ENVIRONMENT Vapor dispersion from LNG spills For further information contact Ronald P. Koopman (423-0163). We have carried out a series of experiments on vapor dispersion from spills of liquefied natural gas (LNG) at the Naval Weapons Center, China Lake, California. In each of these tests, about 5 m? of LNG were dumped ona water pond in winds ranging from 3 to 10 m/s. Our main objective was to evaluate gas sensorsto be usedin future largescale tests, but in addition, we achieved good agreement between experimental data and computer simulations. We have recently begun a series of 40-m? test spills. In these and planned larger scale experiments we will measure the dispersion of LNG vapor clouds with a view to developing better models of the effects of density, temperature, and turbulence on dispersion. The final product of this research will be a set of experimentally validated models that predict the consequences of a large-scale LNG accident. These models will help DOE provide improved safety guidelines for the transport and storage of LNG. Ocean-going tankers filled with liquefied natural gas (LNG) may. supply at least 10% of the natural gas consumed in the U.S. by the mid-1980s. However, this means of transport involves potential hazards far beyond those already accepted in conventional natural gas use.* To develop a detailed understanding of the potential hazards so that they can be controlled, the Division of Environmen- tal and Safety Engineering of the U.S. Department of Energy has initiated a Liquefied Gaseous Fuels Safety and Environmental Control Assessment Program in which LLNL is participating. Methane, the principal constituent of natural gas, remains liquid only at or below 113K 27 tt JUUG Ge Ff (-160°C), and 1 m? ofliquid ex- pands at atmospheric pressure to produce 600 m” of gas. The gas is flammable when mixed with 5 to 15 times as much air. Thus, 1 m“of liquid can form 10 000 m?ofa highly flammable air-gas mixture. Because of its low temperature and high relative density, the vapor released by an LNG spill will hug the ground and spread in a cloud over a large area. Some fraction might become flammable or detonable, depending onthe spill rate, the spill site, and the exact LNG composition. If a flammable