ATLANTA -- Despite a $425 million lawsuit and counter suit over added costs, Georgia Power executives filed testimony Wednesday swearing that expansion of Plant Vogtle remains on schedule and on budget.

In fact, it will cost $200 million less than originally projected to add two reactors to the nuclear-power plant, according to the testimony. The written testimony was submitted jointly by Kyle Leach, director of resource policy and planning for Georgia Power, and David McKinney, vice president of nuclear construction support for Southern Nuclear, the subsidiary that operates the plant for Georgia Power and the other utilities that own it.

The testimony is required as part of the Public Service Commission's semiannual review of construction costs. So far, the company has spent $2.3 billion on the project out of the $6.2 billion it's budgeted for. If costs go up for legitimate reasons, the company has to ask the commission to boost the budget in order to pass any increase along to its customers.

What the filing doesn't include is the impact of the legal dispute which could add $425 million to the company's share of the total project.

"Once those disputes are resolved, the owners may conclude that the project cost should be revised to reflect additional costs -- as necessary and prudent -- at that time," the executives testified.

The company has tried to negotiate with the builder over which of them is on the hook for costs due to a delay in getting a federal construction license and design changes. When negotiations failed, each sued the other Nov. 1 in federal court.

"Additional claims by the contractor or Georgia Power (on behalf of the owners) are expected to arise throughout the construction of the facility," the pair testified.

The filing also identified $80 million in various cost increases, from $3 million for cyber security to $1 million for enhancements related to lessons learned from the March earthquake and tsunami that struck nuclear plants in Japan. Another $2 million is from lessons gathered while watching Chinese companies construct reactors with the same design. Legal fees added $8 million.

But the company isn't asking that any of those increases be added to the budget. Its projections show that even if operation is delayed 18 months, the plant will still represent a bargain for electricity customers compared to building the same amount of generating capacity fueled by natural gas.