1、Designation: C992 16Standard Specification forBoron-Based Neutron Absorbing Material Systems for Usein Nuclear Fuel Storage Racks in a Pool Environment1This standard is issued under the fixed designation C992; the number immediately following the designation indicates the year oforiginal adoption or
2、, 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 specification defines criteria for boron-based neu-tron absorbing material
3、 systems used in racks in a poolenvironment for storage of nuclear light water reactor (LWR)spent-fuel assemblies or disassembled components to maintainsub-criticality in the storage rack system.1.2 Boron-based neutron absorbing material systems nor-mally consist of metallic boron or a chemical comp
4、oundcontaining boron (for example, boron carbide, B4C) supportedby a matrix of aluminum, steel, or other materials.1.3 In a boron-based absorber, neutron absorption occursprimarily by the boron-10 isotope that is present in naturalboron to the extent of 18.3 6 0.2 % by weight (depending uponthe geol
5、ogical origin of the boron). Boron, enriched inboron-10 could also be used.1.4 The materials systems described herein shall be func-tional that is always be capable to maintain a boron-10 arealdensity such that subcriticality is maintained depending on thedesign specification for the service life in
6、 the operatingenvironment of a nuclear spent fuel pool.1.5 Observance of this specification does not relieve theuser of the obligation to conform to all applicable international,national, and local regulations.1.6 This standard does not purport to address all of thesafety concerns, if any, associate
7、d with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C859 Terminology Relating to Nuclear MaterialsC1187 Guide for
8、Establishing Surveillance Test Program forBoron-Based Neutron Absorbing Material Systems forUse in Nuclear Fuel Storage Racks In a Pool EnvironmentE105 Practice for Probability Sampling of MaterialsE2971 Test Method for Determination of Effective Boron-10Areal Density in Aluminum Neutron Absorbers u
9、singNeutron Attenuation MeasurementsASTM Dictionary of Engineering Science and Technology2.2 ANSI and ASME Standards:3ANSI N45.2.2 Packaging, Shipping, Receiving, Storage andHandling of Items for Nuclear Power PlantsASME NQA-1 Quality Assurance Requirements for NuclearFacility Application2.3 U. S. G
10、overnment Documents:410CFR50 Title 10, CFR, Energy Part 50 Licensing ofProduction and Utilization Facilities10CFR72 Title 10, CFR, Energy Part 72 LicensingRequirements for the Storage of Spent Fuel in an Inde-pendent Spent Fuel Storage Installation (ISFSI)3. Terminology3.1 Terms shall be defined in
11、accordance with TerminologyC859 or the ASTM Dictionary of Engineering Science andTechnology3.2 Definitions of Terms Specific to This Standard:3.2.1 accelerated testinga procedure for investigating thepotential for long-term changes in physical properties orchemical composition of a material importan
12、t to safety, causedby a system operating parameter such as temperature, chemicalenvironment or radiation.3.2.1.1 DiscussionThe procedure uses a value of theidentified parameter that is outside the normal bound of theoperating parameter being investigated, in order to (1) increasethe rate of degradat
13、ion, if any, (2) identify the operating limitfor acceptable limit of the parameter, and (3) to provideinformation that might assist in interpreting the degradation1This specification is under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and is the direct responsibility of Subcommittee
14、 C26.03 onNeutron Absorber Materials Specifications.Current edition approved Jan. 15, 2016. Published February 2016. Originallyapproved in 1983. Last previous edition approved in 2011 as C992 11. DOI:10.1520/C0992-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AST
15、M Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from the American National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.4Available from Superintendent of Docum
16、ents, U. S. Government PrintingOffice, Washington, DC 20402.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1mechanism(s) involved. In this manner, the long-term behaviorof a material may be simulated in an appreciably shorter periodof
17、 time.3.2.2 areal densitythe boron-10 per unit area of a sheet,which is equivalent to the mass per unit volume of boron-10 inthe material multiplied by the thickness of the material inwhich that isotope is contained.3.2.3 buyerthe organization issuing the purchase order.3.2.4 degradationa change in
