The South Texas Project Electric Generating Station (also known as STP, STPEGS, South Texas Project), is a nuclear power station southwest of Bay City, Texas, United States. STP occupies a site west of the Colorado River about southwest of Houston. It consists of two Westinghouse Pressurized Water Reactors and is cooled by a reservoir, which eliminates the need for cooling towers.
History
1971–1994
On December 6, 1971, Houston Lighting & Power Co. (HL&P), the City of Austin, the City of San Antonio, and the Central Power and Light Co. (CPL) initiated a feasibility study of constructing a jointly-owned nuclear plant. The initial cost estimate for the plant was $974 million (equivalent to approximately $ in 2015 dollars).
By mid-1973, HL&P and CPL had chosen Bay City as the site for the project and San Antonio had signed on as a partner in the project. Brown and Root was selected as the architect and construction company. On November 17, 1973 voters in Austin narrowly approved their city's participation and the city signed onto the project on December 1. Austin held several more referendums through the years on whether to stay in the project or not.
An application for plant construction permits was submitted to the Atomic Energy Commission, now the Nuclear Regulatory Commission (NRC), in May 1974 and the NRC issued the permits on December 22, 1975. Construction started on December 22, 1975.
By 1978, the South Texas Project was two years behind schedule and had substantial cost overruns. A new management team had been put in place by HL&P in late 1978 to deal with the cost overruns, schedule delays and other challenges. However, events at Three Mile Island in March 1979 had a substantial impact on the nuclear industry including STNP. The new team again moved forward with developing a new budget and schedule. Brown and Root revised their completion schedule to June 1989 and the cost estimate to $4.4–$4.8 billion. HL&P executives consulted with its own project manager and concluded that Brown and Root was not making satisfactory progress and a decision was reached to terminate their role as architect/engineer but retain them as constructor. Brown and Root was relieved as architect/engineer in September 1981 and Bechtel Corporation contracted to replace them. Less than two months later, Brown and Root withdrew as the construction contractor and Ebasco Constructors was hired to replace them in February 1982 as constructor.
Austin voters authorized the city council on November 3, 1981 to sell the city's 16 percent interest in the STP. No buyers were found.
Unit 1 reached initial criticality on March 8, 1988 and went into commercial operation on August 25. Unit 2 reached initial criticality on March 12, 1989 and went into commercial operation on June 19.
In February 1993, both units had to be taken offline to resolve issues with the steam-driven auxiliary feedwater pumps. They were not back in service until March (Unit 1) and May (Unit 2) of 1994. The history of STNP is somewhat unusual since most nuclear plants that were in the early stages of engineering construction at the time of the Three Mile Island event were never completed.
2006–present
On June 19, 2006, NRG Energy filed a letter of intent with the NRC to build two 1,358-MWe advanced boiling water reactors (ABWRs) at the South Texas Nuclear Project site. South Texas Nuclear Project Partners CPS Energy and Austin Energy were not involved in the initial letter of intent and development plans.
On September 24, 2007, NRG Energy filed an application with the NRC to build two Toshiba ABWRs at the South Texas Nuclear Project site. It was the first application for a nuclear reactor submitted to the NRC since 1979. The proposed expansion would generate an additional 2700 MW of electrical generating capacity, which would double the capacity of the site. The total estimated cost of constructing the two reactors is $10 billion, or $13 billion with financing, according to Steve Bartley, interim general manager at CPS Energy.
In October 2009, main contractor Toshiba had informed CPS Energy that the cost would be "substantially greater," possibly up to $4 billion more. As a result of the escalating cost estimates for units 3 and 4, in 2010 CPS Energy reached an agreement with NRG Energy to reduce CPS's stake in the new units from 50% to 7.625%. To that point, CPS Energy had invested $370 million in the expanded plant. CPS Energy's withdrawal from the project put the expansion into jeopardy.