Description: The Braidwood Station is located in Will County in northeastern Illinois. It serves Chicago and northern Illinois. Braidwood's recent up rates make it the largest nuclear plant in the State. The three largest Illinois' plants, however, are nearly equal (LaSalle is only 2 net megawatts smaller than Braidwood and Byron is only 4 net megawatts less in capacity than LaSalle). According to the Exelon Corporation's web site, the plant has a workforce of 800 employees and contractors with an annual payroll of over $60 million. In April 2006, it was announced that tritium was discovered in groundwater at the site. In a company press release, it was stated that "Exelon has taken full responsibility for the releases into the ground and has held itself publicly accountable for cleaning up the groundwater, much of which remains on plant property." According to the U.S. Nuclear Regulatory Commission (NRC):

Tritium is a mildly radioactive type of hydrogen that occurs both naturally and during the operation of nuclear power plants. Water containing tritium and other radioactive substances is normally released from nuclear plants under controlled, monitored conditions the NRC mandates to protect public health and safety. The NRC recently identified several instances of unintended tritium releases, and all available information shows no threat to the public.

On June 30, 2006, NRC announced a ‘white’ finding and issued a Notice of Violation to Exelon Generation Company for “failures to perform surveys following historical leaks, to assess the environmental impact on the public, and to control licensed material.” Exelon has thirty days to respond.

There was also some good news from NRC for the Braidwood plant. In August 2006, the NRC reported that the number one nuclear generating unit at Braidwood ranked 12th Internationally and first in the Nation in output. (To enable comparison with foreign units, the NRC based this on gross output. Gross output includes the electricity used by the plant and, although it can vary significantly, is generally about 5 percent greater than net output.) For additional information on tritium, consult the NRC web site.

Braidwood, Unit 1

Nuclear Steam System Supplier (NSSS Vendor) =  Westinghouse Electric Company
Architect Engineer =  Sargent & Lundy
Owner = Exelon Corporation 
Operator (Licensee) = Exelon Corporation

Braidwood, Unit 2

Nuclear Steam System Supplier (NSSS Vendor) =  Westinghouse Electric Company
Architect Engineer =  Sargent & Lundy
Owner = Exelon Corporation 
Operator (Licensee) = Exelon Corporation

Pressurized-Water Reactor (PWR)

In a typical commercial pressurized light-water reactor (1) the reactor core generates heat, (2) pressurized-water in the primary coolant loop carries the heat to the steam generator, (3) inside the steam generator heat from the primary coolant loop vaporizes the water in a secondary loop producing steam, (4) the steam line directs the steam to the main turbine causing it to turn the turbine generator, which produces electricity. The unused steam is exhausted to the condenser where it is condensed into water. The resulting water is pumped out of the condenser with a series of pumps, reheated, and pumped back to the steam generator. The reactors core contains fuel assemblies which are cooled by water, which is force-circulated by electrically powered pumps. Emergency cooling water is supplied by other pumps, which can be powered by onsite diesel generators. Other safety systems, such as the containment cooling system, also need power.

© U.S. Nuclear Regulatory Commission

Containment: According to the U.S. Nuclear Regulatory Commission, the constructor for Braidwood is Commonwealth Edison Company and the design is dry, ambient pressure¹

_________________________________________

¹Dry, Ambient Pressure: a reactor containment design whose safety has been evaluated on the basis of having a dry air atmosphere at ambient pressure (0 psig) prior to the onset of a loss of coolant accident or steam pipe break. The containment design (concrete and steel tendons) must be able to take the full thermal and pressure stresses associated with the rapid energy release (steam) from a major pipe break.

Sources for Data in Table: Capacity, for purposes of this report, is the net summer capability as reported in Energy Information Administration (EIA) Form EIA-860, "Annual Electric Generator Report." Capacity Factor is a percentage calculation in which the maximum possible generation (based on net summer capability) is divided into the actual generation then multiplied by 100. Generation is the net electricity output reported by plant owners on Form EIA-906, “Power Plant Report.” Type of Unit: All U.S. commercial reactors currently in operation are one of two types: BWR (boiling water reactor) or PWR (pressurized light water reactor). The type, on-line date, and the license expiration date are published annually in Information Digest by the U.S. Nuclear Regulatory Commission.