October 30, 2011

IIChE special issue on Process Safety

The Indian Institute of Chemical Engineers is bringing out a special issue on Process Safety and risk management to coincide with the anniversary of Bhopal disaster in December. You can view the call for papers in this link.

October 26, 2011

Safe distances during a BLEVE

Firefighters have to maintain a safe distance when responding to a possible Boiling Liquid Expanding Vapour Explosion. A video in you tube demonstrates that for a 400 L bullet, the minimum observations distance is at least 90 M. But at this distance, they may still be hit by projectiles. See the video in this link. Worth watching for all emergency response teams. Another information in the video is that for a 400 L bullet, you will need 200 lpm of water to keep it cool, for a 4000 L bullet you will need 700 lpm and for a tanker you will need 2000 lpm of water...

October 25, 2011

When things go wrong – Parkinsons law in emergencies

A hydrocarbon spill occurred in a plant and caught fire. Sulphuric acid pipelines nearby leaked and were dumping suplhuric acid into the hydrocarbon spill. The sulphuric acid was breaking down the fire fighting foam used by firefighters and delayed the extinguishing of the fire.
In my experience of handling many emergencies, things will go wrong during an emergency. The better prepared you are, the better you are equipped to handle surprises.

October 24, 2011

Chlorine incidents

An article in the Scientific American highlights the following:
"Over the past 10 years, chlorine has been involved in hundreds of accidents nationwide, injuring thousands of workers and townspeople, and killing some, according to federal databases. It is second only to carbon monoxide when it comes to the percentage of accidents that cause injuries, according to the newest federal data.
 Chlorine is one of the most widely used industrial chemicals in the world today, with 13 million tons produced annually in the United States alone.
In 2009 alone, chlorine was involved in 181 reported accidents with 56 resulting in injuries, based on the latest report from a federal database called Hazardous Substances Emergency Events Surveillance (HSEES). That amounts to 3.8 percent of all the reported chemical emergencies that year. Chlorine had a high percentage with victims, 30.9 percent, second only to carbon monoxide, which had 41.7 percent with victims. Roughly one-third of the states reported, and only for a part of the year, so the real number of accidents and injuries is much higher, experts say
Incidents are rare" in the production of chlorine among Chlorine Institute members, said Frank Reiner, president of the national trade group of 220 manufacturers and distributors. In an e-mail, Reiner said, "the safety performance of the industry has been very good" and his group shares information among members to avoid future problems".Read the article in this link

October 23, 2011

H2S leak in lubricant plant

A H2S leak has been reported at a lubricant plant in USA. It is reported that a small amount of the gas was released when an additive for oil-based vehicle engine lubricants overheated. Other news reports indicate that a tanker truck overheated and released H2S. I just randomly looked up a MSDS of an automotive lubricant and it does warn about heat as one of the conditions to avoid and also identifies H2S under exposure controls/personal protection.
Read the article in this link. Read another report in this link
Read the MSDS of a automotive lubricant in this link
Read a technical bulletin of an overview of H2S including its hazards in this link.

October 22, 2011

Explosion protection and instrinsic safety

Pepperl + Fuchs have brought out a simple and effective presentation of explosion protection and intrinsic safety. Their presentation summarizes the following:
  • "A hazardous location is an area in which the atmosphere is explosive or anticipated to be explosive
  • Intrinsic safety dates back to 1913 following a disastrous mine explosion in England
  • The Ignition Triangle consists of three components (fuel, ignition energy and oxidizer) that must be present simultaneously, and in suitable proportions, to cause an explosion.
  • Minimum Ignition Energy (MIE) is the ideal ratio of fuel to air where the mixture is most easily ignited
    Any area above or below the Minimum Ignition Energy contains a smaller fraction of air or combustible gas/fuel and cannot be ignited
  • Hazardous areas in North America are broken down into three classifications: Class I (flammable gases or liquids), Class II (dust), and Class III (fibers and flyings)
  • The classifications are further broken down in Division 1 or Division 2 based on the probability of the materials being present in a potentially hazardous quantity
  • The Division Method of North America is comparable to the Three-Zone Model practiced in Europe
  • There are three basic methods of explosion protection: containment, segregation, and prevention
  • Intrinsic safety is the principle of keeping the electrical energy below the MIE and is the preferred method of explosion protection for low power devices"
Download the complete presentation from this link

October 19, 2011

Adding chemicals -fast or slow??

