Liquid Sampling and Tank Farm Example Assessment

DOE-HDBK-3010-94

7.0 Application Examples; Liquid Storage and Ion Exchange Examples

would be 11.6 m3, albeit with a smaller density. It is not out of the question that a

chimney effect could be created as well, depending on the use of floor and ceiling

openings.

The ARF and RF for continuous boiling of liquid are 2 E-3 and 1.0 (subsection

3.2.1.2). For a general fire in the vicinity of the tanks, the initial respirable source

terms for DRs of 0.1 and 1.0 are:

42,000 g * 0.1 * 2E-3 * 1.0 = 8.4 g

42,000 g * 1.0 * 2E-3 * 1.0 = 84 g

The range of possible release could be even higher if it is assumed the liquid becomes

superheated. The liquid will become superheated if the rate of liquid boiloff exceeds

the rate of vapor removal through the vessel vent line. The vessel relief valves lift

at ~ 0.07 MPag (10 psig), thus limiting the potential level of superheat to ~ 15 oC.

However, the lifting of the vessel relief valves presents problems of its own.

Potential pressure and superheat are limited, but the release is now occurring directly

into a process room as opposed to the vessel vent system. The ARF and RF for

depressurization of liquid above the boiling point with 50 oC superheat are 1E-2

and 0.6 (subsection 3.2.2.3.3). The associated initial respirable source terms for DRs

of 0.1 and 1.0 are:

42,000 g * 0.1 * 1E-2 * 0.6 = 25 g

42,000 g * 1.0 * 1E-2 * 0.6 = 250 g

7.3.5.3

Liquid Sampling and Tank Farm Example Assessment

The spill examples are not particularly different from the previous spill assessments, and in

general, they support the obvious conclusion that it is desirable to avoid spilling confined

carcinogenic material. Even the large quantities of material involved do not generate releases

above the relatively small range estimated for previous operations. The large room fire, on

the other hand, can be considered genuinely insightful with regard to design and operation.

Up to this point in the examples, bounding initial releases have been on the order of gram

quantities or less. The large room fire is potentially very unrepresentative of this spectrum,

even though the releases cited for this unlikely, but not impossible, event would still not

result in catastrophic consequences to the public. In terms of defense in depth, in

comparison to events previously examined, this event represents a potentially significant

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