Double-Jeopardy

Confusion in Terminology: DOUBLE-JEOPARDY versus SIMULTANEOUS FAILURES versus COMMON CAUSE

In the world of HAZOP/PHA, double-jeopardy (D-J) is defined as a scenario where two independent causes exist at the same time. One Cause (in LOPA terms, one Initiating Event) can occur in time much earlier than another, and not be corrected or maybe not even discovered. Then a second cause occurs and the scenario progresses. [...]

By |2016-12-07T01:33:33-07:00August 14th, 2015|Double-Jeopardy|1 Comment

Is Consideration of Double-Jeopardy valid in PHA/HAZOP Discussion?

Double-jeopardy (D-J) is NOT an independent protection layer (IPL) failure after an initiating event (IE). All PHA/HAZOP scenarios are of the type of: IE occurs, then IPL 1 fails, then...., leading to Consequences. However, the definition of double jeopardy (D-J) is when two initiating events, which are independent (or we had hoped they were so), [...]

By |2016-09-05T08:48:48-07:00August 13th, 2015|Double-Jeopardy, HAZOP, PHA|0 Comments