Dissolved Non-Condensable Gas Testing

The Naval Nuclear Laboratory is seeking to perform a series of experiments to quantify the changes in concentration of non-condensable gases (NCGs) dissolved in water when experiencing various transients including phase change. The following transients are being considered for testing:

• The rate of diffusion of dissolved NCGs across a steam/water interface.

• The rate at which NCGs are dissolved into solution in a condensate that is formed in an environment consisting of a mixture of steam and NCGs.

• The rate at which dissolved NCGs are removed from solution in a volume of water that is boiling.

• The rate at which dissolved NCGs are removed from solution as water is flashed to steam.

The NCGs of interest include nitrogen, hydrogen, and oxygen. Testing should be repeated using each gas species individually rather than as a mixture. The following provides specific considerations for the various tests listed above.

Diffusion Transient Tests

The rate of diffusion of dissolved NCGs across a steam/water interface should be measured over a range of temperature and pressure conditions. The goal of this experiment would be to develop gas species specific diffusion coefficients as a function of temperature and pressure over a range of interest.

Condensation Transient Tests

The rate at which NCGs are dissolved into a solution in a condensate that is formed in an environment consisting of a mixture of steam and NCGs should be measured over a range of temperatures, steam partial pressures, and NCG partial pressures. The goal of this experiment is to obtain sufficient data to thoroughly characterize the rate at which NCGs are removed from the steam/NCG mixture as steam is being condensed.

Boiling Transient Tests

The rate at which dissolved NCGs are released from solution in a volume of liquid water that is boiling should be measured over a range of saturation pressures and dissolved NCG concentrations. The goal of the experiment is to obtain sufficient data to thoroughly characterize and model the rate of NCGs being removed from solution during boiling.

Flashing Transient Tests

The rate at which dissolved NCGs are being removed as flashing occurs should be measured over a range of conditions. The goal of this experiment is to obtain sufficient data to thoroughly characterize and model the rate at which dissolved NCGs are released from solution during the flashing process.