1、Designation: C1128 01 (Reapproved 2008)C1128 15Standard Guide forPreparation of Working Reference Materials for Use inAnalysis of Nuclear Fuel Cycle Materials1This standard is issued under the fixed designation C1128; the number immediately following the designation indicates the year oforiginal ado
2、ption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the preparation and characterization of working refer
3、ence materials (WRM) that are produced by alaboratory for its own use in the destructive analysis of nuclear fuel cycle materials. Guidance is provided for establishingtraceability of WRMs to certified reference materials by a defined characterization process. The guidance provided is generic; itis
4、not specific for a given material.1.2 The information provided by this guide is found in the following sections:SectionPlanning 6Preparation 7Packaging and Storage 8Characterization 9Statistical Analysis 10Documentation 111.3 The values stated in SI units are to be regarded as standard. No other uni
5、ts of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regu
6、latorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C859 Terminology Relating to Nuclear MaterialsC1009 Guide for Establishing and Maintaining a Quality Assurance Program for Analytical Laboratories Within the NuclearIndustryC1068 Guide for Qualification of Measurement Methods
7、by a Laboratory Within the Nuclear IndustryC1215 Guide for Preparing and Interpreting Precision and Bias Statements in Test Method Standards Used in the NuclearIndustry2.2 ISO Standards:3ISO Guide to the Expression of Uncertainty in MeasurementISO 17025ISO/IEC 17025 General Requirements for the Comp
8、etence of Calibration and Testing Laboratories3ISO Guide 30 Terms and Definitions Used in Connection with Reference Materials3ISO Guide 34 General Requirements for the Competence of Reference Material Producers2.3 Joint Committee for Guides in Metrology:4JCGM 100:2008 Evaluation of Measurement DataG
9、uide to the Expression of Uncertainty in Measurement (ISO GUM 1995with Minor Corrections (2008)JCGM 200:2008 International Vocabulary of MetrologyBasic and General Concepts and Associated Terms (VIM) (ISO/IECGuide 99)1 This guide is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle
10、and is the direct responsibility of Subcommittee C26.08 on Quality Assurance,Statistical Applications, and Reference Materials.Current edition approved June 1, 2008Feb. 1, 2015. Published July 2008February 2015. Originally approved in 1989. Last previous edition approved in 20012008 asC1128 01.C1128
11、 01 (2008). DOI: 10.1520/C1128-01R08.10.1520/C1128-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Avail
12、able from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from Bureau International des Poids et Mesures, Pavillon de Breteuil, F-92312 Svres Cedex, France, www.bipm.org.This document is not an ASTM standard and is intended
13、only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current ve
14、rsionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology53.1 Definitions of Terms Specific to This Standard:3.1.1 certified reference material (
15、CRM)6a reference material with one or more property values that are certified by atechnically valid procedure, accompanied by or traceable to a certificate or other documentation that is issued by a certifying body(as defined by ISO Guide 30).Acertifying body is a technically competent body (organiz
16、ation or firm, public or private) that issuesa reference material certificate (as defined by ISO Guide 30).Areference material certificate is a document certifying one or moreproperty values for a certified reference material, stating that the necessary procedures have been carried out to establish
17、theirvalidity (as defined by ISO Guide 30).3.1.2 reference material (RM)6a material or substance one or more properties of which are sufficiently well established to beused for the calibration of an apparatus, the assessment of a measurement method, or assigning values to materials (as defined byISO
18、 Guide 30). A reference material may be referred to in this guide also as a standard, such as calibration standard or controlstandard.3.1.3 working reference material (WRM)6a RM usually prepared by a single laboratory for its own use as a calibrationstandard, as a control standard, or for the qualif
19、ication of a measurement method (see Guide C1068) as indicated in Fig. 1.4. Summary of Guide4.1 This guide covers the preparation of WRMs from nuclear fuel cycle materials. These materials are compounds and metalof uranium and plutonium, absorber materials such as boron carbide, and cladding materia
20、ls such as zirconium and stainless steel.The criteria governing the preparation of reliable WRMs are identified and discussed. Because this guide is generic, requirementsand detailed information for specific nuclear materials are not given.Aflow diagram to illustrate an approach to producing WRMsis
21、given in Fig. 2.5. Significance and Use5.1 Certified reference materials (CRMs) prepared from nuclear materials are generally of high purity, possessing chemicalstability or reproducible stoichiometry. Usually they are certified using the most unbiased and precise measurement methodsavailable, often
22、 with more than one laboratory being involved in making certification measurements. CRMs are generally used ona national or international level, and they are at the top of the metrological hierarchy of reference materials. A graphicalrepresentation of a national nuclear measurement system is shown i
23、n Fig. 3.5.2 Working reference materials (WRMs) need to have quality characteristics that are similar to CRMs, although the rigor usedto achieve those characteristics is not usually as stringent as for CRMs. Similarly, producers of WRMs should comply withapplicable requirements of ISO Guide 34, whic
24、h are less stringent for WRMs than the requirements for producers of CRMs. Where5 See C859 for other terms specific to the nuclear fuel cycle.6 It is important that a well defined uncertainty in the stated value(s) be given in the certificate.FIG. 1 Quality Assurance of Analytical Laboratory DataC11
25、28 152possible, CRMs are often used to calibrate the methods used for establishing the concentration values (reference values) assignedto WRMs, thus providing traceability to CRMs as required by ISOISO/IEC 17025. A WRM is normally prepared for a specificapplication.5.3 Because of the importance of h
26、aving highly reliable measurement data from nuclear materials, particularly for control andaccountability purposes, CRMs are sometimes used for calibration when available. However, CRMs prepared from nuclearmaterials are not always available for specific applications. Thus, there may be a need for a
27、 laboratory to prepare WRMs fromnuclear materials.Also, CRMs are often too expensive, or their supply is too limited for use in the quantities needed for long-term,routine use. When properly prepared, WRMs will serve equally well as CRMs for most applications, and using WRMs willpreserve supplies of
28、 CRMs.5.4 Difficulties may be encountered in the preparation of RMs from nuclear materials because of the chemical and physicalproperties of the materials. Chemical instabilities, problems in ensuring stoichiometry, and radioactivity are factors involved, withall three factors being involved with so
29、me materials. Those preparing WRMs from nuclear materials must be aware of how thesefactors affect preparation, as well as being aware of the other criteria governing the preparation of reliable WRMs.6. Planning6.1 Producing a WRM requires forethought to ensure the credibility of the completed WRM.
