Add FHR tritium calculation

    ├── core_decay_1MTIHM.f71

    ├── core_decay_1MTIHM.ii.json

    ├── core_decay_1MTIHM.sublibs23.ii.json

    ├── flibe_salt.f33

    ├── pb_fhr_mk1_core_equilibrium.v7-252.t6-depl.252g.3dmap

    ├── pb_fhr_mk1_core_equilibrium.v7-252.t6-depl.2g.3dmap

    ├── pb_fhr_mk1_core_equilibrium.v7-252.t6-depl.inp

    ├── pb_fhr_mk1_core_equilibrium.v7-252.t6-depl.out

    └── pb_fhr_mk1_core_model.png

    ├── pb_fhr_mk1_core_model.png

    ├── tritium_calculation.inp

    └── tritium_calculation.out

```

- inp: text input file

- out: text output file

- ii.json: inventory interface JSON file

- f33: ORIGEN binary library file

- f71: ORIGEN binary concentration file

- 3dmap: binary mesh tally file

=shell

cp ${INPDIR}/flibe_salt.f33 ${TMPDIR}/flibe_salt.f33 

end

=origen

case{

    mat{ iso=[f19=7.0622e7 li7=1.29004e7 li6=645.51 be9=8.37533e6] units=GRAMS}  %Total mass of FLiBe in the reactor coolant system

    lib{

        file='flibe_salt.f33'

        }

time{

    units=YEARS

    t=[0.001 0.01 0.1 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.5 46I 3 50]

    }

   flux=[60r 5.93347e13] %This value is the average flux in the core (n/cm2-s) multiplied by the fraction of total FLiBe in the active core

save{file="pb_fhr_tritium.f71" steps=ALL}

}

end