HOUSTON, Oct. 16 -- The US Coast Guard on Tuesday lifted a 20-day ban on imports of liquefied natural gas through Boston harbor, which some feared might become a target for terrorist attack.
The ban imposed Sept. 26 by Coast Guard Capt. Brian Salerno, captain of the Boston port and commanding officer of the USCG Marine Safety Office there, was lifted following a report last week by marine insurer Lloyd's Register of Shipping that there is little danger to that city from a LNG explosion or fire.
That report acknowledged that an explosive projectile or bomb could rip open the refrigerated tanks that keep the natural gas liquefied at -260° F. That could release a nontoxic cloud of gas in enough volume to spread 3.7 miles. But since natural gas is lighter than air at ambient temperatures, it would tend to move up, rather than out, and would be more likely to burn than explode before dissipating into the air, said the report.
That report was commissioned by Distrigas of Massachusetts LLC, which operates the LNG import terminal in Everett, Mass., outside of Boston.
The Lloyd's Register conclusions also were verified independently by Roger Roue, technical adviser at the Society of International Gas Tankers & Terminal Operators, a nonprofit organization that promotes high operating standards and best practices for gas tankers and terminals around the globe.
Responding to an earlier inquiry by OGJ Online, Roue said there have been "no serious fires and no explosions" involving LNG tankers or terminals "during the 40 years that LNG has been transported around the globe by sea.
"Understandable as they are in the aftermath of the tragic events of Sept. 11, the fears being expressed in the Boston area are, in my opinion, entirely without foundation," he said.
Nevertheless, Distrigas officials agreed to "certain permanent changes" in security for the Everett terminal and the operation of LNG vessels in Boston's harbor that are not being imposed at the other two operative US LNG terminals (OGJ Online, Oct. 3, 2001).
The end of the ban on LNG imports through Boston harbor was timely, with local temperatures in the 40-60° F range Tuesday.
The Distrigas LNG imports supply 15%-20% of the total annual demand for natural gas for all of New England. The Everett terminal and its area network of LNG storage facilities supply 35% of New England's peak demand during winter when interstate transmission lines to that market are filled at to capacity.
A lengthy disruption of LNG imports to that facility could have created a shortfall in winter gas supplies and triggered a price escalation for customers, officials said.
Distrigas' Everett LNG terminal is the oldest and longest operating US unit of that type. Since 1971, it has taken delivery of 438 LNG cargoes, accounting for more than half of all the LNG imported into the US.
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