Accidental Limit State
Events with an annual probability of exceedance less than 10-2 and larger than 10-4.
- NOTE: 1 The accidental limit state (ALS) corresponds to conditions with a longer return period than ULS. ALS requires that the system survive, but has a higher risk of damage than ULS conditions.
- NOTE: 2 When considering potential damaged conditions, the damage should not lead to an escalation of undesirable events.
- EXAMPLE A failed mooring line, a flooded compartment, a tensioner failure, a tubing leak or unintended shut in conditions are some ALS cases.
Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards