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A SAFE PROJECT

Safety concerns have been paramount at every stage of the Rabaska LNG terminal project.

From the project design to the basic engineering planning stage, Rabaska has made use of the best technology available. The designers have also developed a general safety management plan for the terminal and drawn up a list of safety measures to be implemented.

In addition to providing project safeguards, Rabaska must also demonstrate to the authorities that possible accident scenarios have been analyzed and the facilities are designed such that they represent an acceptable risk for the population in accordance with internationally recognized standards.

To do this, the project managers had various studies conducted to help identify and simulate various accident scenarios and estimate and assess their consequences and probability of occurrence. In industrial settings, this step is called a technological risk analysis.

This risk analysis required by government authorities was conducted in 2005 and reviewed by numerous regulatory bodies, including Bureau d'audiences publiques sur l'environnement (BAPE), ministère du Développement durable, de l'Environnement et des Parcs (MDDEP), ministère de la Santé et des Services sociaux (MSSS), ministère de la Sécurité publique, Transports Canada (TC), and Natural Resources Canada (NRC). 

The in-depth knowledge of potential dangers this risk analysis provides helps?

  • Reduce risks at the source using the safest technology available and the most appropriate safety measures
  • Convey important information to the authorities so that they can judge the environmental acceptability of the project in terms of the proposed safety measures
  • Keep the public informed. Quebec and Canadian environmental assessment procedures provide an essential opportunity for public input. A thorough understanding by the local population of the risks associated with the project allows area residents to be more involved in emergency response planning
  • Design an emergency response program that more precisely addresses the identified technological risks

To conduct this analysis, Rabaska retained the services of DNV (Det Norske Veritas), an international firm with a world-renowned reputation. It reviewed all aspects of the project, including the terminal itself, the jetty and gas pipeline, the maritime risks, and the safety of LNG tankers.

Headquartered in Norway, DNV was founded over 145 years ago. It boasts a network of 300 offices in some 100 countries on all continents. The firm numbers over 9,000 employees, most of whom are professional engineers. DNV has adopted a motto that clearly expresses its main mission-"Safeguard life, property, and the environment."

DNV is the world leader in risk, safety, environmental, and accident impact assessment.

Using the guidelines developed by Ministère du Développement durable, de l'Environnement et des Parcs and the CEAA, DNV conducted an in-depth study involving detailed analysis of close to 300 different scenarios.

These analyses were conducted on the basis of industrial codes and standards in effect in Canada, the United States, and Europe (CAN/CSA-Z276-01, NFPA 59A, and EN1473). The maritime risk study followed the recommendations of the Society of International Gas Tanker and Terminal Operators (SIGTTO) and was conducted using the TERMPOL process under the authority of Transport Canada, which requires this type of risk analysis for LNG tankers from the time they enter the Gulf of St. Lawrence until they reach the terminal jetty.

LNG TERMINAL RISK ANALYSIS

The DNV experts developed accident scenarios for each type or set of terminal equipment. In each case, they conducted their analyses by bringing a number of variables into play, such as the size of a leak and the success or failure of isolating a leak by means of an emergency shutdown.

A total of 238 potential accident scenarios were studied. Using special software and databases universally recognized in the industry, they assessed both the probability of occurrence of each scenario and the possible consequences. In each instance, they looked at the specific characteristics and operating conditions of the terminal equipment.

Once all the scenarios had been studied, the experts cross-referenced the data for theoretical frequency and possible consequences to assess individual risk level. The term "individual risk" refers to the probability of death for an individual permanently located in the area under study.

Risk quantification makes it possible to plot "iso-contour lines" or iso-risk contours around the terminal facilities. These imaginary lines join all the points having the same risk level, which helps determine, based on the probability of occurrence, whether the population living within these lines faces a negligible, acceptable, or unacceptable risk, as the case may be.

According to the recommendations of the Major Industrial Accidents Council of Canada (MIACC) as risk acceptability criteria, the project is acceptable in terms of risk evaluation for major technology failures. There are no homes within the iso-contours with a calculated risk factor of 10-5 (one occurrence per 100,000 years) and only three homes within the iso-contours with a calculated risk factor of 10-5 to 10-6. As for other sensitive elements in the human environment such as motels, campgrounds, the Sainte-Famille school, and roads, the study shows that they will be exposed to risks of less than 10-7 (negligible risks occurring less than once per 10 million years) because of their distance from the facilities.


(Click map to zoom in)

These results are the outcome of multiple improvements throughout the facility design stage to integrate various risk reduction measures. In this respect, special attention was paid to the jetty, the failsafe tanks, the size of the retention basins, and offloading pipes, which will be underground and protected by a concrete caisson.

Many other safety measures have been included in the design of the LNG terminal:

  • Flanges, valves, and other parts that could be sources of leaks have been kept to a minimum.
  • The retention basins are located away from the facilities to prevent a chain of accidents from occurring.
  • Permanent facility monitoring (inspection rounds, surveillance cameras and other instruments) will ensure an immediate response in the event of an anomaly.
  • The disaster response plan calls for staff training to handle emergency situations and fight fires as well as installation of water pipes, distribution lines, mobile equipment, and fire extinguishers.
  • An emergency response plan describes the measures to take in the event of an accident.

