Periodic Hazard Review as an essential part of your PSM system

Gerry Brennan, Lead Principal Consultant, ABB Consulting / Piper 25 Conference June 18-20 2013

Periodic Hazard Review as an essential part of your PSM system

Contents

Process Safety Management

Need for periodic hazard review

Techniques: HAZOP vs HAZID

Learning points from experience of periodic hazard review

Process Safety versus Personal Safety

Major

Accident

Hazards

Slips, trips

and falls

Very

Unlikely

Possible

Process

Safety

Personal

Safety

What is Process Safety?

“The prevention of unplanned & uncontrolled loss of

containment from plant and process equipment that

might cause harm to people or the environment”.

Process Safety Management

Commit to Process Safety

Process safety culture

Compliance with standards

Process safety competency

Workforce Involvement

Stakeholder Outreach

Understand Hazards and Risk

Process knowledge management

Hazard Identification and Risk Analysis

Manage Risk

Operating Procedures

Safe work practices

Asset integrity and Reliability

Contractor Management

Training and Performance Assurance

Management of Change

Operational Readiness

Conduct of operations

Emergency Management

Learn from Experience

Incident Investigation

Measurement and Metrics

Auditing ▪ Management Review and Continuous Improvement Guidelines for Risk Based Process Safety, CCPS 2007

Learning

phase

Hardware wearout

Loss of corporate memory

Change in people

Creeping Changes in plant

Why is periodic hazard identification and risk analysis needed?

HAZOP Ongoing risk assessment?

Accident

Life of Plant

Plant

Safety

Performance

Objective for Periodic Hazard Review

Evaluate controls for the hazards of the process as they

are currently understood

because

Process changes have introduced new hazards

New knowledge on hazard consequences is available

Recent incidents have revealed new scenarios

Barriers previously credited have changed

HAZOP or HAZID?

Loss of

Containment

FAULT TREE EVENT TREE

HAZID

CA

US

ES

CO

NS

EQ

UE

NC

ES

Mitigation

Measures

Prevention/Control

Measures

HAZOP

Methodology

1. Split process into sections;

HAZOP node is a process line

HAZID node is unit operation, typically 1 or more P&ID’s

2. Describe design intent for node;

operating parameters

key aspects of process control system

protective systems, trips/relief's/bunds

3. Apply guidewords - can it happen?

4. Assess consequences - does it matter?

5. Assess design safeguards - are they adequate?

6. Agree actions required to reduce risk

HAZOP Guidewords (IChemE)

No (not, none)

More (more of, higher)

Less (less of, lower)

As well as (more than)

Part of

Reverse

Other than

Earlier/later than

With appropriate process parameter

Flow

Pressure

Temperature

Level

Concentration

Mixing

Etc.

Look for deviations from intent

HAZID Guidewords

Burst

Internal Explosion

Overpressure

Runaway Reaction

Puncture

Impact

Weakening

Corrosion

Wear

Temperature extreme

Openings

Vent/Drain

Overflow

Flange/Seal Look for causes of Loss of Containment

Comparison application to offshore installations

Re-HAZOP of UK and overseas platforms during 2010-

2013

Hazard Study Equivalent days per platform: 90-150

Recommendations for improvement: ~500

HAZID of UK Platforms during 2011-13

Hazard Study Equivalent days per platform: 15

Recommendations for improvement: ~100

Learning Points from experience of periodic hazard review

1. Write down clear Terms of Reference

Scope of review; what is included/excluded

Timescale; duration of commitment;

Team leader; competence

Hazard study team; essential disciplines

Method; guidewords, recording detail, recording tool;

stipulations about safeguards

Time required; hours of work; how many days per week?

Meeting room; lighting; space; projection; away from the

installation

Data Gathering; up to date PIDs, process information;

2. Specify the right team

Leader

Operations Manager Operator or Supervisor

Process,

Engineering /

Maintenance

Independent

Team Member

Other specialists as required

3. Choose process node carefully

HAZOP: line or vessel HAZID: system by system

4. Correct level of detail in records

Example of poor recording

GW Cause Consequence Safeguard Recommendation

No Flow Valve closed , etc Overpressure of Vessel XXXX Alarm and trip Consider pressure relief on

Vessel xxxx

Individual causes should be

detailed. Manual valve HVxxx

closed through human error, OR

Flow control failure FICxx, OR spurious closure

XV xxx

Sequence should be determined – Tell the ‘Hazard story’. No flow causing

build up in pressure – this will be slow as

feed is low at y m3/min.

Overpressure maximum up to 4x design, but as slow rate of pressure rise line leakage at 2 to 3x design. Release

of flammable substance into local process area. 1 to 2 fatalities if ignited – normal occupancy.

Separate safeguards.

Alarm response

detailed. Trip tags and actions.

“Consider” should be avoided. Should

detail HAZOP team concern – Normal design practice to

have pressure relief. Should be a review to determine if relief is required against

design requirements and protection

required to avoid fatality

consequences.

5. Recording: Can Link Hazop to bow tie

GW Cause Hazard Consequence Sev

erity

Safeguard L R Recommendation

6. Hazard Study Recommendations

Need to carefully word to avoid confusion

Person given action may not have been at the meeting

Use “what – where – why” format

“Add instructions for securing of double block and bleed isolations on the fuel gas supply line XYZ123 to the Burner 1-B-07 prior to maintenance into plant operating instruction 23, in order to protect against the flow of fuel into the burner and risk of explosion at start-up”

Limit the number of actions generated

Complete simple design checks before report is issued

Keep a separate list of observations for project team

7. Hazard study followed by LOPA

Hazard study provides the list of initial failures

and the risk screening to pick out significant

hazard scenarios

Layer of Protection Analysis (LOPA) provides

a more detailed risk estimate

Increasingly applied where there is a

significant consequence or a Safety

Instrumented Function

7 Cont: But there some points to bear in mind…..

Scope of LOPA: Only those with a SIF? Which severity level?

If HAZOP records are sketchy, lengthy discussion in LOPA is likely

Failure sequence not quantifiable: Must be an equipment or human failure

Poor: ‘Operator error’

Good: ‘Block valves HV1 and HV2 left closed after maintenance’

Poor logic in HAZOP: e.g. failure of a safeguard as ‘cause’

Failure to determine ultimate consequence and hence all safeguards

SIF can’t be identified as no tag number on HAZOP record

Also other safeguards, e.g. alarms, procedures, relief systems

LOPA is top down from hazardous event, HAZOP is bottom up from cause

Need to cross reference all causes in HAZOP record

8. “Evergreen Records” and revalidation programmes

Goals:

Accurate, current, detailed description of hazards and

safeguards available for reference in ORAs, MOCs

Reduce resources demanded for periodic process

hazard review

Method:

Update the periodic review record with

Recommendations Closures and risk assessment

results (such as LOPA);

Revalidate the periodic review of hazards, every 5

years

8 Cont.: Revalidation Method

Select first node

Ask the following questions

Have all the recommendations been completed?

Have the changes since the baseline Hazard Study been fully assessed?

Have there been any relevant process safety incidents, has the learning

from these been acted upon?

Are there any current concerns?

Is there any new knowledge or relevant good practice applicable to this

node?

In view of the above, does the hazard study need repeating?

Repeat over all nodes

Table updated and new recommendations in the revalidation report

© ABB Group June 19, 2013 | Slide 24

© ABB Group June 19, 2013 | Slide 24

QUESTIONS?