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LNG: Benefits and Risks, a European and

Dutch Perspective

Hans PasmanEmeritus Delft University of Technology, NL

Research Professor MKOPSC, Texas A&M

Benefits of LNG

LNG in Europe and in Rotterdam, the Netherlands

Example of Dutch QRA for license of terminal

Uncertainties in hazard and risk analysis

WCCE8, Montreal, Canada, 24-27 Aug 2009

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Benefits natural gas seen by Dutch eyes

1940s Cold winters, no gas, no heating

1950s Coal shoveling, few houses with central heating in the Netherlands

1960s Groningen gas; distribution network built

1970s Plans for terminal + tank ships but only peak shaving realized

1980s Continuous flow of income Dutch government; social security

1990s Ever higher efficient household heaters: central heating/hot water

2000s Alternative sources: Norway, Russia, LNG from other sources

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European terminals:

Graph according toWeems and Beck ofKing & Spalding, 2006

Spain, France andBelgium haveconsiderableexperience.

Delays in realization ofproposed terminals dueto long authorizationtrajectories and creditcrunch

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Rotterdam Rijnmond projects: GATE and LionGas

Maasvlakte at the mouth of the Nieuwe Waterweg, Hoek van Holland

4

Location Papegaaiebek

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Rotterdam GATE and LionGas terminal projectionsreproduced with courtesy to Port of Rotterdam

Design LNG terminals

Gate terminal

LionGas terminal

Looking West towards North Sea Looking East towards city of

Rotterdam and industrial harbor area

Note the oil depots and chemical

plants

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Situation ship entry, separation dams, MaasvlakteNearest towns: Hook of Holland, Oostvoorne; beach recreational area

LionGas:Two terrain

parts, separated

by a PET plant,

connected by

pipelines.

2 km

LionGas

Port of Rotterdam port signposting system map 2005

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Actual situation

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Port of Rotterdam Ship admission policy

MARINinstitute and Delft University of Technologyconducted: Ship maneuvering and collision avoidance studies

Detailed investigation of consequences of collision on ship hulland damage to tanks

Results:

Optimization of routing system Rotterdam approach (model SAMSON)

Avoid cross-traffic at high speed

Policy plan with projection of three stages:

Stage 1 (gaining experience, 15 calls or half a year) LNG ships shallarrive between 0:00 4:00 A.M.

Stage 2 (100 calls or two years) more arrival windows

Stage 3 (final) LNG carrier considered as normal traffic

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License procedure LionGas terminal: Seveso II Directive.Safety report, incl standard QRA as part of Env. Impact Assessment

Submission of application to Competent authority: Prov. South-Holland, DCMR

(Rijnmond Central Environmental Protection Agency). License granted Sep 2006

Analysis of nautical grounding and collision risks performed by MARIN and DelftUniversity of Technology:

Event frequency by Ship Traffic Models (30 yr data + model SAMSON)

Penetration depth distribution by model MARCOL

QRA ofspills at ship maneuvering, berthing, unloading, terminal operations and

re-gasification carried out by Royal Haskoning: Purple Book for accident scenarios (today Bevi Manual + SAFETI-NL); safety measures

TNO EFFECTS 5.5 model for LNG spill and evaporation on water with check against

Sandia report 2004-6558

Gas dispersion: Heavy gas model (1st part); neutral gas (2nd part; Gaussian model)

RPT effects and BLEVEs disregarded

When LNG cloud with no confinement present: no overpressure, only fire or flash fire

Exceptions: limited amount of gas (1000 m3) can explode under unloading platform or at

re-gasification plant (15% methane-air; MEM strength 5)

Flame envelope determined by LFL contour at ignition

Heat radiation threshold for 100% lethality: 35 kW/m2

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Dutch risk acceptance criteria

Individual risk:

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Max Cred Acc (MCA), MNonCA and Domino effects:

1. MCA scenarios were calculated: IR and GR remained within limits.

2. MNCA (100 Fire, no effect Fire and explosion cause

damage

Propylene spheres, 450

tonnes, NEREFCO (now

BP) terrain

1150 BLEVE: 0.2 bar at 1036

m, see Purple Book,

2005, hence LNG tanksurvives

Possible damage, no

detailed investigation

Wind mill turbines Ca.100 Failure of blade; no

penetration of concrete

tank hull

Certainly damage

Helicopter platform pilots Location not

decided

Crash, pool fire 0.5 km

radius

Not determined

Mutual domino effects of LNG terminal/tanks with neighboring installations

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EIA with QRA resulted in granting of

license by Prov. South-Holland in 2006

The QRA report mentions

uncertainties but states that in case

of doubt a conservative solution was

chosen

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What about uncertainties in QRA?

