Category: Industrial Accidents
Explosion reported at Nuclear Power Plant at Fukushima Japan
March 12, 2011- The situation at Japanese nuclear facilities now seems to be dire, with a reported explosion in the vicinity of the Daiichi Nuclear Power Plant at Fukushima, Japan. Not only this particular site but upto five other sites may be in a dangerous state of operation, say reports. Below is an interview of an expert posted on YouTube regarding an assessmnet of the situation. This is like a nightmare begun for Japan, as well as the rest of the world. Apparently the cooling water pumping failures were caused by the loss of backup power generators that drive the cooling water pumps due to severe damage in the earthquake and Tsunami. Though the reactor buildings themselves are suppposed to be designed to take care of earthquakes, even of this magnitude, the cooling water systems, which are critical for the safe shutdown of the plant apparently are not, going by the sequence of events. There are multiple backup power sources for such critical functions, but in this case the tsunami seems to have crippled all the backup systems. It is unclear how the authorities and experts are planning to handle this increasingly dire situation. Initially residents within a 2 Km radius around the plant were ordered to be evacuated, then after problems continued, residents within a 10 Km radius were also ordered evacuated, then again residents within a 20 Km radius were evacuated and now the latest reports say that residents have been urged to not venture out at all. This may be beacuse radiation may have already contaminated the air for miles around, similar to the Chernobyl accident.
Meanwhile the Japanese government has denied that the explosion affected the actual reactor. Only the outer containment building was affected, the roof of which blew off. This is not good at all as this building is supposed to trap the radioactive material that may come out of the metallic containment vessel surrounding the reactor. One hopes that the actual reactor is in a safer condition than what appears. Radiation rates have increased significantly, with unconfirmed reports citing figures that the daily radiation in the area now equals the total radiation over a year!
The Tokyo Electric Power Company, that runs the plant says that four workers were injured in the explosion.
Other experts opine that since the reactor is a light water reactor, a Chernobyly type incident cannot happen. This must be surely good news to everybody around the area. A loss of coolant may cause a temperature rise, but it will also decelerate the reaction, according to the expert.
More information is available at the link here (at the website of the Union of Concerned Scientists).
Earthquake in Japan causes Oil refinery fire and Nuclear Power Plant fire
For a more recent update on the nuclear plant incident please click here.
Tokyo, March 12 update- Pressure at one of the Daiichi reactors is continuing to rise, worrying the authorities. Reportedly radioactive steam from one reactor was vented out after evacuating residents in a 10 Km radius in Fukushima, about 170 miles north of Tokyo.
Tokyo, Mar 11, 2011- An earthquake of a very large magnitude (8.9 on the Richter scale) has caused massive damage at an oil refinery as well as a nuclear power plant. The Cosmo oil refinery, near the city of Ichihara, in Chiba prefecture experienced a massive blaze after the earthquake hit. You can see it in the video below.
According to reports, natural gas storage tanks were part of the blaze. It is still not clear if the fire is under control. Things are equally bad, if not worse at the various Nuclear Power plants, where safety shutdown systems are automatically programmed to shut down the plants in case of an earthquake above a certain magnitude. Residents near the Fukushima Daiichi Nuclear Power Plant, located about 170 miles north east of Tokyo, were reportedly evacuated after the cooling system failed, triggering a fear of a possible nuclear meltdown. If cooling water is unable to be pumped to the core, then it may cause the reactor to melt and carry over into a steel containment vessel, which also has an outer concrete containment chamber. So far no reports suggest that anything has come into the containment chambers.However this thought itself is scary as if something radioactive does escape, it can cause severe radiation damage to large parts of the countryside.
Meanwhile apparently Ms. Hillary Clinton, US Secretary of State has informed that the US Military has transported additional coolant to the facility and will extend its help as needed.
There are reports of a fire in the turbines of the Onagawa Nuclear Power plant, while another facility at the same site is having a “water leak”, which is not good news at all.
The unprecendented nuclear power shutdown means that large swathes of areas are without any electricity at all, making the disaster worse than it had to be. Though diesel backup power generators are on, they cannot substitute for all the load. The earthquake highlights the consequential accidents and damages that can occur due to a natural phenomenon such as an earthquake.
The incident also highlights that supposedly “clean” nuclear power has a very big disadvantage-the danger of a radiation leak after something like an earthquake. Environmentalists please note!
Meanwhile various news reports suggest that there could be various nuclear facilities in Japan which could have failures that have been unreported so far, which is cause for worry. This has caused the Japanese government to declare an “atomic emergency”, a scary word indeed, not only for the Japanese, but for all of us as well.
