# Updating the Reactor and Repository¶

We can add in Advanced Light Water Reactors that will flexibly switch between UOX and MOX fuel based on their availability. This protoype uses the same template as the other reactors with a few additional entries.

## Reactor Modifications¶

• Fresh Fuel Commodity: Fresh-MOX-Fuel [1]
• Fresh Fuel Recipe: Fresh-UOX-Fuel
• Spent Fuel Commidity: Used-MOX-Fuel
• Used Fuel Recipe: Used-MOX-Fuel-4

Under user level 1, add 2 entries for the “Fresh Fuel Preference List, one for each requested commodity. Since MOX fuel is preferred, the preference for MOX should be 2 times higher than that or UOX. Perhaps:

• MOX = 2
• UOX = 1

The new reactor must be added to the Exelon Reactors institution in the region.

## Repository Modifications¶

Add an accepted commodity for the repository to be Separated-Waste.

## Activity: Save your Input File¶

The input for this example is now complete. Save your input file as ‘recycle_input.xml’. If your simulation runs into errors, sample files can be found here under input_recycle.xml or ouput_recycle.sqlite.

Footnotes

 [1] Note that we are using the UOX recipe for the MOX recipe in order to have

our fuel fabrication facility do its best to match that recipe by blending streams of Pu with natural U.