Dryout modeling in support of the organic tank safety project
This work was performed for the Organic Tank Safety Project to evaluate the moisture condition of the waste surface organic-nitrate bearing tanks that are classified as being conditionally safe because sufficient water is present. This report describes the predictive modeling procedure used to predict the moisture content of waste in the future, after it has been subjected to dryout caused by water vapor loss through passive ventilation. This report describes a simplified procedure for modeling the drying out of tank waste. Dryout occurs as moisture evaporates from the waste into the headspace and then exits the tank through ventilation. The water vapor concentration within the waste of the headspace is determined by the vapor-liquid equilibrium, which depends on the waste`s moisture content and temperature. This equilibrium has been measured experimentally for a variety of waste samples and is described by a curve called the water vapor partial pressure isotherm. This curve describes the lowering of the partial pressure of water vapor in equilibrium with the waste relative to pure water due to the waste`s chemical composition and hygroscopic nature. Saltcake and sludge are described by two distinct calculations that emphasize the particular physical behavior or each. A simple, steady-state model is devised for each type to obtain the approximate drying behavior. The report shows the application of the model to Tanks AX-102, C-104, and U-105.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 663474
- Report Number(s):
- PNNL-11935; R&D Project: 25396; ON: DE98058856; BR: EW3120072; TRN: 99:000474
- Resource Relation:
- Other Information: PBD: Aug 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Organic Tank Safety Project: Effect of water partial pressure on the equilibrium water content of waste samples from Hanford Tank 241-U-105
Developing a model for moisture in saltcake waste tanks: Progress report