This document describes the findings of the Hazard Identification (HAZID) study conducted in support of the Quantitative Risk
Assessment for the LNG Terminal.
A HAZID workshop was conducted on the design of the
LNG Terminal between 26th and 28th October 2004.
As part of the current EIA process and in cognisance
of further developments in the design of the LNG Terminal, an additional HAZID
workshop was held on 19th and 20th October 2005, to
update the earlier study.
A layout review workshop was held on 21st
October 2005. The recommendations
made during the workshop are reflected in the layout drawings used for the EIA
studies.
1.1
Objectives & Scope
The objective of the HAZID study was to
identify hazards posed by the siting of the LNG Terminal in Hong Kong SAR, with
the main aim of identifying major hazards.
The HAZID study was based on the preliminary layout
drawings, design basis and design/construction philosophies for the
facilities. The HAZID study covered
mainly the operational phase of the project.
The study assessed potential hazards associated with,
amongst others, the following areas:
·
LNG Terminal
-
Natural Hazards
-
External Hazards
-
Material Hazards
-
Loss of Utilities
-
Layout Hazards
· Plant Systems
-
Unloading Operation
-
Transfer Pipeline from Jetty to Tank
-
LNG Storage Tanks
-
LP LNG System – Tank Pumpout
-
Compressors – BOG, Ship, Pipeline
-
HP LNG System
-
ORV/SCR Vaporisers
-
Fuel Gas, Gas Heating, Gas Metering
-
Vent & Drain System
-
Utilities & Auxiliary Systems
· Construction Phase
-
Blasting Operations During Initial Construction
-
Third LNG Tank Construction – Expansion
-
Process System Construction - Expansion
The
following documentation was
available for the HAZID studies:
·
PFDs,
Process description;
·
Location
and layout of facilities, plot plans.
1.2.2
HAZID Methodology
The hazards posed by the
facility were identified based on team’s experience, past accidents, lessons
learnt and checklists. The hazard identification was carried out at a high
level, i.e. at the plant and unit level.
In order to ensure that a
systematic approach is adopted, the facility was divided into a number of
‘subsystems’ based on the layout and the process; the guidewords from the
checklist (Table 1.1) was then
applied to each subsystem as relevant. Some of the guidewords such as natural
hazards and external hazards however, were applied at the plant level only.
A “brainstorming” session was
held involving a team of specialists from various disciplines. The objective of
this brainstorming session was to identify all the hazards, particularly those
specific to the plant/project under consideration.
The study team considered
each area in turn and any hazards that apply to it. The hazards discussed
included hazardous materials stored in these areas.
The study included the
assessment of:
· Hazards;
· Potential
Consequences;
· Safeguards; and
· Proposed
Prevention, Control and Mitigation Factors.
The Study Team discussed
recommendations for risk reduction and/or further study as appropriate.
HAZID worksheets were used to
record the hazards, the consequences, safeguards and additional mitigation
measures.
The study output will also
serve as a basis for identification of scenarios for the QRA study.
Table 1.1 Checklist
for Hazard Identification
General |
Material hazards |
Toxic, flammable, explosion, oxidising,
spontaneously flammable, carcinogenic |
|
Plant Level |
Natural hazards |
|
External hazards |
|
Layout hazards |
Unit Level |
Process hazards |
|
Transport hazards |
Shipping Hazards |
1.3
HAZID Sessions and layout
Review Workshop
The HAZID study was conducted
from 19th to 20th October 2005. A layout review workshop was held on 21st
October 2005. The HAZID sessions
and layout review workshop were held in Foster Wheeler’s office in
The HAZID
team comprised a multidisciplinary team of personnel involved with the project
and having adequate experience of design, operations, and safety and loss
prevention.
Representatives from CLP Power, ExxonMobil, ARUP
and Foster Wheeler participated in the HAZID sessions. Venkatesh S of ERM
chaired the HAZID sessions.
The details (names, discipline and company) of the HAZID team members who attended each HAZID session are presented in Table 1.2.
Table 1.2 List
of Participants for the HAZID Study during the EIA Studies
Name |
Company |
Discipline |
19th Oct 2005 |
20th Oct 2005 |
Jim Power |
CLP |
Technical Advisor |
Ö |
Ö |
Siu Fung Wong |
CLP |
Technical
Associate |
Ö |
Ö |
Francis Chau |
CLP |
Technical
Services |
Ö |
Ö |
Peter Thompson |
Arup |
Civil Design |
Ö |
Ö |
Cathy Duke |
EM |
Gas Engineering |
Ö |
Ö |
Cheryl Grounds |
EMDC |
Safety and Risk |
Ö |
Ö |
Charles Hughes |
EMDC |
Marine and Civil |
Ö |
Ö |
Winston Shu |
EMDC |
Senior Technical
Advisor, Gas Engineering |
Ö |
Ö |
Steven Wu |
EMDC |
Civil and
Structure |
Ö |
Ö |
Gary Spargo |
EMDC |
Construction
Advisor |
Ö |
Ö |
William Duncan |
EMDC |
Captain |
Ö |
Ö |
Patrick Wong |
EMDC |
Geotechnical |
Ö |
Ö |
Efren P Rocha |
EMPC |
Operations
Advisor |
Ö |
Ö |
Sam Hwong |
Foster Wheeler |
Project Manager |
Ö |
Ö |
Zupeng Huang |
Foster Wheeler |
LNG Process |
Ö |
Ö |
C C Yang |
Foster Wheeler |
Director, LNG
Technology |
Ö |
Ö |
David Labay |
Foster Wheeler |
Piping Engineer |
Ö |
Ö |
Risk Speicher |
Foster Wheeler |
Construction |
Ö |
Ö |
Justo Benitez |
Foster Wheeler |
Electrical
Engineering |
Ö |
Ö |
K B Tammana |
Foster Wheeler |
Instrumentation |
Ö |
Ö |
Ted Ban |
Foster Wheeler |
Civil |
Ö |
Ö |
Larry Watrous |
Mustang |
Fire Protection |
Ö |
Ö |
Robin Kennish |
ERM |
EIA Permitting |
Ö |
Ö |
Venkatesh S |
ERM |
HAZID
Facilitator/ QRA |
Ö |
Ö |
The session proceedings were recorded using PHA-Pro
6 software. The records
were projected on a screen for comments and agreement by the team members
during the sessions.
