Code Manual for CONTAIN 2.0 - Federation of American Scientists

the user-defined source table capabilities. The latter are still considered the standard method of
performing CONTAIN DCH calculations and guidance for defining these source tables is included ~
in Section 13.3.1.2.2.
Section 6.1 of this chapter summarizes the DCH phenomena modeled and describes the multiple
debris field modeling features. Section 6.2 describes the debris transport and intercell flow models,
including the RPV and cavity models and also the options for introducing debris into the calculation
via source tables when the RPV and cavity models are not used. The models for debris trapping,
DCH chemistry, and DCH heat transfer are described in Sections 6.3 through 6.5. Section 6.6
extends the treatment of debris-gas heat transfer and chemical reaction to the nonairbome debris”
field. Known limitations of the DCH models are summarized in Section 13.2.3 and practical
guidance for the user is offered in Section 13.3.2. The description of DCH input is given in Chapter
14. Key elements of DCH models are illustrated in Figure 6-1.
6.1 General Description of the CO NTAIN DCH Model
The DCH model is based on a multiple field representation of debris particles. With this modeling
approach airborne debris can be represented by a range of particle sizes and material compositions.
Any number of particle fields can be represented in the model, and each field has its own
characteristic size, mass, chemical composition, and temperature. The exchange of mass and energy
from the debris to the atmosphere and its surroundings are modeled in CONTAIN for each debris
field. The processes that are treated are briefly discussed in the following subsection.
6.1.1 Phenomena Modeled
Table 6-1 lists the collection of processes contributing to the DCH phenomena that are modeled in
CONTAIN. Some of these processes are modeled mechanistically; however, others are represented
by parametric models that rely upon user-specified input. This input may be picked using
engineering judgment or can be based upon the results of calculations performed using a stand-alone
model. Table 6-1 also summarizes how the major processes that drive DCH are treated in the
CONTAIN model. The options employing the RPV and cavity models as well as the options for
user-specified debris source tables are both included in Table 6-1.
It is important to recognize that like other analyses, DCH analyses with CONTAIN require that
certain information about the containment geometry be specified by the user. This includes sizes of
the control volume compartments, the flow path connections, initial conditions of the containment
atmosphere, structure masses and surface areas, and a variety of other information.
6.1.2 Multiple Debris Field Modeling Features
The CONTAIN DCH model is based on a multiple field representation of debris particles. With this
modeling approach airborne debris can be represented by a range of particle sizes and material
compositions. Any number of particle fields (also called “bins”) can be represented in the model,
and each field has its own characteristic size, mass, chemical composition, and temperature. The
Rev O 62 6/30/97