ASTM C1514-2008 Standard Test Method for Measurement of 235U Fraction Using Enrichment Meter Principle《用同位素浓缩度计原理测定铀235微粒的标准试验方法》.pdf
《ASTM C1514-2008 Standard Test Method for Measurement of 235U Fraction Using Enrichment Meter Principle《用同位素浓缩度计原理测定铀235微粒的标准试验方法》.pdf》由会员分享,可在线阅读,更多相关《ASTM C1514-2008 Standard Test Method for Measurement of 235U Fraction Using Enrichment Meter Principle《用同位素浓缩度计原理测定铀235微粒的标准试验方法》.pdf(8页珍藏版)》请在麦多课文档分享上搜索。
1、Designation: C 1514 08Standard Test Method forMeasurement of235U Fraction Using Enrichment MeterPrinciple1This standard is issued under the fixed designation C 1514; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、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 test method covers the quantitative determinationof the fraction of235U in uranium using measurement of the185.7 keV g
3、amma-ray produced during the decay of235U.1.2 This test method is applicable to items containinghomogeneous uranium-bearing materials of known chemicalcomposition in which the compound is considered infinitelythick with respect to 185.7 keV gamma-rays.1.3 This test method can be used for the entire
4、range of235Ufraction as a weight percent, from depleted (0.2 %235U) tohighly enriched (97.5 %235U).1.4 Measurement of items that have not reached secularequilibrium between238U and234Th may not produce thestated bias when low-resolution detectors are used with thecomputational method listed in Annex
5、 A2.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard may involve hazardous materials, opera-tions, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with
6、itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 1030 Test Method for Determination of Plutonium Isoto-pic Composition
7、 by Gamma-Ray SpectrometryC 1490 Guide for the Selection, Training and Qualificationof Nondestructive Assay (NDA) PersonnelC 1592 Guide for Nondestructive Assay MeasurementsC26.10 Terminology Guide2.2 ANSI Standard:N42.14 Calibration and Use of Germanium Spectrometersfor the Measurement of Gamma-Ray
8、 Emission Rates ofRadionuclides33. Terminology3.1 For definitions of terms used in this test method, refer toTerminology C26.10.4. Summary of Test Method4.1 The test method consists of measuring the emission rateof 185.7 keV gamma-rays from an item in a controlledgeometry and correlating that emissi
9、on rate with the enrich-ment of the uranium contained in the item.4.2 Calibration is achieved using reference materials ofknown enrichment. Corrections are made for attenuating ma-terials present between the uranium-bearing material and thedetector and for chemical compounds different from thecalibr
10、ation reference materials used for calibration.4.3 The measured items must completely fill the field ofview of the detector, and must contain a uranium-bearingmaterial which is infinitely thick with respect to the 185.7 keVgamma-ray. If the field of view is not filled, a correction factormust be app
11、lied.5. Significance and Use5.1 The enrichment meter principle provides a nondestruc-tive measurement of the235U fraction of uranium-bearingitems. Sampling is not required and no waste is generated,minimizing exposure to hazardous materials and resulting inreduced sampling error.5.2 This method reli
12、es on a fixed and controlled geometry.The uranium-bearing materials in the measured items andcalibration reference materials used for calibration must fill thedetector field of view.5.3 Use of a low resolution detector (for example, NaIdetector) to measure uranium with235U fraction approximately10 %
13、 which is contained in a thin-walled container can provide1This test method is under the jurisdiction ofASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.10 on NonDestructive Assay.Current edition approved July 1, 2008. Published August 2008. Originallyappr
14、oved in 2002. Last previous edition approved in 2002 as C 1514 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM web
15、site.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.a rapid (typically 100 s), easily portable measuremen
16、t systemwith precision of 0.6 % and bias of less than 1 %.5.4 Use of a high resolution detector (for example, high-purity germanium) can provide measurement with a precisionbetter than 0.2 % and a bias less than 1 % within a 300-smeasurement time when measuring uranium with235U fractionin the range
17、of 0.711 % or above which is contained inthin-walled containers.5.5 In order to obtain optimum results using this method,the chemical composition of the item must be well known, thecontainer wall must permit transmission of the 185.7 keVgamma-ray, and the uranium-bearing material within the itemmust
18、 be infinitely thick with respect to the 185.7 keV gamma-ray. All items must be in identical containers or must have aknown container wall thickness and composition.5.6 Items to be measured must be homogeneous withrespect to both235U fraction and chemical composition.5.7 When measuring items, using
19、low-resolution detectors,in thin-walled containers that have not reached secular equi-librium (more than about 120 days after processing), either themethod should not be used, additional corrections should bemade to account for the age of the uranium, or high-resolutionmeasurements should be perform
20、ed.5.8 The method is often used as a enrichment verificationtechnique.6. Interferences6.1 Appropriate corrections must be made for attenuatingmaterials present between the uranium-bearing material andthe detector. Inappropriate correction for this effect can resultin significant biases.6.2 Incorrect
21、 knowledge of chemical form of the uranium-bearing materials can result in a bias.6.3 Depending on the dead-time correction method used,excessive dead time can cause errors in live time correctionand, thus, result in a measurement bias. Excessive dead timecan usually be eliminated by modifications t
22、o the detectorcollimator and aperture.6.4 Background gamma-rays near 185.7 keV can result in abias. Table 1 is a list of interfering gamma-rays which maycause an interference.6.5 Any impurities present in the measured items must behomogeneously distributed and well characterized. The pres-ence of im
23、purities, at concentrations which can measurablyattenuate the 185.7 keV gamma-ray and which are not ac-counted for will result in a bias.6.6 The presence of radioactive impurities can affect thedetermination of the 185.7 keV peak area. This type ofinterference is most often encountered in low-resolu
24、tion mea-surement, but can affect high-resolution measurements.6.7 Other factors, such as the paint on the outside of thecylinders and the condition of the cylinder inner walls afterexposure to UF6, may affect the precision and bias for both theNaI and the HPGe measurement methods.7. Apparatus7.1 Ga
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ASTMC15142008STANDARDTESTMETHODFORMEASUREMENTOF235UFRACTIONUSINGENRICHMENTMETERPRINCIPLE 同位素 浓缩 原理 测定
链接地址:http://www.mydoc123.com/p-464962.html