SafetyBarrier

i

Viewer

HydrogenFuellingOptions..sbmx

Liquid Hydrogen Station - Truck delivery and unloading action

Liquid Hydrogen Station - Truck delivery and unloading action Unloading Inspection Unloading Inspection 0.01 Inspection of hoses Inspection of hoses 0 Inspection of connections Inspection of connections 0 Supervision during unloading Supervision during unloading 0 Hydrogen sensors Hydrogen sensors 0 Collision prevention Collision prevention 0 Venting prior disconnection Venting prior disconnection 0 Limited access Limited access 0 Personal protection Personal protection 0 Truck has defects on arrival Truck has defects on arrival 1 /y Defects in unloading hoses Defects in unloading hoses 0 /y Incorrect coupling to fixed facility Incorrect coupling to fixed facility 0 /y Liquid hydrogen in unloading hose Liquid hydrogen in unloading hose 1 /y Vehicle movement into truck or unloading facility Vehicle movement into truck or unloading facility 0 /y Release from unloading facility Release from unloading facility 0.01 /y Continued release from unloading facility Continued release from unloading facility 0 /y Liquid hydrogen spill Liquid hydrogen spill 0.01 /y Loss of containment/ unloading Loss of containment/ unloading 0 /y Unnoticed explosive atmosphere Unnoticed explosive atmosphere 0 /y Cryogenic burn/personnel Cryogenic burn/personnel 0 /y Cryogenic burn/third parties Cryogenic burn/third parties 0 /y
Liquid Hydrogen Station - Truck delivery and unloading action (This Diagram has no Measures assigned) Unloading Inspection Unloading Inspection 0.01 Inspection of hoses Inspection of hoses 0 Inspection of connections Inspection of connections 0 Supervision during unloading Supervision during unloading 0 Hydrogen sensors Hydrogen sensors 0 Collision prevention Collision prevention 0 Venting prior disconnection Venting prior disconnection 0 Limited access Limited access 0 Personal protection Personal protection 0 Truck has defects on arrival Truck has defects on arrival 1 /y Defects in unloading hoses Defects in unloading hoses 0 /y Incorrect coupling to fixed facility Incorrect coupling to fixed facility 0 /y Liquid hydrogen in unloading hose Liquid hydrogen in unloading hose 1 /y Vehicle movement into truck or unloading facility Vehicle movement into truck or unloading facility 0 /y Release from unloading facility Release from unloading facility 0.01 /y Continued release from unloading facility Continued release from unloading facility 0 /y Liquid hydrogen spill Liquid hydrogen spill 0.01 /y Loss of containment/ unloading Loss of containment/ unloading 0 /y Unnoticed explosive atmosphere Unnoticed explosive atmosphere 0 /y Cryogenic burn/personnel Cryogenic burn/personnel 0 /y Cryogenic burn/third parties Cryogenic burn/third parties 0 /y

Liquid Hydrogen Station - Liquid Storage

Liquid Hydrogen Station - Liquid Storage Overfilling protection Overfilling protection 0 Pressure Relief Valve Pressure Relief Valve 0 Pressure Safety Valve Pressure Safety Valve 0 Rupture disc Rupture disc 0 Tank filling operation Tank filling operation 0 /y Release from inner tank Release from inner tank 0 /y Boil-off exceeds consumption Boil-off exceeds consumption 0 /y External damage of jacket External damage of jacket 0 /y Pressure rise in tank Pressure rise in tank 0 /y Overpressure storage tank Overpressure storage tank 0 /y Loss of vacuum insulation Loss of vacuum insulation 0 /y Liquid hydrogen release Liquid hydrogen release 0 /y tank burst - instantaneous release of full tank contents tank burst - instantaneous release of full 0 /y Release of full tank contents Release of full tank contents 0 /y Hydrogen release from jacket Hydrogen release from jacket 0 /y
Liquid Hydrogen Station - Liquid Storage (This Diagram has no Measures assigned) Overfilling protection Overfilling protection 0 Pressure Relief Valve Pressure Relief Valve 0 Pressure Safety Valve Pressure Safety Valve 0 Rupture disc Rupture disc 0 Tank filling operation Tank filling operation 0 /y Release from inner tank Release from inner tank 0 /y Boil-off exceeds consumption Boil-off exceeds consumption 0 /y External damage of jacket External damage of jacket 0 /y Pressure rise in tank Pressure rise in tank 0 /y Overpressure storage tank Overpressure storage tank 0 /y Loss of vacuum insulation Loss of vacuum insulation 0 /y Liquid hydrogen release Liquid hydrogen release 0 /y tank burst - instantaneous release of full tank contents tank burst - instantaneous release of full 0 /y Release of full tank contents Release of full tank contents 0 /y Hydrogen release from jacket Hydrogen release from jacket 0 /y

