Exponent has recommended that “high inlet spike” concentrations be verified for accuracy regarding their representation of the maximum measured headspace concentrations for tanks at Hanford. Exponent further recommended that “high inlet spike” concentrations of chemicals of potential concern (COPCs) be inclusive of surrogate COPCs. In the initial analysis (Rev. A Test Plan), only analytical results from the Site-Wide Industrial Hygiene Database (SWIHD) were used. The reason for this initial decision was a concern about Washington River Protection Solutions (WRPS) taking responsibility for results that were not produced during their contract tenure. As a result of Exponent’s comments, WRPS verified the “high inlet spike” values for accuracy against the data for single-shell tanks in all the historical databases, not only SWIHD. Measurements made prior to interim waste stabilization or waste retrieval were not considered in the verification of maximum measured concentrations as they are not representative of current tank farm conditions. Data for surrogate COPCs were also considered in determining the “high inlet spike” concentrations. Table S.1 shows the newly evaluated concentrations (COPC and surrogate). The original and revised test conditions are also shown with changes indicated by red text.
Revised: July 30, 2019 |
Published: March 19, 2018