Code Manual for CONTAIN 2.0 - Federation of American Scientists

(AI-120)i,n= (~)~oAtC
Am,j,.,,=-((A~in)[~); k=metrds fi,AI,ancIcr
Am,j,n,,=-(@Efl)in)(~); ~.Femet~
Am~,i,n,~=+[(A~)(~]; lc=oxicies ZrO,,AKll,,CIO1,
Am,i,n,,=+[PEQ~)in)[~); k= Feooxide
(AH,),,. ‘ ‘[(A~}’n)MH~ ‘from “‘)
2
(6-146)
Similar but more piecemeal expressions (using several if-then branches) are used to calculate
chemical reactions under other conditions. For simplicity’s sake, these more involved expressions
are not shown, since the physical modeling is represented adequately by the expressions above for
the simplest case.
The gas transport rate in the above expression is calculated for debris field n in cell i from Equations
(6-122) and (6-123). As noted previously, the steam transPort equation is ev~uated with the PEQ=
O,and ~E~is used as shown above to account for non-zero v~ues of PEQ.The net effect is that the
correct value of pEQis used for ~1 the metals.
The above equations are applied to each debris field sequentially. The metal masses reacted and
oxide masses produced in a cell are divided by the timestep to give the chemistry terms in the debris
mass conservation equation. The same procedure applies to the masses of oxygen and steam
consumed and the mass of hydrogen produced, but with two important differences. First, the gas
mass changes from the reaction of all debris fields must be added together. Second, hydrogen gas
produced can burn if oxygen is available in the cell. This is described in the following subsection.
Note that if multiple generations are included, all sizes in a generation are calculated first before
moving onto the next generation.
The energy released by the chemical reactions is added to the debris field. The amount of metal
burned by oxygen and steam is multiplied by the energies of reactions given in the following table.
R O 659 6/30/97