Exact Sample Size for Special Nuclear Material Inventory Verification

• Activity Number: 146
• Type: Contributed
• Date/Time: Monday, August 10, 2015 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistics in Defense and National Security
• Author(s): James Wendelberger*
• Companies: Los Alamos National Laboratory
• Keywords: Sample Size ; SNM ; Inventory ; Population ; Mixture

Abstract

The tables to compute the exact sample sizes for special nuclear material are provided based upon United States Department of Energy (DOE) sampling parameters for physical inventories for a population size up to 15,000 items. The paper motivates the exact computation of item sizes by showing exact correspondence to integer number of defects and enforcing the constraint of exactly attaining the minimum detectable defect rate. This is accomplished with a bivariate number of defects population mixture distribution. The number of defects in the bivariate mixture being sequential and bracketing the possibly non-integer defect number obtained by multiplying the minimum detectable defect rate times the population size (expected number of defects). There are allowances described and made for populations which would not have at least one defect based upon the minimum detectable defect rate. R code and output is provided in easy to follow examples.