Project

NAME: HydrogenFuellingOptions..sbmx
DESCRIPTION
Safety barrier analysis of Liquid Hydrogen Station based on the FMEA analyses and other information from: "Failure Modes and effects analysis for hydrogen fuelling options, California Energy Commission (CEC) Consultant report Nov. 2004, CEC-600-2005-001/Technical Consultant report TR-03-177 TIAX Case D0130.
The analysis is performed by Nijs Jan Duijm, Risø National Labortory, Denmark, using the barrier type classification as developed under the ARAMIS project.
This analysis is only qualitative - therefore all PFD's and frequencies are zero.

Initial Event

NAME: Tank filling operation
Expected Frequency of Occurrence per Year: 0

Intermediate Event

NAME: Overpressure storage tank
Expected Frequency of Occurrence per Year: 0

Consequence

NAME: tank burst - instantaneous release of full tank contents
Expected Frequency of Occurrence per Year: 0

Consequence

NAME: Release of full tank contents
Expected Frequency of Occurrence per Year: 0

Consequence

NAME: Unnoticed explosive atmosphere
Expected Frequency of Occurrence per Year: 0

Intermediate Event

NAME: Pressure rise in tank
Expected Frequency of Occurrence per Year: 0

Initial Event

NAME: Truck has defects on arrival
Expected Frequency of Occurrence per Year: 1

Intermediate Event

NAME: Release from unloading facility
Expected Frequency of Occurrence per Year: 0.01
DESCRIPTION

Initial Event

NAME: Defects in unloading hoses
Expected Frequency of Occurrence per Year: 0

Initial Event

NAME: Incorrect coupling to fixed facility
Expected Frequency of Occurrence per Year: 0

Intermediate Event

NAME: Continued release from unloading facility
Expected Frequency of Occurrence per Year: 0

Consequence

NAME: Cryogenic burn/personnel
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Consequence

NAME: Cryogenic burn/third parties
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Intermediate Event

NAME: Liquid hydrogen spill
Expected Frequency of Occurrence per Year: 0.01
DESCRIPTION

Initial Event

NAME: Liquid hydrogen in unloading hose
Expected Frequency of Occurrence per Year: 1
DESCRIPTION

Initial Event

NAME: Vehicle movement into truck or unloading facility
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Consequence

NAME: Liquid hydrogen release
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Intermediate Event

NAME: Loss of vacuum insulation
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Initial Event

NAME: Boil-off exceeds consumption
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Intermediate Event

NAME: Loss of containment/ unloading
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Initial Event

NAME: Release from inner tank
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Consequence

NAME: Hydrogen release from jacket
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Initial Event

NAME: External damage of jacket
Expected Frequency of Occurrence per Year: 0
DESCRIPTION

Barrier Diagram

NAME: Liquid Hydrogen Station - Truck delivery and unloading action
DESCRIPTION
Safety analysis of the truck delivery and unloading activities
This analysis does not include the liquid hydrogen storage tank

Barrier

NAME: Unloading Inspection
Probability of Failure on Demand (PFD): 0.01
DESCRIPTION

BARRIER TYPE: 10 Activated Barrier - Procedural (Observation of local conditions not using instruments)
BARRIER TYPE DESCRIPTION

Barrier

NAME: Inspection of hoses
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 10 Activated Barrier - Procedural (Observation of local conditions not using instruments)
BARRIER TYPE DESCRIPTION

Barrier

NAME: Inspection of connections
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 10 Activated Barrier - Procedural (Observation of local conditions not using instruments)
BARRIER TYPE DESCRIPTION

Barrier

NAME: Supervision during unloading
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 10 Activated Barrier - Procedural (Observation of local conditions not using instruments)
BARRIER TYPE DESCRIPTION

