Corrosion likely culprit in roof collapse

The partial collapse of a shopping mall roof last weekend was likely the result of a combination of factors the most likely cause was corrosion of the reinforced concrete, said Mark Green, a Queen’s University engineering professor.

On Saturday afternoon a section of the roof at the Algo Centre Mall (Kingston, Ontario) collapsed.

A section of roof about 12 metres by 24 metres fell.

The roof supported a parking lot and at least two vehicles fell into the mall when the roof came down. Because the roof served as a parking lot, corrosion could have been an even greater issue because of the salt used to clear the surface of ice during winter.

Green said it was also possible that the design of the building may have included an aspect that made it more susceptible to collapse.

Twenty-two people were injured in the collapse.

Police also said at least 30 were missing.

In 2010, mall owners Eastwood Malls Inc. spent about $1 million to repair leaks in the roof that had been ongoing for several years.

But hints of a catastrophic collapse may have been easily overlooked, Green said.

“The warning signs may not have been that obvious,” he said.

In April 2010, a section of the parking garage at Confederation Place hotel in Kingston collapsed, damaging about 20 vehicles and closing the hotel for several days for repairs.

In 2006 a bridge in Laval collapsed, killing five people. That bridge had been inspected shortly before it fell, Green said

That bridge collapse prompted inspections of other bridges in Quebec and Green said he expects buildings similar in age and design to the Algo Centre to undergo additional inspections in the coming weeks.

On Monday a small piece of concrete fell off the Gardiner Expressway hitting a car below.

SOURCE: http://www.thewhig.com/2012/06/25/corrosion-likely-culprit-in-roof-collapse-expert

DOE to delay new cost, schedule for vit plant over corrosion concerns

The Department of Energy will delay coming up with a new cost and schedule for Hanford’s huge vitrification plant after a technical panel agreed with an employee that erosion and corrosion within the plant must be addressed.

David Huizenga, DOE’s senior adviser for environmental management, made the announcement today in a national media call after congressional leaders were briefed this morning.

Resolving technical issues, including how to keep radioactive waste well mixed and to prevent erosion and corrosion within the plant, is expected to take more than a year and cost tens of millions of dollars, Huizenga said.

The testing is intended to give additional confidence that the Waste Treatment Plant can operate for the full 40 years planned to treat up to 56 million gallons of radioactive waste for disposal, Huizenga said.

The waste, held in underground tanks, is left from the past production of plutonium for the nation’s nuclear weapons program.

“We’re trying to address technical issues head on and realistically,” Huizenga said.

By acknowledging issues now, the plant will not end up with unanticipated costs and maintenance issues in the future, he said.

Now the plant is legally required to start operating in 2019 and is projected to cost $12.2 billion, but DOE will not be able to finish it by then and at that price.

DOE had instructed its contractor Bechtel National in February to propose a new cost and schedule for the vitrification plant, which was due in August.

But with technical questions to be addressed for parts of the plant that will handle large quantities of high level radioactive waste, Bechtel will proceed only with a cost and schedule revision for the plant’s Low Level Waste Facility, the Analytical Laboratory and about 20 support facilities.

When testing is finished, it then can address additional cost and schedule information for the vit plant’s High Level Waste Facility and Pretreatment Facility.

Those two buildings have areas called “black cells,” that will be too radioactively hot for workers to safely enter after the plant begins operating for maintenance or to make repairs.

Construction at those facilities already has been ramped down and no further layoffs are anticipated.

Don Alexander, a DOE scientist, raised questions regarding erosion and corrosion in piping and tanks in black cells within the plant in September in a Difference of Professional Opinion report, disagreeing with scientific opinion accepted by DOE.

It was the third set of issues he’d raised in an ongoing Difference of Professional Opinion.

DOE addressed his concerns with a panel of technical experts that concluded his concerns are legitimate, and now DOE is planning testing that will be done in conjunction with already planned mixing testing to resolve them, Huizenga said.

“I think this demonstrates if people raise issues, we are willing to make tough decisions to address them,” Huizenga said.

