Experimental Studies cont'd

DOE-HDBK-3010-94

3.0 Liquids; Aqueous Solutions

The liquid water at the start of the calculation is the total water

inventory less the amount of water necessary to pressurize the

containment to the initial pressure.

The liquid water is depleted throughout the calculation by vaporization

and entrainment. The removed water is not returned to the pool.

The liquid water is assumed to reside in a pool of constant surface in a

large single volume.

Kataoka and Ishii tabulated (April 1983; Table G-11, "Entrained Water and Droplet

Size") the mass of water entrained, mass geometric mean diameter and GSD of the

droplet size distribution as a function of initial pressure and vent hole area. The

largest mass entrained at each pressure was associated with the largest vent hole area

due to the rate of release. The ARF and RF values for the largest sized vent hole for

each pressure listed are:

0.3 MPa: 2.4E-1 and 3E-3 to 1.0E+0 and 6E-7

0.5 MPa: 3.4E-1 and 2E-3 to 1.0E+0 and 4E-7

0.7 MPa: 3.9E-1 and 6E-7 to 7.4E-1 and 4E-7.

Not all the water was entrained at the highest pressure, because the liquid volume in

the pool reduces by vaporization, thus reducing the superficial gas velocity under

these conditions. The possible effect of secondary flashing by the droplets was

assessed and found not to be a serious concern but the possible reduction of the

droplets due to evaporation of the solvent after release was not evaluated. Thus,

although the author stated that the model tends to overestimate the entrainment, the

possible increase in the fraction of dissolved FPs entrained due to the reduction of

droplet size could result in significant underestimation. Nonetheless, the values for

droplets in the respirable fraction from flashing sprays under these conditions do not

appear to result in a significant fraction of the material as droplets in the respirable

fraction (range of 7E-4 to 3E-7). The values for the many of the variable parameters

are temperature dependent and methods for determining temperature or change in

temperature and values for parameters as a function of temperature are not provided.

Experiments have been performed to measure the airborne release and size

distribution of aqueous solution over a limited range of conditions. Table 3-5 lists the

experimental results obtained (Ballinger, Sutter and Hodgson, May 1987). Aqueous

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