Barrier

NAME: Hydrogen sensors
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 8 Activated Barrier - Warned (Human Action based on passive warning)
BARRIER TYPE DESCRIPTION

Barrier

NAME: Collision prevention
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 3 Temporary Passive Barrier - Put in place (and removed) by person
BARRIER TYPE DESCRIPTION

Barrier

NAME: Venting prior disconnection
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 10 Activated Barrier - Procedural (Observation of local conditions not using instruments)
BARRIER TYPE DESCRIPTION

OR Gate

NAME: OrGate1

Barrier

NAME: Limited access
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 8 Activated Barrier - Warned (Human Action based on passive warning)
BARRIER TYPE DESCRIPTION

Barrier

NAME: Personal protection
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 3 Temporary Passive Barrier - Put in place (and removed) by person
BARRIER TYPE DESCRIPTION

Barrier Diagram

NAME: Liquid Hydrogen Station - Liquid Storage
DESCRIPTION
Design Intent: Store 2000 gallons (7.6 m3) of liquid hydrogen at 10 psig (0.7 barg) and -420 F (22 K)

Barrier

NAME: Overfilling protection
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 7 Activated Barrier - Manual (Human action triggered by active hardware detection)
BARRIER TYPE DESCRIPTION

OR Gate

NAME: OrGate2

OR Gate

NAME: OrGate3

Barrier

NAME: Pressure Relief Valve
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 5 Activated Barrier - Hardware on demand
BARRIER TYPE DESCRIPTION

Barrier

NAME: Pressure Safety Valve
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 5 Activated Barrier - Hardware on demand
BARRIER TYPE DESCRIPTION

Barrier

NAME: Rupture disc
Probability of Failure on Demand (PFD): 0
DESCRIPTION

BARRIER TYPE: 5 Activated Barrier - Hardware on demand
BARRIER TYPE DESCRIPTION

Consequences

Barrier Diagram Consequence Prob./Expected Freq. (Unit) Severity
Liquid Hydrogen Station - Truck delivery and unloading action Unnoticed explosive atmosphere 0 Expected Frequency of Occurrence per Year  
Liquid Hydrogen Station - Truck delivery and unloading action Cryogenic burn/personnel 0 Expected Frequency of Occurrence per Year  
Liquid Hydrogen Station - Truck delivery and unloading action Cryogenic burn/third parties 0 Expected Frequency of Occurrence per Year  
Liquid Hydrogen Station - Liquid Storage Liquid hydrogen release 0 Expected Frequency of Occurrence per Year  
Liquid Hydrogen Station - Liquid Storage tank burst - instantaneous release of full tank contents 0 Expected Frequency of Occurrence per Year  
Liquid Hydrogen Station - Liquid Storage Release of full tank contents 0 Expected Frequency of Occurrence per Year  
Liquid Hydrogen Station - Liquid Storage Hydrogen release from jacket 0 Expected Frequency of Occurrence per Year  

Critical Events

Barrier Diagram Critical Event Prob./Expected Freq. (Unit)

Risk Matrix

  Expected Frequency of Occurrence per Year insignificant significant serious
Frequent More likely than: 0.1      
Probable Less likely than: 0.1      
Improbable Less likely than: 0.001      
Very Improbable Less likely than: 1E-5      

