The three companies invited to take part in a tender to build new nuclear units at the Dukovany nuclear power station in the Czech Repuublic have agreed to undergo a security check, utility ČEZ announced on Friday, according to local reports.

Radio Prague International reported that the companies are EDF of France, Korea Hydro & Nuclear Power (KHNP) of South Korea and Westinghouse of the US. ČEZ had said in June that prospective bidders should present the relevant security documentation by the end of November.

CNG of China and Russia’s state nuclear corporation Rosatom were excluded from the process.