The completed HAZID worksheets are attached in the Appendix.
Table 1.3 lists the
actions identified during the HAZID sessions. These actions will be incorporated in
the detailed design.
Table 1.3 Actions
for Each Area Considered
Action No. |
Hazards |
Action |
1 |
Natural Hazards
- Typhoon - high wind & storm waves |
Design criteria
for jetty design at |
2 |
Natural Hazards
- Lightning |
Consider the impact
of power dips due to lightening in equipment specification for motor drives |
3 |
Natural Hazards
- Hill fire |
Liaise with
AFCD and FSD to provide a fire barrier at the boundary fence to prevent fire
propagation |
4 |
Natural Hazards
- Subsidence |
Consider past
experience in |
5 |
Natural Hazards
- Sea water - seasonal variation in salinity |
Consider seawater
salinity variation in the design of loading arm and jetty design as well as
the dredging requirement at the berth to accommodate the carrier |
6 |
External
Hazards - Aircraft crash |
Include in the
QRA study for Soko, the likelihood of aircraft crash |
7 |
External
Hazards - Helicopter crash |
Consider
establishing no fly zone over the terminal area or impact of helicopter
flight path on the facility to be considered |
8 |
Loss of
Utilities - Loss of Power supply |
Reliability of power
supply to the LNG terminal to be studied during pre-FEED. Options may include
direct supply from station, redundant supply sources |
9 |
Loss of
Utilities - Loss of sea water supply |
Design of sea
water intake to consider potential for blockage due to debris including
fishing nets etc to ensure reliability of sea water supply |
10 |
Loss of
Utilities - Loss of fresh water supply |
Fresh water
supply to Soko to be reviewed during pre-FEED |
11 |
ORV/SCV
Vaporisers -Heavy metals in sea water |
Potential
impact on ORV due to mercury content in sea water to be (re)confirmed during
design based on vendor data |
12 |
External
Hazards - Radio-isotopes |
Review the
regulatory requirements for storage and handling of radio-isotopes for
welding/ inspection and make suitable provisions at the site |
13 |
Transfer
Pipeline from Jetty to Tank - Collision of drifting vessels or fishing
vessels with trestle structure |
Review the
requirements for a safety zone around jetty. |
14 |
LNG Storage Tanks
- Loss of containment |
Develop a write
up documenting this scenario, i.e. the impact of overpressure inside the tank
on the outer containment/ roof |
15 |
LNG Storage
Tanks - Hydrotesting of tanks |
Consider the impact
of seawater for hydrotesting on tank metallurgy |
16 |
LP LNG System –
Tank pumpout - inspection of pressure vessel |
Investigate
whether on-line inspection is feasible and meets regulatory requirements |
17 |
ORV/SCV
Vaporisers -Overpressure in vaporizer outlet piping |
Review, during
detailed design, overpressure safeguards for piping downstream of vaporiser |
18 |
Vent &
Drain System - Discharge of gas from vent stack |
Analyze the pros
and cons of a vent versus flare option to determine the appropriate path
forward |
19 |
Natural Hazards
- Landslip - landslides |
Detailed layout
will consider pipe rack routing from/to tanks to not be at the base of the
rock cut |
20 |
Natural Hazards
- Tsunami - associated with subsea earthquake |
Consider
developing procedures for LNG carrier departure following Tsunami warning |
Appendix
System: 1. LNG Terminal
Overview |
Subsystem: 1.
Natural hazards |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Typhoon - high wind & storm waves |
1.
High wind |
1.
Possible impact on structures due to high wind |
1.
Design basis for the facility - HK Code of Practice for Wind Effects 2004 by
BD (3 sec gust for 50 yr return period) for land buildings/ structures. Port Work Design Manual will be
followed for marine structures (3 sec gust for 50 yr return period). Based on
the design factors specific to the HK Code, this may be considered equivalent
to 1 in 100 year return period of other international codes |
1.
Design criteria for jetty design at |
2.
Storm waves |
2.
Impact on berthing and unloading operation |
2.
Operating practice with regard to berthing & unloading in adverse
conditions |
||
3.
Possible damage to structures/ facilities due to storm wave and associated
flooding |
3.
Site elevation to be based on wave height for 1 in 100 year return period.
Sea wall will be constructed along the shoreline. Elevation at |
|||
2.
Lightning |
1.
Lightning |
1.
Possible ignition of discharges from vent stack/ PSVs on tank roof |
1.
Fire snuffing system for PSVs on tank top and vent stack |
2.
Consider the impact of power dips due to lightening in equipment
specification for motor drives |
2.
Possible ignition of discharges to vent at ship end |
2.
Radiation effects from ignited vent stack considered in vent stack design
(i.e. height and proximity to other features) |
|||
3.
Possible impact on instrumentation and control due to power surge |
3.
Plant instrumentation system designed for fail safe condition |
|||
4.
Power dips leading to possible interruption in plant |
4.
Procedure to shut down cargo transfer operations |
|||
3.
Earthquake |
1.
Earthquake |
1.
Possible damage to facility; potential leaks due to loss of containment |
1.
Tank designed as per code EN1473 requirement |
|
2.
Other process structures - piping & jetty designed as per EN1473 |
||||
3.
Occupied buildings designed to |
||||
4.
Heavy rainfall - flooding |
1.
Heavy rainfall |
1.
Possible damage to facilities due to flooding |
1.
Stormwater drainage system designed to DSD Manual for 1 in 50 year storm on
the basis that this is a urban branch drainage system with diameters not
exceeding 1.8m. |
|
5.