30、completed WRM meets the needsof the laboratory and its data users. Planning also ensures that the necessary resources are available. Time, funding, and materialscan be wasted easily without thorough planning. Planning should include developing an outline or general scheme for preparingthe WRM. The i
31、ntended use of the WRM, the sources available for obtaining needed materials, and the equipment required aresome areas of planning that should be considered. These considerations and others, i.e., that is, initial planning, a production plan,and a statistical plan (see Fig. 2), are discussed in this
32、 section. Initial planning generally starts with the application or need for aWRM and the quantity needed.As planning progresses into the actual preparation, a production plan and a statistical analysis planwill be developed.6.2 Initial Planning:FIG. 2 Producing a Working Reference MaterialC1128 153
33、6.2.1 Application of WRMAWRM can be prepared for a single method of analysis or for several methods. For example, onemight be prepared for the determination of uranium in uranium dioxide. If a standard is also required for the isotopic analysis ofuranium, it might be possible to prepare and characte
34、rize thatWRM for isotopic analysis as well. During the preparation of aWRMfor the determination of a major constituent, it might be possible to add desired impurities and to establish values for thoseimpurities. Careful consideration should be given to the preparation of multi-purpose WRMs, however,
35、 because they tend to bedifficult to prepare and characterize.FIG. 3 United States National Nuclear Measurement SystemC1128 1546.2.2 QuantityThe quantity of WRM prepared will depend on such factors as the length of time required for its use, thefrequency of use, the amount of material available, and
36、 the WRMs anticipated shelf life. Consideration should be given to theamount of WRM that will be needed for characterization and for archival purposes. Needs may develop during the use of a WRMsuch as the exchange of materials with another laboratory for an interlaboratory testing program. For this
37、and other possiblecontingencies, the preparation of a quantity over the anticipated amount should be planned.6.3 Production PlanAn outline that specifies how the WRM will be produced should be prepared during planning. Thesubjects discussed in 6.2 and in this section should be considered and address
38、ed if appropriate. A preparation procedure should bewritten and included as a part of the production plan (see 7.4). The production plan must be integrated with the statistical plan (see6.4).6.3.1 MaterialsThe selection of materials is an important part of planning because proper selection is critic
39、al to achievingcredible WRMs. Selection depends on availability (source), cost, chemical and physical properties, and stability or reproduciblestoichiometry. The material selected for a WRM must be as similar as possible to the sample material in chemical and physicalproperties, particularly in thos
40、e that will affect the method of analysis. One way to achieve similarity in composition is to preparethe WRM material by the same or similar process used to prepare the sample material. Probably the most important criterion forselection is stability. The WRM composition must be sufficiently stable t
41、o make the preparation of the WRM cost effective, andthe stability must be known well enough to establish a shelf life with a high degree of confidence. Somewhat unstable materialswhose stoichiometries can be reproduced easily can be used for WRMs.Given the presence of radioactive constituents in WR
42、Ms,it may be necessary to account for radioactive decay as a function of time.6.3.2 EquipmentGenerally, standard laboratory equipment will be involved in preparing a WRM. Analytical setups andinstrumentation will be required, possibly to analyze starting materials for impurities and other constituen
43、ts and certainly to analyzethe prepared material during final characterization of the WRM. Depending on packaging requirements, equipment may berequired for such things as sealing glass ampoules or packaging a WRM in a special atmosphere.6.3.3 UseThe degree of attention given to some steps in produc
44、ing a WRM may vary depending on its planned use. Usually,WRMs are used for calibration and measurement control. A common approach to producing a control standard is to take materialfrom a batch of production material, treat it as necessary to ensure homogeneity, and establish initial measurement con
45、trol limitsby using the same method and conditions used for sample analysis. To produce a calibration standard, more care in preparationand rigor in characterization are required.6.3.4 Characterization of MaterialsPlanning must provide for the characterization of materials used for a WRM (SeeAppendi
46、x X1). Characterization may include the analysis of starting materials for impurities and major constituents. It shouldinclude a scheme for establishing the value to be assigned (reference value) to each constituent of interest. In planning forcharacterization, consideration must be given to the deg
47、ree of reliability required for a reference value. This will involve planningfor the statistical collection and analysis of characterization data (see 6.4).6.3.5 PackagingPackaging of the WRM should be planned. Decisions need to be made concerning the division of the WRMinto portions, selecting cont
48、ainers, uniquely identifying containers, sealing containers, and using additional means to protect theintegrity of the WRM. It may be necessary to package some WRMs soon after preparation to preserve integrity; in that case,packaging materials and equipment should be readied prior to material prepar
49、ation. Inadequate packaging may lead to loss of theWRMs integrity through such consequences as contamination, evaporation, degradation and absorption.6.4 Statistical PlanA statistical plan for characterization should be developed during planning. Such a plan is necessary toallow an uncertainty to be determined for each reference value. The statistical plan establishes how characterization will be done.It includes sampling of the WRM, the frequency and number of measurements to be made of the WRM, any reference materialto be measured with the WRM, and the o
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