18、a material property thatlessens the original design functionality.3.2.5 individual piecea discrete section of neutron ab-sorber material whose individual dimensions conform to thosein the purchase specification.3.2.6 irradiationthe incidence of neutron, gamma, andbeta radiation from spent fuel assem
19、blies on materials in awater-filled spent fuel pool.3.2.7 production batcha group of neutron-absorbing ma-terial pieces produced in a continuous production period, all ofwhich can be shown to have the same chemical composition,physical, and nuclear properties within specification limits.3.2.8 seller
20、the neutron absorbing system manufacturer.3.2.9 service lifethe period of time for which properties ofthe neutron-absorbing material system are expected to remainin compliance with the contract requirements which relate tomaterial functionality.3.2.10 supplierany outside source of raw materials ands
21、ervices used by the seller.4. Ordering Information4.1 The buyer should specify a material for which there isdocumented evidence that the neutron absorbing materialsystem is capable of acceptable performance in the followingenvironmental conditions to which the material is expected tobe exposed:4.1.1
22、 Total service life of the neutron absorbing materialsystem,4.1.2 Maximum integrated irradiation over the total servicelife of the neutron absorbing material system, and4.1.3 Environment of the fuel pool in which the neutronabsorbing material system will be located, including consider-ation of norma
23、l operation and effects of anticipated operationaloccurrences.4.2 The buyer shall specify the following material proper-ties and applicable tolerances of the neutron absorbing materialsystem; this may include archive or in-service surveillancecoupons:4.2.1 Total quantity of individual pieces require
24、d,4.2.2 Physical dimensions of each individual piece required,and may also include physical form limitations includingflatness, camber, bow, etc.,4.2.3 Boron-10 isotopic content of the neutron absorbingmaterial system expressed in terms of grams of isotopic B-10per cm2of surface area. Alternatively,
25、 the boron-10 contentmay be specified by material density, the weight percent boron,minimum thickness, and the minimum acceptable weightfraction of boron-10 in the boron.4.2.4 Material for the components of the neutron absorbingmaterial system shall be in accordance with applicable speci-fications o
26、r standards.4.2.5 Mechanical properties of the neutron absorbing mate-rial system for structural requirements, as required.4.2.6 Acceptance criteria for gas evolution, productcleanliness, or other physical characteristics, if applicable.5. Material System Properties5.1 The boron-10 shall be uniforml
27、y distributed throughoutthe neutron absorbing material as defined in 7.3 and 8.1.4.5.2 The neutron absorbing material system may contain, inaddition to the boron or boron compound, any matrix materialsnecessary to maintain that boron in the state of specifieduniformity and boron-10 areal density thr
28、oughout the stipu-lated service life of the spent fuel storage system.5.2.1 The seller shall provide to the buyer a chemicalanalysis of the neutron absorbing material system, so that thebuyer may determine the compatibility of the neutron absorb-ing material with the spent fuel storage rack and the
29、poolenvironment.5.3 The seller shall provide the buyer with the elemental andboron isotopic composition of the neutron absorbing materialsystem and the particle size distribution when necessary of theboron compound so that the buyer may determine the neutronattenuating and absorbing properties of th
30、e material and itssuitability for the buyers application.5.4 Material systems neutron absorbing capability shall notbe reduced below the allowable limit within the stated servicelife (see 6.1.1) including geometric changes, loss of boron, orother degradation.5.5 In-service surveillance tests shall b
31、e performed to moni-tor the material system properties (for example, see GuideC1187).6. Test Documentation6.1 The seller shall provide to the buyer documentation oftests performed to characterize the neutron absorbing materialsystem performance and mechanical properties.6.1.1 When appropriate, accel
32、erated test may be performedto demonstrate compliance to 5.4. The test reports shall includeboth a description of procedures and a review of results.6.2 The buyer shall determine the suitability of the neutronabsorbing material system for the buyers application on thebasis of evidence offered by the
