Publication Date: 2/1/73     Pages: 1     Date Entered: 2/22/84     Title: STANDARD ANALYTICAL METHODS FOR THE MEASUREMENT OF URANIUM TETRAFLUORIDE (UF4) AND URANIUM HEXAFLUORIDE (UF6)     2/2/73     U.S. ATOMIC ENERGY COMMISSION     REGULATORY GUIDE     DIRECTORATE OF REGULATORY STANDARDS     REGULATORY GUIDE 5.4     STANDARD ANALYTICAL METHODS FOR THE MEASUREMENT OF     URANIUM TETRAFLUORIDE (UF(4)) AND URANIUM HEXAFLUORIDE (UF(6))A. INTRODUCTION     Paragraph 70.22(b) of 10 CFR Part 70 "Special Nuclear Material,"     requires, in part, an applicant for a license to possess certain     quantities of special nuclear material in unsealed form to describe his     procedures for control of and accounting for special nuclear material.     This guide identifies acceptable methods for subsampling and chemical     and isotopic analysis of uranium tetra-and hexafluoride which an     applicant may specify as part of his procedures for accounting for     special nuclear material. B. DISCUSSION     Subcommittee N15-2, Measurements, of the American National     Standards Institute (ANSI) Standards Committee N15 on Methods of Nuclear     Materials Control has developed standards containing analytical     standards for the measurement of uranium tetrafluoride and uranium     hexafluoride. These standards, ANSI N15.6-1972 ("Analytical Standards     for Accountability of Uranium Tetrafluoride")(1) and ANSI N15.7-1972     ("Analytical Standards for the Accountability of Uranium     Hexafluoride")(1), were approved by ANSI on April 20, 1972. The     measurement methods are intended to apply to materials that meet     existing uranium hexafluoride purity specifications of the USAEC.     Materials containing impurities at levels above these specification     limits require the use of supplemental procedures to obtain satisfactory     uranium accountability. C. REGULATORY POSITION     The analytical standards for the measurement of uranium     tetrafluoride contained in ANSI N15.6-1972 and for the measurement of     uranium hexafluoride contained in ANSI N15.7-1972 are generally     acceptable to the AEC Regulatory staff and provide an adequate basis for     the subsampling, the gravimetric determination of uranium content, the     spectrographic determination of metallic impurities, the isotopic     analysis by mass spectrometry, and the determination of uranium isotopic     abundance by thermal ionization mass spectrometry of uranium     tetrafluoride and uranium hexafluoride that meet the existing uranium     hexafluoride purity specification of the USAEC (32 F.R. 16289, "Uranium     Hexafluoride - Base Charges, Use Charges, Special Charges, Table of     Enriching Services, Specifications, and Packaging").     ----------     (1) Copies may be obtained from the American National Standards     Institute, Inc., 1430 Broadway, New York, New York 10018.     ----------     42