Fog - poor visibility |
1.
Fog |
1. No
significant impact during unloading or facility operation |
1.
Collision hazards while the vessel is berthed considered in marine traffic
impact study |
|
2.
Possible collision of other craft with the LNG vessel while berthed |
||||
6.
Landslip - landslides |
1.
Landslides from man-made slopes or natural terrain due to slope instability
or earthquake |
1.
Possible damage to tanks, piping, and facility including control room/ admin
buildings |
1.
Geotechnical studies during design phase and slope design and maintenance |
19.
Detailed layout will consider pipe rack routing from/to tanks to not be at
the base of the rock cut. |
2.
Geotechnical studies during design phase and slope stability measures to
consider impact of earthquakes of 1 in 10,000 year return period |
||||
7.
Landslip - boulderfall |
1.
Boulderfall |
1.
Possible damage to tanks, piping, and facility including control room/ admin
buildings |
1.
Geotechnical studies during design phase and boulder removal/ stabilisation
measures. See recommendation 19 |
|
8.
Hill fire |
1.
Hill fire within the boundary fence |
1.
Potential source of ignition |
1.
Vegetation management inside the fence |
3.
Liaise with AFCD and FSD to provide a fire barrier at the boundary fence to
prevent fire propagation |
2.
Hill fire outside the boundary fence - in the vicinity of the fence |
2.
Potential fire spread to vegetation inside the fence & possible impact on
facility |
|||
9.
Subsidence |
1.
Subsidence in reclamation |
1.
Misalignment and damage to tank/ piping structures (at Black Point site, two
tanks will be on rock and one tank on reclamation; future 3rd tank and
process areas on reclamation could be subject to subsidence) |
1.
3rd tank will be built some years after reclamation, providing time for
monitoring |
4.
Consider past experience in |
2.
Geotechnical studies to determine performance of sub-soil and incorporation
in design |
||||
3. If
required, 3rd future tank can be supported on piles |
||||
10.
Tsunami - associated with subsea earthquake |
1.
Tidal waves higher than predicted |
1.
Possible damage to structures/ facilities due to high wave and associated
flooding |
1.
LNG ship cargo transfer operations would be ceased following Tsunami warning. |
20.
Consider developing procedures for LNG carrier departure following Tsunami
warning |
2.
Stormwater drainage system |
||||
3.
Black Point site does not face the open seas & hence less susceptible, as
compared to Sokos |
||||
4.
Analysis has shown that expected Tsunami height at terminal locations would
be approximately equal to the historical extreme sea level (5.5m PD) (based
on 8.5 Richter scale earthquake in the |
||||
|
1.
Salinity varies from 2000 to 45,000ppm depending on |
1.
Sea water density will vary which could affect the LNG carrier draft and
accordingly the loading arm movement envelope |
|
5.
Consider seawater salinity variation in the design of loading arm and jetty
design as well as the dredging requirement at the berth to accommodate the
carrier |
2.
Impact on electrochlorination plant as hypochlorite will not be generated at
low salinity levels. This could impact hypo injection in sea water intake. No
significant consequence |
||||
|
1.
Suspended solids may vary from 40 to 800 mg/l |
1.
Increased siltation leading to increased seawater intake filter maintenance |
1.
ORV and intake filter system design specification will reflect suspended solids
content |
|
2.
Impact on ORV operation |
||||
13.
Tidal currents |
1.
Tidal currents may impact the ability to safely berth |
1.
Possible impact on berthing of LNG carrier |
1.
Maximum current condition to be considered in design basis |
|
2.
Berthing operations will not be undertaken in high current conditions (based
on evaluation of tug capacity to handle berthing operations). |
System: 1. LNG
Terminal Overview |
Subsystem: 2.
External hazards |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Aircraft crash |
1.
During take-off / landing |
1.
Damage to the facility and fire |
1.
Black Point site not in the flight path; site about 20km away from airport |
6.
Include in the QRA study for Sokos, the likelihood of aircraft crash |
2.
Helicopter crash |
1.
Helipad at BPPS and at the radar station |
1.
Damage to the facility and fire |
1.
Helipad at the radar station near BPPS used for specific purpose and not
frequent (about once per week) |
7.
Consider establishing no fly zone over the terminal area or impact of
helicopter flight path on the facility to be considered |
2.
Helipad at Sokos (provided for site access by air- usage infrequent) |
2.
Same as 1 |
|||
3.
Fishing vessels in the vicinity |
|
1.
Fishing vessels may be present within the safety zone while the carrier is
berthed; possible ignition source as well as collision hazards |
1.
Enforce safety zone |
|
4.
Drifting/ Passing vessels |
1.
Loss of power or collision between passing vessels |
1.
Possible damage to the jetty/ trestle and the carrier while berthed; loss of
containment due to damage to piping |
1.
Tugboats in attendance while the carrier is berthed |
|
2.
Isolation valves at the jetty and shore end |
||||
3.
Jetty and trestle designed for certain impact load as per standard practice |
||||
4.
Trestle sheltered by mooring dolphins and connecting structures |
||||
5.
Marine traffic impact study to consider collision of passing and drifting
vessels with the jetty structure as well as carrier while berthed |
||||
6.
Navigation aids, lights, buoys and guard boats |
||||
5.
Radar station |
1.
No issue other than helicopter activity considered above |
|
|
|
6.
Oil or chemical spills on the sea |
1.
Due to collision or sinking of passing vessels or due to incidents associated
with oil barges serving BPPS |
1.
Contamination of seawater intake leading to shutdown of ORV operation |
1.
Intake at about 10m depth |
|
2.
Possible ignition of spill affecting the jetty and trestle structure |
2.
Emergency response measures |
|||
7.
Hikers in the vicinity |
|
1.
Impact on hikers in the event of any incident at the terminal |
1.
Impact considered in the risk study |
|
2.