In hours, caustic vapors wreaked quiet ruin on biggest US refinery

In the end, all it took was a small chemical spill — perhaps less than a barrelful — to bring down the newest, mightiest oil refinery in the United States.

Three weeks ago, while workers repaired a minor leak at the Port Arthur, Texas plant owned by Motiva Enterprises, a few gallons a day of so-called “caustic” was inadvertently seeping into the newly built crude distillation unit (CDU), the 30-story-high network of interconnected cylinders and latticed pipelines at the heart of the refining process.

While harmless when mixed with crude, the undiluted caustic vaporized into an invisible but devastating agent of corrosion as the chamber heated up to 700 degrees Fahrenheit ( 370 Celsius); the chemical gas raced through key units, fouled huge heaters and corroded thousands of feet of stainless steel pipe.

Now, just weeks after they commissioned the biggest U.S. refinery project in a decade, two of the world’s biggest oil titans — Royal Dutch Shell and Saudi Aramco , which own Motiva — are rushing to repair the potentially billion-dollar glitch that has added an embarrassing and costly coda to a landmark $10 billion expansion.

After a five-year effort to double the plant’s capacity, making it the largest in the country, they must now reassemble many of the same people and parts for a blitzkrieg fix that may exceed the original $300 million cost of the unit: corrosion experts are flying in from across the world; hundreds of workers are being hired; bespoke 30-inch (75-cm) stainless steel pipelines and 30-story cranes may need to be obtained quickly, according to sources involved in the repairs.

Sources familiar with the effort provided Reuters with the most detailed account yet of what officials believe went wrong at the 325,000-barrels-per-day (bpd) unit known as vacuum pipestill-5 (VPS-5), showing how a series of seemingly minor glitches crippled the vast plant.

TOO HOT TO HANDLE

Motiva has said little about the incident. Late on Wednesday, 11 days after it occurred, the company confirmed for the first time that the unit might remain shut for “several months”. Sources say officials are telling workers that the unit could be idle for as long as a year.

On Friday, in response to Reuters questions, Motiva spokeswoman Kayla Macke confirmed the contamination: “The preliminary inspection indicates that parts of the new unit have been contaminated with elevated levels of caustic.”

The extent of the damage is still not known as portions of the crude unit are too hot to enter, according to the sources. Some areas may not be accessible for weeks.

Motiva has not reached a final conclusion as to the cause of the damage, but has developed a working theory on what experts said appeared to be a rare instance of “accelerated chemical corrosion”. The unit’s intense heat was critical: the rate of corrosion can double with every 10 degrees Celsius.

Even as it pitted the inside of the atmospheric section, a giant still that performs the initial and most basic stage of converting crude oil into fuel, the damage went undetected. Only when two fires broke out and a heater ruptured — once crude resumed flowing — did operators suspect something was amiss.

“They had the first fire and then they had the second one 20 feet away. They knew they had a problem,” one of the sources said.

Why caustic continued flowing into the unit while it was idled to repair an unrelated leak is unclear, and is a key part of the investigation to establish cause. It is thought a valve failed to shut completely, but why that happened is unknown.

CAUSTIC INVASION

While Motiva’s VPS-5 was idling, authorities believe a few gallons each day of caustic leaked into the unit. The caustics are a base meant to negate the acid in cheaper heavy, sour crude that the new CDU was made to consume. They prevent residue from blocking pipes and reducing crude intake.

Normally, the amount leaked in the CDU would have been harmless, diluted by the crude. But only a small amount of hydrocarbon was circulating through the still while it was out of production, the normal method to maintain so-called “warm circulation” during a brief shutdown.

By the following weekend, unaware of the caustic incursion, Motiva began reheating the unit to resume operations; as the temperature reached 300 to 400 Fahrenheit, the caustic vaporized.

Ground zero was the atmospheric section, one of the simplest but most important machines in a modern plant. Although vast in scale, today’s units are in many ways similar to the simple stills used to convert crude into kerosene for lamps at the start of the U.S. oil industry in the 1850s.

