LIST OF CONTENTSLIST OF CONTENTS

ⅠⅠ INTRODUCTIONINTRODUCTION

ⅡⅡ LOPA STUDYLOPA STUDY

ⅢⅢ CONCLUSIONSCONCLUSIONS

1. Consequence and Severity2. Developing Scenarios3. IPLs

and Frequency of Scenarios

4. Risk Calculation

II INTRODUCTIONINTRODUCTIONDescription of System I

Jetty

PropaneCavern

ButaneCavern

ButaneTank area

PropaneTank area

FlareStack

Un-loading

Area

UtilityPlant

PumpCompressorEvaporator

ETC

Building&

Control room

Parking Lot

1ea1ea AddAdd

II INTRODUCTIONINTRODUCTIONDescription of System II

Facility Equipment Capacity (Unit)

Storage Butane tankPropane tank

20,000 ton (3EA)20,000 ton (5EA)

Loading

Loading arm 1,000M3/hr(2EA)

Jetty Boosting Pump 600M3/hr(1EA)

Boosting Pump 1,000M3/hr(3EA) Heater -46℃ -> 2℃

Unloading Pump 480M3/hr(3EA) Loading arm 120M3/hr(6EA)

Safety Flare stack 8,000 SCFM Butane evaporator 100M3/hr(3EA) Refrigeration compressor 500M3/hr(1EA)

Cavern Tank

Storage Tank Ordoring Tank Lorry

Unloading

140 ~ -6.0 mbarg50 ~ -6.6

Pressure Safety DeviceSafety Valve, Pressure Regulating Valve,

Cryogenic Compressor

Description of System III

Description of System IV

Sensor

Cryogenic Compressor

Safety Valve

Boil-off Gas Condensing

Sensor

EvaporatorPressure

Regulating Valve

Low Pressure(Vacuum)

High Pressure

LOPA I

Release RateCase A : 12.5 mm diameter equivalent(Flange or Gasket)

Case B : 25.0 mm diameter equivalent(25A Rupture)

Case A : 50.0 mm diameter equivalent(50A Rupture)

gcm PgACQ 20

Equivalent diameter of release (mm)

Release rate(kg/s)

Liquid phase Vapor phase

12.5 2.28 0.21

25 9.12 0.85

50 48.57 -*

LOPA II Consequence and Severity 1Jet/Pool Fire, BLEVE, UVCE

Time (s)

Diameter of pool fire (Case A, m)

Diameter of pool fire (Case B, m)

Diameter of pool fire (Case C, m)

0 0 0 0

10 4.3 8.7 17.5

20 5.0 10.1 20.4

30 5.2 10.5 21.0

40 5.2 10.5 21.0

50 5.2 10.5 21.0

60 5.2 10.4 20.8

70 5.1 10.3 20.7

80 5.1 10.3 20.6

90 5.1 10.2 20.6

100 5.1 10.2 20.5

110 5.1 10.2 20.5

120 5.1 10.2 20.5

LOPA III Consequence and Severity 2Heat Flux at 21m by Jet/Pool Fire, and BLEVE

Fire hazard

Equivalent diameter of

release (mm)

Releaserate

(kg/s)

Heat flux

(kW/m2)Corresponding damage Hazard

level

Jet fire

12.5 (Vapor line) 0.21 1.38 No discomfort for long

exposure Low

25 (Vapor line) 0.85 2.77 Time to pain threshold in 30~40 seconds Medium

Pool fire

12.5 (Liquid line) 2.28 15.1 Operators are not likely

to perform duty High

25 (Liquid line) 9.12 41.6 Sufficient to cause damage to equipment High

50 (Liquid line) 48.57 187.1 100% fatality about 10 seconds exposure Very high

BLEVE - - 421 100% fatality less than 3 seconds exposure

Extremely high

mQ xq

LOPA IV Consequence and Severity 3Overpressure at 21m by UVCE

xQ TNTmez

)/( 3/1kgmoP

(kg/s)m(kg) (kg) (kPa)

Corresponding damage

Hazard level

0.21 12.6 6.67 11.16 14.18Minor damage of cooling tower or atmospheric tank

High

0.85 51.0 27.0 2.33 233.0 Catastrophic failure, floating roof tank

Very high

LOPA V

Developing Scenario

Scenario 1 : High pressure causes leak or rupture storage

tank, which results from excess boil-off gas of

butane storage tank

Scenario 2 : Low pressure or over vacuum causes rupture

storage tank results from butane unloading

Frequency Study

J

jij

Ii

Ci PFDff

1

ignitionJ

jij

jetIi

jeti PPFDff

1

,

ignitionJ

jij

poolIi

pooli PPFDff

1

,

heatingJ

jij

BLEVEIi

BLEVEi PPFDff

1

,

ignitiondelayedJ

jij

UVCEIi

UVCEi PPFDff

1

,

Jet Fire

Pool Fire

BLEVE

UVCE

LOPA VI

LOPA VII

IPLs & PFD for Scenario 1

Safeguard IPL Fail rate of IPL

Pressure Gauge 2EA

Pressure High High Alarm 1EA

Pressure Safety Valve 5EA

Pressure Control Valve 1EA

Pressure High Alarm 2EA

Hand Switch 1EA

Human Intervention

Refrigeration compressor (A)Start byStart by pressure high alarm (A) 1 ×

10-1

Refrigeration compressor (B)Start byStart by pressure high alarm (B) 1 ×

10-1

Pressure control valve oopen 1 ×

10-1

Operator action 1 ×

10-1

Relief valve 1 ×

10-2

Total PFD For all IPLs 1 ×

10-6

LOPA VIII

IPLs & PFD for Scenario 2

Safeguard IPL Fail rate of IPL

Pressure Gauge 2EA

Pressure Low Low Alarm 1EA

Vacuum Relief Valve 22EA

Pressure Controller 1EA

Pressure Low Alarm 2EA

Human Intervention

Evaporation 50% on byy pressure low alarm (A) 1 ×

10-1

Evaporation 50% on byy pressure low alarm (B) 1 ×

10-1

Refrigeration compressor (A,B)stop bystop by pressure low low alarm (A) 1 ×

10-1

Pressure control valve oopen 1 ×

10-1

Operator action 1 ×

10-1

Vacuum relief valve 1 ×

10-2

Total PFD For all IPLs 1 ×

10-7

Category 1 Category 2 Category 3 Category 4 Category 5

Optional(evaluate

alternatives)

Optional(evaluate

alternatives)

Action at next

opportunity

Immediate action

Immediate action

Optional(evaluate

alternatives)

Optional(evaluate

alternatives)

Optional(evaluate

alternatives)

Action at next

opportunity

Immediate action

No further action

Optional(evaluate

alternatives)

Optional(evaluate

alternatives)

Action at next

opportunity

Action at next

opportunity

No further action

No further action

Optional(evaluate

alternatives)

Optional(evaluate

alternatives)

Action at next

opportunity

No further action

No further action

No further action

Optional(evaluate

alternatives)

Optional(evaluate

alternatives)

No further action

No further action

No further action

No further action

Optional(evaluate

alternatives)

No further action

No further action

No further action

No further action

No further action

< Table : Risk Matrix with Individual Action Zones >

Frequency

Consequence

10-0/y

10-1/y

10-2/y

10-3/y

10-4/y

10-5/y

10-6/y

10-7/y

CONCLOSIONS

Constructing butane storage tank is

evaluated to have ‘optional action’ criteria

Although the present risk is acceptable,

adding pressure transmitter to butane

storage tank reduces risk by leak/fire

remarkably

Good sample to apply LOPA to design

step