Property/security fence with some setback distance from the facility |
||||
8.
Pleasure fishing in the vicinity |
1.
Same as fishing boats, considered above |
|
|
|
9.
Illegal immigrants or smugglers approaching the facility by fast boats or
other means |
|
1.
Security concern/ trespass |
1.
Security plan for the facility |
|
10.
Fuel oil tank on fire or fuel oil tank rupture at BPPS |
1.
Fuel oil stored as emergency back up fuel for gas turbine |
1.
Facility is about 500m away and hence impact due to fire not likely |
|
|
11.
H2 fire/ explosion at BPPS |
1.
H2 stored at BPPS for generator cooling |
1.
Potential for projectiles causing damage to the facility |
1.
Trailer bay located in a concrete compound with ventilation, leak/fire
detection |
|
2.
No. of cylinders in a trailer limited to 12 or 26 and max 2 trailers |
||||
3.
Trailer house about 1km from LNG terminal |
||||
12.
Projectiles from turbine accidents at BPPS |
1.
Mechanical failure of turbine or lube oil failure |
1.
Potential for projectiles causing damage to the facility |
1.
Periodic inspection of the turbine |
|
2.
Turbine located in a housing and turbine housing is within a structure |
||||
3.
Full containment tank designed to withstand projectile impact |
||||
4.
Natural terrain acts as a barrier between the tanks and the BPPS site and the
turbines are located greater than 500 m from the terminal |
||||
13.
Gas leaks at BPPS |
1.
Leak in the open or in the gas turbine enclosure |
1.
Fire or explosion in the BPPS; impact on LNG terminal considered less likely
due to the separation distance of more than 200m |
1.
Gas leak detection and shutdown system at BPPS |
|
14.
Boiler explosion |
1.
High pressure (100 bar) steam boiler |
1.
Potential for projectiles causing damage to the facility |
1.
Full containment tank designed to withstand projectile impact |
|
2.
Natural terrain acts as a barrier between the tanks and the BPPS site |
||||
3.
Boiler controls/ inspection and maintenance |
||||
15.
Pipeline leak from BPPS to CPPS |
1.
Pipe at about 38barg, 6km long and 600mm diameter |
1.
Possible impact on the access road to BPPS and LNG terminal site; impact on
the LNG terminal is considered less likely due to the separation distance and
the natural terrain barrier |
1.
Pipeline is buried with shutdown valve at either end |
|
2.
Pipeline inspection and maintenance |
||||
16.
Temporary ammonium nitrate emulsion storage near BPPS |
1.
Facility operated by 3rd party |
1.
Potential fire and explosion |
1.
Separation distance is at least 1 km and there is a hill located between the
emulsion storage and the LNG terminal. |
|
2.
Impact considered in QRA |
System: 1. LNG
Terminal Overview |
Subsystem: 3.
Material hazards |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
LNG |
1.
LNG handled as liquid at -162 deg C (at 0.1 to 6barg) and as gas at max of
101 barg (at about 5 to 15 deg C for |
1.
Potential for fire; potential overpressure upon ignition of vapour cloud in
confined and congested environment |
1.
Design as per Codes with appropriate safety systems including detection,
shutdown, area classification |
|
2.
Potential for brittle failure where non-cryogenic material is exposed |
2.
Operating and safety procedures |
|||
3.
Personnel hazards on contact with cold liquid; asphyxiation hazards |
||||
2.
Hypochlorite |
1.
Onsite generation likely using electrochlorination process. Used for
disinfection of seawater intake |
1.
Concentration very low; personnel hazards; small amounts of hydrogen
generated |
1.
Design provision to vent off H2 safely |
|
3.
Caustic solution |
1.
Caustic required for neutralising SCV water discharge |
1.
Personnel hazards |
1.
Operating and safety procedures |
|
4.
Nitrogen |
1.
Nitrogen may be generated onsite or purchased - used for loading arm
operations, maintenance purging |
1.
Asphyxiation hazards, particularly in confined spaces |
1.
Operating and safety procedures |
|
2.
N2 bottles for purging of vent stacks/ fire extinguishment |
||||
5.
Pressurised air |
1.
Generated onsite for process and instrument requirements |
1.
Pressure system hazards |
1.
Design procedures |
|
2.
Operating and safety procedures |
||||
6.
Dry chemical powders |
1.
Used for fire fighting |
1.
Personnel hazards (inhalation) while handling |
1.
Operating and safety procedures |
|
7.
Diesel oil |
1.
For emergency power generation, fire water pumps and other maintenance
equipment (cranes) |
1.
Potential fire hazards |
1.
Design safety and operating procedures |
|
8.
Glycol solution (about 35%) |
1.
Used as heating fluid for the fuel gas heater |
1.
Not a combustible fluid as it is a solution in water and concentration is
low. Personnel handling hazards |
1.
Operating and safety procedures |
|
9.
Lubricants/ greases |
1.
For general machinery maintenance |
1.
Spill/ contamination |
1.
Curb area around user equipment including drip pans |
|
10.
Hydraulic oil |
1.
Hydraulic oil for loading arm movement - pressures of about 300psi |
1.
No significant safety issue. Spill hazard on the jetty platform and possibly
on the sea (from connections) |
1.
Curb area in the jetty platform. Volume in connection piping insignificant |
|
11.
Methanol |
1.
Methanol for de-icing of flanges and valves (external application) - handled
in containers |
1.
Flammable hazards. Personnel hazards in the event of spillage/ contact |
1.
Operating and safety procedures |
|
2.
Storage in approved DG stores |
||||
12.
Paints and Solvents |
1.
For painting use at site |
1.
Flammable hazards |
1.
Operating and safety procedures |
|
2.
Storage in approved DG stores |
||||
13.
Radio-isotopes |
1.
For maintenance operation - welding/ inspection |
1.
Radiation hazards to personnel but low level radiation |
1.
Procedures for handling and storage |
12.