Barriers

Barrier Barrier Diagram Generic Barrier Barrier Type PFD Description 1st ARAMIS Item, Manpower Planning and Availability 2nd ARAMIS Item, Competence and Suitability 3rd ARAMIS Item, Commitment, Compliance and Conflict resolution 4th ARAMIS Item, Communication and Coordination 5th ARAMIS Item, Procedures, rules, and goals 6th ARAMIS Item, Hard/software purchase, build, interface, install 7th ARAMIS Item, Hard/software Inspection, Maintenance, and Replacement 0th ARAMIS Item, Safety Culture
            Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating
Unloading Inspection Liquid Hydrogen Station - Truck delivery and unloading action   10 Activated Barrier - Procedural (Observation of local conditions not using instruments) 0.01 10 Activated Barrier - Procedural (Observation of local conditions not using instruments) On arrival of the truck, the truck is inspected visually for defects by driver or station operator (need to be decided who). The mitigation action what to do in case defects are noted need to be included. This need to be documented and trained as a standard procedure.                                
Inspection of hoses Liquid Hydrogen Station - Truck delivery and unloading action   10 Activated Barrier - Procedural (Observation of local conditions not using instruments) 0 10 Activated Barrier - Procedural (Observation of local conditions not using instruments) Inspection of hoses before unloading/connection                                
Inspection of connections Liquid Hydrogen Station - Truck delivery and unloading action   10 Activated Barrier - Procedural (Observation of local conditions not using instruments) 0 10 Activated Barrier - Procedural (Observation of local conditions not using instruments) Connections are inspected before unloading action is started                                
Supervision during unloading Liquid Hydrogen Station - Truck delivery and unloading action   10 Activated Barrier - Procedural (Observation of local conditions not using instruments) 0 10 Activated Barrier - Procedural (Observation of local conditions not using instruments) The unloading action is monitored by personnel. Note that the personnel may become disabled by freeze burn - consider additional remote monitoring Deviations of the unloading lead to aborting the unloading action                                
Hydrogen sensors Liquid Hydrogen Station - Truck delivery and unloading action   8 Activated Barrier - Warned (Human Action based on passive warning) 0 8 Activated Barrier - Warned (Human Action based on passive warning) Hydrogen sensors are located near the unloading facility The sensors themselves do not mitigate the presence of an explosive atmosphere, so a follow up has to be find in terms of alarms, evacuation, close down of unloading operation, close down of potential ignition sources                                
Collision prevention Liquid Hydrogen Station - Truck delivery and unloading action   3 Temporary Passive Barrier - Put in place (and removed) by person 0 3 Temporary Passive Barrier The unloading facility can be protected against external impacts such as third party traffic. Different options are possible. The FMEA report suggests that driver puts caution cones around the truck. This would be an "activated barrier - warned (Human action based on warning, sign, alarm), where the barrier is also temporary, i.e there are two failure modes: the cones are not placed or the driver ignores the warning. A more robust option would be a combination of collision-resistant barriers (e.g. concrete poles, steel barrier) around the unloading facitily in combination with a collision-resistant temporary barrier (fence) on the access way to the truck's unloading position                                
Venting prior disconnection Liquid Hydrogen Station - Truck delivery and unloading action   10 Activated Barrier - Procedural (Observation of local conditions not using instruments) 0 10 Activated Barrier - Procedural (Observation of local conditions not using instruments) Unloading hoses need to be vented prior to disconnection                                
Limited access Liquid Hydrogen Station - Truck delivery and unloading action   8 Activated Barrier - Warned (Human Action based on passive warning) 0 8 Activated Barrier - Warned (Human Action based on passive warning) A safety distance atround the truck and unloding facility where access is prohibited to third parties and personnel not involved in the unloading action Barrier can be enforced by signs, lights (when unloading) and supervision of personnel                                
Personal protection Liquid Hydrogen Station - Truck delivery and unloading action   3 Temporary Passive Barrier - Put in place (and removed) by person 0 3 Temporary Passive Barrier Unloading operator and truck driver have donned protective clothing against cryogenic burn ("Nomex suit")                                
Overfilling protection Liquid Hydrogen Station - Liquid Storage   7 Activated Barrier - Manual (Human action triggered by active hardware detection) 0 Overfilling protection may consists of several independent systems, instruments, alarms and human intervention 7 Activated Barrier - Manual (Human action triggered by active hardware detection)                                
Pressure Relief Valve Liquid Hydrogen Station - Liquid Storage   5 Activated Barrier - Hardware on demand 0 5 Activated Barrier - Hardware on demand The inner tank is provided with two pressure relief valves. The release will be vented to a safe location (vertical upwards and well above the ground level) These relief valves will be able to handle pressure rise due to normal evaporation rates in the tank by venting vapour. Overfilling will cause the PRV's to dump liquid as well. Capacity will probably be too limited to handle full loss of insulation.                     0.5 0 0.5 0    
Pressure Safety Valve Liquid Hydrogen Station - Liquid Storage   5 Activated Barrier - Hardware on demand 0 5 Activated Barrier - Hardware on demand A pressure safety valve is mounted on the vacuum space between outer jacket and inner tank, that releases at 0 psig (0 barg, i.e. atmospheric pressure)                     0.5 0 0.5 0    
Rupture disc Liquid Hydrogen Station - Liquid Storage   5 Activated Barrier - Hardware on demand 0 5 Activated Barrier - Hardware on demand On the line to the Pressure Relief Valve a ruspture disc is mounted, that will release the tank pressure if the pressure rises above the set pressure of the PRV's. The release will be vented to a safe location (vertical upwards and well above the ground level)                     0.5 0 0.5 0    

