干旱区生态环境知识资源中心(Arid): Preserving Ultra-Pure Uranium-233

Arid

DOI	10.2172/1034000
报告编号	ORNL/TM-2011/287
来源ID	OSTI_ID: 1034000
	Preserving Ultra-Pure Uranium-233
	Krichinsky, Alan M [ORNL]; Goldberg, Dr. Steven A. [DOE SC - Chicago Office]; Hutcheon, Dr. Ian D. [Lawrence Livermore National Laboratory (LLNL)]
英文摘要	Uranium-233 ({sup 233}U) is a synthetic isotope of uranium formed under reactor conditions during neutron capture by natural thorium ({sup 232}Th). At high purities, this synthetic isotope serves as a crucial reference material for accurately quantifying and characterizing uranium-bearing materials assays and isotopic distributions for domestic and international nuclear safeguards. Separated, high purity {sup 233}U is stored in vaults at Oak Ridge National Laboratory (ORNL). These materials represent a broad spectrum of {sup 233}U from the standpoint of isotopic purity - the purest being crucial for precise analyses in safeguarding uranium. All {sup 233}U at ORNL is currently scheduled to be disposed of by down-blending with depleted uranium beginning in 2015. This will reduce safety concerns and security costs associated with storage. Down-blending this material will permanently destroy its potential value as a certified reference material for use in uranium analyses. Furthermore, no credible options exist for replacing {sup 233}U due to the lack of operating production capability and the high cost of restarting currently shut down capabilities. A study was commissioned to determine the need for preserving high-purity {sup 233}U. This study looked at the current supply and the historical and continuing domestic need for this crucial isotope. It examined the gap in supplies and uses to meet domestic needs and extrapolated them in the context of international safeguards and security activities - superimposed on the recognition that existing supplies are being depleted while candidate replacement material is being prepared for disposal. This study found that the total worldwide need by this projection is at least 850 g of certified {sup 233}U reference material over the next 50 years. This amount also includes a strategic reserve. To meet this need, 18 individual items totaling 959 g of {sup 233}U were identified as candidates for establishing a lasting supply of certified reference materials (CRM), all having an isotopic purity of at least 99.4% {sup 233}U and including materials up to 99.996% purity. Current plans include rescuing the purest {sup 233}U materials during a 3-year project beginning in FY 2012 in three phases involving preparations, handling preserved materials, and cleanup. The first year will involve preparations for handling the rescued material for sampling, analysis, distribution, and storage. Such preparations involve modifying or developing work control documents and physical preparations in the laboratory, which include preparing space for new material-handling equipment and procuring and (in some cases) refurbishing equipment needed for handling {sup 233}U or qualifying candidate CRM. Once preparations are complete, an evaluation of readiness will be conducted by independent reviewers to verify that the equipment, work controls, and personnel are ready for operations involving handling radioactive materials with nuclear criticality safety as well as radiological control requirements. The material-handling phase will begin in FY 2013 and be completed early in FY 2014, as currently scheduled. Material handling involves retrieving candidate CRM items from the ORNL storage facility and shipping them to another laboratory at ORNL; receiving and handling rescued items at the laboratory (including any needed initial processing, acquisition and analysis of samples from each item, and preparation for shipment); and shipping bulk material to destination labs or to a yet-to-be-designated storage location. There are seven groups of {sup 233}U identified for handling based on isotopic purity that require the utmost care to prevent cross-contamination. The last phase, cleanup, also will be completed in 2014. It involves cleaning and removing the equipment and material-handling boxes and characterizing, documenting, and disposing of waste. As part of initial planning, the cost of rescuing candidate {sup 233}U items was estimated roughly. The annualized costs were found to be $1,228K in FY 2012, $1,375K in FY 2013, and $1,030K in FY 2014. These costs correlate with the activities mentioned in the three previous paragraphs. This report outlines a recent effort to assess the annual consumption of {sup 233}U in the United States, the gap between current supplies and future needs, and the initial planning for a program to rescue the purest of {sup 233}U materials from destruction by down-blending so they may be preserved for use as a crucial reference for safeguarding nuclear material.
出版年	2011
报告类型	Technical Report
语种	英语
国家	美国
来源学科分类	11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS ; CAPTURE ; CLEANING ; CRITICALITY ; DEPLETED URANIUM ; DISTRIBUTION ; NEUTRON REACTIONS ; ORNL ; PERSONNEL ; PLANNING ; RADIOACTIVE MATERIALS ; SAFEGUARDS ; SAFETY ; SAMPLING ; SECURITY ; STORAGE ; THORIUM ; URANIUM ; URANIUM 233 Uranium-233 ; U-233 ; 233U ; Certified Reference Material ; Isotope Dilution Mass Spectrometry ; IDMS
URL	http://www.osti.gov/scitech/servlets/purl/1034000
资源类型	科技报告
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/270349
推荐引用方式 GB/T 7714	Krichinsky, Alan M [ORNL],Goldberg, Dr. Steven A. [DOE SC - Chicago Office],Hutcheon, Dr. Ian D. [Lawrence Livermore National Laboratory . Preserving Ultra-Pure Uranium-233,2011.