Code Manual for CONTAIN 2.0 - Federation of American Scientists

VTOPEN
= vtopen
TYPE
= {GAS or
POOL}
RESOLVHD
VEQLENB
= veqlnb
VEQLENF
= veqlnf
VELEVB
= velevb
the time at which the vent should open or begin to open. The vent by default
is initially open. Specification of this option will result in the vent being
initially closed unless “vtclos” is also specified and “vtclos” < “vtopen.”
Default = -1030. (s)
keyword to specify whether the path is to carry gas and its associated
constituents or liquid coolant and its constituents from the pool. A given path
may carry only one of these groups.
the keyword to resolve the gravitational head of an engineered vent of type
GAS into three segments: the elevation change between the gas center of
elevation in one cell and the elevation at which the vent is attached to the cell,
the elevation change between the ends of the flow path, and the elevation
change within the second cell. As discussed in Section 4.4.5.1, if
RESOLVHD is specified, the appropriate cell density is always used for f~st
and third segments. Normally, the gas gravitational head is calculated on the
basis of the net elevation change between cell gas centers of elevation and
either a VDI or average density. The latter is used if MSTABLE is specified
in the FLOWS input block. As discussed in Section 4.4.5.1, use of
RESOLVHD is not recommended unless the user has demonstrated that the
resulting gravitational head is acceptable. The user invoking RESOLVHD
should be aware that the default flow path elevations have changed horn prior
versions--gas paths are by default connected to the top of the cell to avoid
flooding by the pool.
the characteristic height over which the gas exiting from a submerged back
(FROM) end of a vent is equilibrated with the downstream pool as it rises.
This height, designated as Iji in the discussion following Equation (4-16), is
assumed to control the equilibration of both the coolant vapor in the bubbles
and the gas temperatures, as discussed in that section. In contrast to the
treatment in the dedicated suppression vent model, for regular flow paths and
engineered vents, aerosols and fission products in the flow are removed
completely from the flow and placed in the pool. As in the dedicated
suppression vent model, core debris (in debris droplet fields) is completely
removed and placed in the intermediate layer, if present, in the lower cell.
Default = 0.01. (m)
the characteristic height over which the gas exiting from a submerged Iiont
(TO) end of a vent, in the case of reverse flow, is equilibrated with the
downstream pool as it rises. This height is defined in a manner similar to
“veqlnb.” (m)
the absolute elevation of the back (FROM) end of an engineered vent. The
default value of “velevb” is the top of the cell to which the end is attached
(Htias shown in Figure 44) for a gas path and the bottom of the cell (~i) for
Rev O 14 28 6/30/97