An incident occurred in UK in 2007 when an operator was adding a solid chemical to a reactor containing a liquid chemical. When they initially failed to react, he added more of the solid chemical Suddenly an uncontrolled runaway reaction occurred. A report by UK Health and Safety executive mentions the following:
 "None of the workers were in the production hall when the alarms - set off by the incident - began to ring, but one of them returned to investigate. He was driven back by the fumes and fled from the building.
The HSE investigation concluded the company had failed to adequately assess the risks of the chemical reaction and ensure that suitable control measures were in place. It also found the employee had not received adequate training, instruction and supervision on the operating procedures, and did not appreciate the danger of increasing the quantity of the chemical".

Read the full report in this link.

October 16, 2011

Process Safety - Ensure you use correct materials of construction

An Australian company has been fined for a sulphuric acid valve failure that led to the amputation of a worker's leg.It appears that when employees went to check the cause of of an acid line choke, a valve failed and sprayed them with concentrated sulphuric acid.Investigation determined that the valve that failed was not of correct material of construction and was designed to carry 40% sulphuric acid. This resulted in the failure of the valve. Often material changes go unnoticed till a catastrophe happens. Ensure your management of change process and your inspection procedures are stringent.

October 14, 2011

Blackberry and Process Safety

The recent disruption is services for people using the Blackberry phone was attributed to the failure of a core switch and failure of its back up. There are lessons in process safety from the blackberry incident! Are your back up systems working properly? Do you check the reliability of your back up devices? Remember, many incidents have occurred because the back up failed when it was needed....
Read the article about the Blackberry failure in this link.

October 12, 2011

Process Safety - Have you considered Tank Tsunami's?

On April 7th this year, a 30,000 gallon water tank in the US state of Florida failed creating a Tsunami like wave that caused a building to collapse, killing two workers. Read about it in this link.
With storage tanks for petroleum and other chemicals becoming larger and larger, you must have a strong integrity management program to ensure these tanks do not collapse and create a man made Tsunami, with accompanying catastrophic consequences.

October 10, 2011

Safety features at Kudankulam Nuclear Plant

The Kudankulam nuclear plant has been in the news recently due to the protests by the locals. An article in the Business Standard by the former Chairman and current member of the Atomic energy commission mentions the following additional safety features provided:
"The nuclear power units in Kudankulam belong to the third generation of design evolution; the Fukushima reactors belong to the first generation design. A special feature of the Kudankulam design is the passive cooling system for the nuclear reactor core. The water cooling the reactor transfers its heat to the water in the steam generators. After driving the turbine, steam condenses into water in the condenser and is pumped back to the steam generator. In an abnormal situation, when no power is available to drive these pumps, the hot water in the steam generator flows to an air-cooled heat exchanger located at a height outside the reactor building. Owing to the difference in height, the hot water rises up on its own due to its lower density and cold water flows down to the steam generator. This is called the “thermo siphon effect” and it does not need any pump to move the water. This feature was incorporated in the Kudankulam design at India’s insistence. The Kudankulam reactors are the first to have the passive cooling feature. The Kudankulam design has another important feature” a “core catcher”. In the event of an extreme accident and were the molten nuclear fuel to breach the reactor pressure vessel, it falls on to a matrix containing a large amount of neutron-absorbing substances (such as boron). Once mixed with this material, the nuclear fuel is rendered incapable of starting a nuclear chain reaction. Only the latest design of nuclear power units have this safety back-up system".
Read the complete article in this link.

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.