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Code Manual for CONTAIN 2.0 - Federation of American Scientists

Code Manual for CONTAIN 2.0 - Federation of American Scientists

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Table 13-4<br />

Standard Values Used in Assessing the Levy Correlation<br />

Data Set SSCALF DSUBS RHDEBS TSUBIS<br />

BNL 0.02381 28.96 0.00953 103 295<br />

SNL 0.1 28.96 0.038 103 325<br />

If the entrainment velocities calculated are physically reasonable, then the default diameter ranges<br />

provided should beadequate mdthe DW~md DW~ke~ords need not be given. The<br />

default standard deviation <strong>of</strong> two is also recommended until further experience is obtained with the<br />

models. Note that this value will provide fairly narrow distributions <strong>for</strong> entrained debris within a<br />

given tirnestep; however, the net particle size distribution could be quite broad as a result <strong>of</strong> a range<br />

<strong>of</strong> entrainment velocities. The user is encouraged to utilize the user-specified diameter option to<br />

per<strong>for</strong>m parameter sensitivity studies, since this option has more flexibility than the Weber model<br />

and can be more directly controlled.<br />

13.3.2.5 Specific Immt Parameters <strong>for</strong> RPV and Cavitv Models<br />

13.3.2.5.1 AHOLE1. The parameter AHOLE1 controls the initial size <strong>of</strong> the hole in the RPV at the<br />

start <strong>of</strong> single-phase debris ejection from the RPV cell. When debris is placed in the trapped debris<br />

bin in the RPV cell, the RPV and cavity models override the gas flow area between the RPV and<br />

cavity cells that was set in the FLOWS block in the input file. During single-phase debris ejection,<br />

the gas flow area between the RPV and cavity is internally set to zero. After gas blowthrough<br />

occurs, the two-phase debris ejection model calculates a time-dependent gas flow area and gives this<br />

value to the <strong>CONTAIN</strong> flow solver <strong>for</strong> gas flow between the two cells.<br />

13.3.2.5.2 CPWALL. The parameter CPWALL is the specific heat <strong>of</strong> the RPV wall. If no value<br />

is specified in input, the code calculates a value based on Fe at the temperature TWALL. It is<br />

provided as input so that the user can simulate other materials.<br />

13.3.2.5.3 CSUBD. The parameter CSUBD is the discharge coefficient at the RPV hole <strong>for</strong> the<br />

exiting debris. The discharge coefficient <strong>for</strong> gas flow is unaffected by the RPV and cavity models,<br />

and will be whatever the user specifies <strong>for</strong> the RPV-to-cavity flow path elsewhere in the <strong>CONTAIN</strong><br />

input.<br />

13.3.2.5.4 RHOWAL. The parameter RHOWA.L is the density <strong>of</strong> the RPV wall. If no value is<br />

specified in the input, the code calculates a value based on Fe at the temperature TWALL. It is<br />

provided so that the user can simulate other materials.<br />

13.3.2.5.5 AFILM. The parameter AFILM is the surface area in the cavity covered by debris. The<br />

product <strong>of</strong> the entrainment rate flux and the area Al?ILMyields the actual entrainment rate <strong>of</strong> debris<br />

in the cavity. The user can determine AFILM <strong>for</strong> a specific cavity geometry by adding up the surface<br />

areas <strong>of</strong> all structures in the cavity that are expected to be covered by debris. As a simple<br />

approximation, AFILM might include all floor and wall areas in the cavity, and exclude any ceiling<br />

O 13 58 6/30/97

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