Pipeline Qra Seminar Title slide Title slide

Pipeline risk assessment Risk reducing measures

Introduction to Risk reducing measures “selecting one or more options for modifying risks and implementing those options” Content slide Content slide

Introduction to Risk reducing measures Depending on the outcome of the risk evaluation Decision-making (i.e. to take mitigating actions or not) Decision could also be to not proceed – showstopper! Mitigating actions (risk reducing measures) influencing the frequency or consequence of the risk Given the implementation of risk reducing measure – is the residual risk tolerable? Content slide Content slide

Introduction to Risk reducing measures We know that the frequency and consequence is combined to the risk in the QRA Reduction in risk through influence the frequency of the scenario or the consequence of the scenario Preferable to influence the frequency (i.e. avoid any kind of accident) Content slide Content slide

Introduction to Risk reducing measures What could be a risk reducing measure? Content slide Content slide

Introduction to Risk reducing measures There are always a number of barriers to prevent the accident from happen (or mitigate the consequences from the accident) When discussing risk reducing measures – we add a barrier In order for the accident to happen the barriers must fail - Active failure – directly linked to the accident (e.g. human error or safety valve failing on operation) - Latent conditions – existing for days, weeks or months (e.g. unsufficient design and insufficient maintenance)

Introduction to Risk reducing measures Decreasing effectiveness in risk reducing measures - Elimination (e.g. reduce the number of valves on the pipeline) - Substitution (e.g. re-think the pipeline routing) - Engineering/isolation (e.g. place the control panel outside the process room) - Administration/training (e.g. establish procedures for shut-down off pipeline and maintenance) - Protective equipment (e.g. respirators and helmet) Increasing success in risk reducing measures!

Introduction to Risk reducing measures Preferable risk reducing measure – elimination! Preferable risk reducing measure – already implemented HSE design – cross-disciplinary activities on design, risk reduction and operability - Increasing focus area - Previously design (engineering) and risk assessment (engineering) separated The earlier risk reducing measures could be specified (compare with risk identification for early stage projects) – the easier implemented

Example of Risk reducing measures San Bruno, September 2010 - rupture gas pipeline – flawed weld during construction - lack of quality control (construction) - inadequate integrity management programme (inspection and maintenance during operation) Suggestion to risk reducing measures? - Review of integrity management programme (e.g. what could inspections actually find and frequency of inspection and maintenance) - RFO (pressure testing of system) Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures New Mexico, August 2000 - rupture gas pipeline – internal corrosion - inadequate integrity management programme (inspection and maintenance during operation) Suggestion to risk reducing measures? - Review of integrity management programme (e.g. what could inspections actually find and frequency of inspection and maintenance) Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures Michigan, July 2010 - rupture oil pipeline – external corrosion (under coating) - undetected for 17 hours - inadequate integrity management programme (inspection and maintenance during operation) - inadequate detection system and adequate preparedness/training/education of operators Suggestion to risk reducing measures? - Review of system for detection of leakages - Establish emergency procedures and conduct exercises Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures Wonowon, June 2012 - leak compressor station - replacement of safety device (not same function) - inadequate knowledge of process equipment (safety device function) - no personal gas detectors and no process room gas detection Suggestion to risk reducing measures? - Review procedures for maintenance (and changes to the process equipment) - Install system for detection of leakages (flashing light) Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures Carthage, February 2011 - leak compressor station - failing check-valve - inadequate design of ESD-system - impingement of process equipment Suggestion to risk reducing measures? - Typical example where HSE design could have been applicable! - Installation of passive fire protection (resist fire for certain period of time) Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures Natural hazards (e.g. earthquakes, erosion, landslides and flooding) - Studies (e.g. location and environment) before pipeline routing - Design (i.e. criteria for earthquake impact) 3rd party interference (e.g. excavation and collision with vehicle) - Warning signs - Protection (e.g. rocks) - Buried or exposed (depending on situation) Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures Process conditions (e.g. moisture and changed conditions) - Internal inspections (e.g. pigging) - Internal corrosion protection - Management of change (i.e. what could be the consequences of this change?) Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures Risk reducing measures for urban areas? - Valves on the pipeline (limiting the possible release) - Increased wall-thickness (resistance to 3rd party interference and damages due to overpressure at other locations) - Ensure ventilation (density lower than air) - Public education (awareness of gas pipelines and possible detection of pending accidents – sound/smell) Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Example of Risk reducing measures Awareness of multiple effects (and possible opposite effects) of risk reducing measures Valves on the pipeline - Advantage – limit the release - Disadvantage – increasing release points Buried or exposed pipeline - Easy to see or not? - Exposed to 3rd party or not?

Risk reducing measures When is a risk tolerable (acceptable)? What is a risk intolerable (unacceptable)? How much risk reduction is possible? How safe is safe enough? Content slide, two columns with image Content slide, two columns with image. Image size: 8,46 cm x 10,76 cm or 320 x 407 pixels

Questions? End slide Endslide