Generic Barriers

Generic Barrier Barrier Type PFD Description 1st ARAMIS Item, Manpower Planning and Availability 2nd ARAMIS Item, Competence and Suitability 3rd ARAMIS Item, Commitment, Compliance and Conflict resolution 4th ARAMIS Item, Communication and Coordination 5th ARAMIS Item, Procedures, rules, and goals 6th ARAMIS Item, Hard/software purchase, build, interface, install 7th ARAMIS Item, Hard/software Inspection, Maintenance, and Replacement 0th ARAMIS Item, Safety Culture
        Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating
tank wall 1 Permanent Passive (Control) 0 1 Permanent Passive (Control)                     0.8 0 0.2 0    
Pressure RV 5 Activated Barrier - Hardware on demand 0.001                       0.5 0 0.5 0    
Operator control operation 7 Activated Barrier - Manual (Human action triggered by active hardware detection) 0.01 Type: Activated Barrier - Manual (Human action triggered by active hardware detection) Normal control operation in response to instrument reading - highly routine operation (rule based)                                

Barrier Types

Barrier Type Description 1st ARAMIS Item, Manpower Planning and Availability 2nd ARAMIS Item, Competence and Suitability 3rd ARAMIS Item, Commitment, Compliance and Conflict resolution 4th ARAMIS Item, Communication and Coordination 5th ARAMIS Item, Procedures, rules, and goals 6th ARAMIS Item, Hard/software purchase, build, interface, install 7th ARAMIS Item, Hard/software Inspection, Maintenance, and Replacement 0th ARAMIS Item, Safety Culture
    Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating
1 Permanent Passive (Control) Detection: none; Diagnosis: none; Activation: hardware. Passive controls are those elements in a process system that are necessary for the system to operate, and essential to avoid the hazardous situations. Typical examples are tanks (tank walls) pipes (pipewalls), anticorrosion paint, floating tank lids, viewing ports in vessels                     0.8 0 0.2 0    
2 Permanent Passive Barrier Detection: none; Diagnosis: none; Activation: hardware. Passive Barriers are elements in a system that are constantly present (i.e. they do not need to be activated), and that are installed with the only reason to avoid or limit hazardous situations (i.e. the installation can in principle operate without those barriers). Typical examples are tank bunds, dyke, blastwalls, fire protection, drainage sump, fence, lightning conductors                                
3 Temporary Passive Barrier - Put in place (and removed) by person Detection: none; Diagnosis: none (must be put in place); Activation: hardware. Barriers temporary put in place such as barriers round repair work, blind flanges over open pipes, spades in pipes, inhibitors in substances                                
4 Permanent Active Barrier Detection: none; Diagnosis: none (need operator activation in some conditions); Activation: hardware. These barriers are constantly present, but need an energy source to work, such as ventilation, active corrosion protection, inerting, heating or cooling.                                
5 Activated Barrier - Hardware on demand Detection: hardware; Diagnosis: hardware; Activation: hardware. Barriers and controls that by hardware take action: Pressure relief valves, interlock systems with "hard" logic, sprinkler installation (barriers) Pressure/temperature/level control (controls or barriers)                     0.5 0 0.5 0    
6 Activated Barrier - Automated Detection: hardware; Diagnosis: software; Activation: hardware. Programmable automated device, control system or shutdown system                                
7 Activated Barrier - Manual (Human action triggered by active hardware detection) Detection: hardware; Diagnosis: behaviour (Rule, Skill or Knowledge based); Activation: Behaviour with possible hardware assist. Actions of operators in response to instrument reading, signals or alarms, e.g. Manual shutdown or adjustment, evacuation, donning breathing apparatus or calling fire brigade on alarm, action triggered by remote camera, drain valve, close/open (correct) valve                                
8 Activated Barrier - Warned (Human Action based on passive warning) Detection: hardware; Diagnosis: behaviour (Skill or Rule); Activation: behaviour. Donning personal protection equipment in danger area, refraining from smoking, keeping within white lines, opening labelled pipe, keeping out of prohibited areas                                
9 Activated Barrier - Assisted (Software presents diagnosis to operator) Detection: hardware; Diagnosis: Software/Behaviour (Rule or Knowledge based); Activation: Behaviour with possible hardware assist. Using an expert system or other software that determines the plant state based on some combination of inputs                                
10 Activated Barrier - Procedural (Observation of local conditions not using instruments) Detection: Human; Diagnosis: Behaviour (Skill or Rule based); Activation: Behaviour with possible hardware assist. (Correctly) follow start up/shutdown/batch process procedure, adjust setting of hardware, warn others to act or evacuate, (un)couple tanker from storage, empty & purge line before opening, drive tanker, lay down water curtain                                
11 Activated Barrier - Emergency (Ad-hoc observation of deviation and improvised response) Detection: Human; Diagnosis: Behaviour (Knowledge based); Activation: Behaviour with possible hardware assist. Response to unexpected emergency, e.g. improvised jury-rig during maintenance, fight fire                                

