PHMSA Gas Transmission (GT) Integrity Management
Time: 09/01/2014 06:28 PM

Protocol Item C.03

C.03 Risk Assessment

Verify that the operator has conducted a risk assessment that follows ASME B31.8S-2004, Section 5, and that considers the identified threats for each covered segment. [192.917(c)] [Note: Application of the risk assessment to prioritize the covered segments for the baseline assessment is covered in Protocol B, continual reassessments in Protocol F, and additional preventive and mitigative measures in Protocol H.]

  1. Verify that the operator's risk assessment supports the following objectives [ASME B31.8S-2004, Section 5.3 and ASME B31.8S-2004, Section 5.4]:
    1. prioritization of pipelines/segments for scheduling integrity assessments and mitigating action
    2. assessment of the benefits derived from mitigating action
    3. determination of the most effective mitigation measures for the identified threats
    4. assessment of the integrity impact from modified inspection intervals
    5. assessment of the use of or need for alternative inspection methodologies
    6. more effective resource allocation
    7. facilitation of decisions to address risks along a pipeline or within a facility
  1. Verify that the operator utilizes one or more of the following risk assessment approaches [ASME B31.8S-2004, Section 5.5]:
    1. Subject matter experts (SMEs),
    2. Relative assessment models,
    3. Scenario-based models, or
    4. Probabilistic models
  1. Verify that the risk assessment explicitly accounts for factors that could affect the likelihood of a release and for factors that could affect the consequences of potential releases, and that these factors are combined in an appropriate manner to produce a risk value for each pipeline segment. [ASME B31.8S-2004, Section 3.1, ASME B31.8S-2004, Section 3.3, ASME B31.8S-2004, Section 5.2, ASME B31.8S-2004, Section 5.3 and ASME B31.8S-2004, Section 5.7(j)] Verify that the risk assessment approach includes the following characteristics:
    1. The risk assessment approach contains a defined logic and is structured to provide a complete, accurate, and objective analysis of risk [ASME B31.8S-2004, Section 5.7(a)];
    2. The risk assessment considers the frequency and consequences of past events, using company and industry data [ASME B31.8S-2004, Section 5.7(c)];
    3. The risk assessment approach integrates the results of pipeline inspections in the development of risk estimates [ASME B31.8S-2004, Section 5.7(d)];
    4. The risk assessment process includes a structured set of weighting factors to indicate the relative level of influence of each risk assessment component [ASME B31.8S-2004, Section 5.7(i)];
    5. The risk assessment approach establishes the documentation requirements for the use of inadequate or unsubstantiated data in the risk analysis [ASME B31.8S-2004, Section 5.7(e)];
    6. The risk assessment approach assumes a threat is applicable , and uses appropriately conservative assumptions, when inadequate or unsubstantiated data is available to eliminate the threat from the risk analysis [ASME B31.8S-2004, Section 5.7(e)];
    7. The risk assessment process incorporates sufficient resolution of pipeline segment size to analyze data as it exists along the pipeline [ASME B31.8S-2004, Section 5.7(k)].
  1. Verify that records demonstrate that the risk analysis data is combined in an appropriate manner to produce a risk value for each pipeline segment. Verify that the records:
    1. Show a defined logic and structure to provide a complete, accurate, and objective analysis of risk [ASME B31.8S-2004, Section 5.7(a)];
    2. Show the frequency and consequences of past events, using company and industry data is considered[ASME B31.8S-2004, Section 5.7(c)];
    3. Shows the risk assessment approach integrates the results of pipeline inspections in the development of risk estimates [ASME B31.8S-2004, Section 5.7(d)];
    4. Show how factors with missing or unsubstantiated data was used in the risk analysis [ASME B31.8S-2004, Section 5.7(e)]
    5. Show that conservative assumptions are used whenever inadequate or unsubstantiated data was used in the risk analysis [ASME B31.8S-2004, Section 5.7(e)]
    6. Shows a structured set of weighting factors to indicate the relative level of influence of each risk assessment component [ASME B31.8S-2004, Section 5.7(i)];
    7. Shows that sufficient resolution of pipeline segment size was used to analyze data as it exists along the pipeline [ASME B31.8S-2004, Section 5.7(k)].
  1. Verify that adequate time and personnel have been allocated to permit effective completion of the selected risk assessment approach. [ASME B31.8S-2004, Section 5.7(b)]

Related Rule Sections:

Related Topics:

PHMSA Home | Pipeline Safety Website | Feedback | Privacy Policy | FOIA