Bhopal QRA V3

5/21/2018 Bhopal QRA V3

1/29

Toxic QRAs 8/7/2014

Fig. 1: Logic Diagram For Toxic Mini-QRA

Start at

Tab QRA

Tab QRA Tab VM Tab VM

Select Select Vulnerability Model Obtain 4

Toxic Chemical (1 - 20) 1 = CPQRA LC50 Concentrations

4 Scenario Descriptions 2 = TNO

4 Release Durations 3 = Specific Rat Data

4 Generic Failure Rates 4 = Manual Input of k1, k2 & nAuto Sort Fatality Data

Determine IR Data

Determine Societal Risk

Tab FR Tab IR

Select Failure Plot Individual Risk to 1E-06 and 1E-08 Fatalities/Yr

Rates For 4

Generic Systems

Tab SR

Plot Societal Risk vs Dutch QRA Criteria

Tab PP

Select Physical

Properties

Tabs S1 - S9

Select Source Term Models - Delivers Rate Of Discharge and Release Durations

S1 = 2 Liquid and 2 Vapour Orifice Calculations - Sonic & Sub-Sonic Flow

S2 = Source Term Model - 2 Liquid and 2 Vapour Models + Logistics

S3 = Evaporation Rate From Un-Restrained Pool Spreading - Transient Release

S4 = Evaporation Rate From Restrained Pool Spreading - Transient release

S5 = Evaporation Rate From Volatile Liquid Below Boiling Point - Steady State Release

S6 = Depressurization of a Pressurized Vessel - Transient Release

S7 = Release From PSV of a Vessel Containing Toxic Liquid Under Fire or Reactive Chemical ConditionsS8 = A Generalized Correlation for Flashing Choked Flow of Initially Subcooled Liquid

S9 = Release of Heavy Toxic gases From Elevated Stacks or PSVs.

Tabs GC & GI

Select Dispersion Model Yields LC50 Distances & Durations For 4 Selected Scenarios


2/29

Mini QRA For MIC Storage 8/7/2014

Basis MIC Plant Under Poor Safety Management System (CPQRA Vulnerability Model)

Release and Dispersion Summary Based on a Continuous Gaussian Dispersion Model, CPQRA Vulnerability Probit Constants and Selected Source Term Models

BHOPAL - Incidents From One 90,000 lb Storage Tank Select (1 - 20) = 4 Chemical = MIC

Select Model (1 - 2) 1 Gaussian Dispersion

Scenario Dischg Rate Duration LC50 Gaussian Source Source Term Frequency

Incident Description kgm - kgm/s Minutes ppmv LC50 Dist, m Term Tab Description Failure/Yr

1 2" Liq Leak 15.4353 60 39.86 2,172 Tab S4 Into 1,000 sm Dyked Area 1.02E-03

2 1/2" Liq Leak 1.54 60 39.86 545 Tab S4 Into 100 sm Restricted Curb Area 2.16E-03

3 Runaway Rx 3.6936 100 18.23 1,869 Tab S7 & S9 PSV to 8 Inch Stack 108' High 4.00E-074 Tank Rupture 30.8739 85 23.38 4,355 Tab S3 Into 1,670 sm Unrestricted Area 1.35E-05

Failure Frequency For System Components

Incident No. 1 - Generic System For 2" Liq Leak

Failure Rate Generic System For Phase Of No. In Frequency Source

No. Incident 1 2" Liq Leak Leak Events/yr System Failure/Yr Fr FR database

34 Valve or Flange Leak Vap or Liq 1.00E-04 10 1.00E-03 Technica

35 Impact Failure Of Pipe Vap or Liq 1.00E-05 1 1.00E-05 CPQRA

54 Med Pipe Rupt >2"


3/29

Toxic Chemical Vulnerability Model 8/7/2014

Case Vulnerability Model (VM) Basis = CPQRA Probits

Toxic Basis 1 (1 = CPQRA, 2 = TNO, 3 = Rat Data, 4 = Manual Input k1, k2, & n)

Select 1 to 20 4 MIC STEL 15 min. = ? ppmv CPQRA Probits

Time = 100 minutes Pr = k1 + (k2)[LN(Dose)] = 4.9999

Avg Conc'n = 18.23 ppmv Dose =S(C^n)(t)= 6.66E+02

Avg Conc'n = 42.52 mgm/m3 @ t = 25.00 C n = 0.6530

% Fatality = 50.16% 51.78% 49.97% k1 = -5.6420

Risk Message Fatality Potential Dose k2 = 1.6370

MW = 57.1

Fatality = IDLH LC1 LC10 LC50 LC90

Probit = 1.6462 2.67 3.72 5 6.28

Minutes Avg ppmv Avg ppmv Avg ppmv Avg ppmv Avg ppmv

1 914.16 2,382.19 6,361.61 21,066.96 69,764.87

2 316.25 824.10 2,200.76 7,287.97 24,134.67

5 77.74 202.57 540.96 1,791.45 5,932.51

10 26.89 70.08 187.14 619.74 2,052.31

60 1.73 4.51 12.04 39.86 132.00

85 1.01 2.64 7.06 23.38 77.43

100 0.79 2.06 5.51 18.23 60.37

Lethal Toxicity Chart For MIC CPQRA Probits (Page down)

0.10

1.00

10.00

100.00

1,000.00

10,000.00

100,000.00

1,000,000.00

1 10 100

AVG

PPMV

EXPOSURE DURATION, MINUTES

FATALITY CHART FOR SELECTED CHEMICAL

LC01

LC10

LC50

LC90

LC99

IDLH

Data

ERP

ERP

eg, LC50 = 50% Fatality


4/29

Toxic Chemical Vulnerability Model 8/7/2014

ppmv - min.

LC99.9

8.09

Avg ppmv

379,313.68

131,220.93

32,255.24

11,158.48

717.71

421.02

328.26

Pt.

2

3


5/29

Failure Rates For Database LOOKUP Case =

Failure Rate

No. Description Phase Per Year Source 95% Confiden

1 Instantaneous Vessel Rupture Liquid 1.00E-06 Nussey HSE

2 Instantaneous Vessel Rupture Vapor 1.00E-06 Nussey HSE Basis: CPQRA,

3 Vessel Leakage Liquid 2.40E-05 Nussey HSE

4 Vessel Leakage Vapor 3.60E-05 Nussey HSE Upper Confiden

5 Catastrophic Dist'n Tower Vap or Liq 6.50E-06 CPQRA, p-459 f1 = 2(x + 1)

6 Serious Dist'n Tower Leak Vap or Liq 1.00E-05 CPQRA, p-459 f2 = 2(n - x)7 2 Inch Hole In Pipe Liquid 1.60E-06 Nussey HSE

