bhopal incident

7/24/2019 Bhopal Incident

1/27

Incident CaseDescription

Bhopal, India1984


2/27

Bhopal located in North CentralIndia

Very old town in picturesquelakeside setting

ourist centre

Industry encouraged to go to!adhya "radesh as part o# apolicy to $ring industry to lessde%eloped states

&nnual rent '4( per acre

Decision $y )nion Car$ide in19*( to $uild was welco+ed

Bhopal Capitol of

Madhya Pradesh

he etting


3/27


4/27

Initially in quiet su$ur$

/ater the town e;pandedaround it

&ttracted a largesquatter ca+p, as in+any third worldcountries

he urroundings


5/27

6VIN +anu#actured #ro+

Car$on !ono;ide 2C-5 i+ported $ytruck

!ono+ethyla+ine 2!!&5

Chlorine 2Cl


6/27


7/27

2National @ire "rotection &ssociation5:ight ide op o# Dia+ond /e#t ide

6;tract #ro+ N@"& *(4


8/27

:eaction yste+:eaction yste+

"hosgene till"hosgene till

"yrolysis"yrolysis

!IC :e#ining till!IC :e#ining till

!IC torage!IC torage

!!& "hosgene

Cl

Chloro#or+

ails:esidue

@lare and cru$$er Deri%ati%es "lant

i+pli#ied "rocess @low Chart


9/27

!IC torage ank


10/27

SAFEGUARD TYPE

10


11/27

10 Ehy it was not categori?ed aspassi%eF It is per+anently installed


12/27


13/27

"assi%e sa#eguards are those which aredesigned in and which do not require anyinitiation 2e0g0 concrete #ireproo#ing,ele%ated %ent stack #or dispersion5Both acti%e and passi%e sa#eguards can$e de#eated through inadequate a#ety!anage+ent yste+s

a#eguards


14/27

&7Napthol plant shut down

6VIN production no longer +aking+oney, so cost sa%ings sought, andplant run inter+ittently!ini+u+ +aintenance

a#ety procedures si+pli#ied #ors+all Go$s

:e#rigeration unit shut down and@reon sold

cru$$er circulation stopped

!anning cut to ((

!orale lowlip $linding no longer +andatoryduring washing

igh te+perature alar+ shut7o## as now H 11 C

:V and "CV headers Goined

2#or +aintenance5 6+ergency #lare line

corroded, disconnected

198171984. accidents withphosgene or !IC

198< audit critical o# !IC

tank and instru+entation 1984 warning o# potential

runaway reaction ha?ard

"lant "ro$le+s "recursor toDisaster


15/27

-ccurred late at night, soon a#ter shi#t change!IC tank o%erheated, o%er7pressured and %ented

through scru$$er

6le%ated discharge o# +assi%e quantity o# !IC2appro;i+ately


16/27

,ource o# Eater

@ilters were $eing #lushed using high pressurewater

Drain line #ro+ #ilter was $locked, operatoro$ser%ed no #low to drain

@lushing continued despite $lockage

igh pressure could cause %al%e leakJ #orcewater into relie# header and thenF

Incident Causes


17/27

:oute o# Eater:V and "CV headers were Goined $y Gu+per pipe,

no $linds

!IC tank could not $e pressurised $ecause tank"CV #ailed openF

/eakage through a single %al%e would allowwater #ro+ :V header to enter tank

ead o# water su##icient #or #low

low initial reaction would allow 1(( l$s0 toenter

Incident Causes


18/27

Water Drain

PI

RV

Valve which let water in

Quench Filter pressure

safety valve lines

!at "round level#

Phosphene $trippin"

$till Filter pressure

safety valve lines

!at "round level#

%o VC$ RW& 'ine

%o V($ and FV& FV& 'ine

)*&eader Isolation Valve

Rupture

Dis+

Concrete Cover

Fro, MR$

Fro, Refri"eration

%o Reactor Conditioner

Refri"erator

%an+ )o- ./0

10 P$I

2ducator

MR$ MIC Reactor $ide

RVV& Relief Valve Vent &eader

PV& Process Valve Vent &eader

V($ Vent (as $cru33er

FV& Flare Vent &eader

Route of water in"ress

%o

VC$

PI

4u,per'ine

Slip Blind

required here

Eaterource&rea

Ultimate destination of water

"ro$a$le :oute o# Ingress o#Eater into ank 1(


19/27


20/27

Water Drain

PI

RV

Valve which let water in

Quench Filter pressure

safety valve lines

!at "round level#

Phosphene $trippin"

$till Filter pressure

safety valve lines

!at "round level#

%o VC$ RW& 'ine

%o V($ and FV& FV& 'ine

)*&eader Isolation Valve

Rupture

Dis+

Concrete Cover

Fro, MR$

Fro, Refri"eration

%o Reactor Conditioner

Refri"erator

%an+ )o- ./0

2ducator

MR$ MIC Reactor $ide

RVV& Relief Valve Vent &eader

PV& Process Valve Vent &eader

V($ Vent (as $cru33er

FV& Flare Vent &eader

Route of "as lea+a"e 3efore 0050

%o

VC$

PI

10 P$I

4u,per

'ine

Rupture dis% )ursts

!n(reased rate of release

"ro$a$le :oute o# as /eakagea#ter ((( hrs


21/27

No alar+ or warning to pu$licVery sta$le at+osphere and low wind

directly into town

urrounding population asleep

-%er


22/27


23/27

Che+istry causing incident is not in

dispute

41 tonnes o# !IC in storage reacted with3(( to 9(( kg water plus conta+inants

:esultant e;other+ic reaction reached4(( to 48(M@

2


24/27

No uni%ersally accepted cause0a$otage theory

Disgruntled e+ployee

&lternati%e theory in%ol%es connection o#water hose to storage tank 1(

6%idence said to include the #inding o# the

disconnected pressure gauge #ro+ tank 1(a#ter the disaster

& rough drawing #ound, said to depict a hoseconnected to a pressure %essel

!anage+ent syste+s theoryInadequate sa#ety +anage+ent allowed water

entry through inadequate slip7$linding anduncontrolled plant +odi#ications

Design sa#eguards should ha%e pre%entedthe disaster o# either case

**

*

*

*

+R ,

Incident Causes


25/27

!any theories can $e put #orward and all+echanis+s gi%e insights into the %ulnera$ility o#the syste+

!ain o$Gecti%e is to learn #ro+ the consequencesJ

+ultiple possi$le causes only ser%e to highlightthe weaknesses

Incident Causes


26/27

6arly sa#ety study would questionha?ardous in%entories and plantsiting

Detailed study would identi#yconta+ination pro$le+

a#ety tudies +ay propose atraining #unction, should in%ol%eparent co+pany sta##

a#ety tudies +ay re%iewprocedures, especially those

in%ol%ing ha?ards 2water washingF5

-essons

-earnt

Ehat Could a#ety tudies ha%edoneF


27/27

a#ety tudies on +odi#ications.

Disconnecting #lare syste+

Not running re#rigeration

Ou+per pipe $etween %ent headers

topping scru$$er causticcirculation

a#ety tudies would e+phasise need#or e+ergency plans

-essons

-earnt

Ehat Could a#ety tudies ha%edoneF

bhopal incident

Documents