Goodyear Tire and Rubber Company accidental ammonia heat exchanger rupture-CSB releases investigation report
CSB Releases Case Study on Fatal 2008 Accident at Goodyear Tire and Rubber Plant in Houston; Cites Need for Emergency Drills, Following Pressure Vessel Codes
Washington DC, January 27, 2011 - A U.S. Chemical Safety Board (CSB) case study released today on the 2008 heat exchanger rupture and ammonia release at the Goodyear Tire and Rubber Company in Houston, Texas, identifies gaps in facility emergency response training and calls for increased adherence to existing industry codes.
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The accident occurred on June 11, 2008, when an overpressure in a heat exchanger led to a violent rupture of the exchanger, hurtling debris that struck and killed a Goodyear employee walking through the area. The heat exchanger contained pressurized anhydrous ammonia, a colorless, toxic chemical, used as a coolant in the production of synthetic rubber; five workers were exposed to ammonia released by the rupture.
On the day prior to the accident, maintenance work required closing several valves on the heat exchanger. CSB investigators found that workers closed a valve that isolated the exchanger from a relief valve, to replace a burst rupture disk located below the relief valve.
The next day, at about 7:30 a.m. an operator closed another valve — this one blocking a second, automatic pressure control valve – to begin cleaning the process line with steam. Unaware that the isolation valve was also closed – thus leaving no means of relieving excess pressure in the exchanger, pressure continued to increase until the heat exchanger exploded violently.
Managers ordered the plant evacuated. However, CSB investigators found that on the day of the accident the employee tracking system was not operating properly, making it difficult to quickly account for all employees.
The CSB found that a malfunction in the computerized electronic employee badge tracking system delayed supervisors in immediately retrieving the list of personnel in their area, requiring handwritten lists to be generated. At about 1:20 p.m. an operations supervisor assessing the damage to the incident area discovered a fatally injured employee buried in rubble in a dimly lit area. The CSB case study notes that because the fatally injured employee had been a member of the emergency response team, her absence from the evacuation muster point was not considered unusual.
CSB Chairperson Rafael Moure-Eraso said, “The absence of this worker had not been noted due to the lack of training and drills on worker headcounts. Plant personnel were not provided with the proper training to effectively manage this emergency. Company procedures called for routine evacuation and shelter-in-place drills four times a year, but such drills were not held for several years prior to the incident. Management’s adherence to company procedures should have allowed for effective communication between all members of the workforce and a more robust emergency response structure.”
The report further notes that maintenance work activity was not properly communicated between maintenance and operations personnel, resulting in a subsequent shift not being notified of the isolation of the pressure relief line.
The CSB’s final report outlines several lessons learned including the need to adhere to existing American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code.
CSB Investigations Supervisor Robert Hall said, “We found the accident likely would not have happened had operators followed the ASME code. It’s crucial that workers continuously monitor an isolated pressure relief system throughout the course of a repair and reopen blocked valves immediately after the work is completed.”
The CSB’s report notes that the ASME code states that “Overpressure protections shall be continually provided…whenever there is a possibility that the vessel can be over-pressurized by a pressure source.”
Editors Note: Good engineering practices always lead to good safety practices, as the above case shows. However these days, the role of engineering in many plants has been whittled down due to outdated ideas of “downsizing” and “rightsizing”.
Bayer Cropscience Accident at Institute- CSB issues final report
Institute, West Virginia, January 20, 2011 – The U.S. Chemical Safety Board (CSB) today released its final report on the August 28, 2008, Bayer CropScience pesticide manufacturing unit explosion that killed two workers and injured eight others. In a report scheduled for Board consideration at a public meeting this evening in Institute, the CSB found multiple deficiencies during a lengthy startup process that resulted in a runaway chemical reaction inside a residue treater pressure vessel. The vessel ultimately over pressurized and exploded. The vessel careened into the methomyl pesticide manufacturing unit leaving a huge fireball in its wake.
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The report found that had the trajectory of the exploding vessel taken it in a different direction, pieces of it could have impinged upon and possibly caused a release from piping at the top of a tank of highly toxic methyl isocyanate (MIC).
(Editors Note: MIC is the same chemical that has killed thousands of people in the infamous Bhopal gas disaster. To think that it could have happened even 25 years later in the US is telling)
The accident occurred during the startup of the methomyl unit, following a lengthy period of maintenance. The CSB found the startup was begun prematurely, a result of pressures to resume production of the pesticides methomyl and Larvin, and took place before valve lineups, equipment checkouts, a pre-startup safety review, and computer calibration were complete. CSB investigators also found the company failed to perform a thorough Process Hazard Analysis, or PHA, as required by regulation.
