The Department of Energy (DOE) is constructing a facility at the Nevada Test Site (NTS) which will be capable of the rapid release of large quantities of cryogenic or pressurized flammable or toxic materials. The facility is being built in concert with and in response to the needs of many industrial and governmental organizations. The facility is designed to satisfy the need for information for risk assessment, emergency response, regulation, plant design, plant siting, and hazard mitigation. It will be capable of spilling up to 200 m3 (53,000 gal) of cryogenic fluids such as Liquefied Natural Gas (LNG) or refrigerated ammonia at rates between 5 and 100 m3/min (1,000-26,000 gpm). In addition, up to 90 m3 (24,000 gal) of ambient temperature materials such as Liquefied Petroleum Gas (LPG) or chlorine, with pressures up to 2,000 kpa (300 psi), can be released at rates between 2 and 20 m3/min (500-5,000 gpm). An extensive sensor and data acquisition system is available to acquire data on spill characteristics such as rate, volume, temperature, and pressure; downwind gas concentration and aerosol characteristics; meteorological parameters; and blast or fire effects. The Frenchman Flat area of the NTS provides a uniquely favorable environment in which to perform large-scale atmospheric dispersion tests. Steady winds from the southwest occur with great regularity during the summer months for a variety of atmospheric stability conditions. Large-scale tests with toxic materials are possible because only limited access, federally controlled land is present for some 60 km (37 mi) downwind.