1、Designation: C 992 06Standard Specification forBoron-Based Neutron Absorbing Material Systems for Usein Nuclear Spent Fuel Storage Racks1This standard is issued under the fixed designation C 992; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification defines criteria for boron-based neu-tron absorbing material systems used
3、 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 compoundcontainin
4、g 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 geological origin
5、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 B10 arealdensity such that subcriticality Keff 0.95 or Keff 0.98 orKeff 1.0 depending on the design specification for the servicelife (
6、approximately 40 years) in the operating environment ofa nuclear spent fuel pool.1.5 A number of acceptable boron-based absorbing materi-als combinations are currently available while others are beingdeveloped for use in the future. This specification definescriteria essential and applicable to all
7、materials combinationsand identifies parameters a buyer should specify to satisfy aunique or particular requirement.1.6 The scope of this specification does not comprehen-sively cover all provisions for preventing criticality accidentsor requirements for health and safety. Observance of thisspecific
8、ation does not relieve the user of the obligation toconform to all applicable international, national, and localregulations.2. Referenced Documents2.1 ASTM Standards:2A 240/A 240M Specification for Chromium andChromium-Nickel Stainless Steel Plate, Sheet, and Stripfor Pressure Vessels and for Genera
9、l ApplicationsB 209 Specification for Aluminum and Aluminum-AlloySheet and PlateC 750 Specification for Nuclear-Grade Boron Carbide Pow-derC 859 Terminology Relating to Nuclear Materials3E 105 Practice for Probability Sampling Of MaterialsASTM Dictionary of Engineering Science and Technology2.2 ANSI
10、 Standards:4ANSI 45.2.2 Packaging, Shipping, Receiving, Storage andHandling of Items for Nuclear Power PlantsANSI-ASME NQA-1 Quality Assurance Requirements forNuclear Facility Application2.3 U. S. Government Documents:5Title 10, CFR, Energy Part 50 (10CFR50) Licensing ofProduction and Utilization Fa
11、cilitiesTitle 10, CFR, Energy Part 72 (10CFR72) Licensing Re-quirements for the Storage of Spent Fuel in an Indepen-dent Spent Fuel Storage Installation (ISFSI)3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Terms shall be defined in accordance with Terminol-ogy C 859 or the A
12、STM Dictionary of Engineering Scienceand Technology, except as defined as follows:3.1.2 accelerated testinga procedure for investigating thepotential for long-term changes in physical properties or1This specification is under the jurisdiction of ASTM Committee C26 onNuclear Fuel Cycle and is the dir
13、ect responsibility of Subcommittee C26.03 onNeutron Absorber Materials Specifications.Current edition approved Feb. 15, 2006. Published March 2006. Originallyapproved in 1983. Last previous edition approved in 1997 as C 992 89(1997).2For referenced ASTM standards, visit the ASTM website, www.astm.or
14、g, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from the American National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.5Available f
15、rom Superintendent of Documents, U. S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.chemical composition of a material important to safety, causedby a system operating parameter such
16、 as temperature chemicalenvironment or radiation. The 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 degradation, if any, (2) identify the operating limitfor acceptable limit of the
17、parameter, and (3) to provideinformation that might assist in interpreting the degradationmechanism(s) involved. In this manner, the long-term behaviorof a material may be simulated in an appreciably shorter periodof time.3.1.3 areal densitythe boron-10 per unit area of a sheet,which is equivalent t
18、o the mass per unit volume of boron-10 inthe material multiplied by the thickness of the material inwhich that isotope is contained.3.1.4 buyerthe organization issuing the purchase order.3.1.5 individual piecea discrete section of neutron ab-sorber material whose individual dimensions conform to tho
19、sein the purchase specification.3.1.6 irradiationthe incidence of neutron, gamma, andbeta radiation from spent fuel assemblies on materials in awater-filled spent fuel pool.3.1.7 production batcha group of neutron-absorbing ma-terial pieces produced in a continuous production period, all ofwhich can
20、 be shown to have the same chemical composition,physical, and nuclear properties within specification limits.3.1.8 sellerthe neutron absorbing system manufacturer.3.1.9 service lifethe period of time for which properties ofthe neutron-absorbing material system are expected to remainin compliance wit
21、h the contract requirements which relate tochemical and physical integrity.3.1.10 supplierany outside source of raw materials andservices used by the seller.4. Ordering Information4.1 The buyer should specify a material for which there isdocumented evidence that the neutron absorbing materialsystem
22、is capable of acceptable performance in the followingenvironmental conditions to which the material is expected tobe exposed:4.1.1 Total service life of the neutron absorbing materialsystem (considered forty years unless otherwise specified),4.1.2 Maximum integrated irradiation over the total servic
