ASTM_C_1233_-_15.pdf

Designation:C123315Standard Practice forDetermining Equivalent Boron Contents of NuclearMaterials1This standard is issued under the fixed designation C1233;the number immediately following the designation indicates the year oforiginal adoption 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 standard details a recommended practice for thecalculation of the Equivalent Boron Content(EBC)for nuclearmaterials.The EBC is used to provide a measure of themacroscopic neutron absorption cross section of a nuclearmaterial.EBC factors for the natural elements are determinedfrom their atomic masses and thermal neutron absorption crosssections.This practice is illustrated by using EBC factors thatare based on thermal neutron(2200 m/s)absorption crosssections.Other EBC factors may be used depending upon theactual neutron energy spectrum.1.2 The EBC is a characteristic of a homogeneous material.Characterization of inhomogeneous materials and calculationof neutron multiplication factors require techniques that arebeyond the scope of this practice.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.2.Referenced Documents2.1 ASTM Standards:2C696 Test Methods for Chemical,Mass Spectrometric,andSpectrochemical Analysis of Nuclear-Grade Uranium Di-oxide Powders and PelletsC698 Test Methods for Chemical,Mass Spectrometric,andSpectrochemical Analysis of Nuclear-Grade Mixed Ox-ides(U,Pu)O2)C761 Test Methods for Chemical,Mass Spectrometric,Spectrochemical,Nuclear,and Radiochemical Analysis ofUranium HexafluorideC799 Test Methods for Chemical,Mass Spectrometric,Spectrochemical,Nuclear,and Radiochemical Analysis ofNuclear-Grade Uranyl Nitrate SolutionsC859 Terminology Relating to Nuclear Materials3.Terminology3.1 Terminology used in this practice is in accordance withTerminology C859.4.Significance and Use4.1 Use of this standard practice yields an equivalent boroncontent(EBC)that can be used to characterize the neutron-absorbing properties of a nuclear material.The elementsincluded in the calculation are typically chosen so that the EBCrepresents either the entire material(for example,for a mod-erator)or the impurities in the material(for example,for anuclear fuel).This practice is typically used for materials inwhich thermal neutron absorption is undesirable.The EBC isnot intended for use as an input to any neutronic calculation.The EBC factors in Table 1 were selected to represent neutronabsorption in water reactors under normal operating condi-tions.It is the responsibility of the user to evaluate theirsuitability for other purposes.5.Procedures for EBC Determination5.1 Agreement shall be reached between the buyer andseller as to which elements shall be analyzed for calculation oftheir EBC.It is recommended that B,Cd,Dy,Eu,Sm,and Gdbe included in this calculation.Analytical methods for suchelements shall be those given in Test Methods C696,C698,C761,and C799 as applicable or as otherwise agreed uponbetween buyer and seller.5.2 The individual EBC values are calculated using the EBCfactors from Table 1 as follows:EBC of constituent=(EBC factor of constituent)(g of constituent/g of material)where:EBC factor of constituent=(atomic mass of boron)(a ofconstituent)/(atomic mass of constituent)(a of boron),anda=atomic neutron absorption cross section in barns.The EBC factors have been calculated using a value of 764barns for the neutron absorption cross section(a)of boron.This value may vary in nature according to the isotopic1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.02 on Fuel andFertile Material Specifications.Current edition approved June 1,2015.Published June 2015.Originallyapproved in 1993.Last previous approved in 2009 as C1233 09.DOI:10.1520/C1233-15.2For 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 website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 TABLE 1 Equivalent Boron Content FactorsElementNeutron Absorption Cross SectionA(Barns)at2200 m/sAtomic MassBEBC FactorAluminiumC0.23126.981.21E-04Antimony5.1D121.755.93E-04Argon0.6839.952.41E-04Arsenic4.574.928.50E-04BariumC1.2D137.331.24E-04BerylliumC0.0076D9.011.19E-05BismuthC0.0338208.982.29E-06Boron764E10.811.00E+00Bromine6.979.911.22E-03Cadmium2520112.413.17E-01CalciumC0.4340.081.52E-04CarbonC0.003512.014.12E-06CeriumC0.63D140.126.36E-05Cesium29132.913.09E-03Chlorine33.535.451.34E-02Chromium3.0752.008.35E-04Cobalt37.258.938.93E-03Copper3.7863.548.42E-04Dysprosium940162.508.18E-02Erbium159.2167.261.35E-02Europi