Mar. 16--The government has failed to adequately study the potential effects of a terrorist attack on a large-scale liquefied natural gas facility, according to a congressional study released this week.

The report found that an Energy Department research project on potential dangers of accidents at the facilities addresses only three of the top 10 areas that need more study. These issues include the potential for chain-reaction fires aboard a tanker an the effects of wind, waves and weather if there was an LNG fire. Concerns about terrorism and an expectation that U.S. imports of liquefied natural gas will increase fourfold in the next decade spur the need for further study, said the report by the General Accountability Office, which called on the Energy Department to conduct more research.

With permits pending for more than 30 new on- and off-shore LNG terminals in the United States, more information about the risks would help determine where terminals can be safely built, lawmakers said. These facilities are used to import this super-chi led form of natural gas. "Although LNG tankers have not been subject to a catastrophic accident or attack, we need to ensure regulators are making decisions with a large enough margin of safety to account for the threats in a post-9/11 environment," said Rep. John Dingell, D-Mi h., chairman of the House Committee on Energy and Commerce. There is limited information about the hazards, in part, because in nearly 50 years of importing LNG, there has not been a major spill or fire, said Rep.

Joe Barton, R-Ennis. Previous studies have relied on computer modeling and extrapolating data from mall spills and fires, which provide varying results. For example, in the six unclassified studies the GAO reviewed, the distance at which the heat from a fire at an LNG facility could quickly cause burns ranged from one-third of a mile to 1 1/4 miles. The GAO said the the Energy Department needs to study the possibility of a chain-reaction fire on a tanker, known as cascading failure. Ships typically are built with multiple storage tanks to limit the danger. The GAO is asking for research on whether fire in one tank could spread to the other tanks and what damage that could cause.

For its study, the GAO assembled a panel of 19 experts and had them evaluate the reliability of previous research. The group agreed that the greatest public safety threat of an LNG spill is the heat impact of a fire and that explosions are unlikely to o cur in a spill. A small majority, 11 of the 19, agreed that a one-mile protection zone is "about right" or "should be smaller" to protect the public from the heat hazard of a fire. A mile-zone is used by federal regulators when assessing waterways and permitting termin ls. Four panelists thought it should be smaller. Suez LNG agrees with those who think a mile is too much, said Julie Vitek, a spokeswoman for the Houston-based company.

Suez operates the nation's only urban LNG terminal, near Boston, and is building another terminal in the Massachusetts Bay. Bill Cooper, executive director of the Center for Liquefied Natural Gas, said a previous study of the risks in 2004 provided sufficient information about LNG risks. Still, he said, no harm would come from more study. brad.hem@chron.com