GAS PIPELINE RISK ANALYSIS

The quantitative analysis of risks related to operating the gas pipeline that connects the LNG terminal to the provincial distribution network was conducted by DNV following the same steps as for the terminal, including the development of accident scenarios, an evaluation of their probability of occurrence, a risk assessment, and a description of safety measures adopted to ensure the integrity of the pipeline and public safety.

The risk analysis was conducted on both the gas pipeline and related facilities, including:

  • The pigging station (for regular inspection of the pipeline) and the block valve, both of which are located on terminal property
  • A second block valve located mid-way
  • The delivery gate in Saint-Nicolas

Using 44 accident scenarios, the risk analysis examined all the natural and technological dangers of both internal and external origin that could threaten the integrity of the gas pipeline.

As in the case of the terminal, event frequency and consequences were cross-referenced to determine level of risk. Risk quantification was conducted by plotting individual risk iso-contours on a map illustrating the path of the gas pipeline.

The illustration opposite indicates that the probability of death for individuals permanently located within 100 meters of the gas pipeline running through Lévis and Saint-Nicolas is one occurrence every 10 million years. The risk is therefore qualified as negligible.


(Click map to zoom in)


The DNV analysis also shows that the risk is one occurrence every 100,000 to one million years around the block valve and at connecting points upstream at the terminal and with TQM Pipeline facilities. Given that the maximum acceptable risk is one occurrence every 10,000 years, the risk is deemed acceptable for these three gas pipeline facilities.

The gas pipeline impact study led to adoption of a series of safety measures with regard to the design, construction, and operation of the pipeline. These various measures address the most probable accident causes, including accidental breakage of the pipeline during excavation work performed by a third party.

Active and passive measures include the following:

  • Strict compliance with design and construction codes and standards in effect
  • Emergency shutdown system consisting of three block valves over the length of the gas pipeline
  • A 23 meter right-of-way plus an obligation to declare all work performed within 30 meters of this zone
  • Burial depth that varies depending on the area being crossed
  • Thickness and grade of steel selected based on population density
  • Quality control of welding using X-rays
  • Protective epoxy/urethane coating of pipeline together with cathodic protection
  • Hydrostatic tests to verify the leak tightness of the pipeline before it is put into service
  • Protective concrete slabs at road crossings, ditches, and waterways
  • Alert tape indicating buried pipeline
  • Strategically located signs along the gas pipeline path
  • Regular pipeline inspections with internal inspection instruments
  • Regular aerial surveillance
  • Control center for continuous surveillance of all network operations

An emergency response plan will set out the procedures to follow in case of an accident and how to communicate and coordinate with the authorities.

MARITIME RISK ANALYSIS RESULTS

For the purposes of the study, the tanker course was divided into five sections, running from the entrance to the Gulf of St.&q160;Lawrence to Les Escoumins, where pilots board ship; Les Escoumins to the North Traverse; the North Traverse to Saint-Laurent on Île d'Orléans; Saint-Laurent to the Rabaska jetty; and finally, the jetty to the wharf berthing bays. The study differentiates between winter-when ice is present-and the rest of the year.

After identifying the various possible scenarios, the dangers considered as presenting the highest frequency of occurrence or having the most serious potential consequences were retained for the quantitative risk analysis.

To perform this analysis, the DNV experts used data from Lloyds Register Fairplay, which gathers information on all ships worldwide, as well as data compiled by the Canadian Transportation Accident Investigation and Safety Board on incidents that have occurred in Canadian waters and on the St. Lawrence River.

The scenarios studied were, among others, ship sinking, ship grounding, collision on the river or at a wharf, fires aboard or near ships, and failure of an offloading arm at the jetty.

Like for the terminal and gas pipeline risk studies, each accident scenario was assessed by calculating the frequency of occurrence and its potential consequences. Each time, the scenarios were evaluated using special, universally recognized software.

To better assess risk level, each scenario was placed in a matrix based on its probability of occurrence and the seriousness of its potential consequences. The figure below is a graphic illustration of the matrix the experts used.

The matrix defines three risk levels:

  • Negligible risk
  • Acceptable risk if ALARP (As Low As Reasonably Practicable)
  • Unacceptable risk


The maritime risk assessment concluded that ship grounding is the accident most likely to occur. Industry reports show that in the past 45 years, there have been two major LNG tanker groundings (El Paso Paul Kaiser, LNG Taurus), but they did not lead to any spills. There have been no spills or major collisions involving LNG tankers in over 46,000 voyages and 200 million kilometers traveled during this period.

The risk level for each scenario is acceptable.

The DNV experts also considered LNG tanker breach scenarios that would lead to an LNG leak. Once again, DNV stressed that, no matter what size the breach, it would have to be deep enough to penetrate several barriers in order for a leak to occur, including the outer hull, ballast tank, double hull, layers of insulation, and the walls of the tanks.

The risk of an accident leading to a spill followed by a fire causing death was evaluated at one occurrence every 7 million years for a collision on the river, one occurrence every 9 million years for a collision at the jetty, and one occurrence every 77 million years for a ship grounding between Saint-Laurent on Île-d'Orléans and the jetty.

