Savannah River National Laboratory (report SRNL-STI-2016-00033) performed in-situ gamma-ray measurements of Cells 6 to 9 on the West Cell Line of the 235-F Plutonium Fuel Form Facility in late 2015. A shielded 120% HPGe detector was used, with the PHDS GeGI mapping the Pu-238 distribution to inform an MCNP efficiency model. Three Pu-238 gamma lines (99.85, 152.7, and 766.4 keV) gave independent mass estimates whose weighted mean put total West Cell Line holdup at 0.90 plus or minus 0.058 grams, substantially more precise than the 2006 and 2013 assays.
