Korean builder was asked to take 25% more work on Dukovany for 1.3% more money, report says

The numbers come from the letter Korea Hydro & Nuclear Power sent on Oct. 30 to end construction talks with Daewoo Engineering & Construction, according to an industry official cited by Seoul Economic Daily. Daewoo's last offer priced the full bid volume (100%) at 7.6 trillion won. KHNP countered with 7.7 trillion won, but for 125% of that volume. The budget rose about 1.3%; the work grew by a quarter. If Daewoo's quoted costs scale with quantities, the paper calculated, the larger scope would cost 9.5 trillion won, or 1.8 trillion more than KHNP offered.

A second dispute covered work added after the final bid: a port facility to bring in materials, bigger worker housing and other support buildings. KHNP wanted all of it inside the final price. Daewoo, which values that work at 1 trillion won, says KHNP accepted under 40% of the amount it calculated and refused to settle design changes after signing. Added to the volume gap, Daewoo's extra exposure approaches 3 trillion won. The site will get APR1000 reactors, a Korean design never built before, so quantities are likely to shift as the design is completed.

KHNP says it tried to cut that risk. It proposed building the expected volume growth into the price up front, fixing the total around July 2029, once the basic design wins approval, and paying for most civil work, where quantities are least certain, on measured amounts. In return it asked Daewoo to lower unit prices and overhead and to fix errors such as double-counted social insurance charges. KHNP says Daewoo's construction cost would have taken a share of total project cost between 7 and 11 percentage points above other nuclear jobs. Neither company confirmed the amounts.

Negotiators met 91 times after the Czech contract was signed in June 2025. KHNP issued new terms on Oct. 7; Daewoo says it was pressed to accept them within three weeks. KHNP now plans a competitive tender for a new builder. The two units, Dukovany 5 and 6, are estimated at roughly 400 billion koruna ($18.3 billion), Korea JoongAng Daily reported.