The safety measures governing LNG tankers and their navigation on the St. Lawrence River are numerous and exceedingly stringent. With regard to the main measures, it must be stressed that:

  • These ships are specifically designed to transport LNG; the properties of LNG guarantee excellent, long term performance of the cargo tanks
  • LNG tankers have double hulls, which not only minimize the possibility of spills, but also strengthen the structure of the ships, which means added protection in case of grounding or collision
  • The cryogenic steel tanks aboard the tankers are equipped with a number of safety systems to prevent spills, surges, vacuums, and accidental leaks
  • The safety facilities aboard the ships include firefighting equipment that use powder and seawater to deal with any accidental leak of LNG cargo
  • LNG tankers undergo a regular program of technical inspections, including annual inspections, periodic inspections every two years, and special inspections every four years during which all equipment and structures are carefully examined
  • The ships that serve the Rabaska terminal in winter will be specially built for navigating in ice and cold temperatures

LNG tankers that navigate the St. Lawrence River will have to comply with very strict safety rules. In winter, ice pilots will be required aboard to assist the captain. Two pilots will board at Les Escoumins to help take the ship to Saint-Laurent, Île d'Orléans, where a river pilot will board and help the captain berth the ship at the Rabaska terminal jetty. This pilot will remain aboard throughout the call.

Expert recommendations were issued as part of the TERMPOL process and will apply to all LNG tankers on the St. Lawrence River. An escort tug, for example, will assist the LNG tanker through the North Traverse, where passage is one way. The escort tug will remain on standby throughout the call and tugs will assist the tanker during docking and undocking maneuvers.

EXCLUSION ZONES

As its name indicates, an exclusion zone is a buffer zone that establishes a minimum distance between an industrial facility and areas that are inhabited or frequented by the public, such as residences, hospitals, schools, and other gathering areas. There are various standards to determine these exclusion zones.

Rabaska made the decision to reference not only Canadian standards (CSA-Z276), but American standard NFPA 59A and European standard EN 1473 as well. The European standard sets exclusion zone limits based on technological risk analysis. The buffer zone Rabaska has proposed around the LNG terminal goes beyond the strict application of these already stringent standards.

The Canadian and American standards require the installation of retention basins at various strategic locations at the terminal; for example, near the tanker offloading arm, near LNG tanks, and in the immediate vicinity of the "operations zone" (area where the LNG is regasified).


(Click map to zoom in)

The European approach bases the exclusion zones on the technological risk analysis. As mentioned previously, the firm DNV, based on internationally recognized criteria, established the maximum acceptable risk for the public as one occurrence per 10,000 years. Based on probability, this risk level means that no more than one accident will occur over the next 10 centuries resulting in the death of anyone permanently located within the identified perimeter.

In the diagram, an orange line illustrates the perimeter of each terminal exclusion zone, as determined by the DNV experts based on these criteria.  This treshold complies with the risk acceptability criteria set out by MIACC

The project designers have complied with all three standards - Canadian, American, and European - for these exclusion zones. The exclusion zones that will be submitted to regulatory authorities for approval greatly exceed the limits set by national and international standards.

Rabaska has decreed:

  • A 500-meter-radius exclusion zone around the offloading arm at the wharf
  • A 100-meter-radius exclusion zone around the retention basin at the riverside facilities
  • A 400-meter-radius exclusion zone around the LNG tanks and operation facilities

It should be noted that the exclusion zone perimeter for onshore facilities is entirely within the area earmarked for the proposed LNG terminal and for which Rabaska holds purchase options.

EMERGENCY RESPONSE PLANNING

Despite proper management of the overall risks, there will always be a residual risk, and an accident requiring immediate and adequate action could still occur. To this end, the emergency response plan outlines measures to be put in place in emergency situations such as fires, leaks, natural disasters, etc.

A preliminary emergency response plan submitted to the City of Lévis outlines Rabaska's emergency management team and the internal emergency response teams, along with the roles and responsibilities of each. External resources (police, firefighters, coast guard, ambulances, etc.) are also identified with their responsibilities and respective roles in the event of an emergency. A number of emergency scenarios are outlined, along with the procedures and equipment required for alert, danger mitigation, rescue, evacuation, and normalization phases. Lastly, the preliminary plan lists the exercises to be carried out on a regular basis to assess the emergency teams' response capacities and ability to inform the public.

Rabaska will sit on Lévis' Joint Municipality/Industry Committee (CMMI), which seeks to pool resources, knowledge, professional expertise, and equipment as part of the technology risk management process. Representatives from ministries and organizations such as Environment Canada, Ministère du Développement durable, de l'Environnement et des Parcs, and health and social services agencies sit on the committee along with Ministère de la Sécurité publique. As per the recommendations issued by the TERMPOL Committee and BAPE, representatives from the Île d'Orléans RCM, the Bellechasse RCM, Transport Canada Marine Safety, the Quebec City Port Authority, and the Canadian Coast Guard will be invited to participate.

The final emergency response plan will be completed at least six months before the terminal begins operating.

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