Evaluation of an Interlaboratory Comparison Involving Pyrocarbon- and Silicon Carbide-Coated Uranium-Thorium Carbide Beads and Green Rods. Phase III

摘要

The New Brunswick Laboratory (NBL) had the responsibility for the design, conduct, and evaluation of the program which included obtaining sample materials, preparing and distributing the samples, and receiving and evaluating the data. The following three materials were used in Phase III of the program: (1) 48 green rods from each of three separate production blends (A, B, and C; numbered A-1 through A-48, B-1 through B-48, and C-1 through C-48, respectively), (2) 100 TRISO bead material samples (numbered 1 through 100), (3) 100 TRISO bead reference material samples (numbered 101 through 200). All of the 48 green rods from each blend were circulated to each participant for uranium analysis by NDA techniques, then returned to the NBL for subsequent distribution for chemical analysis. The participants then performed chemical assay for uranium in duplicate on six rod samples from each blend and nine bead samples from each bead material. Actual measurements by both techniques were performed in a specified sample order and in an short a time span as possible to minimize the time contribution to the measurement variance. Participants were also asked to provide complete descriptions of chemical and NDA measurement methods.