Ukraine is not a nuclear state as it does not have nuclear weapons.
Since we have both technological expertise and practical means (from uranium ores to delivery systems), it’s a matter of time.
The former nukes belonged to the USSR and only they had the codes to arm them.
No idea, I haven't seen any. Another thing Russia inherited from USSR war nukes as well as debt.
edit (I misspelled): from USSR was nukes
The conclusion part made me think that the subject was negociated between constituant parts in the devolution treaty. However the paper does highlight that the UN is under ever more pressure for rule-based functioning and transparency, so who knows.
Personally if it were me, I'd rather try and get Russia's membership or voting rights suspended, based on the fact that article 4 states that the UN is for peace loving nations. In the current climate this has a chance of passing in the general assembly, where the veto can not be used. Russia has evoked article 41 'right of self-defense' but that seems problematic.
Another question is if you want to exclude Russia. It sets a precedent, and erodes the position of the UN if not (near-) unanimous. The previous vote had 144 out of 193 voting against Russia, with only 5 against (Russia, Belarus, Venezuela, etc)
https://scholarship.law.cornell.edu/cgi/viewcontent.cgi?arti...
You'd still be prevented by NPT (which Ukraine is part of) like all other non-nuclear states, even without the Budapest Memorandum.
Blown up nuclear power plants are equal opportunity weapons.