Data quality objective to support resolution of the organic solvent safety issue

The Tank Waste Remediation System (TWRS) has adopted a data quality objective (DQO) process to define informational needs required to address waste tank safety issues. This document, the Organic Solvent DQO, provides a process to resolve the Organic Solvent Safety Issue. Organic solvents in the presence of air (a source of oxidizer) in a waste tank headspace can combust when heated to the flash point of the solvent. Separable phase organic liquids can form a combustible situation by being present as a pool on the waste surface, or by collecting in sufficient concentration entrained in the waste solids to form a combustible mixture at the waste surface by capillary or wicking behavior. Organic solvent combustion would result in an increase in pressure and temperature of the gas in the waste tank headspace. A significant pressure increase could result in the release of radionuclides and toxic materials to the environment. The Organic Solvent DQO is based on several technical documents, summarized and referenced throughout, that provide the technical bases for threshold values (decision limits) used to develop decision rules that address the problem statement. Likewise, this DQO supports characterization documents, such as the tank sampling analysis plan (TSAP) and tank characterization plan (TCP). The threshold values are based upon approved technical documents. Any changes to these technical documents will be reflected in subsequent changes to this DQO. This DQO applies to static organic waste as presently stored in single-shell tanks (SSTs) and double-shell tanks (DSTs). Waste undergoing retrieval, pretreatment, and processing are outside the scope of this DQO