1. INCIDENT SHARING

2. INCIDENT SHARING INCIDENT 1 Date - 5th August 07
Location - Workshop in Nongbon, Thailand
Incident - A furnace module to be sent to Nigeria was being fabricated. The company was doing a pneumatic coil test at approximately 100 bar. An employee from other project was walking pass the pressure test area. The testing flange blew off and struck the employee on the head.

3. Causal Factors
The area around the pressure test had not been identified in any way.
Area not barricade.
No warning signage.
No standby person keeping watch to warn passers-by.
There had been no general warning of any testing taking place.

10. Chernobyl Disaster

11. Chernobyl
Built in
Chernobyl

12. Ukraine

13. Background
Reacktor Bolshoy Moshehnosty Kipyashiy
RBMK, a Russian acronym translated roughly means “reactor cooled by water and moderated by graphite”

14. RBMK Reactor

15. Control Rods
The Control Rods: long metal rods which, in the Chernobyl reactors, contain boron; they help control the chain reaction

16. Reactor Plant Scenario
As the reaction occurs, the uranium fuel becomes hot
The water pumped through the core in pressure tubes removes the heat from the fuel
The water is then boiled into steam
The steam turns the turbines
The water is then cooled
Then the process repeats

17. April 25, 1986 01:00 The preparation for the test
13:47 Lowering of the reactor power halted at 1,600 MWt
14:00 The ECCS was isolated
23:10 The power reduction resumed

18. April 26, 1986 24:00 Operation shift change
24:28 Power level is now 500 MWt and kept decreasing to 30 MWt
24:40 The operator withdrew some control rods
01:00 Power had risen to 200MWt
01:03 Connecting the fourth main cooling pump to the left loop of the system 200MWt
01:07 Connecting the fourth main cooling pump to the right of the loop system - this was a violation of NOP

19. April 26, 1986 (cont.)
01:19 Increased feed water flow to the steam drums and removed more control rods -violation of NOP
01:23 The test was started
01:23:10 Automatic rods withdrawn from the core
01:23:21 Two groups of automated control rods were back to the core

20. April 26, 1986 (cont.) 01:23:30 Power kept increasing
01:23:40 Emergency button pushed
01:23:44 Power is at MWth
01:23:48 1st thermal explosion
01:23:55 2nd explosion

21. Power Chart

22. Direct Casualties 31 employees and firefighters died
134 emergency workers suffered from acute radiation sickness

23. Indirect Casualties
By the year 2000 there were 1800 case of thyroid cancer in children and adolescent
High number of suicide and violent death among Firemen, policemen, and other recovery workers

24. Radiation

25. Radioactive Fallout

26. System Analysis Use of graphite as a moderator
Lack of a well-built containment structure
Inadequate instrumentation and alarms for an emergency situation
There were no physical controls that prevented the operators from operating the reactor in its unstable state

27. Human Errors Isolation of the emergency core cooling system
Unsafe amount of control rods withdrawn
Connection of the four main cooling pumps to the right and left of the system

28. Human Errors (cont.) Mental model Overconfidence Beta too high
The operator did not have a good mental model of the system itself
Overconfidence
By having an electrical engineer on site for an electrical test
No confirmation of cues obtained from the system
Beta too high
Many missed signals before the accident

29. Accident Prevention

30. Recommendations
Have proper Standard Operating Procedures (SOP) for both normal and emergency situations
Have scheduled trainings and practices for normal and emergency situations

31. Recommendations (cont.)
Always have a reactor expert on site
Have operators confirm any cues from the system before making hypothesis or take action
Have a team work kind of environment such that every body is involved

32. Bhopal Gas Tragedy Worst industrial disaster in history
2,000 people died on immediate aftermath
Another 13,000 died in next fifteen years
10-15 persons dying every month
520,000 diagnosed chemicals in blood causing different health complications
120,000 people still suffering from
Cancer
Tuberculosis
Partial or complete blindness,
Post traumatic stress disorders,
Menstrual irregularities
Rise in spontaneous abortion and stillbirth
India, the second most populated country of the world is one of the most disaster prone countries of Asia.

33. Second generation effect
ICMR, IMA, AMA studies show
Children born with genetic defects
Growth retardation in boys
Hormonal chaos among girls
Ground water contamination with high level of mercury, lead, nickel, VOCs and HCH
High prevalence of skin and gastro-intestinal diseases
Bioaccumulation of toxins found in vegetables and breast milk

34. Background The plant produced pesticides
An intermediate compound in the process is methyl iso-cyanate (MIC)
MIC is an extremely dangerous compound
MIC is reactive, toxic, volatile and flammable
Reacts isothermally with water. Although the reaction is slow, with inadequate cooling the temperature will increase and the MIC will boil

35. Methylamine (1) reacts with phosgene (2) producing methyl isocyanate (3) which reacts with 1-naphthol (4) to yield carbaryl (5)

36. How it happened
December 3-4, 1984: 40 tonnes of methyl iso-cyanate (MIC) released from Union Carbide plant at Bhopal
Accidental release caused by leakage of water into MIC storage tank
None of the six safety systems worked
Safety standards and maintenance system ignored for months
Complete absence of community information and emergency procedures
Public alarm system operated after the gas had leaked for nearly four hours

37. THE END
THE END