NATIONAL RESEARCH COUNCIL CANADA
ARCHIVED - What is a Quantitative Risk
Assessment (QRA)?
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What is a Quantitative Risk Assessment (QRA)?
A QRA evaluates the consequences and risks to individuals working or residing near a project
area. As part of the initial Synthetic Fuels Facility project conceptualization, NRC requested a QRA
to examine the potential risks of temporarily storing and testing with hydrogen and carbon monoxide
on the Montreal Rd. Campus.
Quantitative Risk Assessment Results:
Less than 0.01 in 1,000,000 risk of the SFF project
causing death or lethal injury to the public.
100 times safer than the Canadian stardards
for acceptable risk levels.
The QRA process for the SFF project included:
• Modelling the consequences of potential release scenarios.
• Evaluating the frequency with which accidental releases may occur and
the frequencies of wind speed and wind direction.
• Calculating individual risks based on combining the frequency data
and consequence predictions.
• Comparing the predictions to Canadian standards for acceptable risk levels. Individual
risk is acceptable if there is less than 1 chance in 1,000,000 for the adverse effect to occur.
List of some common individual risk levels that Canadians are exposed
to on a daily basis that may result in death or lethal injury:
• Accidents (all causes): 247 in 1,000,000
• Motor vehicle accidents: 87 in 1,000,000
• Falls: 53 in 1,000,000
• Accidental poisoning: 2.8 in 1,000,000
By comparison, the risk level from the SFF project (0.01 in 1,000,000) is more than 8,700 times
less likely than the risk from motor vehicle accidents (87 in 1,000,000).
Explosion Consequence Analysis:
No risk to surrounding communities
• Additional explosion consequence analysis was conducted to address comments from the public.
• Several release scenarios were assessed including a worst-case, highly improbable scenario
in which four hydrogen or carbon monoxide trailers simultaneously released their contents
and ignited producing a vapour cloud explosion.
• The analysis for the worst-case release scenario predicted that the maximum distances
from the SFF for adverse effects such as lethality, building destruction and serious injury
would all occur within the NRC property.