Review the regulatory requirements for storage and handling of radio-isotopes
for welding/ inspection and make suitable provisions at the site |
14.
Gas cylinders |
1.
Helium or other gas for GC calibration, lab analysis |
1.
Physical explosion hazards |
1.
Storage in approved DG stores |
|
2.
CO2 cylinders for fire extinguishment |
||||
15.
Laboratory Chemicals |
1.
For any lab analysis of samples |
1.
Flammable, toxic hazards to personnel handling chemicals |
1.
Operating and safety procedures |
|
16.
Chemicals for sewage treatment at Soko |
1.
Alums |
1.
Personnel hazards during handling |
1.
Operating and safety procedures |
|
System: 1. LNG
Terminal Overview |
Subsystem: 4.
Loss of Utilities |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Loss of Power supply |
1.
For Black Point site, power will be supplied externally |
1.
Terminal will shutdown in safe mode; gas export will stop leading to loss of
supply to BPPS; boil-off gas may be vented to stack; unloading operation will
likely stop; heat leak in piping and equipment leading to overpressure under
blocked condition |
1.
Insulation and thermal/pressure relief |
8.
Reliability of power supply to the LNG terminal to be studied during
pre-FEED. Options may include direct supply from station, redundant supply
sources |
2.
For Soko site, onsite generation may be required in addition to external
supply |
2.
Emergency generator & UPS for critical users/systems including lighting,
controls and other safety critical systems |
|||
2.
Loss of Instrument air supply |
|
1.
System designed to go to safe shutdown mode |
1.
Redundant air compressors; air receiver; emergency power supply |
|
3.
Loss of Nitrogen supply |
1.
N2 required for unloading arm swivel joint operation when in use (and for
draining and purging after unloading); continuous purging requirements for
electrical junction boxes and potentially for vent stack purging |
1.
Potential impact on swivel joint operation. Delay in completion of unloading |
1.
Redundant N2 source (generation and small liquid storage/vaporizer) |
|
2.
Potential moisture ingress or gas ingress into junction boxes |
2.
Operating procedures |
|||
4.
Loss of sea water supply |
1.
Sea water used for ORV operation; power supply failure or debris in sea water
intake or flooding of pump house may cause loss of sea water supply |
1.
Impact on ORV operation leading to partial loss of sendout gas |
1.
SCVs may be operating or on standby for partial supply of gas |
9.
Design of sea water intake to consider potential for blockage due to debris
including fishing nets etc to ensure reliability of sea water supply |
2.
Multiple sea water supply pumps & power source |
||||
5.
Loss of fuel gas supply |
1.
Fuel gas supplied from LNG |
1.
For the Black Point site, it will affect SCV operation and reduce sendout gas
supply (under peak supply condition) |
1.
Redundancy in fuel gas supply considered in design |
|
2.
For Sokos site, it will affect onsite power generation and hence the sendout
of the gas |
2.
External power supply for Soko |
|||
6.
Loss of diesel supply |
1.
Diesel used for fire water pumps and emergency power generator |
1.
Impact on emergency response |
1.
On-site diesel storage |
|
2.
Day tank storage associated with each user equipment |
||||
7.
Loss of fresh water supply |
1.
Fresh water used for initial fill of SCVs; fire water jockey pump operation;
personnel use; washing/ hose station etc |
1.
No significant consequence to the plant operations; potential personnel issue |
1.
On-site fresh water storage |
10.
Fresh water supply to Sokos to be reviewed during pre-FEED |
2.
Water will be provided via pipeline.
Either the existing line will be used or a new line will be installed.
( |
System: 1. LNG
Terminal Overview |
||||
Subsystem: 5.
Layout hazards |
||||
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Layout Hazards |
1. A
layout review was carried out separately and actions from the review will be
incorporated in the new layout |
1.
The layout will be reviewed based on QRA results & during pre-FEED phase |
|
|
System: 2. Plant
Systems |
Subsystem: 1.
Unloading operation |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
|
1.
Loss of containment |
1.
Unloading arms - leakage from swivel joints |
1.
Leakage from swivel joints would be minor leakages |
1.
N2 purge and leak detection system |
|
|
2.
Unloading arms - leakage from mechanical flange joints |
2.
Liquid spill or vapour release; potential fire; impact on structure due to
cold liquid spill |
2.
Operator monitoring |
|
||
3.
Unloading arms - disconnection under extreme weather condition |
3.
Impact of cold liquid spill leaking from the connection flange on the ship
manifold area |
3.
Emergency shutdown of unloading operation |
|
||
4.
Leak from piping and equipment at the jetty - drain vessel and/or knock-out
drum |
4.
One of the liquid unloading arms can be used as vapour return arm during
maintenance of vapour arm; periodic maintenance of arms/ swivel joints |
|
|||
5.
Gas detection and low temp. detection; fire detection; fire water monitors at
the jetty at different elevation (remote operated) |
|
||||
6.
Loading arm platform designed to withstand cold liquid spill |
|
||||
7.
Arm position limit detection and activation of shutdown valves at jetty end |
|
||||
8.
Powered Emergency Release Coupler with valves at either end of coupling
results in isolation of both ship end and jetty end |
|
||||
9.
Spill containment system at the jetty platform with high expansion foam |
|
||||
10.
Continuous water curtain during unloading localised at the ship manifold area |
|
||||
2.
Spill/ Fire on the carrier while berthed |
1.
Spill from connections on the ship deck |
1.
Radiation effects on the jetty structure and facilities and personnel |
1.
Spill containment system & emergency shutdown system on the ship |
|
|
2.
Fire protection system on the ship |
|
||||
3.
Fire protection system at the jetty |
|
||||
4.
Tugs with fire fighting capability |
|
||||
3.
Manual Operations |
1.
Arm movement and coupling connection between the arm and ship manifold (done
on the ship) thru hydraulic controls operated manually. |
1.
Impact of arm on the ship manifold due to operator error or due to ship
movement. Possible damage to the arm connection coupler |
1.