8 1 Inch Hole In Pipe Liquid 3.20E-06 Nussey HSE Where

9 1/2 Inch Hole In Pipe Liquid 4.00E-06 Nussey HSE

10 1/4 Inch Hole In Pipe Liquid 1.60E-05 Nussey HSE

11 2 Inch Hole In Pipe Vapor 2.40E-06 Nussey HSE Upper Confide

12 1 Inch Hole In Pipe Vapor 4.80E-06 Nussey HSE

13 1/2 Inch Hole In Pipe Vapor 6.00E-06 Nussey HSE Lower Limit of

14 1/4 Inch Hole In Pipe Vapor 2.40E-05 Nussey HSE

15 Gillotine 1 Inch Liquid 1.20E-07 Nussey HSE Where F1 and16 Gillotine 1/2 Inch Liquid 4.00E-05 Nussey HSE Typically, 95%

17 Gillotine 1/4 Inch Liquid 1.60E-04 Nussey HSE

18 Gillotine 1 Inch Vapor 1.80E-07 Nussey HSE Example:

19 Gillotine 1/2 Inch Vapor 6.00E-05 Nussey HSE

20 Gillotine 1/4 Inch Vapor 2.40E-04 Nussey HSE

21 Pipe Splits - 1 Inch Liquid 1.20E-06 Nussey HSE

22 Pipe Splits - 1/2 Inch Liquid 4.00E-04 Nussey HSE Item

23 Pipe Splits - /4 Inch Liquid 1.60E-03 Nussey HSE 1

24 Pipe Splits - 1 Inch Vapor 1.80E-06 Nussey HSE 2

25 Pipe Splits - 1/2 Inch Vapor 6.00E-04 Nussey HSE 3

26 Pipe Splits - 1/4 Inch Vapor 2.40E-03 Nussey HSE 4

27 Gasket (3mm thk) 1/4 Dia Liquid 2.00E-06 Nussey HSE 5

28 Gasket (3mm thk) 1/4 Dia Vapor 3.00E-06 Nussey HSE 6

29 Gasket (1.6mm thk) 1/4 Dia Liquid 1.20E-06 Nussey HSE

30 Gasket (1.6mm thk) 1/4 Dia Vapor 1.80E-06 Nussey HSE

31 Tanker Cplg Transfer Hose Liquid 1.20E-06 Nussey HSE

32 Tanker Cplg Transfer Hose Vapor 1.80E-06 Nussey HSE33 Tanker Cplg Transfer Hose Liquid 5.00E-04 CPQRA

34 Valve or Flange Leak Vap or Liq 1.00E-04 Technica Upper Confide

35 Impact Failure Of Pipe Vap or Liq 1.00E-05 CPQRA

36 PSV Leakage at Norm Press Vap or Liq 1.00E-04 CPQRA

37 PSV Under Fire Vap or Liq 3.00E-06 CPQRA

38 Pump Case Rupture Liquid 6.60E-05 Technica

39 P S l L k Li id 6 60E 04 T h i E 5 5 21


6/29

47 Complete Nipple Screw Fail Vap or Liq 5.00E-03 Technica

48 Leak Errosion / Mech Stress Vap or Liq 1.35E-05 Technica

49 Pipe Rup Along Transfer Line Vap or Liq 6.70E-05 Technica50 Coll'n Vehicle to Pipe support Vap or Liq 4.40E-06 Technica Eqn 5.5.24

51 Sight Glass failure Vap or Liq 4.50E-02 Technica

52 Small Pipe Rupt 2" 6" / meter Vap or Liq 2.60E-06 CPQRA, P-459

58 Brittle Vessel Failure Vap or Liq 6.30E-04 ADL - FT59

60

61

62

63

64

65

66

6768

69

70


7/29

Estimate the Frequency of Leaks and Catastrophic Rupture For An LPG Storage Sphere

ce Limits Of Failure Rate Data - For PV Catastrophic Rupture Failure

, Page 351 See allso V.C. Marshall, Major Chemical Hazards, P-71

ce Limit Lower Confidence Limit

Eqn 5.5.22 f3 = 2(2 - x + 1) Eqn 5.5.25

Eqn 5.5.23 f4 = 2(x) Eqn 5.5.26

x = number of observations of failure

n = sample size, vessel years

ce Limit = (x + 1)F1 / [(n-x) + (x + 1)F1] Eqn 5.5.21 with f1 and f2

onfidence = x / [(n-x + 1)F2 + x] Eqn 5.5.24 with f3 and f4

F2 = value of F-distribution with degrees of freedom f1 and f2 confidence level is used.

Data Of Smith and Warwick, 1983, CPQRA, page 358

20,000 pressure vessels with an exposure of n = 310,000 vessel years = n

This includes pipe failures and vessel failures.

Failures Table 4: F1 Table 4: F2

PV Catastrophic Rupture Failur 2 2.1 5.63

Catastrophic Pipework Failure 10 1.55 1.84

Pipe Work Leaks 34 1.30 1.37

Vessel Leaks 42 1.28 1.33

1 - 2 Inch Leak Size Failures 25 1.35 1.45

2 - 6 Inch leak Size Failures 153 1.00 1.00

Select 1 to 4 1 Observed Failures, x = 2

PV Catastrophic Rupture Failure / vessel yr = 6.45E-06 /vessel yr = x / n

nce limit, f1 = 6 Eqn 5.5.22 f1 = 2(x + 1)

f2 = 619996 Eqn 5.5.23 f2 = 2(n - x)

From Table VII of Hald (1952a) for P = 0.95, F1 = 2.10 Table 4, p-258

U C fid Li it 20 32E 06 PV C t t hi R t F il / l


8/29

From Table VII of Hald (1952a) for P = 0.95, F2 = 5.63 Table 4, p-258

Lower Confidence Limit = 1.15E-06 PV Catastrophic Rupture Failure / vessel-yrs

Failure per 1E06 Hours = 1.31E-04 PERD Lower = 0.00E+00 PERD page = 0

The analyst can be 95% certain the value for PV Catastrophic Rupture Failure

falls in the range Lower Limit = 1.15E-06 to Upper L = 2.03E-05failures per vessel year

Index = 1.00 17.73

PV Catastrophic Rupture Failure / vessel yr = 1.15E-06 6.45E-06 2.03E-05

Failure Rate Within 95% Confidence Limits 1.00 5.63 17.73


9/29

Slope m Constant b

Hole In Pipe - Liq Phase -1.02877 -12.3186 Hole In Pipe - Liq Pha

Inch Fail/Yr Inch Fail/Yr Inch Fail/Yr

2.00 2.40E-06 2 2.19E-06 2 1.60E-06

1.00 4.80E-06 1 4.47E-06 1 3.20E-06

0.50 6.00E-06 0.50 9.12E-06 0.5 4.00E-06

0.25 2.40E-05 0.25 1.86E-05 0.25 1.60E-05

Hole In Pipe - Vapor P

Inch Fail/Yr

2.00 2.40E-06

1.00 4.80E-06

0.50 6.00E-06

0.25 2.40E-05

1.00E-06

1.00E-051.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

0.10 1.00 10.00

Series1

Series2


10/29


11/29

Slope m Constant b

e -1.02877 -12.724

Inch Fail/Yr

2 1.46E-06

1 2.98E-06

0.5 6.08E-06

0.25 1.24E-05

Slope m Constant b

ase -1.02877 -12.3186

Inch Fail/Yr

2 2.19E-06

1 4.47E-06

0.50 9.12E-06

0.25 1.86E-05


12/29

Incident No. 3 - Estimated Fault Tree Analysis For BHOPAL Event - Poor Safety Management System

