Overview

The aim is for all identified Risks and the overall risk posed by the Oil SSTS to be assessed as being Broadly Acceptable. Should this not be the case, the risk should be reduced to a level that is Tolerable and ALARP.

Task

ALARP Process

Using the form below, develop a flow diagram that encapsulates and explains the stages in developing an ALARP Justification, which includes but not limited to:

  • The hierarchy of risk reduction
  • The use of hard and soft risk controls
  • The use of Good Practice
  • The role of Cost Benefit Analysis

You may wish to review ASEMS SMP07 and SMP08.

Made with Padlet

[Hint for an example layout of a process map, see here]

Cost Benefit Analysis

Your preferred option for the Oil SSTS currently uses storage tanks constructed of a single skin. Should this single skin be damaged oil would leak from the storage facility and spread to other levels, which represents a significant fire hazard. To reduce this risk, two solutions have been identified:

  • A tank constructed with a double skin
  • Installing a metal bund around the storage tank to contain any spillage to a safe area.

Using the information below, undertake Cost Benefit Analysis (CBA) to assess the two options and decide if it cost effective to implement either or both options

  • A new bund costs £150,000, and will need to be replaced every 10 years due to the corrosion
  • The Oil SSTS has a life expectancy of 20 years
  • A double walled storage tank would cost £650,000 and would last 20 years
  • The VPF is £2M and the gross disproportion factor (GDF) is 2.

[Hint the equation Detriment = Frequency of Fatalities x VPF x Lifetime of System x GDF]

Option wdt_ID Frequency of Fatalities (per year) Value to Prevent a Fatality Lifetime of the equipment/activity Gross Disproportionate Factor Safety Detriment Safety Benefit of Option (reduction in safety detriment) Cost of implementing Option Is the Option Cost Effective
Baseline 65 0.01 2,000,000 20 2
New Bund 66 1E-5 2000000 10 2
Double Walled Tank 67 1E-9 2000000 20 2

Oil SSTS ALARP Assessment

Apply the ALARP Process to your preferred option for the Oil SSTS, down selected during the Technical Review and Hazard Assessment of Options A, B and C.

  • Apply the hierarchy of risk reduction to each hazard captured in the Hazard Log (for your preferred option only), updating the hazard log as appropriate.
  • Populate the ALARP Argument for each hazard.

[Hint: The ALARP Argument should consider 

  • Can the risk be avoided
  • Compliance with good practice, legislation and regulations
  • Cost Benefit Analysis (CBA), including relevant disproportion factors depending on severity of hazard
    • Where relevant you may wish to include reference to CBA you have just completed
  • Implementation of appropriate risk control measures
  • No overdue actions in hazard log that can compromise ALARP]