Operator training |
|
|
2.
Gangway positioning from the platform to the ship |
2.
Impact with the ship causing damage to the gangway |
2.
Hydraulic control is slow and controlled |
|
||
3.
Weather condition check |
|
||||
4.
Cabling assisted connection to enable loading arm operation under adverse
conditions if required |
|
||||
4.
Personnel Hazard |
1.
Fall from gangway, jetty platform |
1.
Possible injury |
1.
Guard rails on platform and gangway |
|
|
2.
Contact with cold surfaces - coupling connection on the ship (platform piping
is insulated) |
2.
PPE (flotation devices) |
||||
3.
Controlled access to the platform/ gangway |
|||||
4.
Controlled access to the arm coupling connection |
|||||
3.
Ice falling off from the arm after disconnection |
|||||
5.
PPE (hard hats) and controlled access |
|
||||
6.
Operating Procedures |
|
||||
5.
Impact while berthing |
1.
Impact of LNG carrier on the jetty while berthing due to higher than
operational approach speed limit |
1.
Damage to jetty structure; possible damage to piping |
1.
Tug assisted berthing with approach speed limits and indicators |
|
|
2.
Fenders designed for specified impact load |
|
||||
3.
Mooring masters on the shore side to supervise the berthing |
|
||||
4.
Local HK Pilots onboard LNG carriers during berthing |
|
||||
6.
Maintenance |
1.
Maintenance of arm - replacement of seals (about once every 5 years) -
undertaken between unloading operations and will require scaffolding |
1.
General personnel hazards associated with maintenance activities, such as
fall |
1.
Operating and safety procedures |
|
|
2.
Replacement of arm (expected about once every 20 years) - this will require
barge/ crane operation. Operation undertaken between unloading operations |
|
||||
7.
Emergency Egress |
1.
Emergency on the ship or the jetty |
1.
Potential injury if unable to escape |
1.
Normal access to the jetty and secondary egress to the mooring dolphin |
|
|
8.
Others - jetty operator shelter |
1.
Weather shelter for operator presence during unloading operations |
1.
No significant issue |
|
|
|
System: 2. Plant
Systems |
Subsystem: 2.
Transfer Pipeline from Jetty to Tank |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Leak in liquid transfer piping |
1.
Sudden closure of shutdown valve at shore end while unloading leading to
surge or weld defect |
1.
LNG spill and potential fire, and potential exposure of marine traffic to
liquid spill |
1.
Transfer piping on the trestle is welded with no flange connections |
|
2.
Pressure and flow sensors on the transfer piping |
||||
3.
Surge analysis during design |
||||
4.
Provision of shore isolation valve with spill containment system |
||||
5.
Any thermal reliefs required will discharge to a closed system |
||||
6. Activation of Emergency Shutdown
System stops LNG carrier unloading pumps before closing isolation valves |
||||
2.
Collision of drifting vessels or fishing vessels with trestle structure |
|
1.
Possible damage to the structure leading to potential damage to transfer
piping |
1.
Buoys and navigation aids, lights |
13.
Review the requirements for a safety zone around jetty. |
2.
Emergency shutdown valve in piping at jetty end and shore end |
||||
3.
Safety zone around jetty would be documented on navigational charts |
||||
3.
Vehicle accidents on the roadway |
1.
Road access on the trestle for maintenance vehicle & personnel movement |
1.
Possible damage to transfer piping |
1.
Segregation of roadway and piping |
|
2.
Potential for vehicles and passengers to fall off trestle into the sea |
2.
Speed limit and other controls on vehicle movement |
|||
3.
Access lighting will be provided |
||||
4.
Loss of circulation while not unloading |
1.
In-tank pumps used for circulation; multiple pumps provided |
1.
Heat leak and potential pressure build-up over a period of time |
1.
Insulation on transfer piping |
|
2.
Thermal relief valves on piping |
||||
3.
Transfer piping floating with the tank and hence pressure build-up not
expected |
||||
5.
Jetty security |
1.
3rd party access from water |
1.
Access to jetty/ trestle equipment handling LNG |
1.
Cameras at jetty with surveillance in control room |
|
2.
Routine security guard check |
||||
3.
Controlled access at shore end of trestle |
System: 2. Plant
Systems |
Subsystem: 3.
LNG Storage Tanks |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Overfilling |
1.
Level indication failure |
1.
Overflow to the annular space leading to overpressure in tank |
1.
Multiple level indication and trip (2 oo3 voting ) |
|
2.
Overpressure |
1.
LNG received from ship is at higher saturation pressure; loading rate higher
than design; compressor trip |
1.
Potential damage to the tank |
1.
High pressure indication and trip of liquid inflow (2oo3 voting) isolates
tank from fill lines and initiates ESD and shuts down ship's pumps |
|
2.
Relief from tanks to vent stacks (thru PCV and relief valves); relief valves
on tank to atmosphere, as per code requirement |
||||
3.
Underpressure |
1.
Pressure control malfunction; barometric change of pressure; inflow of
sub-cooled liquid |
1.
Potential damage to the tank |
1.
Low pressure trip of compressor & transfer pumps |
|
2.
Make-up gas or N2 |
||||
3.
Vacuum relief valves on tank as per code requirements |
||||
4.
Rollover |
1.
De-stratification of different density liquid |
1.
Potential overpressure due to high vapour evolution rates |
1.
Operating procedures |
|
2.
Instrumentation to detect stratification |
||||
3.
Top and bottom tank loading provisions |
||||
4.
Tank circulation |
||||
5.
Relief system sized for rollover condition |
||||
5.
Failure of tank bottom heating |
1.
Loss of power; heating coil malfunction |
1.
Potential frost heave at the tank bottom leading to tank damage; impact
over a period of time |
1.
Temp. measurement |
|
2.
Replacement of heating element while in operation considered in design |
||||
3.
