Page 18 - LOPC Survey

4. Do you generally include premature/spurious (not related to overpressure per se) opening of
relief devices as scenario initiating causes?
a. Yes, under all circumstances (11, 14.3%)
b. Yes, but only if the release is not contained/treated (e.g., flare) (20, 26%)
c. No (34, 44.2%)
d. Sometimes (10, 13.0%)
e. Only in specific services (2, 2.6%)

Comments
Almost half the respondents do not consider relief discharge as a scenario.

5. Do you generally include opening of drain or vent lines during facility operation as scenario
initiating causes (e.g., by human error, by a valve failing open, or by leak-through of a valve)?
a. Yes (48, 62.3%)
b. No (8, 10.4%)
c. Sometimes (18, 23.4%)
d. Only in specific services. (3, 3.9%)

Comments
A much higher percentage of respondents are concerned about drains and/or vents as compared
to relief discharges.

6. How do you generally identify and evaluate scenarios relating to external forces from unintended
mechanical impact (e.g., forklifts, vehicles, cranes, loss of piping support, etc.), or damage from
ill-advised use of mechanical force to address operability issues (e.g., hammering on solids
handling equipment), impacting the primary containment system and causing loss of
containment?
a. They are specifically excluded from our HIRAs/PHAs. (14, 18.2%)
b. They are included, with standard default values used for the likelihood of occurrence. (7,
9.1%)
c. They are included if specific external force(s) are identified that are relevant to the
process being studied. (31, 40.3%)
d. For every node or segment being studied, we use a checklist of possible external forces
to help identify ones that are relevant to the node or segment (5, 6.5%)
e. It is included as a part of the Facility Siting study (9, 11.7%)
f. Other (10, 13%)

Comments
As with previous answers, many who exclude it from HIRA address it through their Asset Integrity
program.

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