By Isaac Mwangi | Thursday Jul 18, 2019
A burst steam pipe at the Olkaria V Geothermal power plant currently under construction by the Kenya Electricity Generating Company (KenGen) left 10 workers injured.
According to a statement released by the power generator states that the incident occurred on Friday 12th July at 4.00 pm local time during the ongoing commissioning of one of the newly installed units. The pressure in the system was increased in order to step up power generated from 43 MW to 65 MW leading to the the incident. The high pressure safety safeguards installed in the system operated as designed but this triggered a stampede which led to the 10 workers being injured.
Nine of the workers were treated in nearby Naivasha hospital and discharged with one being referred to Nairobi for further treatment. Most of the injured are employees of H-Young (EA) Ltd, one of the companies contracted by Kengen to construct the plant.
The Olkaria V power plant is expected to be fully commissioned by August and will add a total of 165 MW to the grid. The plant uses a direct steam technology where steam from several wells across the geothermal field is collected by use of cladded steam pipes and directed to the power plant and used to turn the turbines to generate electricity. The steam pipes in the geothermal power plants in Naivasha typically carry steam at temperatures of above 150 degrees Celsius and pressures above 10 bar (145 psi). The power plant is operated remotely from the power plant control room by use of a Distributed Control System (DCS). As such, safeguards are very critical to ensure this system operates without causing injuries to people or damage to the other equipment in the system.
Though not unique to geothermal power plants, ‘safety by design’ concept is critical for these plants and helps to ‘design out’ health and safety risks during design development. Safety considerations and the elimination or mitigation of the hazards found in geothermal surface facilities, such as steam gathering systems and geothermal power plants start in the engineering design phase.