The MoUs signed with 10 companies will establish cooperation with the companies involved in areas including the production and supply of valves, technological equipment, crane services, piping systems and automation and control and field instrumentation.
The latest MoUs add to seven agreements signed with local companies in the Czech Republic in January.
The new plant at Dukovany will be built next to the existing nuclear station, which has four VVER units that began commercial operation in the 1980s.
Construction of the new unit should begin in 2029 and be completed by 2036. Industry minister Jozef Síkela said it would be the biggest investment in the modern history of the Czech Republic. The project could cost around €6bn.
Czech state power company ČEZ has said it is planning to build one Generation III+ reactor at the Dukovany site, with a maximum installed capacity of 1,200 MW. However, the company filed for permission to build up to two new units.
There are three companies competing for the tender: Westinghouse, EDF of France and South Korean energy company Korea Hydro and Nuclear Power (KHNP).
Chinese and Russian state companies were excluded from entering the tender process due to security concerns.