# Presentation: 605111

## Hazard Analysis (HA) Process- Basic Concepts and Techniques

**Bill Schleyer**
**NNSA-SC**
** ****for Integrated Safety Management Conference**

## Analysis Process- What it Does

**Hazard analysis is the activity that:**
- Comprehensively evaluates facility and process hazards
- Requires a full understanding of facility activities
- Identifies more important engineered and administrative controls
**Identifies accidents for further analysis due to a public ****consequence potential or extreme harm to workers**

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## Purpose of the Hazard Analysis (HA)

**Document Safety Controls **
**The real value in HA performance stems from:**
- Comprehensive and systematic evaluation of hazards
- Coverage of a complete spectrum of accidents for both normal and abnormal conditions and events
- Assessing the effectiveness and adequacy of controls
- Recommending additional controls as needed
_**Bottom line**_**:  A better understanding the ****spectrum of controls that make any facility or work safe**
- Construction and processing facilities
- Environmental restoration activities

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## Information Derived from HA

**Independent of the Method, the HA Should:**
- Identify facility or process hazards
- Identify potential accident scenarios involving the hazards and initiating events
- Qualitatively estimate the uncontrolled consequences of potential accident scenarios
- Qualitatively estimate the frequency that a potential accident scenario may occur
- Rank the accident scenario according to its relative risk
- Identify potential preventive and mitigative controls
- Recommend actions to reduce facility or process risk

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## Selecting the Hazard Analysis Method

**Fit the hazard analysis method to the complexity ****of the operations and magnitude of the hazards**
**Typical hazard analysis methods include:**
- Hazard Identification Checklist
- What-If Analysis
- Hazard and Operability (HAZOP) Study
- Process Hazard Analysis (PrHA)
**Systematic tabular (text) method**

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## Methods Overview

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## A Recommended Hazard Analysis Approach

**The Steps to Perform include:**
- Preparation Activities—Get Ready
- Hazard Identification & Screening
- Scenario Analysis
- What-If Analysis & Screening
- Process Hazards Analysis
- 		_or_
- HAZOP Study (for system/process parameter analysis)
- Selection of Major Accidents (for more detailed analysis)

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## Slide 8

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## Benefits of This HA Approach

**Complex, Diverse Facilities are Too Costly to ****Comprehensively Analyze Each Hazard/Scenario**
- Need to Focus on Significant Hazards
- Need to Screen Out Standard Industrial Hazards and Low Consequence Scenarios
**This Method Progressively Selects Concerns or ****Events that Require Additional Analysis, using**
- Hazard Screening
- Scenario Screening
- Bounding Accident Selection (worst feasible)

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## Benefits of This Approach (continued)

**Comprehensive coverage of hazards & scenarios**
- Cost-effective (efficient) analysis of important facility and process safety concerns
**Methods are “State-of-the-Art”**
- Can be applied to a variety of facilities/processes
- Can be tailored to existing, new, or D&D projects

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## Hazard AnalysisPre-Start Activities

**Establish Matrices **
- for Frequency, Consequences, and Risk
**Establish Basis for Frequencies**
**Establish Reductions from Typical Controls **
- of Frequency and Consequences
**Establish Use of HA Forms and Terminology **
- for Consistency

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## Framework for Consequence, Frequency and Risk

**Consequences**
- Level of harm
- Dose
- Degree of injury
_**To**_
- Receptors
- Immediate Worker
- Collocated Worker
- Offsite public (MOI)
- Environment

**Frequency**
- Conservative estimate of HOW OFTEN a scenario may occur
**Risk**
- Relative rank based on consequences and frequency of incident
- Possibility of a loss or injury

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## HA Frequency Matrix

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## Consequences Matrix

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## HA Risk Matrix

- 1 = High Risk
- 2 = Moderate
- 3 = Low Risk
- 4 = Negligible
- Risk # is relative,
- not absolute,
- to allow ranking.

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## Basis for HA Frequencies

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## Reductions from Controls

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## Screening

**	**Screening is the _decision_ to remove from evaluation those hazards or scenarios that present a minimal risk or insignificant consequences*
**Criteria should be **_**Defined**_** prior to the Analysis**
**Screen at Several Levels**
- Hazard ID
- What-If Analysis
**To Screen or Not to Screen?**
- when in doubt do not delete a hazard or scenario
***Screening may impact ability to identify normal/abnormal conditions leading to incidents**

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## Starting Hazard Analysis

**Assemble the HA Team**
- Should be able to discuss operations, design, and safety
- Should be knowledgeable on hazard analysis methods
**Establish Analysis Approach**
**Obtain baseline information**
- Facility Walk-through
- Document Review
- Personnel Interviews
**Identify the Basic Operations or Areas to Study**

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## Facility and Process Information

**Become familiar with baseline information:**
- Site and location characteristics
- Facility design information
- Process/activity information
- Historical operational information
- Materials information
- Safety documents and records
**A process flow sheet can help understand hazards**

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## Slide 21

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## Hazard Identification and Analysis

**Hazard Identification**
- Identifies workforce hazards and activities
- What are the “energies” and how is each transferred
- Systematic tabular (text) method
- Leads into What-If analysis
- Supports Process Hazards Analysis

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## Hazard Identification

**Identify Hazards**
- Use a Standard, Comprehensive Checklist
- Use a Separate Checklist for Each Operation/Area
**Screen Standard Industrial Hazards**
- Adequate controls covered by OSHA
**Screen Non-Significant Hazards**
- If < 25% RQs in 40CFR302/40CFR355
- If < Criteria you decide (BMP, consensus stds)

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## Hazard ID Checklist

- * Includes characterization of hazard particulars (quantity, form, location, etc.)