MIC Flows To Atm Fr Top VGS

E6 = E5*P5 = 4.00E-07 per Yr

And

MIC Flows To Flare Stack Flare Stack Not Available Due To

Line Maintenance

E5 =P4*E4 = 4.00E-06 per Yr P5 = 0.1

And

VGS Pump Fails to Start MIC Flows To Off Line VGS

VGS On Standby

Est'd P4 = 0.01 E4 = E3*P3 = 4.00E-04 per Yr

And

Tank At Amb Temp & Runaway Operator Does Not Control

Reaction Starts Very Fast Runaway

E3=E1+E2 = 2.00E-03 per Yr P3=P1+P2 = 0.20

Or Or

Water Fr N2 Header Water Enters By Sabotage Inst Alarms & Oprs Do Not Operators Fail To Notice Alarms

Operator error Disgruntled Employee Respond. Incorrect Set Pt. Runaway Takes Off

E1/Yr = 1.00E-03 E2/Yr = 1.00E-03 Prob P1= 0.10 Prob P2= 0.10


13/29

IR

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

AccumulatedRiskPerYear

Individual Risk

Data Pts.

Best Fit


14/29

Societal F_N Curve 8/7/2014

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1 10 100 1000 10000

Freq Of N or MoreFatalities/Yr

No. Fatalities, N

Societal F-N Curve For MIC Storage Area

Acceptable

Unacceptable

Case StudyUnacceptable

Mitig'nReqd

Acceptable

Dutch Criteria For Acceptable To Unacceptable - BM - HSE Escape Model


15/29

Physical Properties

Chemical = MIC

Vessel Pressure at Failure =. 7.02 barg Press, P = 116.35

Vessel Temp. at Failure, T = 115.56 C T = 240

Atm Boiling Point, Tnb = 38.89 C Tnb = 102

Mol Wt. = 57.1 Atm Press. = 14.696

UEL, vol % = % Relative Humidity, RH = 50.00%

LEL, vol % = %

Heat Of Combustion, HC = 4.4.E+05 J/kgm HC = 189Spec Heat Ratio, Cp/Cv = 1.146 Ideal Gas Cp-Cv = 2 Cp = 15.71

Liquid Density @ atm bp = 977.10 kgm.cu.m. DL = 61

Latent Ht @ atm bp, L = 4.03E+05 J/kgm L = 173.3

Liq Heat Capacity, CpL = 1,800 J/kgm/K CpL = 0.43

Vapor Pressure, vp = 7.02 barg Vapor Pressure, vp = 116.35

Ambient Temperature = 293.00 K 68.00 F 20.00

Liquid Head, hL = 6.10 meters hL = 20

TNT Equivalent Heat Of Combustion 4.65E+06 J/kgm TNT HC = 2,000

Vessel Failure During = PSV Flow See Tab S7Special Conditions = Nitrogen Pad Lost

Basis Engineering Data Book - Natural Gas Process Suppliers Association - 9th Edition - 1972 - Cha


16/29

Antoinne Constants

Not added to PP yet

vp, psi =10^(A+B/(C+C))

psia C = 115.56

F A = 5.01922143

F B = -976.81162

psia C = 215.1785

Default = 50%

BTU/lbBTU/lb mole/F

lb/cf

BTU/lb

BTU/lb/F

psia

C

ft.

BTU/lb (Default = 2,000)

pter 16


17/29

Screen 4 Calculation of Source Terms (See Tab PID for Typical Credible Scenarios)

Liquid Leaks For Vessel Holes, Full Bore and Partial Pipe Diameter Breaks

Basis = Eqn 2.1.7 CPQRA, P449

Scenario = 1 2" Liq Leak Scenario = 2 1/2" Liq

Dia. = 0.0508 meters Dia. = 0.0127 meters

Area = 0.0020 sq.m. Area = 0.00013 sq.m.

GL = 47.67 kg/sec GL = 2.98 kg/sec

Drain Time = 14.27 minutes Drain Time= 228.35 minutes

Type = Long Term - Continuous Type = Long Term - Continuo

Determine % Flash If Flash is less than 10%, assume rainout will occur and special pool d

Frac Flashed = 1-EXP(-CpL*(T - Tnb) / L) = 28.99% > 10%, Assume No

Vapor Leaks For vessel Holes, Full Bore and Partial Pipe Diameter Breaks

Basis = Eqn 2.1.1 Page 450 CPQRA

Scenario 3 = 2 Inch Vapor leak Case = 25% Dia., mDia. = 0.0508 meters Dia = 0.0127 meters

Area = 0.00203 sq.m. Area = 0.000127 sq.m.

Critical Ratio = 1.74 Crit Ratio = 1.74

DP Ratio = 8.02 DP Ratio = 8.02

Is Flow Sonic? Sonic Is Flow Sonic? Sonic

Flow factor = 0.68 Flow factor 0.68

Alpha 221.04 Alpha = 221.04

GV for 2 Vapor Lines = 10.05 kg/s Gv = 0.63 kg/sec

Frac Flashed as above = 28.99% Frac Flshd= 28.99%

Flash Vapor wo Entrain't = 26,095 kgms Q wo Ent = 26,095 kgms

Time to Depressure = 43.29 minutes Time to Dep 692.65 minutes

Type For 1 Lines = Long Term - Continuous Type = Long Term - Continuous


18/29

Leak

0.50 Inch

Note

s

ispersion is ( Note)

ainout for Any Liquid Releases & Assume 100% vapor

To be checked out

0.50 Inch

Note

Assumes constant flash vapor rate.


19/29

Representative Set Of Source Terms 8/7/2014

Turbulent Free Jets

New TNO Yellow Book, Chapter 3

Example , Part 6, Page 22 Turbulent Free Jet

Data Chemical MIC Outflow = Upwards

MW = 57.1

Cp/Cv = 1.30 ideal gas where Cp-Cv = 2

Ves Press = 72.1 psia 497,057.40 pascals 4.97 bar abs

Atm Press = 14.7 psia 101,341.80 pascals 1.01 bar abs

Amb Temp = 77 F 298.20 K

Hole Dia = 2.00 inches 5.08 cm Hole area, Ao 0.00202688 sq.m.

