(13b) Half a Century of Olefin Plant Accidents: The Role of Mechanical Integrity

Sebastian Diaz,
Aon energy Risk Engineering, League City, TX.

Email: sebastian.diaz@aon.com

Russ Davis, CSP Aon Energy Risk Engineering, League
City, TX.

Email: russ.davis@aon.com

Keywords: mechanical integrity, loss of
containment, major accidents

Abstract

Since
OSHA's Process Safety Management standard went into effect in 1992, the Mechanical
Integrity element of the standard has been expected to be a key factor in reducing
the occurrence of major chemical incidents.

Past
statistics show that, in the refining industry, olefin units
accidents/incidents account for close to one sixth of the total accidents, and close
to one fifth of the total cumulative economic losses. We would expect, then, to
see a significant reduction of these occurrences through the implementation of
mechanical integrity programs, industry wide.

This
work presents a brief examination of past records of several major incidents
involving olefin plants from the last 50 years. The aim was to identify common
causes and the impact of mechanical integrity on these causes. We found that approximately
half of the incidents were caused by or involved mechanical integrity
deficiencies, and even though the PSM standard has helped reduce the incidence,
major losses due to MI deficiencies keep occurring.