Common Elements

Barrier Element PFD Description 1st ARAMIS Item, Manpower Planning and Availability 2nd ARAMIS Item, Competence and Suitability 3rd ARAMIS Item, Commitment, Compliance and Conflict resolution 4th ARAMIS Item, Communication and Coordination 5th ARAMIS Item, Procedures, rules, and goals 6th ARAMIS Item, Hard/software purchase, build, interface, install 7th ARAMIS Item, Hard/software Inspection, Maintenance, and Replacement 0th ARAMIS Item, Safety Culture
      Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating Weight Rating

Gates

Gate Barrier Diagram Gate Type Description
       
OrGate1 Liquid Hydrogen Station - Truck delivery and unloading action OR Gate  
OrGate2 Liquid Hydrogen Station - Liquid Storage OR Gate  
OrGate3 Liquid Hydrogen Station - Liquid Storage OR Gate  

Conditions

Condition Condition Type Freq. or Prob. Unit Description Severity
Tank filling operation Initial Event 0 Expected Frequency of Occurrence per Year    
Overpressure storage tank Intermediate Event 0 Expected Frequency of Occurrence per Year    
tank burst - instantaneous release of full tank contents Consequence 0 Expected Frequency of Occurrence per Year    
Release of full tank contents Consequence 0 Expected Frequency of Occurrence per Year    
Unnoticed explosive atmosphere Consequence 0 Expected Frequency of Occurrence per Year    
Pressure rise in tank Intermediate Event 0 Expected Frequency of Occurrence per Year    
Truck has defects on arrival Initial Event 1 Expected Frequency of Occurrence per Year    
Release from unloading facility Intermediate Event 0.01 Expected Frequency of Occurrence per Year Release form either truck or unloading hose or connection facility at station  
Defects in unloading hoses Initial Event 0 Expected Frequency of Occurrence per Year    
Incorrect coupling to fixed facility Initial Event 0 Expected Frequency of Occurrence per Year    
Continued release from unloading facility Intermediate Event 0 Expected Frequency of Occurrence per Year    
Cryogenic burn/personnel Consequence 0 Expected Frequency of Occurrence per Year Cryogenic burn of operating personnel  
Cryogenic burn/third parties Consequence 0 Expected Frequency of Occurrence per Year Cryogenic burn of third parties and personnel not involved in the unloading operation  
Liquid hydrogen spill Intermediate Event 0.01 Expected Frequency of Occurrence per Year uncontrolled spill of liquid hydrogen from damaged truck or unloading facility  
Liquid hydrogen in unloading hose Initial Event 1 Expected Frequency of Occurrence per Year There is always liquid hydrogen in the unloading hose after unloading and before disconnection  
Vehicle movement into truck or unloading facility Initial Event 0 Expected Frequency of Occurrence per Year Two possibilities exists: third party vehicles moving into the direction of the truck at the unloadng facility, and the truck itself threatening the fixed installations  
Liquid hydrogen release Consequence 0 Expected Frequency of Occurrence per Year In case of overfilling or pressure rise, the PRV will dump liquid hydrogen. In that case the safe relief location may need further protection against fire and explosion  
Loss of vacuum insulation Intermediate Event 0 Expected Frequency of Occurrence per Year In case of failure of the outer tank (jacket) the vacuume insulation will disappaer and heat transfer to the inner tank will cause excessive boil off an pressure rise in the inner tank  
Boil-off exceeds consumption Initial Event 0 Expected Frequency of Occurrence per Year Evaporation in tank due to lack off vehicle filling (less than 1 vehicle per 2 weeks),  
Loss of containment/ unloading Intermediate Event 0 Expected Frequency of Occurrence per Year Vehicle impact may lead to loss of containment  
Release from inner tank Initial Event 0 Expected Frequency of Occurrence per Year Leakage of inner tank will cause pressure built up in the vacuum shell between jacket and inner tank  
Hydrogen release from jacket Consequence 0 Expected Frequency of Occurrence per Year The jacket (outer tank) is not designed to withstand internal pressure, leakage from the inner tank will pressurise the vacuum space  
External damage of jacket Initial Event 0 Expected Frequency of Occurrence per Year External damage will destroy the vacuum inside the jacket  