Flow Coeff = 0.60

Viscosity = 0.0083 centipoise

LEL = 2.10%UEL = 9.50%

Test For Sonic Flow 15,363 lb/hr

MW Air = 28.84 21% O2

Pr/Pa = 4.90 [Pr/Pa]^(1/k)= 3.40

Crit Ratio = 1.83

Note Pr/Pa > Crit Press Ratio - Sonic Flow

TNO Initial Flow Rate, mo = 1.94 kg/sec

Ambient Air density = 1.18 kg/m3

Gas Density In Vessel, Dg,r = 11.44 kgm/m3

Gas expansion factor = 0.63

Gas Density at Opening, Dg,o 7.18 kgm/m3

Gas Velocity at Opening, Uo 221.61 m/s

Test For turbulence - Re No. greater than 2.5E+04

Re No. = 7.54E+06 Re > 25000 - Turbulent Flow - Eqns apply.

Gas Dens After Expan'n, Do,e 3.37 kgm/m3

Equivalent Dia., deq = 0.0575 meters 2.26 inches

b1 = 106.93 Eqn (6), p-12, Constant for the velocity distribution

b2 = 104.18 Eqn (7), p-12, Constant for the concentration distribution.

(b1+b2)/b1= 1.97

Density of Gas relative to air = 1.98 Relative Density Outside 0.14 to 1.53 Limits - Extrapolations Are Approximate

Rela gas density after exp = 2.86 Eqn 8, p-13

0.32 denominator term = 0.37

Eqn 14, p-14 At LEL, jm = 2.10% x/deq = 253.46 x LEL = 14.56 meters

Eqn 14, p-14 At UEL, jm = 9.50% x/deq = 58.06 x UEL = 3.34 meters

-0.80

-0.60-0.40

-0.20

0.00

0.20

0.40

0.60

0.80

0.00 10.00 20.00

JetWidth,Meters

Jet length, Meters

Concentration Profile in the Free jet

LEL

LEL

UEL

UEL


20/29

Representative Set Of Source Terms 8/7/2014

Calculation Of Jet Footprint at LEL 7.88224006

x/deq Incs = 22.33x/deq Conc'n, Jm y/deq x, meters y, meters -y,meters b3 x"

253.46 2.10% 0.00 14.56 0.00 0.00 0 #DIV/0!

231.13 2.31% 6.91 13.28 0.40 -0.40 0.0299126 13.2820663

208.81 2.55% 9.06 12.00 0.52 -0.52 0.04337723 11.999155

186.48 2.86% 10.18 10.72 0.59 -0.59 0.05460403 10.7162437

164.16 3.26% 10.67 9.43 0.61 -0.61 0.06499374 9.43333244

141.83 3.78% 10.66 8.15 0.61 -0.61 0.07517899 8.15042114

119.51 4.51% 10.23 6.87 0.59 -0.59 0.08561338 6.86750985

97.18 5.57% 9.40 5.58 0.54 -0.54 0.09676832 5.58459855

74.86 7.29% 8.18 4.30 0.47 -0.47 0.10931158 4.30168725

52.53 10.55% 6.54 3.02 0.38 -0.38 0.12448862 3.0187759630.21 19.09% 4.40 1.74 0.25 -0.25 0.14556116 1.73586466

7.88 100.00% 1.52 0.45 0.09 -0.09 0.19257183 0.45295336

Calculation Of Jet Footprint at UEL 7.88224006

x/deq Incs = 4.56

x/deq Conc'n, Jm y/deq x, meters y, meters -y,meters

58.06 9.50% 0.00 3.34 0.00 0

53.50 10.35% 1.54 3.07 0.09 -0.09

48.94 11.37% 2.03 2.81 0.12 -0.12

44.38 12.61% 2.31 2.55 0.13 -0.13

39.82 14.16% 2.46 2.29 0.14 -0.14

35.25 16.14% 2.51 2.03 0.14 -0.14

30.69 18.76% 2.48 1.76 0.14 -0.14

26.13 22.40% 2.37 1.50 0.14 -0.14

21.57 27.79% 2.19 1.24 0.13 -0.13

17.01 36.60% 1.94 0.98 0.11 -0.11

12.44 53.59% 1.60 0.72 0.09 -0.09

7.88 100.00% 1.18 0.45 0.07 -0.07

Calculation Of Volume Of Gas Between UEL and LEL by Eqn 19, p-16

1 to LEL 0.021 0.0225 0.025 0.0275 0.03 0.035 0.04 0.045

(a) = /3/b2 = 0.010052249 0.01005225 0.01005225 0.01005225 0.01005225 0.01005225 0.01005225 0.01005225

(b) = 2nd term = 0.003604627 0.00360463 0.00360463 0.00360463 0.00360463 0.00360463 0.00360463 0.00360463

(a)(b) = 3.62346E-05 3.6235E-05 3.6235E-05 3.6235E-05 3.6235E-05 3.6235E-05 3.6235E-05 3.6235E-05

(c) = 3rd term = 3.847577893 3.84757789 3.84757789 3.84757789 3.84757789 3.84757789 3.84757789 3.84757789

(d) = 1/jh^2-1 2266.573696 1974.30864 1599 1321.31405 1110.11111 815.326531 624 492.82716

(e) = (c)(d) = 8720.818846 7596.30628 6152.27705 5083.85873 4271.23897 3137.03233 2400.88861 1896.19089

(f) = 4th term = -534.1622151 -497.787532 -446.862977 -405.197431 -370.476143 -315.914119 -274.992601 -243.164754

(g) = 5th term = 21.97008552 21.5777252 20.9785432 20.4365172 19.9416862 19.065036 18.3056471 17.6358186

(h) = 6th term = 0.921114028 0.91970272 0.91735054 0.91499836 0.91264618 0.90794181 0.90323745 0.89853309(e) - (f) + (g) + (h) = (i) = 9277.872261 8116.59125 6621.03592 5510.40767 4662.56945 3472.91943 2695.09009 2157.88999

(i)(a)(b)=Vg,Gas Vol, Eq19= 0.3362 0.2941 0.2399 0.1997 0.1689 0.1258 0.0977 0.0782

Vgas 1-2 0.04 0.05 0.04 0.03 0.04 0.03 0.02 0.01

Vgas/javg 1.93 2.28 1.53 1.07 1.33 0.75 0.46 0.30

Sum (V/j) 10.34 m3 total volume of gas By Simple Inc'ts, Vol. Gas = 10.07 m3


21/29

Methodology For Evaporation From Unrestricted Spill 8/7/2014

Summary Table, Evaporation of Refrigerated MIC

CASE 1: BHOPAL - Incident No. 4 - Loss Of Refrigerated MIC

Unrestrained Circular Pool On Average Soil Surface is Penetrable

Total Spill 40,824 kgms Pool Ht, mm 25 Rough Sand or Gravel

Flash Liq 40,824 kgms From Pool of Area = 1,670.37 sq. m.

Flash Vap 0 kgms During First Minute of Spill

Wind 11.18 mph Atmospheric Stability = Neutral Conditions

Ground at 21.11 deg C

SEE TABLE 4, Page 7 Incremental Total Ground Incremental Total Total

Wind Ground Conduction MIC MIC MIC

Convection Conduction From Maxim Lost To Lost To Remaining

Evaporation Evaporation Pool Formed Atmosphere Atmosphere In Spill AreaTime Fr, sec Time to, sec kgm. kgm. kgm. kgm. kgm kgm.

