October 8, 2011

R & D and Pilot Plant Vs Process Safety

I visit a number of pilot plants that are run by the R & D department of companies. I see a common trend that affects process safety. In many plants, the R &D and pilot plant is being run by competent doctorates in Chemistry. However, designing and operating a pilot plant requires knowledge of chemical engineering principles. The common gap I observe is the lack of application of chemical engineering principles when pilot plants are attached to R & D setups. Ideally the pilot plant must be designed by technical personnel and operated by experienced plant operators, in the presence of R & D personnel. What is occurring in your unit?

October 6, 2011

Nuclear Safety in India - lessons to learn

The Nuclear Power Corporation of India Limited had conducted an extensive study on the safety of the existing nuclear power generation facilities after the Fukushima disaster. Their recommendations are given as follows:
"The four task forces after evaluating the four different designs of reactors in NPCIL fleet have come out with certain recommendations which are common to all the types of NPCIL reactors. These are:
  • Provision of automatic reactor trip on seismic event at all plants except where it is already available (NAPS & KAPS)
  • Additional Diesel operated fire tenders and diesel operated pumps to enable water addition at high and low pressures to the different systems based on the need.
  • Diesel driven electric generators (air cooled and not requiring external cooling) to cater to power needs.
  • Use of nitrogen gas from liquid nitrogen tanks to passively pressurize water tanks and transfer the water to systems at required pressure.
  • Provisions to use water from suppression pool except in RAPS-2 
  • Qualifying existing water storages/tanks in the plants like deaerator storage tanks, for earthquake resistance
  • Conditioning signal override facility for ECCS in PHWRs where it is not available.
  • Additional Battery operated devices to monitor important plant parameters
  • Providing shore protection structures to withstand tsunami at coastal plants where they are not available
  • Review of Emergency Operating Procedures for external events and retraining of operator
  • Alternate make up provisions for spent fuel pool during extended station black out
  • Feasibility of providing solar powered lighting
  • Provision of boreholes at suitable locations to augment water supply.
  • Provision of suitably designed flood proof enclosure and doors for important safety related electrical power sources
  • Review of containment venting provisions at suitable points to vent the containment structure to stack" 
Read the complete report in this link.
While appreciating the work done by the NPCIL, there are lessons also to learn from them in the field of process safety also.

October 4, 2011

Four Process Incidents

A spate of process incidents have been reported in the past week.
In Kuwait, in a major refinery 4 Indian contract workers were killed due to exposure to a "gas" during maintenance work in a gas liquefaction unit. Read about it in this link.
A major fire has been reported in Dallas in a chemical mixing plant. The fire apparently overwhelmed the sprinkler system and destroyed a fire truck. Massive explosions are heard in the video. Read about it in this link. See the video in this link.
In India an explosion has taken place in a fireworks manufacturing facility killing two people. A news article in the Times Of India mentions that "This takes the number of deaths in the fireworks industries to 26 this year, making it the highest death toll recorded in recent years. The latest mishap is the fifth major accident in 2011". Read about it in this link.
In a fertilizer plant in USA, while workers were performing hot work on tank containing aqua ammonia an explosion occurred. Be very careful when doing hot work on tanks. They may appear harmless but are very dangerous! See the video in this link.

PSM and Money


I am slightly changing a statement made by the great Mahatma Gandhi (Earth has enough for every man’s  need but not enough for every man’s greed), to suit process safety management – PSM has enough for every man’s need but not for every man’s greed! In PSM’s context, by “greed”, I mean pressure to cut costs and increase profits without looking at the process safety consequences. Time and again, when you look at various incidents that have occurred and continue to occur even today around the World, the finger points towards cost cutting or insufficient budgets implicitly affecting process safety performance. Whatever model of PSM you adopt, “greed” cannot be managed by a system– is has to be managed by a human being and that too the ones at the top.  .They can manage this only by understanding the consequences of their actions. Not understanding the consequence of a decision that involves cost cutting or even by not properly allocating and approving budgets can have serious consequences on any process safety management system. Even though you might have implemented a system that addresses cost cutting etc, such systems have a tendency to get bypassed in times of pressure.This happens even in the "best" of companies. Any solutions???