EU benchmark project ASSURANCE 2000 has confirmed wide spread in QRA

results (orders of magnitude): scenarios large source of variability.

Largest and smallest 10-5

IR risk contour

Comparison of Group Risk results of 6 (experienced)

teams participating in the exercise.

Other sources dispersion and explosion models, and failure frequencies

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EU project ARAMIS tried to remedy scenario definition: bowties: FTA-CE-ET

Even then difficult to predict escalations: small fire large leak big

release; damaged tanks / ship hull presents confinement.

Can BLEVE be excluded?

Failure rates: Influences by management qualityand human error; data

availability including confidence intervals

Source terms, consequence models produce spread in results. Which model

is sufficiently accurate: (FLACS, LES), model certification?

Fire: SEP 250 kW/m2, decrease with scale?

Explosion effects: increase with scale?

What about uncertainties in QRA? (2)

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Uncertainty explosion effects:

Largest uncertainty is effect after delayed

ignition. Cold LNG vapor is not very reactive, but what

about scale effects?

Scale effects in VCE have been investigated in

the 90s MERGE, EMERGE, JIP with only

limited success (Buncefield VCE was again asurprise not a reactive substance, no wide

explosion limits, not much confinement). Do we

know all mechanisms involved?

Does CH4 differ that much from C4H10 or C8H18?

It differs quantitatively not qualitatively.

Reactivity, run-up distances, flame-turbulence

interaction

Many researchers feel that tests so far have

been on too small a scale: J HazMat 140 (2007)

1981 Coyote test: No flash-backto the source

yellow range:possibly heatexplosion

0 10 20 30 40 50 60 70 80 90 1000

10

20

30

40

50

60

70

80

90

1000

10

30

40

100

Propene C3H6 [Vol.-%]

N2[Vol

.-%] O

2[Vol.-%

]

stoich

iometricC3

H6+1.5

O2->

3CO

+3H2

stoichio

metric

C3H6

+3O2

->3CO

+3H2

O

stoichiometric

C3H

6

+4.5O2

->3CO2

+3H2O

range ofdeflagrative explosion,

5 bar abs, 200 C

rangeof

deton

ative

explosion

soot

isformedhere

(41vol.-%up

to75vol.-%

)

propene/air-mixtures

90

50

60

70

80

20

0 10 20 30 40 50 60 70 80 90 100

0

10

20

30

40

50

60

70

80

90

1000

10

20

60

70

90

100

Methane CH4 [Vol.-%]

N2[

Vol

.-%] O

2[Vol.-%

]

yellow range:possibly heatexplosion

80

50

30

40

methane/air-mixtures

stoichio

metric

CH 4

+2O

2->

CO2

+2H

2O

stoich

iometric

CH 4

+1.5O

2->

CO

+2H

2O

sootformation

starts

at55vol.-%CH4

range of detonativeexplosion

range

of

deflagrative

explosion,

5barabs,25

C

stoichi

ometri

cCH4

+0.5O2

->CO+

2H2

Project SAFEKINEX, 20 l vessel

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Conclusions The scale of LNG operations in the world is rapidly growing to fulfill the need of

energy supply. The process of liquefying, transportation, storage and re-gasification has been

so far without significant incidents and the technology is considered safe.

Risk assessments are conducted at various places building on existing

knowledge gained for a large part in the early 80s in relatively small scale tests.

Methane is a low reactive hydrocarbon but shows all the features of its fellowhydrocarbons when pressed hard enough.

In view of the huge quantities present and corresponding combustion energy

potential it is recommendable to test present assumptions in larger scale tests.

Scenarios should be thought through in a multi-disciplinary team with an open

mind and paying attention to possible escalation of at first insignificant failure.

High quality safety management offers of course good protection but we have

to safeguard against drift in organizations