Lessons Learned in Streamlining the Preparation of SNM Solution Standards

Improved safeguard measures have produced a demand for greater quantities of reliable SNM solution standards. At the Savannah River Plant (SRP), the demand for these standards has been met by several innovations to improve the productivity and reliability of standards preparations. With the use of computer controlled balances, large batches of SNM stock solutions are prepared on a gravimetric basis. Accurately dispensed quantities of the stock solution are weighed and stored in bottles. When needed, they are quantitatively transferred to tared containers, matrix adjusted to target concentrations, weighed, and measured for density at 25°C. Concentrations of SNM are calculated both gravimetrically and volumetrically. Calculated values are confirmed analytically before the standards are used in measurement control program (MCP) activities. The lessons learned include: • MCP goals include error identification and management. • strategy modifications are required to improve error management. • administrative controls can minimize certain types of errors. • automation can eliminate redundancy and streamline preparations. • Prudence and simplicity enhance automation success. The effort expended to increase productivity has increased the reliability of standards and provided better documentation for quality assurance.