0.00 16.47 0.00 898.01 0.00 898.01 898.01 39,925.99

16.47 60.00 138.77 2,188.94 2,188.94 2,327.71 3,225.72 37,598.28

60.00 120.00 191.26 1,186.79 3,375.72 1,378.05 4,603.77 36,220.23

120.00 180.00 191.26 866.87 4,242.59 1,058.13 5,661.90 35,162.10

180.00 240.00 191.26 717.62 4,960.21 908.88 6,570.78 34,253.22

240.00 300.00 191.26 626.18 5,586.39 817.45 7,388.23 33,435.77

300.00 360.00 191.26 562.74 6,149.13 754.01 8,142.23 32,681.77

360.00 420.00 191.26 515.39 6,664.52 706.66 8,848.89 31,975.11

420.00 480.00 191.26 478.30 7,142.82 669.57 9,518.46 31,305.54

480.00 540.00 191.26 448.22 7,591.05 639.49 10,157.95 30,666.05540.00 600.00 191.26 423.19 8,014.24 614.46 10,772.41 30,051.59

600.00 660.00 191.26 401.94 8,416.18 593.21 11,365.61 29,458.39

660.00 720.00 191.26 383.60 8,799.78 574.87 11,940.48 28,883.52

720.00 5,112.00 14,000.59 14,882.57 23,682.36 28,883.17 40,823.65 0.35

Time To Evaporate Spill = 85.20 Minutes Total Lost To Atm in Ist Min = 3,225.72 kgms.

Total Lost To Atm in Ist Min = 7,111 lbs

% Vaporzd in ist Minute = 7.90%

Initial rate = 3,225.72 kgm/min. 426,569 lb/hr

Avg rate = 479.15 kgm/min. 63,363 lb/hr 1056.34 lb/min.Dispn rate = 1,852.44 kgm/min. 244,966 lb/hr 1/2 way between initial and avg rate

Dispn rate = 30.87 kgms/sec


22/29

Methodology For Major Spill Into Dyked Area 8/7/2014

Summary Table, Evaporation of Refrigerated MIC

CASE BHOPAL - Scenario 1 - Leak Into 1,000 m2 Restricted Area

Bunded Circular Pool On Average Soil Surface is Penetrable

Total Spill 40,824 kgms Dyke Dia = 35.84 Tank Dia = 3 meters

Flash Liq 40,824 kgms From Pool of Area = 1,001.32 sq. m.

Flash Vap 0 kgms During First Minute of Spill

Wind 11.18 mph Atmospheric Stability = Neutral Conditions

Ground at 21.44 deg C

See Table 5, Page Incremental Total Ground Incremental Total Total

Wind Ground Conduction MIC MIC MIC

0.016666667 Convection Conduction From Maxim Lost To Lost To RemainingEvaporation Evaporation Pool Formed Atmosphere Atmosphere In Spill Area

Time fr, hour Time to, hour kgm. kgm. kgm. kgm. kgm kgm.

0.00 0.0167 100.42 1,540.51 1,540.51 1,640.93 1,640.93 39,183.07

0.02 0.0333 100.42 638.10 2,178.62 738.52 2,379.45 38,444.55

0.03 0.0500 100.42 489.63 2,668.25 590.05 2,969.51 37,854.49

0.05 0.0667 100.42 412.78 3,081.03 513.20 3,482.71 37,341.29

0.07 0.0833 100.42 363.67 3,444.69 464.09 3,946.79 36,877.21

0.08 0.1000 100.42 328.78 3,773.47 429.20 4,375.99 36,448.01

0.10 0.1167 100.42 302.34 4,075.82 402.76 4,778.75 36,045.250.12 0.1333 100.42 281.41 4,357.23 381.83 5,160.59 35,663.41

0.13 0.1500 100.42 264.31 4,621.54 364.73 5,525.32 35,298.68

0.15 0.1667 100.42 249.99 4,871.53 350.41 5,875.73 34,948.27

0.17 0.1833 100.42 237.77 5,109.31 338.19 6,213.92 34,610.08

0.18 3.22 18,296.38 16,303.29 21,412.59 34,599.67 40,813.59 10.41

Time To Evaporate Spill = 3.22 Hours Total Lost To Atm in Ist Min = 1,640.93 kgms.

Loss To Atm in 2nd Min. = 738.52 kgms

Initial Rate = a 1,640.93 kgm/min.Avg Rate = b 211.30 kgm/min.

Leak Rate and Source term Disp'n Rate = (a+b)/2 926.12 kgm/min.

Disp'n Rate = (a+b)/2 15.44 kgm/sec

Initial Rate = a 3,617.60 lb/min.

Avg Rate = b 465.84 lb/min.

Disp'n Rate = (a+b)/2 2,041.72 lb/min.

Disp'n Rate = (a+b)/2 122,503.31 lb/hr


23/29

Methodology for Liquid Evaporation Rate - Non Boiling Liquids 8/7/2014

CONVECTIVE EVAPORATION OF VOLATILE LIQUIDS FROM RECTANGULAR POOLS

Basis: Lihou Course, p-4, Clancy V.J. Chem Proc Hazards, 1974, p-80, IChemE Symp. Ser. No. 39a

Liquid = Acrylonitrile U.S. EPA Example 4Vapor Mol Wt = 53.1 If multicomponent, evaporation rate may be unsteady state

Liq Temp, T = 77 deg F 298.00 deg K 25.00 deg C

VP at T, Ps = 2.06 psia 0.1420 bar

Pool width, y = 110.43 feet 33.66 meters Area, sf = 12195.00

Pool Length, x = 110.43 feet 33.66 meters, (wind across this dimension)

Wind Speed, U 3.355 mph 1.50 meters/sec

Calculations per equations 9, Page 4

Satd Vap Density 0.018984 lb/cu. ft. 0.3041 kgm/cu. m RHOS = MW*VP/(10.73*R)

Unstable Neutral Stable

n factor 0.2 0.25 0.2

K factor 0.001278 0.00157 0.001786

Rate, kgm/s = 0.44562 0.50161 0.62275 Eqn 9 No Conduction

Rate, kgm/min 26.74 30.10 37.36

Rate, lb/min = 58.94 66.35 82.37

Rate, lb/hr = 3,536.64 3,981.03 4,942.44

CONVECTIVE EVAPORATION OF VOLATILE LIQUIDS FROM CIRCULAR POOLS

Basis: Clancy V.J. Chem Proc Hazards, 1974, p-80, IChemE Symp. Ser. No. 39a

Liquid = Acrylonitrile Example 2, Page 4, Lihou Course

Vapor Mol Wt = 53.1 If multicomponent, evaporation rate may be unsteady state

Liq Temp, T = 77 deg F 298.00 deg K 25.00 deg C

VP at T, Ps = 2.06 psia 0.1420 bar

Pool Radius, r = 62.30 feet 18.99 meters Area, sf = 12,195.00Wind Speed, U 3.355 mph 1.50 meters/sec

