ATLANTA (AP) — Expensive delays are piling up for the companies building new nuclear power plants, raising fresh questions about whether they can control the construction costs that crippled the industry years ago.

The latest announcement came this week from executives at SCANA Corp., which has been warned by its builders the startup of the first of two new reactors in South Carolina could be delayed two years or more. SCANA Corp. and plant co-owner Santee Cooper have not accepted that timeline from the companies designing and building the reactors, nor have they accepted responsibility for additional costs.