RG 5.37-74 相关标准章节.docxVIP

Publication Date: 8/1/74  Pages: 8  Date Entered: 1/5/93  Title: In Situ Assay of Enriched Uranium Residual Holdup  August 1974  U.S. ATOMIC ENERGY COMMISSION  REGULATORY GUIDE  DIRECTORATE OF REGULATORY STANDARDS  REGULATORY GUIDE 5.37  IN SITU ASSAY OF ENRICHED URANIUM RESIDUAL HOLDUP 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. Certain licensees  authorized to possess more than one effective kilogram of special  nuclear material are required to conduct measured physical inventories  of their special nuclear materials more frequently than annually  depending on the materials. 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 are detailed in Regulatory Guide  5.13, Conduct of Nuclear Material Physical Inventories.  Enriched uranium residual holdup is defined as the inventory  component remaining in and about process equipment and handling areas  after those collection areas have been prepared for inventory. Whenever  possible, process equipment should be designed(*) and operated so as to  minimize the amount of holdup. This guide describes procedures  acceptable to the Regulatory staff for the in situ assay of the residual  uranium holdup.(**) Assay information can be used in one of two ways: 1. When the limit of error of uranium holdup is compatible with the  plant limit of error on material unaccounted for (LEMUF), the material  balance can be computed using the measured contents of uranium holdup.  Additional cleanout and recovery for accountabili