By Anton Caputo
San Antonio Express-News

Mayor Julián Castro is ready to pull out of the nuclear project if CPS Energy executives don't return from Japan with a significantly lower cost estimate.

Castro said Thursday that he wouldn't wait until January - when the next official cost estimate from contractor Toshiba is due - to begin the process of "prudently" getting out of the nuclear project if CPS officials fail to bring back a much lower estimate on Monday.

"I'd like to hear definitely whether or not this falls within the affordability plan articulated by CPS," he said. "If not, then we move to option B."

CPS Energy, which is partnering with New Jersey-based NRG Energy to build two more reactors outside of Bay City, has told the community all summer the project will cost $13 billion. At that level, the utility said it can build the reactors and hold bill increases to 5 percent every other year for the next decade. But a recent revelation of a cost estimate from Toshiba as much as $4 billion more than the utility is willing to pay has caused something of a political crisis in San Antonio.

CPS interim General Manager Steve Bartley led a team to Japan this week to negotiate with Toshiba and is expected to divulge the results of the trip at the city-owned utility's board meeting Monday.

Councilman Ray Lopez said he agreed with Castro that the city should be ready to react if the news from the trip isn't good.

"There's no reason to go into January if CPS Energy can't keep the cost below the 5 percent bill increases every other year, and there's always been concern about that," he said.

Lopez said he hoped the utility would come back to the council and change its recommendation to move forward with the nuclear expansion project if the estimate hasn't come down significantly.

NRG Spokesman David Knox wouldn't comment on the possibility of CPS pulling out of the deal, but said that the company was working hard to bring the costs of the project down.

At issue is the price Toshiba will charge to build the plant. In CPS' $13 billion estimate, Toshiba gets $8 billion. The remaining money is: $1 billion for licensing and other fees, $1 billion is kept for contingencies and $3 billion is financing if for financing.

However, Toshiba's preliminary estimates, which were leaked the mayor and the San Antonio Express-News, came in at $12 billion.

"We've already reduced that estimate substantially and will continent to reduce it further," Knox said. "If we thought the cost would be the original estimate - we wouldn't do it."