The Tennessee Valley Authority (TVA), which had earlier said it was considering the construction of up to four reactors at its Bellefonte site in Alabama, US, is now looking into building just one unit at the site. The company had been considering finishing two partly built reactors at the Bellefonte plant or constructing two new units at the site. The option of constructing all four units had also been considered. However, the company has now said it is preparing a supplemental environmental impact statement (SEIS) which will evaluate three alternatives: completing and operating one of the partially completed reactors; constructing and operating a new Westinghouse AP1000 nuclear unit; and taking no action to operate a nuclear unit at the site. The SEIS will also evaluate the impact of refurbishing, re-energizing and upgrading several existing 16kV and 500kV transmission lines and switchyards needed for single-unit operation. TVA expects to finalize the SEIS in 2010. TVA stressed that no decision to build any new generating capacity at the Bellefonte site has yet been made.