RG 5.38-74 相关标准章节.docxVIP

Publication Date: 9/1/74  Pages: 7  Date Entered: 1/5/93  Title: Nondestructive Assay of High-Enrichment Uranium Fuel Plates by Gamma Ray Spectrometry  September 1974  U.S. ATOMIC ENERGY COMMISSION  REGULATORY GUIDE  DIRECTORATE OF REGULATORY STANDARDS  REGULATORY GUIDE 5.38  NONDESTRUCTIVE ASSAY OF HIGH-ENRICHMENT URANIUM  FUEL PLATES BY GAMMA RAY SPECTROMETRY A. INTRODUCTION  Part 70 of Title 10 of the Code of Federal Regulations requires  each licensee authorized to possess more than 350 grams of contained  U-235 to conduct a physical inventory of all special nuclear material in  his possession at intervals not to exceed 12 months. Each licensee  authorized to possess more than one effective kilogram of  high-enrichment uranium is required to conduct measured physical  inventories of his special nuclear materials at bimonthly intervals.  Further, these licensees are required to conduct their nuclear material  physical inventories in compliance with specific requirements set forth  in Part 70. Inventory procedures acceptable to the Regulatory staff for  complying with these provisions of Part 70 are detailed in Regulatory  Guide 5.13, Conduct of Nuclear Material Physical Inventories.  For certain nuclear reactors, the fuel consists of highly enriched  uranium fabricated into flat or bowed plates. Typically, these plates  are relatively thin so that a significant percentage of the U-235 gamma  rays penetrate the fuel cladding. When the measurement conditions are  properly controlled and corrections are made for variations in the  attenuation of the gamma rays, a measurement of the U-235 gamma rays can  be used as an acceptable measurement of the distribution and the total  U-235 content of each fuel plate. In lieu of assaying the product fuel  plates, fuel plate core compacts may be assayed through the procedures  detailed in this guide,