The core of any refinery, the main still boils crude at intense temperatures to split the hydrocarbon molecules into the initial components of fuels such as gasoline and diesel; the bulk of the output is an intermediate feedstock that requires further refining in a host of specialized secondary units.

Unlike a refinery blast, the misfortune unfolding at Motiva was relatively slow to materialize. The fires that erupted from small pipeline cracks that Saturday were small enough to be quickly extinguished by the workers on hand at the crude unit.

The extent of the damage was understood within two days.

“We have the worst-case scenario,” one of the sources said. “Extensive damage throughout the crude unit. All of it.”

Three engineering experts agreed that what one called “accelerated chemical corrosion” was rare, but not unheard of.

“The temperature issue could be a factor as well,” said Kevin Garrity, president of NACE International, a global organization for engineers studying corrosion, and a 38-year veteran of the industry. He compared the effect to pouring sugar into hot tea, which dissolves the crystals much more quickly than in a cup of cold tea.

Normally, corrosion problems can be prevented.

“From a general sense you would not expect this kind of deterioration and problems in such a short period of time. You might not even expect it in 30 years if you have the right combination of technology and inspection practices,” he said.

REPAIRS

Motiva has yet to examine the fractionation towers — tall, thin, metal columns — as well as the main part of the atmospheric section, because they are still cooling from their operating temperatures, said sources recruited for the repair work.

The vacuum section of the VPS-5 — which takes the heaviest “residue” created in the atmospheric section and refines it in a vacuum, increasing the yield of feedstocks for other units — was not damaged, they said.

Operators have continued to run many of the unharmed secondary units, although without the crude tanks they must buy intermediate feedstock from other refiners or shut peripheral units, as Motiva did last week.

But stainless steel piping, some sections as large as 30 inches in diameter, was damaged. Such equipment, part of more than 700 miles of pipe used on the expansion project, is often built to order, and may be difficult and costly to replace.

“If someone has 30-inch stainless steel pipe for sale, I would guess they’re going to charge a premium price,” one of the sources said.

Instrumentation on the unit is also known to be damaged, according to the sources.

Up to 50 heat exchangers will need to be cleaned throughout portions of the new plant, according to IIR Energy, an industrial intelligence firm that gathers data on operations and project activity on thousands of assets globally.

Work on exchangers 300 feet (90 meters) above the ground will require large cranes, though likely not the giants needed for the original construction. The heat exchangers, which look like 30-foot-long cylinders collected in a metal frame, house lengths of tubing where feedstocks are warmed and refined products are cooled as they go to and from a refining unit.

IIR also told Reuters that all trays in the distillation column and components within the furnace would need to be replaced. It said no restart timeframe had been determined.

Soon the question of who is to blame will arise. The cost to complete repairs may be as much as replacing the whole unit, which was originally estimated to cost some $300 million when the project was launched in April 2005, according to IIR.

Without knowing exactly why the caustic leaked, it’s not possible to say who, if anyone, is at fault. The two main contractors for the project — Bechtel and Jacobs Engineering — declined to comment.

Meanwhile, the investigation continues, and oil traders await any word on when the plant will resume operations. Motiva will likely be “extra-cautious” in restarting, Auers of Turner, Mason and Co said.

“They’re really focused on the repairs,” one of the sources close to refinery operations said. “They don’t need to know the cause now. They’ve got 12 months to figure that out and fix it.”

SOURCE: http://in.reuters.com/article/2012/06/25/usa-refinery-motiva-idINL2E8HO4GH20120625

Corrosion Committee to Explore Effects of Crude to be Transported by Keystone XL

NACE International Logo
Committee will analyze whether diluted bitumen has an increased potential for release compared to other crude oils.

NACE International – The Corrosion Society along with three of its ‘Fellow’ membership will participate on a newly appointed National Academy of Sciences (NAS) committee formed to analyze whether diluted bitumen (dilbit) transported by transmission pipeline has an increased potential for release compared with pipeline transmission of other crude oils. The NACE Fellows are Dr. Brenda J. Little of the Naval Research Laboratory, Dr. Srdjan Nesic of Ohio University and Dr. Joe H. Payer of the University of Akron.

