Precision and Source of Variation of Oxygen-to-Metal Determinations for (U, Pu)O₂

With a statistically designed experiment, it is demonstrated that gravimetric determinations of the oxygen-to-metal ratio of (U,Pu)O₂ depend strongly on the day of analysis, slightly on the particular sintering run, and not detectably on position in either the sintering furnace or the analysis furnace. The average oxygen-to-metal ratio of a single sintering run can be determined to a precision of ±0.005 at the 95% confidence level.