23、elife of the neutron absorbing material system, and4.1.3 Chemical and thermal environment of the water in thespent fuel pool in which the neutron absorbing material systemwill be located.4.2 The buyer shall specify the following physical andchemical properties of the neutron absorbing material syste
24、m;this may include archive or in-service surveillance coupons:4.2.1 Total quantity of individual pieces required,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 neut
25、ron absorbingmaterial system expressed in terms of grams of isotopic B-10per cm2of surface area. Alternatively, 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 Applicable to
26、lerances for each dimension or property,including minimum boron-10 areal density.4.2.5 Material specifications for the components of theneutron absorbing material system shall be in accordance withSpecifications A 240, B 209, and C 750, if applicable.4.3 In addition to the properties of 4.2, the buy
27、er shallspecify the following system properties as required by thespecific spent fuel storage rack design:4.3.1 Structural properties for the neutron absorbing mate-rial system, if required, and4.3.2 Limitations on gas evolution, product cleanliness, orother physical characteristics, if applicable.5
28、. Material System Properties5.1 The boron-10 shall be uniformly distributed throughoutthe neutron absorbing material system as defined in 7.3 and8.1.4.5.2 The neutron absorbing material system may contain, inaddition to the boron or boron compound, any matrix materialsnecessary to maintain that boro
29、n in the state of specifieduniformity and areal density throughout the stipulated servicelife 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 abso
30、rb-ing material with the spent fuel storage rack and the 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 determ
31、ine the neutronattenuating and absorbing properties of the material and itssuitability for the buyers application.5.4 The loss of boron through any degradation mechanismsshall not lower the areal density below the allowable limitswithin the stated service life (see Section 6.1.1).5.5 It is recommend
32、ed that in-service surveillance tests beperformed to monitor the areal density. It is further recom-mended that these tests determine both physical and perfor-mance characteristics. The physical tests should determine atleast the size, weight, density, and surface appearances, includ-ing any surface
33、 blistering, delamination, or pitting. The perfor-mance tests should determine at least the neutron attenuationcapabilities and mechanical strength, if applicable. The testsamples should be positioned to maximize the irradiation dosesthe samples will receive during each exposure period. Thebefore an
34、d after exposure test results should be compared todetermine any unfavorable changes in the physical or perfor-mance characteristics.6. Test Documentation6.1 The seller shall provide to the buyer documentation oftests performed to characterize the neutron absorbing materialsystem performance and mec
35、hanical properties.6.1.1 When appropriate, accelerated test may be performedto demonstrate compliance to 5.4. The test reports shall includeboth a description of procedures and a review of results.C9920626.2 The buyer shall determine the suitability of the neutronabsorbing material system for the bu
36、yers application on thebasis of accelerated test documentation and other evidenceoffered by the seller and by additional testing and evaluationperformed by the buyer.7. Sampling7.1 Sampling plans to meet acceptance criteria and inspec-tion and measurement procedures that describe the method ofcompli
37、ance with this specification shall be established 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 E 105 isreferenced as a guide.7.2 Each sample taken shall be sufficient for qua
38、lity controltests, acceptance tests, referee 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 areal density is adequate forestablishing that the minimum boron-10 areal density isachieved throughou
39、t the product with a probability and confi-dence 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 b
40、y individual piece.8.1.1 Evaluation of chemical composition, density, arealdensity, and uniformity may be made on a production batchbasis.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
41、(for example, any oils or foreign materi-als) shall be performed by individual piece.8.1.4 The boron-10 quantity and uniformity may be deter-mined by a neutron attenuation measurement or by a combi-nation of isotopic analysis, chemical analysis, and physicalmeasurements. The validity of other techni
42、ques 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 waiver be-longs to the buyer. The s
43、eller 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 specified in the purchase order or contr
44、act, 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 the material shall accompany the ce
45、rtification.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 system shall be marked on one face in a
46、location 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 withstand normal handling. The buyer
47、shall 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 condition11.2.1 The buyer shall indicate to the seller unusual condi-tions of handling or storage and specify add
48、itional 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 the buyer. Theselected method shall be
49、 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. CFR Title 10, Part 50, Appendix B, CFRTitle 10, Part 72, and ANSI-ASME NQA-1 are referenced asguides.13. Keywords13.1 boron; spent fuel; storage rackC992063ASTM 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 th