A chief concern about the transport of Canadian crude through the proposed Keystone XL pipeline is a claim that dilbit poses more release risks than other types of crude. In particular, the committee will examine whether there is evidence that dilbit has corrosive or erosive characteristics that elevate its potential for release from transmission pipelines when compared with other crude oils. Should the committee conclude there is no evidence of an increased potential for release, it will report this finding to the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) by spring 2013. Alternatively, if the committee finds evidence indicating an increased potential, it will examine the adequacy of PHMSA’s pipeline safety regulations in mitigating any increased risk and report back to PHMSA by the fall of 2013.

“With all of the controversy surrounding Keystone XL, it is very important that a well-qualified team analyzes the risks, if any, of diluted bitumen,” said NACE Executive Director Bob Chalker. “NAS has put together the right group for the job. NACE supports this effort and I will be interested, along with many others, in seeing the final results.”

SOURCE: http://www.virtual-strategy.com/2012/06/21/committee-explore-effects-crude-be-transported-keystone-xl-includes-three-nace-fellows

Texas refinery unit shut down for ‘several months’ as it investigates major corrosion problem

Motiva Enterprises LLC has announced it is preparing to keep its new crude oil unit shut for “several months” as it investigates major corrosion problems that have crippled the country’s biggest refinery weeks after a massive expansion.

In the first public acknowledgment of a potentially long-term outage at the Port Arthur, Texas, plant, Motiva co-owner Royal Dutch Shell Plc confirmed the 325,000-barrel-per- day (bpd) unit was shut due to “corrosion problems,” as posted on integritythatworks.com earlier this week.

“The outage of the new crude unit may continue for several months, while the causes of the issue are established and rectified,” Shell said in a statement late Wednesday.

Sources said earlier this week the outage, initially estimated at two to five months, could now extend to a year.

Shell, which runs the Motiva joint venture with state oil firm Saudi Aramco, said all secondary units built as part of the five-year, $10 billion project were fully operational, although some were running at reduced throughput.

Separately, sources familiar with operations said one of the new units — a catalytic feed hydrotreater that removes sulfur from feedstock going to the refinery’s gasoline-producing fluidic catalytic cracking unit — was being shut down this week because of a lack of feedstock from the idled crude unit.

The sources also said Motiva was shutting an older catalytic reformer, which creates gasoline additives.

Motiva officials were not immediately available to comment on details of the secondary unit operations.

In the statement, Shell said the refinery’s original 275,000 bpd complex was operating “as per plan.”

Motiva’s Port Arthur refinery is not shutting the refinery’s FCC, but will emphasize production of diesel, which is yielding higher returns for U.S. refiners as an export, the sources said.

The new crude distillation unit, which began production in April and was shut following a June 9 fire, may be idle for up to a year to repair extensive corrosion found in the unit.

SOURCE: http://in.reuters.com/article/2012/06/21/refinery-operations-motiva-portarthur-idINL1E8HL2TI20120621

Extensive Corrosion Found – Port Arthur Refinery

Extensive corrosion, that may require up to five months to repair, has been found inside a new 325,000 barrel per day (bpd) crude distillation unit at a 600,000 bpd Port Arthur, Texas, refinery, according to sources familiar with refinery operations.

The root cause of the corrosion, found in vessels and piping on the crude distillation unit (CDU), has not been determined, the sources said.

Damage from a fire on the CDU during an attempted June 9 restart was seen as negligible, the sources said.

The refinery owner won’t know the full scale of repair work needed until it determines the cause of the corrosion, the sources said.

A representative was not immediately available to discuss refinery operations. On Friday, the owner said there was no timeline for bringing the crude unit back into production.

The unit began refining crude oil in April and was officially commissioned at a May 31 ceremony

This particular refinery’s Port Arthur CDU was built to run heavy, sour crude oil grades that have a high risk of corroding refinery units due to high sulfur content.

“There’s extensive corrosion in the crude unit itself,” one of the sources said. “All of it. Piping, vessels, all of it. It could take up to five months to fix. It will be several months.”

