Burning of Small Volume/Surface Area 30% T B P-K erosin e Solutions, No Vigorous Boiloff

DOE-HDBK-3010-94

3.0 Liquids; Organic, Combustible Liquids

by turbulence of the vapor generation, the capillary action at the edge of the liquid, and the

evolution of water vapors from the aqueous solution trapped beneath the organic layer, the

suspension of non-volatile components increases. If the evolution of water vapors is very

rapid, a large volume of the aqueous layer may be ejected and quench the fire. Flaming

combustion (smoldering combustion is observed in some solid fuels such as cellulosics) may

also be quenched when the oxygen concentration diminishes to the range of 11% to 17.5%

(generally flaming combustion ceases at ~ 16%) (Malet et al., 1983, Jordan and Lindner,

1983, 1985).

3.3.1. B urn in g of S m all V olu m e/S u rface A rea 30% T B P-K erosin e S olu tion s, N o

V igorou s B oiloff

For quiescent fire (relatively undisturbed liquid surfaces), the ARFs measured by Mishima

and Schwendiman (June 1973) for the combustion of 30% TBP in a kerosine-type diluent

traced with various radionuclides (U, Cs, Ce, Zr, I) are applicable. The measured values

are reproduced in Table A.18 and the experimental apparatus is shown in Figures A.8a and b

in Appendix A. Twenty-five ml of 30% TBP-kerosine were placed in a 50-ml borosilicate

beaker. Air (1- and 2-cfm) was drawn through a 2.7-in.-diameter stainless steel chimney

around and over the beaker. Iodine (during the experiments using iodine tracer) was

collected in a charcoal trap at the top of the chimney and airborne particulates in a glass fiber

filter. The liquid was ignited and the liquid gently heated by a hand-held propane torch.

Experiments were performed to self-extinguishment (no heating after initiation of flaming

combustion) and supplemental heating to complete dryness. No aqueous phase in contact

with the combustible organic was used in these experiments. The pertinent data are tabulated

in Table 3-12.

Under the experimental conditions, the ARFs for all non-volatile materials appear to be less

than 1E-2. Uranium ARFs range from 2E-4 to 3E-3, an uncertainty of approximately an

order of magnitude. Cesium ARFs also show an order of magnitude uncertainty ranging

from 2E-3 to 1E-2. ARFs for both cerium and zirconium are more consistent for the limited

number of measurements made. The ARFs for iodine range from 7E-1 to 8E-1 and are

assumed to be essentially 1E+0. In the absence of any measured airborne particle size

distribution, all the airborne material is conservatively assumed to be in the respirable

fraction. The volatile materials are considered to remain in the gaseous state although the

volatile materials (generally iodine but may include other halogens and possibly some cesium

compounds) may condense on various surfaces contacted or on pre-existing airborne particles

and behave like the host particle thereafter. The effect cannot be readily characterized and

the conservative assumption is that all the material is respirable. For the more industrial

types of stresses encountered in nonreactor nuclear facilities, as opposed to LWR and BWR

core melt conditions, semi-volatiles such as cesium and ruthenium are not expected to behave

Page 3-43