Code Manual for CONTAIN 2.0 - Federation of American Scientists

output after a run is completed, this keyword may be specified on a restart. A restart at a given
restart time will automatically include energy accounting information up to that time.
Aerosol materials can be either a nongaseous thermodynamic material or a dedicated aerosol material
defined by the user in the AERNAMES and global AEROSOL input blocks. (If an aerosol material
is declared to be the H20V material, a usage that is now considered obsolete, the material will be
treated as the liquid H20L.) Only the aerosol components that are thermodynamic materials are
included in the mass and energy accounting. Both suspended and deposited aerosol masses are
considered. It should be noted that fission products, by convention, cannot be comprised of
thermodynamic materials and are, therefore, excluded from the scheme.
The details of the accounting scheme are described in Appendix A. The strategy used in the mass
and energy accounting is discussed in Section A.2. The repositories considered and the mass and
energy contributions reported in the accounting scheme are discussed in Section A.3.
As discussed in Appendix A, the present mass and energy accounting scheme is repository-oriented.
The mass and energy output is organized so that the mass and energy balance for each repository may
be obtained by inspection, without having to refer to other repositories. An example of the mass and
energy accounting output (enabled by the PRENACCT keyword) is given in Figure 3-2. As shown
in this figure, a number of repositories and their mass and energy balances are reported. The mass
reporting in this case includes only the coolant mass, given in kilograms, since “nmtrac” and
TRACKMAT were not specified. In Figure 3-1, the present energy EP for each repository should be
compared with the second column labeled “i+e+r+i- c,” which is a combination of the first letters
of the labels of the next five columns. This column contains the sum EO+ E. + E, + E~- EC,which ~
according to Equation (A-11) should be equal to EP, plus any work done by the repository against
its geometric constraints (see Section A.3), if no energy accounting errors have occurred.
The format shown is that obtained when the implicit flow solver is used. If the explicit flow solver
is used, the atmosphere mass and energy balances for each cell are replaced by a single mass and
energy balance representing the sum over all cell atmospheres. The reason for reporting this sum
is that the explicit solver has not been upgraded to track the change in audit energies resulting from
intercell flow.
Note that because all internal interfaces are conservative with respect to audit energies, the sum of
the influx energies E~over all repositories should be zero. The user can check this if desired.
It should be noted that a sizeable relative error in the energy balance, based on repository contents,
does not necessarily imply that the error is significant in terms of the calculated thermodynamic state.
For example, a repository may have a great deal of mass and energy cycled through it but contain
only a small fraction of the total cycled mass and energy at any given time. A relatively small error
in the calculation of the thermodynamic state may buildup overtime to a relatively large error, based
on the repository contents. The error may actually be tolerable if the measure of significance is the
error relative to the total mass and energy cycled through the repository.
Rev O 6/30/97