October 2, 2011

Cathodic protection and process safety

Any corrosion protection system is an integral part of  maintaining process safety. One of them is cathodic protection. For a plant operator, these systems are seldom seen and operators are often not trained on the importance of these systems. A good interview by the Australian Pipeliner with Mr Mark Drager stresses the following points:
"Typically there are two types of CP systems:
Impressed – This CP system works by applying a small current (typically milliamps per kilometre) to the pipeline via units known as transformer-rectifiers. These units convert AC electricity into DC and use this electricity to lower the ‘energy’ of the pipeline. This system enables an asset owner to protect several kilometres of pipeline, provided the AC power remains connected.
Sacrificial – This CP system essentially performs a similar function via the electrical connection made between the pipeline and the buried anodes, namely zinc or magnesium. This system differs in that the DC electricity generated is due to the galvanic difference between the pipeline and the anodes. This system is also limited in protection range but is relatively maintenance free, however the anodes have a finite life and will need to be replaced.

There are few limitations to the usage of CP, but all can be overcome through careful design, construction and operation:
  • Excessive negative potentials;
  • May cause pipeline coating disbondment due to the excess hydrogen evolution;
  • In some instances hydrogen cracks have also developed within pipelines due to the excess hydrogen evolution;
  • Combined with the incorrect coating selected for the operating conditions, it may contribute to the development of stress corrosion cracks;
  • Interference (stray currents) from the anode bed can affect neighbouring foreign utilities if the location of the anode bed is too close them; and,
  • Disbonded coating or other foreign objects located next to the pipeline can cause a shielding effect. This would mean that the pipeline could not be protected locally at that point of shielding."
Read the full interview with more details in this link.

September 30, 2011

September 29, 2011

Diesel tankers accident

The Telegraph reports that "Fifteen tankers loaded with fuel were gutted and more than 10 lakh litres of diesel burnt when a goods train carrying them jumped tracks in Chanabana on the Bihar-Bengal border this morning.The inferno caused the tracks to melt, leading to disruption in train services on the Aluabari-NJP route.The heat from the burning fuel also scorched to death a villager, whose body was found after the flames were doused. Paddy on 500 acres along the tracks have been burnt.
The Northeast Frontier Railway (NFR) said the goods train, with 51 tankers and each of them filled with 70,000 litres of diesel from the Numaligarh Refineries Limited, was on its way to Jamshedpur from Maligaon in Assam. 
Read the report (with photos) in this link.

September 25, 2011

Molten Aluminium + water = explosion

An interesting theory by a scientist postulates that the twin tower collapse on 9/11 was cause by an aluminium water explosion. The article mentions the following:
"If my theory is correct, tonnes of aluminium ran down through the towers, where the smelt came into contact with a few hundred litres of water," Christian Simensen, a scientist at SINTEF, an independent technology research institute based in Norway, said in a statement released Wednesday.
"From other disasters and experiments carried out by the aluminium industry, we know that reactions of this sort lead to violent explosions." Given the quantities of the molten metal involved, the blasts would have been powerful enough to blow out an entire section of each building, he said.
This, in turn, would lead to the top section of each tower to fall down on the sections below.
The sheer weight of the top floors would be enough to crush the lower part of the building like a house of card, he said."The aluminium industry had reported more than 250 aluminium-water explosions since 1980," he said. Aluminium alloy, which in jet hulls also contains magnesium, melts at 660 degrees Celsius (1,220 degrees Fahrenheit). If heated to 750 C (1382 F), the alloy "becomes as liquid as water," Simensen said. This molten aluminium could then have flowed downward through staircases and gaps in the floor, causing a chemical reaction with water from sprinklers on the levels below.
The mix would immediately boost temperatures by several hundred degrees, releasing combustible hydrogen in the process. Such reactions are even more powerful in the presence of rust or other catalysts, which can boost temperatures to more than 1,500 C (2,700 F)."
Read the complete article in this link.



