I don't suppose it's possible to find who the major shareholders are for U-One. But while searching, I did find that this company - Turbine Technology AAEM, LLC - is a subsidiary of Uranium One, and is a "joint venture between Atomenergomash JSC (51%) and General Electric(49%).
http://aaemturbines.com/en/
Also found an interesting article on all the goodies that General Electric's Immelt hoped to gain from the Zer0 years:
"Obama announced a concession to Russia: He would scrap U.S. plans to build a missile shield in Eastern Europe. Reuters reported, "Shortly after the pullback on the shield programme was announced, Russia's government said Prime Minister Vladimir Putin would meet several U.S. executives on Friday from firms including General Electric.
https://www.washingtonexaminer.com/the-decline-and-fall-of-general-electric-the-poster-child-of-obamanomics
Correction:
Both Atomenergoprom (Uranium-One) and Turbine Technology AAEM LLC (joint venture Atomenergomash/General Electric) are subsidiaries of Rosatom.
Thank you for that info. Will check it out later.