33、 seller, which may includeaccelerated test documentation, and by additional testing andevaluation performed by the buyer.7. Sampling7.1 Sampling plans to meet acceptance criteria and inspec-tion and measurement procedures that describe the method ofcompliance with this specification shall be establi
34、shed by theseller and submitted to the buyer for approval prior tomanufacture of the required product. The degree of samplingshall be specified by the purchase order. Practice E105 isreferenced as a guide.C992 1627.2 Each sample taken shall be sufficient for quality controltests, acceptance tests, r
35、eferee tests, and archive samples asnecessary or desired by the buyer.7.3 To show uniformity of the boron-10, the seller shalldemonstrate that the sampling for boron-10 areal density isadequate for establishing that the minimum boron-10 arealdensity is achieved throughout the product with a probabil
36、ityand confidence approved by the buyer.7.4 Archive samples shall be retained by the seller for aperiod of time specified by the buyer and delivered to the buyerupon request.8. Inspection8.1 Inspection of the neutron absorbing material shall be byproduction batch and by individual piece.8.1.1 Evalua
37、tion of chemical composition, density,boron-10 areal density, and uniformity may be made on aproduction batch basis.8.1.2 Inspection of dimensions and physical form shall bemade by individual piece.8.1.3 Inspection of the neutron absorbing material for de-fects and cleanliness (for example, any oils
38、 or foreign materi-als) shall be performed by individual piece.8.1.4 The boron-10 quantity and uniformity shall be deter-mined. Determination may be performed by a neutron attenu-ation measurement per Test Method E2971 or by a combina-tion of isotopic analysis, chemical analysis, and physicalmeasure
39、ments. The validity of other techniques must bedemonstrated.9. Rejection9.1 Items that fail to conform to the requirements of thespecification may be rejected by the buyer. The seller maypetition to the buyer to waive the specifications for specificout-of-specification items. Decision to grant such
40、waiver be-longs to the buyer. The seller may also effect any remedy tobring rejected items into specification providing he can dem-onstrate to the buyer that such remedy does not impair thefunction or preclude the certification of the neutron absorbingmaterial system.10. Certification10.1 When speci
41、fied in the purchase order or contract, theseller shall prepare a certification that the neutron absorbingmaterial system was manufactured, sampled, tested, and in-spected in accordance with the specifications and has beenfound to meet the requirements. When specifically required,testing results of
42、the material shall accompany the certification.Each certification furnished shall be signed by an authorizedagent of the seller.11. Marking, Packaging, and Shipping11.1 For marking, packaging, and shipping, ANSI N45.2.2is referenced as a guide. Each individual piece of neutronabsorbing material syst
43、em shall be marked on one face in alocation agreed upon by the buyer and seller with a serialidentification traceable to the test analysis, production batch,and certification. The characters of the markings shall be ofsuch size as to be clearly legible. The markings shall besufficiently durable to w
44、ithstand normal handling. The buyershall approve the method of marking.11.2 The neutron-absorbing material shall be packaged forshipment in a suitable manner to assure that the material willnormally arrive in an undamaged condition.11.2.1 The buyer shall indicate to the seller unusual condi-tions of
45、 handling or storage and specify additional protectivepackaging as necessary.11.2.2 Each package of neutron-absorbing material shall beidentified as to buyer, seller, contents, and quantity as aminimum and any other information specified by the seller.11.3 Method of shipping shall be specified by th
46、e buyer. Theselected method shall be suitable to protect the neutronabsorbing material system from direct weather exposure andmechanical damage.12. Quality Assurance12.1 Quality assurance requirements shall be specified inthe purchase order. 10CFR50, Appendix B, 10CFR72, andANSI-ASME NQA-1 are refer
47、enced as guides.13. Keywords13.1 boron; spent fuel; storage rackASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any suc
48、h patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invite
49、d either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (sing
