1. DNV SOFTWARE - A LEADING PROVIDER OF SOFTWARE FOR MANAGING RISK
safeguarding life, property and the environment
PhastTM
Effectively meeting the LNG hazard management challenge
Global use of Liqueied Natural Gas (LNG) has increased signii-
cantly in recent years along with concern related to the proper
management of the hazards associated with processing and
transport. Such concerns are particularly heightened around
land-based installations (or LNG carriers when berthed) due to
the potential impact to local populations.
Understanding how these hazards present themselves is central to
their management. Phast is the tool of choice when it comes to
assessing the impact potential associated with LNG and other
hazards. Phast is the world leading consequence analysis software
tool, extensively validated for a wide range of materials and
release scenarios, including LNG.
As an endorsement of its robust modelling capabilities, Phast
received speciic approval from the US Department of Transpor-
tation Pipeline and Hazardous Materials Safety Administration
(PHMSA) for use in modelling accidental releases of LNG in
facility siting considerations. The PHMSA approval covers the use
of Phast for the following scenarios:
• Dispersion from circular shaped LNG pools
• Dispersion from LNG pools in impoundments with low aspect
ratios
• Dispersion from releases in any direction, including releases
due to lashing, venting, and pressure relief.
Phast is the world’s leading consequence analysis software tool, extensively validated for a wide range of
materials and release scenarios including LNG.
WITH PHAST, YOU CAN:
» Develop a robust understanding of hazards related to an LNG release in a
single integrated calculation run. All possible outcomes are modelled auto-
matically in Phast.
» Take into account a wide range of factors that can influence the develop-
ment of a hazard.
» Be confident in the results. Phast utilises extensively verified and indepen-
dently validated models. It is also approved and endorsed by regulatory
agencies (e.g. PHMSA).
» Produce results that are verifiable and reproducable. An important factor
in decision making, quality control and information sharing across teams.
» Execute studies in an efficient manner.
» Visualise the calculated hazard ranges on location maps, thus allowing for
clearer understanding and communication of the impact zones.
“PHMSA is approving PHAST-UDM for use in
calculating the vapour gas dispersion exclusion zone
for LNG. Such approval ensures that these facilities are
sited in a manner consistent with public safety.”
PHMSA

2. DET NORSKE VERITAS AS
NO-1322 Høvik, Norway
Contact us on:
web: www.dnvsoftware.com
email: dnv.software@dnv.com
DNV Software is a leading provider of software for managing risk in the energy, process and maritime industries – offering solutions for design, engineering,
strength assessment, risk and reliability, QHSE and asset integrity management. DNV Software is part of DNV and almost 300 DNV offices in 100 countries
enable us to be close to our customers and share best practices and quality standards throughout the world.
RIGOROUS MODELLING CAPABILITIES
Phast is an integrated consequence modelling package which
models all stages of an accidental release (including LNG), from
discharge (including rainout, pool evaporation/spreading) to
dispersion (from the pool and the discharge oriice as shown in
above igure to effects (e.g. pool ires, lash ires, explosions) taking
into account various contextual factors that can inluence the
development of the hazard.
A ROBUST SOLUTION TO THE LNG HAZARD MANAGEMENT
CHALLENGE
Phast’s modelling capabilities are numerous and diverse and allow
for the evaluation of a wide range of hazard types in different
situations. At Phast’s heart is the Uniied Dispersion Model (UDM)
which enables complete and rigorous modelling of various release
types accounting for transition to jet, dense and passive clouds,
buoyancy effects, substrate interaction, plume lift-off, capping at
the mixing/inversion layer, droplet formation and rainout.
The modelling takes into account various contextual factors that
can inluence the development of the hazard.
Phast utilises and combines recognised and validated models
for the various physical phenomena, automatically selecting
the appropriate model depending on the circumstances of the
release. Since its launch over 20 years ago, Phast has undergone
a continuous programme of development to relect advances in
knowledge gained through research, user feedback and techno-
logical advances such that it represents the state of the art with
regards to consequence modelling.
Rev0313
1. More volatile components
remain as a vapour in vessel
3. Composition of droplets
and vapour change
with distance downwind
4. Discontinuity in cloud
composition as heavy
droplets rainout
5. Re-evaporation
lighter pool components
2. Heavy
components
form droplets
Complete solutions • Most user friendly • Most value for money • Professional service
Initial stages of an accidental release as modelled by Phast