Measures

Measure Description Applies to: Barriers Applies to: Initial Conditions Management Issue

Management Issues

Management Issue Performance Description
1st ARAMIS Item, Manpower Planning and Availability 1 Manpower Planning covers allocating the necessary time (or numbers) of competent people to the tasks that have to be carried out, at the moment (or within the time frame) when they should be carried out. It also covers the process of planning and allocation of tasks over time, including coverage for: Holidays, Sick leave, Peak loads, Ensuring breaks and rest pauses, and Limiting overtime and fatigue. Personnel Availability ensures that personnell is available for all relevant tasks in relation to the functioning and management of barriers (operations, maintenance, emergency), including: Operating personnel, Maintenance personnel, Inspection & testing incl. general plantwalk-rounds, Supervision, and Back-up & emergency crews,.
2nd ARAMIS Item, Competence and Suitability 1 Competence covers the knowledge, skills, and abilities of first-line and/or back-up personnel for the safe execution of safety-critical tasks related to barrier functioning or management. Competence covers the cognitive aspects of behaviour, which can be learned through training, experience and practice. They include: Job content/safety, e.g.: Plant & process knowledge: - Operating procedures, critical tasks, action alternatives, skills - Boundary of safety operations - Hazards, safety consequences of actions, safety priorities - Safety responsibility/task boundaries Inspection & testing procedures: - Fault diagnosis & response - Emergency procedures - Maintenance diagnosis - Safe isolation and recommissioning - Equipment dismantling, repair, testing & reassembly Other skills: - Communications - Team work - Supervision/management - Issuing instructions Suitability covers physical attributes that are usually more permanent characteristics of an individual, though some can be modified or compensated for over the longer term. They include: Size, strength, dexterity, Physical condition, health, Visual acuity, colour blindness, and Hearing.
3rd ARAMIS Item, Commitment, Compliance and Conflict resolution 1 Commitment and conflict resolution are concerned with: - Information, training and discussion on what is important and has priority - Rapid confrontation and correction of deviations from the desired working method, state or condition - High (publicity) profile and reward for achievements on safety - Appraisal schemes with explicit attention to safety performance - Recurrent active attention to safety in meetings, discussions and actions - Procedure violations - Keeping to the prescribed operating envelope - Safety and production/time pressures e.g. production pressures reducing scheduled maintenance/inspection, operations which come under time pressure for implementation, reluctance to declare emergencies or shutdown plant because of loss of production - Safety critical maintenance priority over production - Balancing production targets, resource availability/costs and inspection and maintenance requirements via e.g. time schedules and budget setting - Safety budget (increased/decreased)
4th ARAMIS Item, Communication and Coordination 1 The communication and coordination concerns itself with: - Communication channels (phone, radio, minutes, reports, etc.) - Coordination methods (e.g. meetings, supervision) - Communication between: Different persons engaged on one task as team or working in sequence, and Shifts at changeover - Communication about: Work content Barrier/plant status Job instructions Priorities Who does what, where and when Need for action or (back-up) personnel and equipment - Communication systems for sharing operation/maintenance hazard concerns and experience
5th ARAMIS Item, Procedures, rules, and goals 1 The procedures, rules and goals delivery system is occupied with identifying tasks that need (detailed) written rules and procedures, and subsequently providing and promulgating these. This system also delivers output goals for tasks that do not need a detailed procedure. Procedures and rules are specific performance criteria, which specify in detail, usually in written form, a formalised 'normative' behaviour or method for carrying out an activity (checklist, task list, action steps, plan, instruction manual, fault-finding heuristic, form to be completed, etc.). Output goals are performance measures for an activity, which specify what the result of the activity should be, but not how the results should be achieved. They are objectives, goals or outputs. The procedures, rules and goals delivery system concerns itself with: Coverage (i.e. all safety situations), Accuracy, Readability/usability, Size/complexity/overload or rule sets, Clarity/ambiguity, Up-to-date, Indicating priorities.
