Method of characterizing VOC concentration in vented waste drums with multiple layers of confinement using limited sampling data

Abstract

Characterization of transuranic waste destined for the Waste Isolation Pilot Plant currently requires detailed characterization of the volatile organic compound (VOC) concentration in the void volume headspaces (drum headspace, the large polymer bag headspace, and the innermost layers of confinement headspace) of the waste drums. A test program is underway at the Idaho National Engineering Laboratory (INEL) to determine if the drum headspace VOC concentration is representative of the concentration in the entire drum void space and demonstrate that the VOC concentration in the innermost layer of confinement can be estimated using a model incorporating diffusion and permeation transport principles and limited waste drum sampling data. A comparison of model predictions of VOC concentration in the innermost layer of confinement with actual measurement from transuranic waste drums demonstrate that this method may be useful in characterizing VOC concentration in a vented waste drum.