Code Manual for CONTAIN 2.0 - Federation of American Scientists

CORCON Mod2 is used. That model does not treat gas barbotage or subcooling effects during film
boiling. It should be noted that Section 10.4 is a complete and somewhat revised version of the
corresponding discussion in Reference Bra93 on boiling heat transfer, as modeled in CORCON
Mod3.
A basic description of the layer configurations in the lower cell with and without CORCON active
is provided in Section 5.1. Sections 5.2 through 5.4 describe specific physical models and user
options associated with the concrete, intermediate, and pool layer types in the lower cell system.
This includes the conduction model that is used when CORCON is not active, and special options
or unique features included to link CORCON to CONTAIN. Interlayer heat transfer coefficients
used in the conduction model and user-specified heat transfer coefficient option are described in
Section 5.5. The use of mass and energy sources to the various layers, including decay and
volumetric heating, is discussed in Section 5.6. Section 5.7 addresses any implementation specific
capabilities ador limitations of the CONTAIN implementation of CORCON not covered in the
preceding sections. Section 5.8 addresses the physics modeling in CORCON. Rather than duplicate
the governing equations and discussions in the CORCON Mod3 User’s Manual, ~ra93] this section
provides a guide for applying this existing documentation to the CONTAIN implementation of
CORCON. Section 5.8 also describes any changes made to CORCON Mod3 since the publication
of Reference Bra93. Section 5.9 discusses limitations and assumptions of the lower cell modeling.
Key elements of the lower cell and cavity models are illustrated in Figure 5-1.
5.1 Laver Confimrations
The fwst subsection below describes the layer conf@ration when CORCON is not active. Note that
this is applicable to problems in which CORCON is invoked but CORCON is not yet active or was
active and has been deactivated. Section 5.1.2 describes the layer configuration used when
CORCON is invoked and active. This describes how the CONTAIN lower cell layer system
represents the CORCON layer.
5.1.1 Layer Configuration Without CORCON
The layer configuration and the relationship of the layers to the phenomena modeled in the lower cell
without CORCON is depicted in Figure 5-2. Each of these layers, with the exception of the pool
layer, is assumed to have the cross-sectional area given by the lower cell GEOMETRY keyword (see
Section 14.3. 1.1). Layers are defined in the CONTAIN input beginning at the bottom. Thus, the
first layer is the concrete layer which is shown in Figure 5-2 as being nodalized into 12 equal-size
nodes. Any number of nodes greater than or equal to 5 can be specified for the concrete layer using
the “jconc” input in the cell control block. If “jconc” is specified as non-zero but smaller than 5, the
code will use 5. Only one concrete layer may be specified. Above the concrete layer are “jint”
intermediate layers, each with only one node. When CORCON is not invoked, intermediate layers
are allowed to have only one node. The user can specify an arbitrary number of intermediate layers
by specifying the desired number as “jint” in the cell control block. Also, each layer can be given
an arbitrary name when CORCON is not invoked. A pool layer is shown above the topmost
intermediate layer. The pool, like an intermediate layer without CORCON, is allowed to have only
a single node and is indicated by ‘\pool” = 1. Only one pool layer maybe specified. If specified,