Boiling Liquid

DOE-HDBK-3010-94

7.0 Application Examples; Dissolving Operations Examples

The additional multiple of 3 discussed in relation to this equation in subsection

3.2.3.1 is not used as it applies only to solutions with a density less than 1.2 g/cm3.

The maximum fall height is 1.2 m (4 ft), and the viscosity of 60% nitric acid at

ambient temperature is 2E-2 poises. These values yield an ARF of 5E-6. After initial

dissolution, however, and during initial transfer to the vacuum run tank, the solution

temperature is between 90 and 100 oC, not ambient. If the spill occurs at that point,

solution viscosity is decreased to 7E-3 poise. The resulting ARF would be 1.5E-5.

As for the powder spill examined for the feed preparation operation, the bounding

value of 2E-5 is used for the sake of conservatism and consistency.

B. Boiling Liquid. If the temperature control system on the dissolver heat exchanger

malfunctions, sufficient steam flow could occur to initiate boiling. Testing of the heat

exchanger at full capacity has indicated that complete boiloff of surrogate water in the

vessel does not result in significant vessel pressurization as the vessel vent system can

handle the rate of vapor generation. However, if the condition occurs during

operation and remains undetected, the entire contents of the dissolver can eventually

be boiled, with the resulting vapor flowing to the vessel vent system. In this case, the

MAR would again be 1322 g with a DR of 1.0.

The ARF and RF assigned for continuous boiling of liquids are 2E-3 and 1.0

(subsection 3.2.1.2). The maximum initial respirable source term is:

1322 g * 1.0 * 2E-3 * 1.0 = 2.6 g

This source term is generated within glovebox and piping system confinement.

C. Criticality. A solution criticality is unlikely in the geometrically favorable

dissolvers. Mechanical distortion of the vessel and/or severe overbatching of feed

could, however, produce a criticality. A yield of 1E+19 fissions is assessed to be

bounding for solution criticalities (subsection 6.2.3.1). A simple method for

estimating fission product release from criticality is to use NRC results for a 1E+19

fissions plutonium criticality. The DR refers to the fraction of isotopes generated in

the criticality exposed for release, and is 1.0 for gases and volatiles in solution.

The ARF is 1.0 for noble gases and 0.25 for radioiodines in solution based on NRC

precedents. Table 7-5 shows a simplified release estimation based on important

isotopes identified by the NRC. The potential dose from this release is well under

100 mrem at the site boundary, although prompt worker fatalities can occur due to

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