GL8B is an exception to EO14024 explicitly *allowing* transactions with those entities until the end of June (another 2.5 months).
EO14024 is basically an anti-oligarch/collusion executive order, not really energy sanctions.
The order you want to look at more is EO14066, although it almost certainly doesn't ban uranium purchases, only some specific other commodities as well as more generally "investment" in Russian energy (so utilities can buy yellowcake, but not buy a stake in Rosatom, for example). Still, expansions/refinements to this may eventually change the situation (don't hold your breath, though, it's been a while already).
The things you ACTUALLY want to watch are Senate bill S. 3856 introduced by Wyoming's Senator Barrasso (~4 Republican co-sponsors), & the House of Representatives bill introduced by Minnesota's Pete Stauber (~4 co-sponsors, bi-partisan). The progression of these is most likely where we will see sanctions occurring, if at all. They've been having hearings with various experts presenting, including some uranium CEOs (there was a great diagram of the regulatory steps for setting up a uranium mine in the US, with the poster being several metres wide at the talk). I'd imagine likelihood of the bills passing will depend largely on the government's assessment of whether Western-available deposits and enrichment/conversion facilities are capable of fully picking up the slack if we're cut off entirely from Rosatom.
IMHO confirmation of sanctions against Russia would see an immediate +10% day (minimum) in both equities and spot price, potentially much more, so if you're looking at those and the numbers are +3% or -2% or something, you can be relatively sure sanctions aren't confirmed yet. And also kick off an immediate hugely volatile bull run. Confirmed refusal of sanctions would probably see a few days of nasty bleeding, but overall I think we are poised for a move up regardless (look at SWU prices, spot price, the original thesis, etc) and even throwing out sanctions doesn't rule them out forever, nor does it rule out Russia playing around with its uranium exports as a tool for threatening the West, so for once I really do think the worst case downside possibility from this binary outcome we are approaching should still be pretty mild.
(20min delay)