How safe is natural gas in its liquid form?

"The energy content of a single standard LNG tanker (125,000 cubic metres) is equivalent to seven-tenths of a megaton of TNT, or about 55 Hiroshima bombs."

- Brittle Power Energy Strategy for National Security: U.S. Pentagon Study

Ninety-one years ago an explosion in Halifax Harbour of early 20th century munitions created horrific damage that was not seen again until August 1945, when an atomic bomb was dropped on Hiroshima, Japan. Before, the blast experts of the day could only calculate how such explosive material in a constricted space would react if ignited, but most agreed that the reality of such an explosion was preposterous. This very sentiment is felt today by the proponents of liquid natural gas carriers, huge tankers that will soon be sailing off the Nova Scotia coast.

Liquid natural gas (LNG) is mostly made up of methane gas that has been cooled to minus 160 C for storage and transportation purposes. In liquid form, the volume is about 1/600th of the gaseous state, making it economically viable for transport.

Maple LNG, an affiliate of Netherlands LNG terminal operator 4Gas, chose Goldboro, Nova Scotia, in Guysborough County, as the site for a regasification plant. This means that the LNG will be warmed and mixed with air, reverting it back to a state where it can be burned as fuel.

A large facility is to be built next to the Maritimes & Northeast pipeline, the conduit that sends natural gas to Canadian utilities and those in the northeastern U.S.

The Goldboro facility is to include three LNG storage tanks capable of holding 160,000 cubic metres of the freezing liquid. This amounts to nine billion cubic metres a year of natural gas flowing through the terminal and is expected to double within a few years.

Large LNG carriers, the size of three football fields and capable of packing 250,000 cubic metres of the refrigerated liquid, will feed the facility. This will undoubtedly provide a boost in the economy of both Guysborough County and the province at a time when jobs are really needed.

The plan does have its detractors. Opponents of the project equate the LNG carriers as "megabombs" and cite an explosion at an Algerian gas plant where natural gas is cooled into LNG as an example.

In January 2004, explosions and resulting fires there killed 27 people and sent another 80 to hospital. Sixty-four years ago LNG leaking into a Cleveland sewer system was ignited by accident and one square mile of the city was incinerated.

Right now in the U.S. there are more than 30 communities slated for LNG entry points.

Opponents have organized presentations that warn the population of these areas how even a slight spill of LNG mixing with air could start a fire so fierce that people a mile from the scene of the explosion could be burned.

They go on to say that "people who don't like us much" are provided with a smorgasbord of targets, any of which could cause a disaster of 9-11 proportions. And this is not to mention collisions and other maritime incidents that could rupture a carrier's hull and cause a huge volatile cloud that could erupt with a spark.

The gas companies refute this pessimism by saying that disasters couldn't happen at an importing facility because the liquid is transformed back to a gaseous state using warm water. There is no electricity or open flames around, the causes of the Algerian tragedy.

Based on results, LNG carriers have been plying the waves for almost half a century without a mishap.

However, there have been close calls, with one just 10 months ago. On Feb. 11, tugboats raced to help a LNG carrier that lost power in the high seas off Cape Cod, Mass. With coast guard abilities stretched to the max, will the next incident be the "Big Bang" of which the opponents are warning us?

weeklydartmouth@hfxnews.ca

Kim Kinrade is a Dartmouth writer with a penchant for penning novels and blogging. His Dartmouth-Cole Harbour Weekly News blog can be found at www.halifaxnewsnet.ca. (Click on blogs down the left side of the site.)