Risk Ranking : An Example Process

and Method

Risk Ranking : An Example Process

and Method

www.STRUCTINT.com877-4SI-POWER

Nuclear Cable WorkshopAugust 6-7, 2012

Richmond, VA

Shane A. McManusSenior Engineer, SI

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Objectives

• Project Basis• Cable Aging Management Tools• Yard Cable Assessment• Data Handling • Risk Ranking• Inspection Prioritization • Concepts within a Building

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Determine Scope – Define which cable / connector components (MV, LV, Instrument, EQ and/or non-EQ, splices, etc.) are within the scope of the program at each plant.

Data Collection/Integration – Relevant data, whether from existing databases (e.g., cable, operating experience, corrective action) or other sources are collected and organized.

Risk Ranking – A risk assessment is performed to gain insights that best focus station resources in a way that mitigates the likelihood of failure and potential consequences of failure.

Inspection Planning – Develop risk prioritized inspection walkdown scope and most appropriate tests based on environment, service conditions and materials of construction.

Determine Scope

Data Collection and Integration

Risk RankingInspection Planning

Baseline Phase – Scoping & Prioritization

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Project Basis• NUREG/CR-7000

– Select cables to be monitored.– Develop database for monitored cables.– Characterize and monitor service environments.– Identify stressors and expected aging mechanisms.– Select condition monitoring techniques suitable to monitored

cables.– Establish baseline condition of monitored cables.– Identify cable characteristics and aging effects being monitored

by each selected condition monitoring technique.– Perform test and inspection activities for periodic condition

monitoring of cables.– Periodically review and incorporate plant and industry

experience.– Periodically review, assess, and trend the condition of

monitored cables.– Identify degraded conditions and take prompt corrective

actions.

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Cable Aging Management (CAM)

Tools

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Yard Cable Assessment Example -GIS Tools

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Visualization of Cable InformationA visual representation of cable database information (inspection & risk results, drawings, PDF or pictures) through a GIS interface can offer the following benefits.  – Visual review and analysis of data allows for multi-variant

analysis and the recognition of patterns not possible with tabular information.

– Combinations of cable information (layers) can be selectively ‘turned on’ by user.  Simply ‘clicking’ on a feature reveals a table of information relevant to the cables in that area.

– View assets associated with a specific cable or other information near cables (pipes, equipment, tanks, etc.) that may potentially contribute to degradation, such as from leakage.

– Data can help facilitate inspection planning. – For underground cable, the risk associated with accidental

contact during excavations (associated with fencing installation, buried pipe excavations, monitoring wells and other modifications) can be minimized.

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SQL Database CAM Solution

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CAM Foundation and Design Inputs

• Raceway

• Cable Type

• Equipment

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Dynamic Segmentation

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Risk Calculations

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Risk Calculations

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Walkdowns, Inspections, and Testing

• Based on the raw risk data derived from the CAM Algorithms and the IsoRisk graphs a few observations were made:– MV submerged cables selected for testing and

inspections per GALL AMP X1.E3.– Cables with the highest ROF values selected for

walkdowns. Walkdown results dictated further inspections and testing.

– Cables with the highest LOD selected for inspections.• Overall COF was low.• Did not impact plant operability.• Located in more adverse environments.• Sentinel concept implemented and results extrapolated.

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Building Interior Cable Concept

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Conclusions• NUREG/CR-7000 CAM Program Elements Addressed

– Select cables to be monitored.– Develop database for monitored cables.– Characterize and monitor service environments.– Identify stressors and expected aging mechanisms.– Select condition monitoring techniques suitable to monitored

cables.– Establish baseline condition of monitored cables.– Identify cable characteristics and aging effects being

monitored by each selected condition monitoring technique.– Perform test and inspection activities for periodic condition

monitoring of cables.– Incorporate plant and industry experience.– Periodically review, assess, and trend the condition of

monitored cables.– Identify degraded conditions and take prompt corrective

actions.

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Questions?