Calculations per equations 10, Page 4

Satd Vap Density 0.018984 lb/cu. ft. 0.3041 kgm/cu. m RHOS = MW*VP/(10.73*R)

Unstable Neutral Stable

n factor 0.2 0.25 0.2

K' factor 0.003846 0.004685 0.005285

Rate, kgm/s = 0.44966 0.50775 0.61791 Eqn 10 No Conduction

Rate, kgm/min 26.98 30.46 37.07

Rate, lb/min. = 59.48 67.16 81.73

Rate, lb/hr = 3,568.76 4,029.73 4,904.03


24/29

TIME TO DEPRESSURE A VESSEL WITH LIQUID AT ITS BOILING POINT 8/7/2014

Case No. Chlorine 90 Ton Tank Car Example

FlowPhys Properties of CHLORINE No Inert Gas Pad

Starting Liq Temp = 77.00 F Vessel Dia., ft 10

Starting Psia 112.90 Vap Press Tan-Tan L, ft 40

Final Psia 14.70 % Full 66.00%

Number Incs 20 Vessel Vol., cf 3,142 89 m3

Dp/Inc 4.91 Liq cf= 2,073 181,077 lbs

Number of Nozzles 1 Vapor cf 1,068 1,671 lbs

Flow Coeff Assumed = 1.0000 Conservative

Nozzle Dia., inches 2.00 Cp/Cv = 1.36

Time Vapor Rate Vessel Press Flow Liq In Vessel Vapor Lost to Accumulated

Minutes lb/hr Psia Condition Lbs Atmos., lbs. lbs Vapor

0.00 48,154 112.90 Sonic 181,077 0 0

1.46 46,091 107.99 Sonic 179,972 1,145 1,145

3.04 44,045 103.08 Sonic 178,828 1,187 2,331

4.76 41,997 98.17 Sonic 177,638 1,234 3,565

6.64 39,947 93.26 Sonic 176,397 1,286 4,8518.71 37,897 88.35 Sonic 175,102 1,343 6,194

11.00 35,844 83.44 Sonic 173,746 1,405 7,599

13.54 33,789 78.53 Sonic 172,325 1,473 9,072

16.36 31,732 73.62 Sonic 170,835 1,545 10,616

19.53 29,671 68.71 Sonic 169,270 1,621 12,238

23.10 27,608 63.80 Sonic 167,626 1,703 13,940

27.14 25,541 58.89 Sonic 165,900 1,788 15,728

31.73 23,471 53.98 Sonic 164,087 1,877 17,606

37.00 21,396 49.07 Sonic 162,186 1,970 19,576

43.09 19,317 44.16 Sonic 160,192 2,066 21,64350.20 17,233 39.25 Sonic 158,103 2,165 23,807

58.60 15,143 34.34 Sonic 155,919 2,265 26,072

68.67 13,048 29.43 Sonic 153,638 2,367 28,439

81.07 10,844 24.52 Sub Sonic 151,259 2,469 30,908

97.57 7,858 19.61 Sub Sonic 148,783 2,572 33,480

126.99 3,048 14.70 Sub Sonic 146,211 2,673 36,153

Overall Mass Balance Dispersion Modeling Of Transient Conditions

Initial Final Initial lb/hr = 48,154 Sonic

Lb in Liquid = 181,077 146,211 Avg lb/hr = 17,082 Sonic

Lb in Vapor = 1,671 383 Final lb/hr = 3,048 Sub Sonic

Lb Lost To Atm = 0 36,153

Totals = 182,747 182,747 For Disp'n, lb/hr = 1/2(Init'l + Avg Rates)

% of Total Lost to Atm = 19.78% Disp'n, lb/hr= 32,618 Sonic


25/29

SIZING AND COST OF FARRIS PSV SYSTEMS 8/7/2014

PSV SIZING FOR FIRE CODITIONS

Chemical MIC PSV 109 V-11Mol Wt 57.1

Method (1=NFPA,2=API-520) 1

Orientation (1=H,2=V) 1 Horrizontal Vessel Fator for Wetted Area = 0.75

Diameter 8 ft.

Tan to Tan 40 ft.

Max Liq Height 6 ft.

Tot Vessel Area 1,125.95 sq. ft

Wetted Area = 844.46 sf to max 50 ft. if Vertical

Heat Input, Q = 2,710,643 BTU/Hr

Gas Constant 315 (If unknown, set = 315, See Area_Phys_Prop)

Atmospheric Pressure = 14.7 psiaCredit Factor (1 to 5) 3 Insulation in accordance with 2-2.5.7 (generally only double steel walled)

NFPA Protection factor = 0.3

Operating Pressure = 14.7 psia

Design pressure = 40 psig

PSV Set Pressure = 75.4545455 psig Design = 40 psig

PSV Flow factor For Fire = 1.21

PSV Flow Pressure = 106 psia Set pressure adjusted so that Temp > 212F to boil cooling water applied to vessel

PSV Flow Temp = 240 F From Phys Props

Latent Heat at Flow Temp, L = 173.3 BTU/lb Fr Phys Prop

Vapor Density at Flow Temp = 1.03 lb/cf Fr Phys Prop

Ideal Vap Den @ Flow Temp = 0.8058 lb/cf Compress Factor @ Flow Temp= 0.7824 Assume 1.0 if unknown

Flow Factor For Max PSV Cap = 1.8741 Set at 1 for design. Adjust for max PSV flow capacity

Vapor Flow = Q/L 29,314 lb/hr G = 3.6936 kgms/sec

Back Press < 55% flow Press ? 1 1 = yes, 2 = 0Vaiable or fixed?

Kb, Back Press factor = 1 See Farris , p-3.06 Sizing Section

PSV Oficie Area Req'd 2.8530 Sq. inches Adjust till Area Req'd = Selected Area

Select PSV Class = L

Selected Orifice Area = 2.853 sq. in.

