(122b) Process Safety in Power Plants

Process Safety is a very common and used topic in the chemical industry. According to CCPS, an incident is reported as a process safety incident if it meets all four criteria (process involvement, above minimum reporting threshold, location and acute release).

In the first criteria, a process must have been directly involved in the damage caused and CCPS explains that for this purpose, the term "process" is used broadly to include the equipment and technology needed for chemical, petrochemical and refining production, including reactors, tanks, piping, boilers, cooling towers, refrigeration systems, etc.

According to this criteria, the power plant industry (where not directly involved with chemical, petrochemical or refining industry) are not included in this topic. Although it may have the same equipments (boilers, tanks, cooling towers, reactors) .  

Many catastrophic incidents had occurred in power plants and, as long as these systems usually are managed by electrical or mechanical engineers who does not have a solid culture of process safety developed, sometimes it does not have specifics risk analysis (such as hazop and LOPA), barriers management, mechanical integrity discipline, management of change structured.

Even understanding that nuclear power plants usually have a very developed sense of safety, the CCPS criteria do not mention the radioactivity.

Follows some examples of disasters occurred in power plant industry:

- The most famous was the Chernobyl disaster. On 26 April 1986, a nuclear reactor suffered a catastrophic power increase, leading to explosions in its core. This dispersed large quantities of radioactive fuel and core materials into the atmosphere.

- Fukushima  Disaster was a series of equipment failures, nuclear meltdowns, and releases of radioactive materials at the Fukushima I Nuclear Power Plant, following the earthquake and tsunami on 11 March 2011.

 - Russian Hydroelectric Dam Disaster occurred on 17 August 2009 when a turbine of the Sayano–Shushenskaya hydroelectric power station broke apart violently. The turbine hall and engine room were flooded, the ceiling of the turbine hall collapsed, 9 of 10 turbines were damaged or destroyed, and 75 people were killed.

- Iranshahr Thermal Power Plant Disaster and all coupling failure followed by an overspeed occurrences in turbines, pumps and compressors.

- Power Transformer Explosion all over the world (in all kinds of industries), where the mineral oil from the insulation burns and explodes.

- Variety of occurrences involving the chemical energy of fuel (such as natural gas and fuel oil)

In this way, if it happens to be a break of coupling in a turbo gas compressor at an ethylene plant without the correct operation of the safety overspeed protections it would be reported as a process safety incident.

On the other hand, if it happens to be a break of coupling in a turbogenerator at a power  plant without the correct operation of the safety overspeed protections it would not be reported as a process safety incident, because there is no chemical product associated.

In this way, it becomes clear that “process safety” needs to be applied not only in chemical industry but in all facilities with similar risks such as energy departments. It is a very hard challenge to create a broad criteria and a "World Center for Catastrophic Incidents" and a bigger challenge it is to develop process safety culture in all types of engineers and managers.