Turbine generators on site as back up power supply to the main supply from
the grid ( |
||||
6.
Dropped object |
1.
Dropped object inside tank (primarily in-tank pump during maintenance) |
1.
Possible damage to the tank bottom plate leading to leakage of inner tank
into the outer tank |
1.
Fail safe lifting cables |
|
2.
Maintenance procedures |
||||
3.
Low temp. detector in annular space to detect inner tank leak |
||||
7.
Leaks on roof top |
1.
Flange joints on roof top |
1.
Cold liquid spill and potential ignition |
1.
Spill containment with gas and fire detection and fire protection system |
|
8.
Ignition of relief discharge |
1.
Due to lightning occurring while relief valve is in operation (less likely) |
1.
Radiation effects on tank and valves/piping on roof |
1.
Snuffing provision at the relief discharge |
|
2.
Discharge piping elevation design will provide protection to piping on the
roof |
||||
9.
Accidental relief discharge |
1.
Damage due to maintenance in the vicinity |
1.
Potential vapour release to atmosphere |
1.
Relief valves are sized/provided as n+1. |
|
10.
Inner tank leak (9% Ni) |
1.
Material defect or thermal cycle
stress |
1.
Possible overpressure |
1.
Liner provided on outside of inner shell 9% Ni plate at the bottom to contain
design spill |
|
2.
Low temp. detection at the annular space |
||||
3.
Overpressure protection thru relief valves |
||||
11.
Loss of containment |
1.
Overpressure inside tank |
1.
Potential leak at roof to wall seam with vapour release from tank
surface. No loss of either tank
wall integrity envisioned. |
1.
Relief valves provided. |
14.
Develop a write up documenting this scenario, ie the impact of overpressure
inside the tank on the outer containment/ roof. |
2.
No feasible scenario envisioned for concurrent failure of both inner and
outer walls |
2.
Tank designed to meet EN 1473 |
|||
3.
Operating procedures and indications such as pressure |
||||
12.
External fire |
1.
Fire in process area |
1.
Possible thermal radiation effects on tank |
1.
Concrete outer shell can withstand radiation effects |
|
2.
Fire detection and emergency shutdown system |
||||
13.
Maintenance issues |
1.
Normal maintenance involves only external visual inspection, settlement
monitoring, and foundation heating system monitoring |
1.
No hazards envisioned |
1.
No corrosion issues envisioned due to cryogenic and non corrosive service |
|
14.
Tank start-up |
1.
Cool down operation |
1.
Localized stresses due to rapid cool down which could lead to potential inner
tank failure |
1.
Controlled cooling rate, monitoring temperature drop across shell |
|
2.
Purging of inner tank and annular space with nitrogen purge to remove air and
moisture |
2.
Venting of nitrogen- LNG vapor mix to atmosphere to achieve required cool
down |
2.
Start up plans and procedures |
||
3.
Possible air pockets if purging operations not adequate |
3.
Monitoring of oxygen content leaving tank |
|||
4.
Procedure for purging annular space |
||||
15.
Access and egress to/from rooftop |
1.
Emergency incident |
1.
Need to egress to a safe location |
1.
Two stairways provided from tank top |
|
16.
Hydrotesting of tanks |
1.
Disposal of test water |
1.
Potential environmental impact |
1.
Environmental impact studies will include consideration of tank commissioning
issues |
15.
Consider the impact of seawater for hydrotesting on tank metallurgy |
2.
Use of seawater for hydrotesting |
2.
Potential chloride induced stress corrosion of tank metallurgy (welds and
heat effected zone) |
System: 2. Plant
Systems |
Subsystem: 4.
LP LNG System - Tank pumpout |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Loss of containment |
1.
Leak from piping at recondenser and at HP pump suction |
1.
Potential leak and fires |
1.
Gas and fire detection; emergency shutdown; fire protection systems;
localized containment area |
|
2.
Inspection of pressure vessel |
1.
Inspection and testing of recondenser as per code requirement |
1.
Loss of ability to recondense BOG |
1.
Provision to compress part of the BOG directly to send out system which will
meet a fraction of the BOG volume.
The remaining BOG vapour will be vented to stack. |
16.
Investigate whether on-line inspection is feasible and meets regulatory
requirements |
2.
Recondenser provided with a bypass |
System: 2. Plant
Systems |
Subsystem: 5.
BOG Compressors - BOG, Ship, Pipeline |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Leaks |
1.
Three compressors – boil-off gas, high pressure pipeline send out and vapors
during unloading |
1.
Potential gas leak and fires |
1.
Gas and fire detection; emergency shutdown; fire protection system |
|
2.
Dropped object during maintenance |
1.
Drop compressor parts on adjacent, operating compressor |
1.
Potential damage and loss of containment |
1.
Gas and fire detection; emergency shutdown; fire protection system |
|
2.
Lifting and maintenance procedures |
System: 2. Plant
Systems |
Subsystem: 6.
HP LNG System |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Loss of containment |
1.
Leak from piping downstream of the HP
pump (pressure approx. 100 bar); ; HP pump in canister |
1.
Potential leak and fires |
1.
Gas and fire detection; emergency shutdown; fire protection systems;
localized containment area, provision of splash plates on mechanical
connections |
|
2.
Dropped object during maintenance |
1.
Dropped object on adjacent, operating pump |
1.
Potential damage and leak |
1.
Gas and fire detection; emergency shutdown; fire protection systems;
localized containment area. |
|
2.
Lifting and maintenance procedures |
System: 2. Plant
Systems |
Subsystem: 7.
ORV/SCV Vaporisers |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Leaks |
1.
Leaks from flange connections & small bore piping |
1.
Potential liquid spill; potential gas leaks; ignition and fire |
1.
Gas and fire detection; emergency shutdown; fire protection system |
|
2.
Ingress of LNG vapor into SCV in the event of leak in surrounding environment |
2.
Potential non-uniform combustion in SCV |
2.