Estimated Inlet Size = 3 inches (Check DP less 3% of set pressure to prevent chattering)

Estimated Outlet Size = 4 inches (Check DP less 10% of set pressure to prevent chattering for conventional PSV type)Note: to overcome chattering use a balanced bellows PSV

Orifice Selection Typical Inlet ypical Outlet

Selection Size Size

Class Sq. in. Sq. in. Inches Inches

D 0.110 1 2

E 0.196 1 2

F 0.307 1.5 2

G 0.503 1.5 2.5

H 0.785 1.5 3J 1.287 2 3

K 1.838 3 4

L 2.853 2.853 3 4

M 3.600 3.6 4 6

N 4.340 4.34 4 6

P 6.380 6.38 4 6

Q 11.050 11.05 6 8

R 16 000 16 6 8


26/29

Fauske Generalized Correlation For Flashing Choked Flow 8/7/2014

A Generalized Correlation for Flashing Choked Flow of Initially Subcooled Liquid

J.C. Leung, M.A. Grolmes, Fauske & Associates, Inc., AICheE Journal, April 1988, Vol. 34, No. 4, P-688

Fauske Example, P-690

Initial Liq Temp, To = 512.06 F 540 K

Initial Vessel Pressure, Po = 798 PSIA 5.50 MPa

Vapor Pressure at T, Ps = 760 PSIA 5.24 MPa

Liquid Density, rfo = 48.26 lb/cf 773.00 kg/cu.m. vfo = 1/ rfo = 0.001294

Vapor Density, rgo = 1.6794 lb/cf 26.90 kgm/cu.m. vgo = 1/rgo = 0.037175

Liquid Latent Heat, hfgo = 697.72 btu/lb 1,622.90 kJ/kg

Liquid Specific Heat, Cfo = 1.2035 btu/lb/F 5,039.00 J/kg/K

Omega, w = Cfo*To*Ps*((vfo-vgo)/hfgo)^2/vfo = 5.39 Eqn 5

ns = Ps / Po, by definition, the saturation pressure ratio = 0.9524

nct = (2*Omega-1)/(2*Omega) = 0.9072 Eqn 11

Is ns>=nct? If true, Eqn 10 can be used, = TRUE Eqn 10 can be used

nc = ns*(1/nct)*(1-(1-nct/ns)^0.5) = 0.8211 Eqn 10

Gc* = nc / (Omega*ns)^0.5 = critical mass velocity = 0.3625 Eqn 9a,

Po in psia to kgm/sq.m.*g = psia*703*9.81 = Po' = 5.50E+06 (kgm/sq.m.)(m/sec^2)

Gc = (Gc*)(Po'*rfo)^0.5 1.74E+07 lb/hr/sf 23,644 kgm/sq.m./s by Eqn 9a and 9b

If, for example, the hole diameter is 1.0 inch, calculate the rate of two phase flow?

Orifice Dia = 1.00 inch 2.54E-02 meter

Orifice Area = D^2/4 = 5.45E-03 sf 5.07E-04 sq.m.

2 Flow Rate = (Gc)(A) = 95,086.03 lb/hr 11.98 kgm/sec

This paper gives a generalized correlation for f lashing choked flow of an initially subcooled liquid.

The model assumptions are:

1. Piping resistance are not included, the release is from a hole in the vessel.

2. Isentropic flow.

3. Thermal equilibrium.

4. Equal phase velocities once saturation is reached.

The model is a limiting case, without consideration of nonequilibrium effects.

In this regard, it gives a lower-bound estimate for the mass flow rate and should be a

useful tool for many engineering applications.

For Two Phase Flow With Piping Resistance, 1987 Boston Vapor Cloud Conference, p-257.

To account for piping resistance, Fauske determined a flow reduction factor, FR = 1.9454*(L/D equivalent)^-0.2091

Determine the equivalent length in the usual manner, determine the flow, as above, and mult iply by the flow reduction

factor, FR.


27/29

Touchdown Distance by Hoot and Meroney as presented by Gerry Havens, 1987 VC Conference In Boston, p-568 (R1)

Also, Chapter 3, Page 18, Workbook Of Test Cases For Vapor Cloud Source Models / CCPS / AIChE (R2)

Bordurtha Eq (1) Max Conc = 3.44*Cs*100*[D/(2*H + hs)]^1.95*vs/U*0.000001

Havens Touchdown Distance, X = 0.56*Dj*{(H/Dj) 3*[(2+hs/H)^3-1]*Ua/Uj}^0.5*Frh+Xbar (R1) p-576Havens Touchdown Conc = 3.1*(Q/U/Dj 2)*((2*H+hs)/Dj) -1.95/Dv*1000000 (R1) p-576

Havens Horizontal Froud No., Frh = Ua/((g*Dj*(RHOj-RHOa)/RHOa))^0.5 (R1) p-576

Havens Xbar = (Dj*Ua/Uj)*Fr^2 (R1) p-576

Bordurtha Plume Rise = 1.32*D*(Vs/U)^0.333*SG^0.333*Fr 0.667*0.001

Bordurtha Froud No. Fr = 31.62*Vs/(9.806*D*(SG-1)/SG) 0.5

Source Richardson No. = [g(Dg-Da)/Da](p/4)(Dj)(Uj) / {(Ua)(u*)^2} (R2) p-20

u* = (0.065)(Ua)= 0.3250 m/sec (R2) p-20

Wind Velocity, Ua = 5.00 m/s g = 9.815

Initial Jet Velocity, Vs = Uj = 63.64 m/s Q = 3.693564 kgms/sec

RHO, Initial Jet Density 1.7896 kgm/cu.m.

RHO air = 1.1786 kgm/cu.m.

Jet Diameter, Dj 0.2032 meters D = 203.20 mm 8.00

Bordurtha Froude No., Fr = 77.15 Within HMP Froude No. Range 115.01 to 52.03

Havens Horizontal Froude No. = Ffh = 4.92 Within HMP Horizontal Froude No. Range 5.44 to 0.88

Havens & Bordurtha Plume Rise, H = 13.05 meters max ht 42.80 ft.

Havens X bar, Dist To Max = 95.03 meters downwind distance to max rise 311.76

Existing Stack Height, hs = 32.92 meters 108 ft.

Havens C.L. Touchdown Distance 866.96 meters

Bordurtha Conc'n at Touchdown = 488 ppmv

Havens Concentration at Touchdown = 488 ppmvSource Richardson No. = 97.86 Rio > 10 and Dense Gas Model Justified

Exit Nozzle Reynolds No. = 2.31E+06 Re = 6.31(W)/(d)/(Visc cP) (Min.=2.5E04 by Oohms)

Xbar, m = 95.03

Xbar

2,397 ppmv at stack exit elevation

14 m

108 Ft. Stack Ht. 488.09 ppmv Concentration at Touchdown

32 m A grade level virtual distance will

be established at this concentration

in a heavy gas model.

(x,y) coords at base of stack=(0,0)

TD Radius = 14.39 metersTouchdown Dis, X TD Area = 650.20 m2

866.96 meters

2,844.31 ft.


28/29

CPQRA Simplified Approaches 8/7/2014

All in one eqn with wind at 2m, z = 0 and H = 0 TNO Disp'n Coefficients

ppmv = 1/((Dis+VS) (b+d)/(kgm/s/(PI()*m/s*a*Avg Time Factor*(MW*Atm Press/14.7/1000000/0.082/K Vap)*c)))

Meters = (kgm/s/(PI()*U2*a*ATCF*(ppm*MW*AtmP/14.7/1000000/0.082/K)*c)) (1/(b+d))-Virt Dis

Senario 1 Scenario 2 Scenario 3 Scenario 4

kgms/s = 3.6936 15.44 1.54 3.69 30.8739

Wind meas'd @ 10.00 10.00 10.00 10.00 10.00 ft.

