Therefore, it is not advisable to use the Kovarex process to convert all stockpiled U into U Although, in case of shortage, Used up uranium fuel cells can be reprocessed into a modest amount of U From Official Factorio Wiki. The Kovarex process thus provides the player with a considerably faster and deterministic method of producing U, as well as a use for the surplus U It should be noted that U is not useless it is necessary and sufficient to manufacture uranium rounds magazinesuranium cannon shellsand explosive uranium cannon shellsand is required as a secondary ingredient in uranium fuel cells. Uranium is necessary to create uranium fuel cells and atomic bombsin considerable quantities for the latter, but the probability distribution of uranium processing leads to it being produced slowly and creating large stockpiles of U as a byproduct. This is currently the only probability-based crafting recipe in the game. Uranium processing takes 10 uranium ore and returns 1 uranium with 0. Although the process requires a large amount of the much rarer uranium to start, it can be a good way to get more use out of the available uranium ore. The Kovarex enrichment process is a method for reprocessing uranium in a centrifuge.