The CDU, which does the initial refining of crude oil coming into the refinery and provides the feedstock for all other refining units, is the centerpiece of a $10-billion, 5-year project to expand the refinery to be the nation’s largest.

At the time, the CDU was shut down it was three weeks away from reaching full production, a refinery owner executive had said.

24-Inch Water Pipe Burst Closes Dallas Street

A water main break in Dallas released enough water to stop traffic and close one street for at least a day.

The 24-inch water pipeline burst on Beckley Avenue, under the Commerce Street Bridge.

“The possibilities of the failure could be corrosion, electrolysis that occurs there, it could be ground shift,” explained Randy Payton, with Dallas Water Utilities.

According to Payton, each year Dallas spends about $100 million on pipe replacement.

“Dallas has an aggressive approach in replacing its pipelines annually,” he said.

It’s expected to take a full day, up to 20 hours, to repair or replace the pipe.

There are some 5,000 miles of pipeline running through the city of Dallas.

Payton said it’s unusual for larger pipes to break and that the 24-inch pipe on Beckley is, “…a reliable pipe. Generally, like I said, it only fails once or twice a year — throughout the system.”

The large size of the burst pipe will require more manpower to repair/replace it.

SOURCE: http://dfw.cbslocal.com/2012/06/06/24-inch-water-pipe-burst-closes-dallas-street/

Caissons a solid sign of progress on new Forth bridge

The new Forth crossing will be fitted with dehumidification equipment to cut the risk of the corrosion which has blighted the existing bridge.

At a briefing on the progress of the £1.4 billion project being built by the Forth Crossing Bridge Constructors, Transport Scotland project director David Climie said work was on schedule.

”We are still exactly where we want to be, on time and budget,” he said.

Only three months ago there were 384 people working from the Rosyth base but now that number has more than doubled, with 800 staff working on various parts of the site. At its peak 1,200 staff will be employed.

One of the most important milestones of the entire project has just been reached — the arrival of the first two caissons which will form the foundations of the north and south towers.

In a ”foundation” year for the project, Mr Climie said: ”We are extremely happy with the way things are progressing.”

Carlo Germani, the FCBC project director, said: ”We are into the real construction work now. We have done a lot of the preparation and what you see is work on the bridge itself starting with the arrival of the caissons.”

These are the huge cylinders ranging in height from 21.1m to 30m — around the same as an eight-storey building — with diameters of around 32m.

The largest weighs roughly 1,200 tonnes, making it one of the largest steel caissons ever sunk down to the seabed.

They will be used as moulds for the foundations, comprising underwater and reinforced structural concrete. More caissons are due to arrive in a few days.

FCBC’s Carson Carney explained the process of building the central tower, which will be constructed on site in 4m high increments, would start this year.

The deck sections are being built in China and Spain and will be shipped over and stored at Rosyth.

With corrosion affecting the existing bridge, Mr Carney explained the crossing’s cables are made up of strands containing galvanised steel wires, with a wax coating and covered in plastic.

”There is no way you can get water into the actual strands themselves. This is a state-of-the-art type system.”

Each strand is capable of being individually replaced if necessary without causing widespread disruption to traffic.

There is a dehumidification system at deck level and on the anchorage points.

SOURCE: http://www.thecourier.co.uk/News/National/article/23358/caissons-a-solid-sign-of-progress-on-new-forth-bridge.html

Pipeline Integrity Management Meeting Set

The Pipeline and Hazardous Materials Safety Administration and the National Association of Pipeline Safety Representatives are jointly sponsoring the public meeting June 27 in Fort Worth, Texas.

A meeting to gauge gas distribution pipeline operators’ readiness for federal and state inspections of their integrity management programs has been set for June 27 in Fort Worth, Texas, by the Pipeline and Hazardous Materials Safety Administration and the National Association of Pipeline Safety Representatives. It is open to the public and will be webcast, according to PHMSA’s announcement.

PHMSA and NAPSR representatives will discuss observations from initial inspections of operators’ implemented integrity management programs.