U10 = 5.00 5.00 5.00 5.00 5.00 m/s

Wind at = 2.00 2.00 2.00 2.00 2.00 (1) Wind Speed at 2 meters = U2 = U10(

Wind Corect'n = 0.15 0.15 0.15 0.15 0.15 CPQRA Table 2.3, p-83

U2 = 3.93 3.93 3.93 3.93 3.93 Corrected to 2 meters height

a = 0.128 0.128 0.128 0.128 0.128 Stab (1 - 6) = 4

b = 0.905 0.905 0.905 0.905 0.905 Rough (1 - 5) 2

c = 0.2 0.20 0.20 0.20 0.20

d = 0.76 0.76 0.76 0.76 0.76MW = 57.1 57.1 57.1 57.1 57.1

Probit Constant, -5.64 -5.64 -5.64 -5.64 -5.64

Probit Constant, 1.64 1.64 1.64 1.64 1.64

Probit "n" Const 0.65 0.65 0.65 0.65 0.65

Probit = 5.00 5.00 5.00 5.00 5.00 (2.67 = LC01, 3.72 = LC10, 5 = LC50)

Atm P = 14.7 14.70 14.70 14.70 14.70

K = 293.3 293.30 293.30 293.30 293.30

TD Distance = 866.96 0.00 0.00 866.96 0.00 meters

TD Conc = 488.09 1.00E+06 1.00E+06 488.09 1.00E+06 ppmv

Virt Dist = 192.69 4.96 1.24 192.69 7.22 meters, (Can set conc = 1,000,000 ppmv

Sample Time = 100.00 60.00 60.00 100.00 85.00 minutesATCF = 1.5849 1.431 1.431 1.585 1.534 average time correction factor.

Conc = 18.23 39.86 39.86 18.23 23.38 ppmv

Try Conc = 18.23 18.23 ppmv Dist By CPQRA =

TD - VD = 674.27 674.27

Dis Fr Virt Dis = 1,195 2,172 545 1,195 4,355 meters 3920.92 ft.

ppmv = 18.23 Dis fr Stk = 1,869 Fr All In One Eqn. as a check

EPA and TNO Instantaneous Release Consequence Analysis 8/7/2014


29/29

EPA and TNO Instantaneous Release Consequence Analysis 8/7/2014

EPA PUFF and TNO Point Source Methods For Instantaneous Releases Risk Class Consequence Zone Description Logic

Basis: TNO 1979 Yellow Book, EPA Report 600/3-82-078, Wind Corrctd to 2 Meters Ht. 1 100% Certain Fatality > 50% Fatality

2 Wounded / Req Hospitaization Betwenn 1% & 50% Fatality

Case Study: BHOPAL AS AN INSTANTANEOUS RELEASE FR PRESSURED VESSEL 3 May Require Hospitalization Between 1% Fatal & IDLH Pr

4 Coughing, Choking, Vomiting Between IDLH Pr & ERPG2 Pr

5 No Serious Problems Less Than ERPG2 Probit

Input Data Units Consequences For Special Areas Of Concern (AOCs) Methodology = EPA

Chemical Code No. (1-20) = 4 MIC Risk Class = 5 2 3 4

30 Minute IDLH = 5 ppmv fr database Location = Risk Class 1 Risk Class 2 Risk Class 3 Risk Class 4 Units

IDLH Probit Value = 1.6462 fr database Dist Of Concern= 534 3,362 7,549 11,992 meters

60 Minute ERPG2 = 1.00 ppmv fr database Vir Dis @ 100% 0 0 0 0 meters

ERPG2 Probit = 1.0604 fr database Dist For Dispn = 534 3,362 7,549 11,992 meters

Tons of Product Released = 45 Tons Peak C.L. Conc = 66,434.56 585.86 73.28 22.31 ppmv

Atmospheric Pressure = 14.7 psia Avg Conc = 37,505 331 41 13 ppmv

Amount Vaporized at Atm = 1 Wt. Frac Exposure Min. = 0.69 3.63 7.55 11.47 minutesTemp Of Flash Vapor = 77 F Dose(C^n)(t)= 6.66E+02 1.60E+02 8.58E+01 6.00E+01 ppmv-min

MW of Vapor = 57.1 fr database Probit = 5.0000 2.6700 1.6462 1.0604 Probit

Std Deviations For Cloud = 2.15 < 2.15 For 90% of cloud > % Fatality = 50.17% 0.94% 0.00% 0.00% Fr Probits

Initial Dilution = 1.0000 Vol Frac Risk Conseq = No Problems Wounded>Hospit May Req Hospit Cough/Chkg/Vom See Above

PUFF Methodology = 1 (EPA = 1, TNO = 2) Cld Arriv Time= 2.26 14.27 32.03 50.88 min., W@ 2m

k1 Dose Constant = -5.642 fr database Consequence Summary (With Virtual Distance, If Any) Methodology = EPA

k2 Dose Constant 1.637 fr database 2 m Wind Vel

n Dose Constant = 0.653 fr database Consequence EPA Dist Fr Peak C.L. Fixed on C.L. Cloud Time Of

Ambient Temp = 77 F < Cloud Temp Default > % Fatality Source, m Conc, ppmv Avg PPMV Exp Min. Arrival, Min.

Wind Speed Referenced at = 10 Meter Height 100 50 Out Of Range Out Of Range Out Of Range 0.21

Wind Speed At Ref Ht. = 11.1835 mph m/s= 5.00 90 194 893,514 504,426 0.27 0.82Wind Speed Correctd to 2m = 8.78 mph m/s= 3.93 80 275 365,686 206,445 0.38 1.17

LC50 Peak Concentration = 66,434.56 ppmv (for Briggs Only) 70 354 190,955 107,802 0.47 1.50

Stability Class A,B,C,D,or F D Stabil Class 4 60 438 110,368 62,308 0.57 1.86

Ground Roughness (1 to 5) = 2 Rural, Zo = 0.1m 50 534 66,435 37,505 0.69 2.26

Wind Variation, +/- 20.00 +/- Degrees 40 650 39,989 22,576 0.82 2.76

Wind Speed Ht Corr Factor = 0.15 CPQRA, Table 2.3, p-83 30 805 23,113 13,048 1.00 3.41

20 1,036 12,069 6,814 1.25 4.40

Alternate Disp'n Coeff'ts 10 1,467 4,940 2,789 1.71 6.22

Briggs Dispn Checking Only For Checking Dist 1 3,362 586 331 3.63 14.27

Initialization Counter 2 1 resets Newton Rapson IDLH 7,549 73 41 7.55 32.03

Distance to LC50 Conc = 0.5722 km. - Briggs Disp'n Coef ERPG2 11,992 22.31 13 11.47 50.88

R.A. Hawrelak 7:48 PM 240621230.xls.ms_office

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Bhopal QRA V3