The federal government will conduct a two-year study of how crude oil volatility affects the commodity’s behavior in train derailments, Energy Secretary Ernest Moniz told a Senate panel Tuesday.The Energy Department will coordinate the study with the Department of Transportation, Moniz told the Senate Energy and Natural Resources Committee.

After a series of fiery train derailments, the Transportation Department concluded early last year that light, sweet crude oil from North Dakota’s Bakken region is more volatile than other kinds.

But derailments involving ethanol and other types of crude oil have cast doubt on whether Bakken is likely to react more severely than other flammable liquids transported by rail.

The petroleum industry has been citing its own studies and a recent report from the Energy Department’s Sandia National Laboratory to support its position that there’s no difference. But it’s clear that more crude oil is moving by rail, and an increase in serious accidents has come with that increased volume.

Moniz said the Sandia report was “the most comprehensive literature survey in terms of properties of different oils” but showed the need for more research to determine their relevance in train derailments.

The joint Energy-Transportation study would look at other kinds of crude moving by rail, such as light crude from west Texas and heavy crude from western Canada.

Sen. Maria Cantwell, D-Wash., a member of the Senate Energy panel who requested the departments work together on a study, noted that there had been four derailments of oil trains in the U.S. and Canada since the beginning of the year.

“A number of high-profile incidents have underscored major safety concerns,” she said.

On April 1, North Dakota began setting vapor pressure limits for crude oil loaded in tank cars at no more than 13.7 pounds per square inch.

But the crude oil tested in many serious derailments had a lower vapor pressure than the new standard…..  [MORE]