According to T13, a safety study commissioned by the Empresa Nacional del Petróleo (Enap, Chile's state oil company) marked out a high-risk zone of 1,273 meters around the three gas storage spheres the state company operates at its plant in Maipú, in the Región Metropolitana (the Santiago metropolitan region). The outlet had access to the report, which was prepared by a British consultancy whose name was not disclosed.
The document estimates the probability of a catastrophe at the site at one in 80 million. Even so, it states that an explosion would have serious consequences for people living or passing nearby and for infrastructure in the area.
Beyond the main perimeter, the study sets out a buffer area extending up to 2,228 meters from the spheres. According to T13, these figures update earlier calculations of the reach of a major accident at the facility, although the report does not say what those earlier estimates were.
Within the high-risk zone, the report considers two types of effect: thermal radiation and overpressure. For the first, it sets a level of five kilowatts per square meter. At that intensity, a person would feel pain after 20 seconds and could suffer second-degree burns after 40 seconds.
On overpressure, the study says a level of 1 PSI (pounds per square inch, a unit of pressure) is enough to rupture eardrums and cause serious injuries from objects thrown by the blast.
In the buffer strip, the expected effects are smaller. The text mentions broken glass in windows of various sizes, damaged frames in some cases and minor damage to certain buildings.
T13 reviewed the document with risk prevention specialist Luis Salamanca. He said that "there is no such thing as zero risk" and that, despite mitigation measures, it cannot be ruled out that some system might fail at some point.
Salamanca also warned about the waste and debris visible around the plant. In his view, glass, metal and plastic could be propelled at high speed by a shock wave and strike people, vehicles and buildings.
As a reference, the expert suggested gauging a possible accident against past cases, such as the explosion of a truck loaded with gas on the border between Quilicura and Renca. The Maipú plant stores a considerable amount of liquefied petroleum gas.
So far, the information comes only from T13. The report includes no response from Enap or from the Municipalidad de Maipú (Maipú's municipal government) about the study, and it does not say whether any concrete measures are in place for the area around the spheres.