PHMSA published a final rule in December 2009 setting requirements for ensuring the continued integrity of gas distribution pipelines; it gave operators until Aug. 2, 2011, to implement them. PHMSA and states have conducted some inspections and have many more inspections coming up, the notice says.

The meeting will be held from 8 a.m. to 5 p.m. CDT at the OMNI Hotel, 1300 Houston St., Fort Worth, TX 76102-6556; visit http://primis.phmsa.dot.gov/meetings/Home.mtg to register and for additional information.

SOURCE: http://ohsonline.com/articles/2012/06/11/pipeline-integrity-management-meeting-set.aspx?admgarea=news

Searching for answers after Red Deer’s pipeline spill

For a pipeline that is nearly half a century old, a river crossing can pose all manner of hazards. Bacteria and corrosion can attack from inside. Floodwater, scouring away the river bottom and heaving against the exposed pipe, can damage the outside. Pipes installed using old methods can be particularly vulnerable.

Sometimes, the result is catastrophe.

Last week, the Rangeland pipeline, built in 1966 and run by Plains Midstream Canada, ruptured beneath the flooding Red Deer River. It leaked 160,000 to 480,000 litres of oil, coating the banks with crude when the waters receded and leaving a large stain on Gleniffer Lake, a reservoir that supplies drinking water to Red Deer, Alberta’s third-largest city.

It may take many months to conclude what went wrong with the Rangeland pipe, and Plains has declined to comment on the cause, saying it is focusing on a cleanup effort that continued on Monday with more than 100 workers.

Today, companies building across major rivers typically use horizontal drills to burrow deep beneath the water – anywhere from eight to 30 metres – into stable rock. Those crossings are considered some of the safest parts of a pipeline. “Virtually all creeks and rivers are drilled under,” said Kevin O’Brien, president of IMV Projects Inc., a Calgary engineering firm that works on pipelines. Environmental regulations won’t even allow other methods “except in rare circumstances where not technically feasible.”

Techniques decades ago involved digging into the riverbed. Dredges, diggers and backhoes were all used, sometimes with the help of temporary dams, to open a trench for the pipe. Depending on the method, the pipe might be pulled into place, or coated in concrete, floated above the trench with barrels and then dropped down and covered with sediment.

The risks were numerous: Trenching in a flowing river meant it was difficult to create a clean bed for the pipe. Dropping it into place could introduce stress and strain, creating weak spots. And the cover was not always certain: The pipe might be buried two to three metres from the bottom of the river, but rivers are dynamic systems with the power to sweep away sediment, exposing the pipe. When they do, the force of the water can crack a pipe, or throw rocks that puncture its sides. In other cases, the trench was too shallow, compounding the problem.

“Some of those older ones, they weren’t too deep. They might have a couple, three feet of cover,” said Barry Singleton, senior vice-president of Singleton Associated Engineering Ltd., which designs pipelines. Even then, construction crews knew that what they were doing might not last.

“Lots of times they would install two crossings – they would install a spare,” Mr. Singleton said. “There were concerns back in the day.”

But external issues are only part of the potential problems. River crossings are low parts of the pipe, where water can collect, posing a risk of corrosion. Older pipes also may not be used as consistently – the Plains Rangeland system, for example, operated intermittently – which allows sediment to collect in low spots.

“Things start falling out [of the oil] and start stagnating,” said Izak Roux, technical manager for RAE Engineering and Inspection Ltd., which specializes in pipelines. A kind of mud layer can build up, and “then you can start having what we call a bacterial attack. This bacteria can eat right through the steel, and then you get a leak as well.”

Worse, many older pipes use sharp bends to get into and out of the riverbed. Those bends can make it impossible to push through cleaning tools called pigs. Neither Plains nor Alberta’s Energy Resources Conservation Board responded to questions on whether the Rangeland pipe is accessible to pigs.

But those pipes “constructed in the ‘50s and ‘60s, not all of them are piggable,” Mr. Roux said. “That’s basically the problem we have on the older lines.”

SOURCE: http://www.theglobeandmail.com/news/national/searching-for-answers-after-red-deers-pipeline-spill/article4249733/?cmpid=rss1