They were upgraded instead of simply deleted from the arsenal. Russia maintains a much more active enrichment program than the US. For some reason the US seems

They were upgraded instead of simply deleted from the arsenal. Russia maintains a much more active enrichment program than the US. For some reason the US seems to want to keep it that way, or at least doesn't have a problem with. It's great that we used that fuel for domestic energy but those funds paid to Russia supported their further enrichment activities. Even today the US is supplying Russia with radioactive material and procuring enriched products from Russia. Maybe less in the last year but we generally have an open exchange of supplies and information with nuclear technology. From a war standpoint the nuclear material isn't that big of deal, the delivery system is vastly more important for national security.