A key supervisory board member quit Ukraine's troubled state nuclear energy company, amid broader reforms in the country's state-owned energy forms.

Patrick Fragman, the former CEO of U.S. nuclear energy firm Westinghouse Electric Company, resigned from his position at Energoatom, which operates Ukraine’s three working nuclear power plants, less than five months after being appointed to the board, the company announced on May 15.

The reason was the high workload on the supervisory board, which was much greater than initially planned and therefore incompatible with his "current and future activities," Fragman told the Kyiv Independent in a written comment.

Supervisory boards oversee the executive management of state-owned companies, which dominate Ukraine's energy, banking, and infrastructure sectors.

They were introduced across major state-owned enterprises following the EuroMaidan Revolution in 2014 to create safeguards against corruption and government abuse.