Seismic Release Example Assessment

DOE-HDBK-3010-94

7.0 Application Examples; Seismic Release Example

If a standard resuspension time of 48 hours is assumed, the total additional release

is 1.4 g.

At this point, the initial airborne releases that have been estimated are 3.6 g for the

process solution tank failures, 8E-2 g for damage to the vessel vent system, 11.9 g

from damage to the feed preparation line (excluding contained powder damage that

does not occur for process as is), and 0.1 g from liquid spillage in the metal and

residue dissolving lines and the sampling line. The total initial release estimated is

therefore 15.7 g. Another 1.4 g could be released over 48 hours if no intervention

occurs. Additional material could be considered airborne in gloveboxes outside the

collapse zone if some of the conservative assumptions made for the 0.13 g event are

made for this event as well.

7.3.10.3

Seismic Release Example Assessment

The seismic release example most clearly brings out an inherent factor in any of the release

estimates made in this handbook. The source term is most directly affected by assumptions

regarding what material is where. For most examples in this handbook, bounding

assumptions have routinely been made. However, the associated likelihood of the release

goes down, in some cases by an order of magnitude or more, as a result of these

assumptions. For process operations, there is no such thing as "the amount of material

present." How much material is where is a highly variable function of time. Variability is

inherent even in storage operations, as was demonstrated by the examination of solid waste

in section 7.3.9. The chance of having a large number of pails and or drums loaded to the

maximum limit is, as a minimum, small. It is very easy to loose sight of the accumulated

unlikely conditions that have been assumed in source term calculation when bounding results

are desired.

The basic scenarios examined in this example did not add additional events, such as fires and

explosions, to the seismic phenomena because, for the level of damage postulated, there was

no obvious mechanism for such an event to occur. The 0.13g seismic event did little actual

damage to the facility. The 0.26g event did more damage, but again there was no obvious

condition created that would result in an additional event. Strong vibration would not be

expected to initiate an ion exchange resin exotherm. There are few locations where

sufficient flammable material is present to allow electrical equipment damage and residual

sparking as power is lost to cause a significant fire. Even for the calciner, there is no

compelling reason to believe that a large fire would spontaneously initiate or that the calciner

hydraulic system fluid would be sprayed as a fine mist from piping damage to allow fire

initiation from sparking. For the final earthquake examined, the 0.3g partial collapse, the

collapse zone contained no high combustible loading or major energy sources. These

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