Chlorine leak incident

Thanks to Mr Harbhajan Singh Seghal for sending this incident: 
Incident:
A company in Gujarat was manufacturing Chlorinated Paraffin Wax by feeding Cl2 from the 900 kgs toner in Heavy Normal Paraffins (HNP). On the day of the incident a contract labourer disconnected the empty tonner and took the fresh 900 kgs tonner in line. Immediately after taking it in line, gas started coming out from the fitting of the copper tube at high pressure. The valve of the header and tonner was attempted to be closed by wearing SCBA. But by the time the gas had already spread. Total of 34 person were affected including 15 person from one village Out of the 15 village persons,5 were minor including a 9 month old child. All the affected persons of area were admitted in hospital. The people were complaining about breathing problem, vomiting, & loose motion but their condition was stable.
Root Cause of the Incident:
· Weak copper tube and its fittings
· Not following the correct procedure of taking the filled tonner in line
· Non availability of Safety equipment near the site and extraordinarily long time for its use.
· Non competent person handling Cl2
· Inadequate facilities for Cl2 handling
· Lack of proper training to the operating persons
Action Required:
· Copper tube and its fitting are not to be kept in the open in the atmosphere. It is to be connected with the tonner immediately
· Copper tube should be 8mm I.D., 12mm O.D. and annealed for stress relief and tested at 19.9 kg/cm2 pressure
· Ammonia torch and safety equipments should be near the installation
· While connecting the tonner, the valve should be crack opened to check for leakage. In case of minor leakage the valve is to be closed immediately
· Provision of high capacity vacuum blower to be available at site. The blower to be started in case of heavy leakage in order to avoids spreading of gas
· The operating persons should be trained to wear the safety equipment particularly SCBA in shortest possible time
· In case of leakage beyond control on site/ off site emergency should be initiated
Conclusion:
· Copper tube and its fittings have limited life. Life varies from plant to plant. The tube needs to be replaced before the established Avg. life.
· Leakage must be checked from the Cl2 tonners at the time of connection/ disconnection with ammonia torch by slightly cracking the valve in case of connection and slightly loosening the connection at the time of disconnection
· Regular drills should be conducted for usage of safety equipment and critical equipment need to be provided and tested at regular intervals.

September 23, 2011

Process Safety - union's perspective

The steelworkers union of USA has published an article mentioning that Oil refiners fail to learn from past safety incidents and near misses. This was published in 2009. The article mentions the following:
"OSHA is seeing the same problems repeatedly at refineries as it inspects them as part of its national emphasis inspection program. In the first year of the inspection program OSHA issued nearly 350 process safety management (PSM) citations to 14 refiners. The OSHA statement said the agency sent letters to the management of more than 100 oil refineries, providing them with data on compliance issues found under the emphasis program and urging them to comply with the (PSM) standard.
The API and industry are fighting us on the level of transparency and public reporting for process safety performance indicators.The goal of such transparency and public reporting is to allow refiners and petrochemical companies to learn from each other so accidents and catastrophic events are prevented.
This process also makes the companies more accountable to their workers and the communities where their refineries and petrochemical plants are located. It forces them to not just say they are being safety conscious, but to show they’re actually doing something about it".

Read the article in this link
UPDATE: An article published on Sept. 23rd, 2011 mentions the following:
"The lead negotiator for the United Steelworkers said the union representing employees at 69 U.S. oil refineries is prepared to strike if companies don’t agree to stricter safety procedures at plants and pipelines.
The USW, which failed during contract negotiations in 2009 to get companies to agree to have a USW-trained safety specialist at each refinery, will make a similar demand during talks that begin in January for a new three-year pact, Gary Beevers, a USW vice president, said today."
Read the article in this link.

September 21, 2011

Hydrogen Sulphide leak kills 4

In a leak at a chemical manufacturing facility in Thane, a leak of hydrogen sulphide gas has reportedly killed 4 people. Read about the incident in this link.
In a publication made in 1996, the Oil, Chemical and Atomic Workers International Union has made a simple yet effective safety bulletin on the dangers of H2S. They also list some incidents. Read it in this link.
I have investigated fatalities involving H2S, some of them involving release of H2S when an open vessel containing sludge was moved. The trapped H2S gas under the sludge was released and killed two people. Do not take it for granted.

September 20, 2011

Explosion in Chemical Factory

A news report mentions that fire and explosions in a chemical factory in Canberra made residents think that the place was being bombed! It appears that the fire and explosion was caused by transformer oil. See the news report and video in this link.