COLUMBIA RIVER - An industry move toward bigger liquefied natural gas tankers means slightly increased public safety risks along shipping routes, energy experts have concluded.
In response to growing demand for natural gas imports, LNG companies are building a new fleet of jumbo LNG tankers that can transport the supercooled fuel more efficiently. By the time the Bradwood Landing and Oregon LNG projects are built, if either is approved, the larger models will likely be an industry standard.
A recent study by the Sandia National Laboratory in New Mexico quantified for the first time the increased fire hazards associated with the new ships, some of which carry twice as much LNG as the ships currently in use.
The study also restates the importance of public safety protections, which have been a source of controversy in Clatsop County as local emergency response agencies argue with Bradwood Landing LNG developer NorthernStar Natural Gas Inc. over who will pay for additional firefighting resources.
The current fleet of carriers ranges from capacities of 125,000 cubic meters of LNG to 145,000 cubic meters; the biggest ship in the new fleet can transport 266,000 cubic meters of LNG.
Because the bigger ships carry more LNG in each tank, the lab reported, a tank breach would result in more natural gas spilling out at a faster rate. That means a resulting pool fire would be slightly larger, and it would burn longer.
A tank breach on any LNG carrier is an unlikely event. In fact, its never happened in the 40-year history of LNG transport.
But if it happens, the Sandia report concludes the most significant difference between the smaller ships and the bigger ones is a 7 or 8 percent increase in the thermal hazard distance around a pool fire. Based on the lab's assessment, the hazard zone would grow by less than 100 yards, from 1,300 meters, or .81 miles, to 1,400 meters, or .86 miles.
The worst risk to people within the thermal hazard zone is second-degree burns, which occur on bare skin after 30 seconds of exposure. The biggest public safety risks with the bigger tankers would still be within 500 meters, or a third of a mile, of a pool fire.
Russ Berg, inspection division assistant chief of for the U.S. Coast Guard Sector Portland, said the increase in fire hazards from the larger tanks is relatively minor, especially considering the leap in tanker size. But fire hazard isn't the only safety consideration should the larger tankers come up the Columbia River, he said.
"The zone size increases were relatively small with fairly significant growth in ship size," he said, "but there are other things that come into play as well, such as the ship's dimension, depth of water, length of pier, and the maneuvering characteristics of larger ships."
The Coast Guard's Waterway Suitability Report for the Bradwood Landing project, which outlined all the safety improvements that will be needed before LNG tankers can deliver to the Bradwood terminal, was based on the smaller LNG tanker sizes. The new tankers are longer, jumping from a maximum of 928 feet to 1,131 feet, about 40 feet wider and up to five feet deeper.
"The larger vessels would require a whole different Waterway Suitability Report - or at least an amended assessment," Berg said.
The Coast Guard released last year for the Bradwood project was based on navigation studies and moving simulations that might have to be redone if Bradwood decides to use the larger tankers, said Berg.
The largest ship that can deliver to the Bradwood facility under the rules outlined in the Coast Guard's report is one that carries 148,000 cubic meters of LNG. A new assessment could result in more safety precautions being added onto the existing requirements.
In its application to the Federal Energy Regulatory Commission, NorthernStar reports it is building the Bradwood facility for tankers between 100,000 and 200,000 cubic meters of LNG capacity.
Joe Desmond, vice president of external relations for NorthernStar, said his company doesn't know what size ships will actually be delivering to the terminal.
"It's premature to indicate what ships we'll be using until we finalize supply contract agreements," he said.
Oregon LNG, a bit behind Bradwood in the federal licensing process, is still working with the Coast Guard on its the waterway suitability assessment, which includes the largest tankers being built. That could give the company an advantage when securing supply contracts.
Peter Hansen, chief executive officer of Oregon LNG, visited the shipyards in Korea where the largest LNG carriers are being built and concluded his proposed terminal site on Warrenton's Skipanon Peninsula is well suited to the bigger ships.
"They are very large," he said. "They're much bigger than anything on the Columbia today. I cannot possibly see how anybody would ever dream of taking one of those and going past Astoria and up to Bradwood."
But the larger vessels are more economical and more fuel efficient, said Hansen.
"Whoever uses those can be more competitive and stick the difference in his pocket," he said.
The Sandia report outlines similar suggestions for managing and reducing the risks of an LNG fire from tankers large and small. They include better safety and security systems, more effective tanker escorts, better surveillance and searches and improved emergency response coordination with first responders and public safety officials.
Those recommendations raised red flags for Dan Serres of Columbia Riverkeeper, who worries about the lack of communication between NorthernStar and local emergency responders. Last month, Warrenton Fire Chief Ted Ames spoke out on his concerns that NorthernStar hasn't agreed to provide local agencies with the necessary resources to protect public safety. City of Astoria leaders, including Mayor Willis Van Dusen, have also complained about the company's commitment to providing public safety resources.
"One of the big conclusions they made in the Sandia report was the importance of coordination between local agencies and companies bringing in LNG and the Coast Guard," Serres said. "One of the things we found alarming is this is just not happening. ... The hazard zones they're talking about still encompass most of downtown Astoria. Without having a working relationship with Astoria and Warrenton, how are the risks going to be mitigated effectively?"
Knappa Fire Chief Paul Olheiser, who presides over the fire district closest to the Bradwood terminal site 20 miles east of Astoria, said he's confident the resources and communications systems will be in place if and when LNG tankers start coming up the river.
"That's part of the Coast Guard requirement, so I'm sure that will all be taken care of," he said.