Spill containment system with provision for high expansion foam |
||
3.
SCV air intake provided with gas detection and shutdown of SCV |
||||
2.
ORV tube failure |
1.
ORV tubes of Aluminium at about 80 to 100bar; seawater corrosion |
1.
Gas leak and potential ignition |
1.
ORV tubes provided with external coating to minimise corrosion effect |
|
2.
Periodic inspection and maintenance; spare ORVs provided |
||||
3.
Gas and fire detection; emergency shutdown; fire protection system |
||||
3.
Heavy metals in sea water |
1.
Mercury content in sea water |
1.
Potential impacts if mercury content exceeds equipment vendor's specification
for ORV |
1.
Since initial HAZID, Project has verified with vendors that the current
mercury level in seawater does not exceed the equipment vendor's
specification |
11.
Potential impact on ORV due to mercury content in sea water to be
(re)confirmed during design based on vendor data |
4.
SCV tube failure |
1.
Tubes in water bath heater; possible damage due to corrosion |
1.
Gas leak and potential ignition |
1.
Hydrocarbon monitoring in flue gas stack from SCV |
|
5.
Low temp. hazard in vaporiser outlet piping |
1.
Heating failure in ORV/ SCV likely to result in low temp. liquid or gas in
sendout |
1.
Possible damage to sendout piping (CS material); impact on gas turbine
operation |
1.
Low temp. trip at vaporiser outlet |
|
6.
Overpressure in vaporiser outlet piping |
1.
Blocked condition |
1.
Potential loss of containment due to overpressure caused by heat of
vaporisation under blocked condition |
1.
High pressure trip of HP pumps and vaporizers |
17.
Review, during detailed design,
overpressure safeguards for piping downstream of vaporizer |
2.
Relief valve to HP vent stack from each vaporiser outlet (vent stack designed
for only 1 relief valve load) |
System: 2. Plant
Systems |
Subsystem: 8.
Miscellaneous - Fuel gas, Gas heating, Gas Metering |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Leaks |
1.
Leak from flanges, piping connections; rupture of piping or equipment |
1.
Potential gas leak and fires |
1.
Gas and fire detection; emergency shutdown; fire protection system |
|
System: 2. Plant
Systems |
Subsystem: 9.
Vent & Drain system |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Ignition of gases from vent stack |
1.
Due to lightning |
1.
Potential thermal radiation effects on adjoining equipment |
1.
Stack height will be determined based on thermal radiation threshold on
adjoining equipment |
|
2.
Snuffing system |
||||
2.
Discharge of gas from vent stack |
1.
Venting from HP and LP vent stack |
1.
Potential slumping of cold vapour leading to accumulation in plant area or in
vicinity |
1.
Stack height will be determined based on dispersion distance, taking into
consideration receivers at ground and elevation. Gas expected to become
warmer as it reaches vent stack |
18.
Analyze the pros and cons of a vent versus flare option to determine the
appropriate path forward. |
2.
Knock out drum will be provided for both vent stacks to knock out any liquid
although not expected |
||||
3.
Air ingress into vent header |
1.
Air ingress from vent stack |
1.
Potential for flame flashback upon ignition of vent vapours |
1.
Nitrogen purge |
|
2.
Detailed design will address ignition sequence and purging requirements |
System: 2. Plant
Systems |
Subsystem: 10.
Utility & auxiliary systems |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Gas turbine hazards (at Soko) |
1.
Potential gas leak inside turbine enclosure |
1.
Potential fire and explosion |
1.
Turbine enclosure will be protected with detection and suppression systems
per the manufacturers recommendation. |
|
2.
Transformer and switchgear at substation |
1.
Equipment failure |
1.
Potential fire and explosion |
1.
Protection of transformers will be provided per HK codes and applicable
electrical codes and standards for process plants |
|
System: 3.
Construction Phase |
Subsystem: 1.
Blasting Operations during Initial Construction |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Explosives storage |
1.
Inadvertent ignition of material |
1.
Potential explosion; exposure of construction personnel |
1.
Explosives store will be specifically designed, located, and controlled as
per HK regulations. |
|
2.
Explosives handling |
1.
Inadvertent ignition |
1.
Potential explosion; exposure of construction personnel |
1.
Handling only by Shotfirer |
|
2. Explosives handling will be specifically
designed, located, and controlled as per HK regulations. |
||||
3.
Blasting operations |
1.
Airborne fly rock |
1.
Potential personnel injury |
1.
Blasting will be controlled as per HK regulations. |
|
System: 3.
Construction Phase |
Subsystem: 2.
Third LNG Tank Construction - Expansion |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Construction activity for 3rd tank |
1.
Additional construction staff at the site during construction |
1.
Potential exposure to hazards from the operating facility |
1.
Separate risk assessment for the construction phase (for 3rd tank expansion) |
|
2.
Simultaneous Operations procedures will be developed/implemented |
||||
3.
3rd tank location will be such that blasting will not be required (or
blasting would be accomplished during initial construction phase) |
System: 3.
Construction Phase |
Subsystem: 3.
Process System Construction - Expansion |
Hazards/ Keywords |
Description/ Causes |
Consequences |
Safeguards |
Recommendations |
1.
Diesel storage during construction phase |
1.
Potential loss of containment |
1.
Potential environmental impact, potential fire |
1.
Containment and manual fire protection will be provided |
|
2.
Storage of construction materials including caustic, chemicals, compressed
gas, paints/solvents |
1.
Potential toxic exposure, fire |
1.
Potential exposure of personnel |
1.
Construction operating and safety procedures |
|
2.
Chemical and materials handling and storage per HK codes and MSDS |
||||
3.
Construction and installation of new pumps, vaporiser as part of expansion |
1.
Potential equipment damage of adjoining equipment |
1.
Potential fire |
1.
Simultaneous operations controls will be developed. |
|
2.
Tie-ins will be provided such that new equipment can be brought on line
without requiring a plant shutdown. |