A Temporary Refuge (TR) is required to provide protection against the effects of a major accident events for long enough to allow the workforce to muster, the emergency to be assessed and decisions to be taken and implemented to remove personnel from the hazard.
Temporary Refuge Impairment Analysis (TRIA) is used to assess the risk of impairment of the TR during a major accident event on an offshore installation. Impairments of a TR on an offshore installation can result from one of the following five mechanisms:
Explosion impairment.
Failure of the TR boundary due to fire impingement.
Failure of structure supporting the TR due to fire impingement.
Smoke impairment.
Gas impairment.
A TR is designed to withstand these failure impairment mechanisms for a defined duration. Impairments of the TR which occur within the defined duration contribute to the TR Impairment Frequency (TRIF). Impairments occurring after this defined duration are not included in the TRIF. A significant part of the information required for a TRIA is generally available from the Fire & Explosion Risk Analysis.