6th ARAMIS Item, Hard/software purchase, build, interface, install 1 Management of barrier (and spares) purchase, construction, installation and adjustment deals with the management process for ensuring that the hardware/ software barriers and barrier elements in agreement with specifications are acquired, either by purchase from outside, or by construction on site, are put in place and adjusted and that the spare parts or replacements purchased and stored for the maintenance phase of their life cycle are the correct ones and are in good condition when used. The process should pay explicit attention to the human factors aspects of the interface between barrier elements and their users in the case of mixed barriers.
7th ARAMIS Item, Hard/software Inspection, Maintenance, and Replacement 1 Management of inspection, maintenance and replacement deals with the management processes for ensuring that the specified hardware/software barriers and barrier elements are kept in an effective state. It covers all hardware and software which has a function within any barrier designed to fulfill a safety function in the plant. It forms the part of the life cycle of these barrier elements from the point where they have been installed and adjusted and are ready for use. It covers all the activities which monitor the working of the barriers, detect the (chance of) deviation from the designed working and identify the need for work to be done to restore the functioning or replace the barrier (elements) with new ones. This process also manages small modifications which are carried out at the same time as, and under the same management as the maintenance activities. Where the modifications are of a more major type, which are (or should be) dealt with by a change management process, these are covered by the protocol on learning and change.
0th ARAMIS Item, Safety Culture 0.75 Safety culture can be assessed by questionnaire surveys of the personnel. Safety culture addresses the following issues: Learning and willingness to report: the employees' willingness / reluctance to report accidents and incidents, their perception of feedback from reporting and dissemination of lessons learned. Safety prioritisation, rules and compliance covering use of and familiarity with rules and instructions; the prioritisation of safety versus productivity and ease of work; the extent to which and the circumstances under which safety procedures may be violated Leadership involvement and commitment concerns both the avowed involvement and commitment of management and supervisors and team leaders as well as employee perception of their commitment and involvement Risk and human performance limitation perception concerns management and employee awareness of hazards, risks and human error potentials (fatigue, automation etc.) relevant to their work. Felt responsibility concerns the employee's perception of who is responsible for safety at work including felt ownership of responsibility Trust and fairness involves management's trust in employees and, crucially, employees' trust in top management and their immediate leaders and employee perception of fairness in the workplace Work team atmosphere and support comprises employees' perception of teamwork and the 'spirit' in their respective teams; the extent to which the team gives its members support and help; and the extent to which respondents are willing to speak up and warn each other of dangers. Motivation, influence and involvement comprises (i) work as meaningful; (ii) own influence on work planning and execution; (iii) motivation and involvement; and (iv) feeling informed and finding work predictable

Barrier Diagrams

Diagram Name Number of: Barriers Number of: Gates Number of: Event Tree Branches Description
Liquid Hydrogen Station - Truck delivery and unloading action 9 1 0 Safety analysis of the truck delivery and unloading activities This analysis does not include the liquid hydrogen storage tank
Liquid Hydrogen Station - Liquid Storage 4 2 0 Design Intent: Store 2000 gallons (7.6 m3) of liquid hydrogen at 10 psig (0.7 barg) and -420 F (22 K)

Event Tree Branches

Event Tree Branch Name Diagram Name Number of: Event Tree Branches Event Tree Branches & Probability Description