This resulted in numerous critical omissions, including an overly complex Standard Operating Procedure (SOP) that was not reviewed and approved, incomplete operator training on a new computer control system, and inadequate control of process safeguards. A principal cause of the accident, the report states, was the intentional overriding of an interlock system that was designed to prevent adding methomyl process residue into the residue treater vessel before filling the vessel with clean solvent and heating it to the minimum safe operating temperature.
Furthermore, the investigation found that critical operating equipment and instruments were not installed before the restart, and were discovered to be missing after the startup began. Bayer’s Methomyl-Larvin unit MIC gas monitoring system was not in service as the startup ensued, yet Bayer emergency personnel presumed it was functioning and claimed no MIC was released during the incident.
Here is an animated video of the likely sequence of events that occured.
CSB Chairperson Dr. Rafael Moure-Eraso said, “The deaths of the workers as a result of this accident were all the more tragic because it could have been prevented had Bayer CropScience provided adequate training, and required a comprehensive pre-startup equipment checkout and strict conformance with appropriate startup procedures. This would have revealed multiple dangerous conditions and procedures that were occurring at a time when the company wanted to restart production of a key pesticide product. Startups are always a potentially hazardous operation, but to begin with computer control systems that have not been checked, while bypassing safety interlocks, is unacceptable.”
The investigation report makes recommendations to the company and its Institute plant, to the Occupational Safety and Health Administration (OSHA), the Environmental Protection Agency (EPA), and several West Virginia agencies. Citing a highly successful county program to ensure refinery and chemical plant safety in Contra Costa County, California, the CSB report recommends the West Virginia Department of Health and Human Resources establish a “Hazardous Chemical Release Prevention Program” that would have the authority to inspect and regulate such plants, and make public its ongoing findings.
Dr. Moure-Eraso said, “I believe a state and county-run program like this would go a long way to making chemical operations safer in places like the Kanawha Valley. OSHA and EPA, have limited resources and cannot be everywhere at once. However, local jurisdictions can put together highly effective and targeted inspection and enforcement programs, funded by levies on the plants themselves. The accident rate in Contra Costa County has dropped dramatically, and last year in fact they had no significant accidents, thanks, in my view, to this program.”
CSB Investigations Manager John Vorderbrueggen noted that a major contributing factor to the accident was a series of equipment malfunctions that continually distracted operators. “Human factors played a big part in this accident, and the absence of enforced, workable standard operating procedures and adequate safety systems meant that mistakes could prove fatal. For example, operators were troubleshooting several equipment problems and during the startup, inadvertently failed to prefill the residue treater vessel with solvent. A safety interlock was designed to stop workers from introducing highly-reactive methomyl, but it was bypassed as had been done in previous operations with managers’ knowledge. Once the chemical reaction of the highly concentrated methomyl started, it could not be stopped, and the temperature and pressure inside rose rapidly, finally causing an explosion.”
Board Member John Bresland, who was CSB chairman at the time of the Bayer accident, noted the confusion that resulted in the community’s emergency response following the explosion at 10:33 p.m. “The Bayer fire brigade was at the scene in minutes, but Bayer management withheld information from the county emergency response agencies that were desperate for information about what happened, what chemicals were possibly involved,” Mr. Bresland said. “The Bayer incident commander, inside the plant, recommended a shelter in place; but this was never communicated to 911 operators. After an hour of being refused critical information, local authorities ordered a shelter-in-place, as a precaution.”
“Proper communication between companies and emergency responders during an accident is critical,” said Mr. Bresland, adding, “The community deserved better, especially considering the amounts of hazardous chemicals, in use and being stored at various chemical facilities in the Kanawha River valley.
The CSB report notes that two workers and four volunteer firefighters required examination for possible exposure to toxic chemicals.
The investigation examined the potential consequences of a hypothetical trajectory of the careening residue treater vessel that would result in its hitting the heavy steel mesh ballistic shield surrounding the above-ground MIC tank. The analysis – using blast pressure and impact energy calculations – concluded that the shield would have protected the MIC tank from a residue treater vessel hit. However, the CSB found, had the residue treater struck the shield structure near the top of the frame, the displaced frame could have contacted an MIC pipe, which might have resulted in an MIC release into the atmosphere.
Chairperson Moure-Eraso said, “Any significant MIC release into the atmosphere along the Kanawha valley could have proven deadly, and that concern has been legitimately expressed for decades in the community. This potential was reduced when Bayer announced last year it would no longer store MIC above ground; it will be reduced to zero in approximately 18 months when the company has announced it will end MIC production and use at the Institute facility – the only place in the country still storing large quantities of MIC.”
Dr. Moure-Eraso continued, “Bayer’s decision to end pesticide production using MIC was, I understand, done for its own business reasons. But for whatever reasons, the eventual elimination of this chemical will enhance safety in the Kanawha Valley, for workers and residents alike, and is a positive development in my view.”