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## Hazard Identification (continued)

**Hazards not Screened Out are Evaluated Further**
**Results can be Summarized and Tabulated**
- Allows for checking hazards that may be common to several processes or areas

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## Slide 26

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## Preparation for a What-If Analysis

**Resolve Any Baseline Information Issues**
- Develop or finalize the process flowchart(s) and description(s) of facility/process operations
**Identify Hazard Configurations**
- Physical, Explosives, Toxics
**Establish General Consequences ****for Various Insults to Each Configuration**
- Small release, large release, small fire, large fire
- Major injury/death, minor injury

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## Process Flow Chart

- GENERAL PURPOSE

- HEAT SOURCE FUEL

- PROCESS

- TRANSFER IC

- TO Room 123

- TRANSFER IC,

- ONE OR TWO AT A

- TIME, TO ROOM

-   WATER BATH

- CALORIMETRY  OFIC

- TRANSFER

- CONTAINERS THRU

- AIRLOCK TO

- UNPACKING AREA

- REMOVE

- CONTAINERS FROM

- REMOVE INNER

- CONTAINER(IC) IN

- UNPACKING ROOM AND

- PERFORM CONFIRMATION

- CHECK

- PLACE EACH IC  IN

- WATER TANK (UP TO

- 2   PER SLOT)

- RECEIVE 6-12  CONTAINERS

- AT FACILITY

- 1

- RETURN

- ICTO VAULT

- WATER BATH

- HS1

- HS2

- SST WITH FORKLIFT

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## Configurations and Consequences

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## What-If Analysis

**A Modified What-If Analysis is Performed**
- Brainstorm Scenarios by Asking “What if...”
- Goal is to Reduce and Group the Number of Scenarios that Need Additional Analysis
- Use a Separate Table Used for Each Operation/Area
- Group Questions by Type of Insult for Each Configuration
- Screen Out Non-Significant Consequences
- Equipment Damage Only, Not Physically Possible, Negligible Consequences, etc.

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## Scenario Development

**Scenarios are concise, clear, and present a logical ****description of the factors in an accident chronology.**
- Typically a scenario describes:
- Activity or Area of Interest
- Initiating Event(s) or Cause
- Type of Accident
- Resulting Hazard
- The level of detail will vary
- Less in What-If Analysis
- More in the Process Hazard Analysis

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## Modified What-If Approach

**AIChE 1992, *****Handbook of Chemical Hazard ******Analysis Procedures*****, explains that each What-If ****scenario should include recommendations**
- Either a reason for screening or specific controls
**In this modified approach, can defer control recommendation until bounding accident evaluation**
- Control the worst case conditions

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## What-If Analysis Table

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## AIChE What If Format

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## Slide 35

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## Process Hazards Analysis Concept

**An efficient, systematic technique for evaluating ****and documenting processes/activities of interest**
- Focuses on those accidents expected to result in more adverse consequences or risk, whether from operations, natural phenomena, or external events
- Tabulates both uncontrolled and controlled scenarios
- with and without application of potential controls
- Highlights potential controls with the most benefit
- Provides for robust tracking and clear communication of the risk reduction measures resulting from the hazards and potential accident scenarios

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## PrHA Concept (continued)

**A Process Hazard Analysis (PrHA) ****Evaluates Accident Scenarios that were ****Not Screened Out During the What-If Analysis**
**Organization**
- By Process Logic
- (by operation or activity)
- By Accident Types (Initiators/Consequences)
- operational, natural phenomena, and external events
- (fire, explosion, confinement loss, criticality, rad exposure, earthquake, aircraft crash, etc.)

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## PrHA Performance

**The accident scenario description should be ****specific in identifying the cause (initiating event)**
**The frequency of occurrence and accident ****consequences are qualitatively established**
**First** – frequencies and consequences are recorded without consideration of existing or possible controls (uncontrolled)
**Then** – controls are identified and resulting frequencies and consequences are evaluated
**Risk matrix tables are used to rank scenarios**

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## PrHA Performance (continued)

**Controls that give the most effective reduction ****of the frequency or consequence category are ****checked (****) in the tables**
- Considered as more Important Controls
-  Safety Management Programs collectively reduce by  1⁄2  category (bin)
- Safety Management Programs adequately protect for scenarios of lower risk
**Other controls are noted to support safety**

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## Sample PrHA Table

**CONTROLS DEFINED**

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## Slide 41

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## HAZOPS

**Assumptions**
- _Systems_ work well when operating under design conditions
- Problems arise when deviations from design conditions occur
**Characteristics**
- Comprehensive tool to evaluate scenarios and control risk
- It should be detailed and rigorous
- System and worker controls defined
**Complex systems requiring a more methodical approach to ensure completeness**
- Human/hardware elements involving maintenance/operating procedures

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## HAZOPS Analysis Process

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## HAZOPS Deviation Matrix

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## HAZOP Study Example

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## Slide 46

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## Safety Layers in the Chronology of an Accident or Event

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## Conclusions

**Hazards Analysis can use several methods-pick the one that best fits the hazards/conditions.**
**Plan the analysis**
**Be consistent**
**HA Results**
- Understand the scenario
- Identify consequences and risk
- Define controls

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