PT Notes
Is your facility prepared for natech incidents?
PT Notes is a series of topical technical notes on process safety provided periodically by Primatech for your benefit. Please feel free to provide feedback.
The term “natech” refers to incidents that are caused by natural hazards, such as extreme temperatures, floods, hurricanes, tornadoes, landslides, earthquakes, and wildfires, in facilities that rely on technology, such as chemical plants, refineries, pipelines, and offshore oil and gas platforms.
Although natech incidents are a recurring feature in many natural disasters, often they are overlooked, despite their major impacts on society, people, property, and the environment. The consequences of natech incidents can include interruption to facility operations, equipment failures, fires, explosions , and hazardous material releases.
The importance of ensuring facilities are protected against natech incidents has been highlighted by the recent outage of the electricity supply in Texas. Other recent events that involve natech are the March, 2011 Fukushima nuclear reactor meltdown in Japan which was caused by an earthquake and an ensuing tsunami; the August, 2017 series of explosions and fires at a Crosby, Texas chemical plant following severe flooding caused by hurricane Harvey; and the February, 2021 dam failure in northern India which was caused by part of a Himalayan glacier falling into a river and triggering a flood that resulted in dozens of deaths . Many other natech incidents have occurred in industrial facilities.
It is important to address natech in hazard analysis, facility siting, land-use planning, and emergency preparedness and response. The first step is to identify those natural hazards that pose risks to a facility. A master checklist should be referenced. While many facilities have been built in locations that are susceptible to natural hazards, changes in the environment are making natech incidents more likely , particularly those related to extreme weather, including in locations that previously would not have expected to experience such events.
In hazard analysis, natural hazards are addressed as external events. They can cause hazard scenarios specific to a particular part of a facility, e.g. a lightning strike on a storage tank, or hazards scenarios across the entire facility, e.g. abnormally low temperatures that affect multiple parts of the facility. Such scenarios are identified in hazard analysis by brainstorming how the occurrence of specific natural events may initiate hazard scenarios. Natech scenarios often involve domino effects with a series of cascading events. Consequently, it is important that domino effects be addressed so their escalating consequences are considered. Appropriate safeguards to protect against natural hazards and mitigate the consequences of their occurrence are needed. Since many natural hazards impact an entire facility and can affect multiple pieces of equipment, including process safeguards, the consideration of protection against common cause failures is particularly important.
In facility siting studies for new processes and land-use planning, the proximity of facilities to sources of natural hazards should be addressed, for example, when locations are considered that are close to a body of water, such as a river or ocean, or in an earthquake-prone area. This aspect of facility siting goes beyond US regulatory requirements for process safety to consider the spatial relationship between the hazards of the covered process itself and the location(s) of people but nonetheless is important.
In emergency preparedness and response, contingency plans must address the occurrence of natech incidents. Plans are needed for placing process units in a safe state when the pending occurrence of a natural hazard becomes known. Responders need to be aware of the types of natural hazards that a facility may experience and the types of incidents that may result. The occurrence of the natural hazards may interfere with emergency response activities, for example, sources of power may be lost, access roads to a facility may be blocked, and normal means of communications may not be available. Response plans must provide appropriate contingencies for such occurrences. Preparedness should be enhanced through emergency exercises.
Process safety practitioners need to be aware of the natural hazards that can impact the facilities for which they are responsible and ensure that measures are taken to provide adequate protection against them.
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