(193d) Determining the Frequency and Severity of Vessel Failure Due to Runaway Reactions in Acetylene Reactors

Catastrophic temperature runaways in acetylene reactors that lead to a failure of the reactor are very rare. HAZOP/LOPA teams struggle to determine the frequency and severity of such rare events.

Some HAZOP/LOPAs looked at industry data to assist with determining the frequency of acetylene reactors runaways that resulted in a total failure of the reactor. Each study team reviewed the same data yet came up with different frequencies. A team of SMEs was assembled to resolve this discrepancy. The SMEs did not believe using industry performance was correct as the first assessment requires the initiating even as the response with no consideration given for safeguards. The SMEs looked at metallurgy details, reaction kinetics, and the condition of the reactor contents to come to the correct method to evaluate.