, - to indicate how the concept could be used in inspection qualification according to the European methodology, - to give advice concerning the classification of influential parameters, - to give examples of parameters which can be influential as a function of the specific inspection to be qualified for 2 cases: an ultrasonic inspection of welds and an eddy current inspection of steam generator tubes. RP2 Recommended contents for a technical justification, EUR RP 2 defines a list of recommended contents for writing technical justifications. It should assist those producing technical justifications to identify the material that might be included. It should also assist in producing technical justifications in a uniform format throughout Europe. RP3 Strategy document for technical justification, EUR The purpose of this RP is to describe a strategy on how to use and implement the concept of technical justification, which is an important element of the ENIQ European methodology for qualification of NDT. The main objectives are: to explain the different purposes of technical justifications to indicate how the specific purpose or application of the technical justification may affect its contents to give guidance on the relative weight which has to be given to test piece trials and technical justification taking into account a number of factors such as level, available evidence, specific application etc. 19

23 RP4 Recommended contents for the qualification dossier, EUR This RP should assist those doing qualifications to identify the material which might be included in the qualification dossier, which is defined as an assembly of all the information relevant to the definition and execution of the qualification. It should also assist in producing qualification dossiers in a uniform format throughout Europe, an essential element in providing a general framework for a scheme of recognition of qualifications performed in the EU. Note that the concept of dossier is not that of a single document or report but rather that of a file in which key documents of the qualification are inserted. RP5 Guidelines for the design of test pieces and conduct of test piece trials, EUR The purpose of RP5 is to provide guidelines for the design of test pieces and the conduct of test piece trials, once it is has been decided (for example, as a result of the analysis done in the technical justification) that they are required. It refers especially to those test piece trials (open or blind) that are supervised by the qualification body. RP6 The use of modelling in inspection qualification, EUR This RP deals with the use of mathematical modelling in inspection qualification. Mathematical models have been developed by several organisations for various inspection situations and, where applicable, can provide valuable evidence on inspection capability for inclusion in a technical justification. Authors of technical justifications may therefore be considering the use of models. This RP provides advice on: the types and range of mathematical models which are available how the models can be used to generate evidence for a technical justification important considerations and constraints in using models. 20

24 RP7 Recommended general requirements for a body operating qualification of nondestructive tests, EUR The document provides guidance on the minimum criteria that a body operating qualification of non-destructive testing should follow if it is to be recognised as impartial, independent of operational pressures, competent and reliable. Three types of qualification body are considered within the RP: Type 1: A qualification body which is an independent third party organisation Type 1: A qualification body which is an independent part of the utility s organisation set up on a permanent or long-term basis Type 3: An ad hoc qualification body set up for a specific qualification. The RP is mainly intended to provide guidance on the requirements for qualification bodies of types 1 and 2. An ad hoc qualification body, type 3, being more temporary and inspection-specific in nature, will generally be established in a less formal way than qualification bodies of types 1 and 2. However, many parts of the RP should still provide useful guidance for setting up an ad hoc qualification body. The RP should assist those who want to establish a qualification body and those who have to audit the competence of a qualification body. It should also assist in providing a general framework for a scheme of recognition of qualifications performed in the European Union (EU). RP8 Qualification Levels and Qualification Approaches, EUR This RP is intended to provide guidance on the setting of Qualification Level and on determining the Qualification Approach based partly on this choice of level. The Qualification Level required reflects the assurance required that the inspection will attain its objectives in demonstrating structural integrity and may depend on e.g. safety significance of the component, the role of the inspection in assuring structural integrity and associated costs. In practice, qualification can be done with varying degrees of complexity and cost. The way such work is carried out is defined in this document as the qualification approach, and needs to take into account both the structural integrity significance and difficulty of each specific inspection. The qualification approach determines to what extent the various aspects of qualification, i.e. technical justification, open trials, blind trials etc., are included in a particular case. 21

25 European Commission DG JRC Institute for Energy EUR EN ENIQ RECOMMENDED PRACTICE 1: INFLUENTIAL/ESSENTIAL PARAMETERS Issue 2 Editor: A. Eriksson J. Whittle Luxemburg: Office for Official Publications of the European Communities pp x29.7 cm Scientific and Technical Research Series Abstract ENIQ Recommended Practice 1 should assist those involved in inspection qualification how to use and implement the concept of influential/essential parameters in agreement with the spirit of the European methodology. This version of RP 1 Issue 2 builds upon the experience gained in the use of Issue 1since it was published in The main objectives of this recommended practice are: - to explain the proposed concept of influential/essential parameters, - to indicate how the concept could be used in inspection qualification according to the European methodology, - to give advice concerning the classification of influential parameters, to give examples of parameters which can be influential as a function of the specific inspection to be qualified for 2 cases: an ultrasonic inspection of welds and an eddy current inspection of steam generator tubes.

26 The mission of the Joint Research Centre is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring of EU policies. As a service of the European Commission, the JRC functions as a reference centre of science and technology for the Union. Close to the policy-making process, it serves the common interest of the Member States, while being independent of commercial or national interests.